Barklice: All You Need to Know

Barklice are fascinating little creatures that often go unnoticed due to their tiny size. They belong to the order Psocoptera and can be found in over 300 species across the United States and Canada.

Living primarily outdoors, barklice can be found in various habitats such as tree bark, leaves, and under stones, where they feed on organic materials like fungi, lichen, pollen, and decaying plants.

Interestingly, these tiny insects are harmless to plants and do not require any treatment. To dive deeper, let’s learn some crucial facts about them.

What Are Barklice?

Barklice are small, soft-bodied insects that belong to the order Psocoptera. They measure less than ¼-inch in length and have long antennae and two pairs of wings folded over their backs¹. Here are some key features of barklice:

• Commonly found on trees
• Two pairs of wings
• Soft-bodied and less than ¼-inch long
• Long antennae

These insects are members of the infraorder Psocidae and are related to booklice, which belong to the infraorder Archipsocidae².

The Psocodea order comprises both Barklice and Booklice³. Barklice play a vital role in breaking down organic matter such as fungi, lichen, pollen, and decaying plants⁴.

There are different species of barklice, for example, Cerastipsocus is a common genus of barklice found mainly on tree trunks⁵. These insects are often found in these environments:

• Tree bark
• Leaves of trees and shrubs
• Under stones

Barklice are harmless to plants and trees, and as they feed on fungi and other organic materials, they provide a form of natural cleaning, and treatment is not required.

Since barklice and booklice share some similar features, here’s a comparison table to highlight the differences between the two:

Barklice	Booklice
Mostly outdoors	Mostly indoors
Winged adults	Wingless adults
Found on tree bark, leaves	Found in homes, structures

Physical Characteristics

Size and Color

Barklice are quite small insects, usually having a body length of less than ¼-inch¹. They come in various shades, ranging from translucent white to gray or light brown². Some examples of size and color variation are:

• Small, white barklice
• Gray barklice
• Light brown barklice

Wings and Antennae

These creatures have two pairs of wings, which they carry folded over their backs¹.

Apart from their wings, barklice also have long antennae that play a crucial role in their sensory perception¹.

Nymphs and Adults

Barklice undergo a simple metamorphosis, meaning that the young nymphs resemble the adult barklice, except for a few differences¹.

Nymphs are typically smaller and lack wings, unlike their adult counterparts³. Here is a comparison table of nymphs and adults:

Feature	Nymphs	Adults
Size	Smaller	Up to ¼-inch3
Wings	Wingless3	Two pairs of wings1

Life Cycle and Reproduction

Eggs

Barklice females lay their eggs on tree bark or underneath web-like coverings they create.

The eggs are small and often difficult to see with the naked eye. An interesting feature of barklice eggs is their variety of colors, such as white, pale green, or yellowish-brown.

Nymphal Stages

The life cycle of barklice consists of several nymphal stages. Barklice undergo simple metamorphosis, meaning the nymphs resemble adults but are smaller in size.

During these stages, the barklice molt and increase in size, passing through various instars until they reach adulthood.

Typical characteristics of nymphal stages include:

• Shorter antennae
• Smaller size
• Absence or underdeveloped wings

Generations

There are multiple generations of barklice in a year, with reproduction occurring during warm months. Barklice have a fairly rapid life cycle, allowing for several generations to thrive.

However, the exact number of generations per year may vary depending on the species and environmental conditions.

Comparison of Barklice and Booklice:

Feature	Barklice	Booklice
Habitat	Tree bark, outdoor environments	Indoors, near damp materials or moldy food
Wings	Two pairs of well-developed wings	Reduced or no wings
Size	Usually less than ¼-inch	Less than 1/8 inch
Diet	Feed on lichen, mold, algae on trees	Feed on mold or starchy materials indoors

Habitat and Distribution

Barklice are small, soft-bodied insects that belong to the order Psocoptera. They can be found in a variety of habitats, including trees and trunks.

Usually, you can spot them on smooth-barked trees, like maple and beech.

• Trees: Barklice are commonly found on the trunks of trees.
• Rocks: Although less common, you may also find them on rocks.
• Houses: Occasionally, barklice may enter homes, especially in damp spaces like bathrooms.

There are over 300 species of barklice in the United States and Canada, with most species living outdoors.

Some species of barklice choose leaf litter or under loose tree bark as their habitat, while others prefer the eastern half of the country, particularly in the south.

Feeding Habits and Diet

Barklice are relatively harmless insects that feed on a variety of organic materials. Their diet consists of:

• Mold
• Lichens
• Algae
• Fungi

These tiny creatures play a crucial role in the ecosystem by consuming these organisms, which grow on tree barks, leaves, and shrubs.

Barklice may also feed on dead insects and aphids, but they don’t harm living plants. They prefer to inhabit foliage, staying close to their food sources.

For example, barklice are commonly found on tree trunks and shrubs with mold or lichen growth. Their presence is generally considered beneficial, as they help maintain the overall health of the plants by consuming excess growth.

Comparison Table:

Food Source	Description	Barklice Preference
Mold	Microscopic fungi	High
Lichens	Symbiotic organisms (algae and fungi)	High
Algae	Photosynthetic, plant-like organisms	High
Fungi	Spore-producing organisms	High
Dead Insects	Deceased insects	Low
Aphids	Small, soft-bodied insects	Low

Behavior and Movement

Searching for Food

Barklice are known for their herd behavior, which means they live and move around in groups. Some key points about their feeding habits:

• They feed mainly on fungi, algae, and dead plant material.
• They help in cleaning up the bark of trees and other surfaces.

For example, a large group of barklice can be found on tree trunks, enjoying a meal together.

Web Spinning

Web spinners, or barklice, are known to produce silk to create protective webbing. Some interesting aspects of their web spinning include:

• Their silk is generated from specialized glands in their front legs.
• The webbing provides a safe place for them to live and feed without being disturbed.

Barklice vs. Other Web Spinners:

Feature	Barklice	Other Web Spinners
Silk	Yes	Varies
Webbing	Yes	Varies
Nuisance	Usually not	Often

Identifying and Managing Barklice

Distinguishing Features

Two common barklice species are Cerastipsocus venosus and Archipsocus nomas. To differentiate them, consider the following characteristics:

Feature	Cerastipsocus venosus	Archipsocus nomas
Wing Pattern	Net-like veins	Distinct patches2
Web Formation	Yes	Yes2

Managing Populations in Homes

Barklice, often referred to as booklice when indoors⁴, are generally not harmful.

However, if their population grows, managing them becomes necessary. Here are some steps to take:

1. Identify the infested area and regularly vacuum or clean it.
2. Use a dehumidifier to reduce moisture, as booklice thrive in humid environments³.
3. Ensure proper ventilation in confined spaces like closets or storage rooms.

For outdoor populations, biological control methods and containment are effective ways to manage them.

Since barklice feed on fungi, lichen, pollen, and decaying plants¹, maintaining a clean and healthy garden can help keep their numbers in check.

Impact on Humans and Ecosystem

Harmless to Trees and Plants

Barklice are generally harmless to trees and plants. They are often found on the bark, feeding on various organic materials such as fungi, algae, and lichens¹.

These insects don’t harm plants but instead help in keeping the bark clean.

Beneficial Insects

Barklice can be considered as beneficial insects in the ecosystem.

They help in natural pest control⁴ as they feed on other insects and their eggs, thus reducing the population of potentially damaging pests.

Moreover, they aren’t considered a threat to humans or pets. No need for insecticide treatment as these insects pose no harm.

Advantages of barklice:

• Natural pest control
• Harmless to humans and pets
• Contribute to a healthy ecosystem

Table: Barklice vs. Harmful Pests

Features	Barklice	Harmful Pests
Impact on plants	No damage	Damaging to plants and crops
Role in the ecosystem	Beneficial	Detrimental
Insecticide treatment	Not needed	Often necessary

In conclusion, barklice are harmless to trees and plants, contribute positively to the ecosystem by acting as natural pest control, and don’t require any insecticide treatment.

Conclusion

Barklice are benign insects that inhabit tree barks and are often mistaken for pests. Contrary to common misconceptions, they do not harm trees or plants.

Instead, they feed on fungi, algae, and other organic matter present on tree barks, essentially cleaning the surface. Their presence is often an indication of a healthy ecosystem, as they contribute to the natural decomposition process.

While they might appear in large numbers, causing concern for tree owners, understanding their harmless nature and ecological role can alleviate unwarranted fears.

Footnotes

1. https://hgic.clemson.edu/factsheet/barklice/ ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶ ↩⁷ ↩⁸ ↩⁹ ↩¹⁰
2. https://content.ces.ncsu.edu/booklice ↩ ↩² ↩³ ↩⁴
3. https://uwm.edu/field-station/barklice/ ↩ ↩² ↩³ ↩⁴ ↩⁵ ↩⁶
4. https://extension.umn.edu/product-and-houseplant-pests/psocids ↩ ↩² ↩³ ↩⁴ ↩⁵
5. https://content.ces.ncsu.edu/barklice ↩

Reader Emails

Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about barklice. Scroll down to have a look at some of them.

Letter 1 – Booklice infest buckwheat pillows

Subject:  Bug identification in buckwheat
Geographic location of the bug:  Seattle WA
Date: 02/12/2018
Time: 04:13 PM EDT
Your letter to the bugman:  Hello,
I develop natural filled bed pillows and we recently came across a bugs in our pillows that are filled with buckwheat hulls. We are trying to get them identified to better know how to treat our problem.

We normally order the buckwheat from a local supplier that imports it from Europe.  Any insight would help.
How you want your letter signed:  Best, Beatrice

Dear Beatrice,
You have Booklice.  The good news is that according to Bugwood Wiki:  “Within a home booklice are almost always found in damp areas that support the molds on which they feed.

Bathrooms are common areas where they are encountered. Occasionally they may build in large numbers on grain products that have been stored poorly. The common name relates to their occasional association with books, papers and fabrics where they feed on the starchy materials (e.g., glues, fillers).

Booklice are considered to be very minor household pests and the arid climate of Colorado suppresses the occurrence of many species. Booklice cannot bite humans.” 

The bad news is that despite being somewhat benign, the presence of large numbers of Booklice in your pillows will probably be off-putting to some customers.  Furthermore, your damp Seattle climate is probably contributing to the Booklice reproducing and increasing their numbers.

Letter 2 – Booklice

Subject: Tiny bugs crawling on walls
Location: Singapore
December 23, 2012 3:15 am
Hello, u have these tiny light brown bugs all over my partition walls. The adult is about 0.15cm and sometimes accompanied by babies as well. They can crawl pretty fast. What r they?
Signature: Bugged

Dear Bugged,
Your image is blurry, but we believe you have Booklice, tiny insects with a worldwide distribution. 

Booklice are benign creature and there is no conceivable benefit to trying to eradicate them from your home, which will most likely be a nearly impossible task.  See BugGuide for more information on Booklice.

Letter 3 – Barklice commonly called Tree Cattle

Subject: What are these bugs and do we need to remove them??
Location: Southern Louisiana
August 2, 2014 3:33 pm
Hi! my husband was working on the trees in our yard and found these bugs on one of our crepe myrtles and on a live oak tree. Both trees are on the north side of the house.

The other crepe myrtle, on the southern side, and the two nuttal oaks, in the front yard, do not seem to have these bugs (at least not that we’ve found).

They are in clusters and from a distance look like black patches on the bark. I’ve included two pics, one is a close up shot the other is a bit farther away. The ones I saw were moving and they moved together.
Hope you can help!
Signature: Mandy

Dear Mandy,
Though they look highly problematic, these Barklice or Tree Cattle in the genus Cerastipsocus, and most likely Cerastipsocus venosus, are harmless, benign insects that feed upon lichens.  From the look of your image, there is an ample food source for them on the trunk of the tree. 

We are highly intrigued by your comment that they “were moving and they moved together” because they indicates they move like a herd.  We cannot recall having researched the origin of the common name Tree Cattle, and that seems like a very good rationale for the name. 

According to Michigan State University Extension:  “Tree cattle, Cerastipsocus venosus (Psocoptera: Psocidae) are large barklice and get their common name from their habit of forming large colonies that move about in unison (much like a herd of cattle, I guess).

Tree cattle are harmless and no cause for concern.  According to University of Florida Horticulture:  “Suring some years they make extensive silken webs that often cover the trunks and branches of live oaks in the southeastern U.S.  The webs are believed to protect the barklice from predators. 

To some, the glistening webs are unsightly, but neither the barklice nor the webs will cause any harm to trees.  This is referred to as a NBD, ‘no big deal’ bug.  these insects are scavengers, cleaning the bark of lichens, fungi and dead animal and plant matter. 

The adult barklice are brownish-black and approximately 1/4 inch long.  the immature stage or nymphs, are brownish-gray and resemble the adults, except they are wingless.  The adults and nymphs feed in a group.  When the webbing is disturbed they scatter rapidly as a group and are referred to, in the older literature, as tree cattle because of this herding behavior.” 

According to the Galveston County Master Gardeners Beneficials in the Garden site:  “The term ‘lice’ as part of the common name of these tree dwellers is quite misleading as these insects are neither parasitic nor louse-like in appearance. Upon being informed of the identification of this insect, the typical response of a gardener is a widening of the eyes and other momentary indications of being aghast!

Our Galveston County Extension Horticulture Agent advises us to precede the identification with a notation of  ‘Congratulations, you have beneficial insects in your landscape!’  When disturbed, Cerastipsocus venosus exhibits the fascinating behavior of moving en masse, somewhat like a flock of sheep or herd of cattle.

They may also temporarily scatter when suddenly disturbed, only rejoin again as a “herd.” Not surprisingly, they are also known as “bark cattle” or “tree cattle.” Barklice are most often noticed on smooth-barked shrubs and trees such as crape myrtle and on oaks although they occur on a variety of hardwood ornamental plants (we have seen them on Bradford pear).”

“

Letter 4 – Barklouse, not Winged Booklouse found indoors

Subject: Help w/ ID-ing Tiny bugs found in moldy bathroom
Location: NY
February 12, 2013 9:21 pm
I have a whole bunch of these bugs in my moldy bathroom. There are no windows, no exhaust, no fans in my bathroom so I’m pretty sure thats why the mold is forming. OK, so back to the bugs, they are brownish, very tiny and some are even teeny tiny, which I think might be the babies.

They look like they have wings but I see them crawling most of the time, only rarely do I see them fly or if I sprayed bathroom odor spray on them they’d fly.

They look like they have 6 legs and 2 long antennas and the back 1/2 of the body has stripes. I see them on the walls only and there’s one corner where they’re packed and lined up. It just looks so disgusting to be using the bathroom with all these bugs on the walls.
I would really like to ID these bugs and then find the best way to clear them away.
Signature: Sheri

Hi Sheri,
This is a member of the insect order Psocodea, and it is either a Booklouse or a Barklouse.  They do not bite humans. 

Booklice which are often found indoors are generally not winged and Barklice are generally found outdoors, so this is a bit of a mystery to us. 

Perhaps one of our readers will be able to provide additional information.  You can also get information on BugGuide.

Eric Eaton provides some clarity
Daniel:
It is a barklouse, but I have no idea what family, let alone genus or species.  I suppose they could hibernate….I really know very little about them other than how to recognize them.
Eric

Letter 5 – Booklouse

Small house bug?
Location: Halifax, NS, Canada
March 12, 2011 4:48 pm
Hi my name is Dillan and i was wondeirng what kind of bugs these are?
I have found about 10-20 of them on my window sill in my bedroon over the last couple of days. I’m not sure if they are in other parts of the house because they are so small I wouldn’t normally notice them.

I live in Halifax, Nova Scotia, Canada, and found the bugs in March, 2011. The weather has been warming up lately but they bugs might have been here for a while I just never noticed them.
Thanks for your help!
Signature: Dillan

Hi Dillan,
You have Booklice, minuscule insects that are often found in damp locations indoors where they feed on mold.  They will not harm you or your home, but if they are present in large numbers, they may be an indication that there is a serious mold problem. 

They can also sometimes infest stored foods.   You can read more about Booklice on the Texas A&M Agricultural Extension Service website.

Letter 6 – Booklouse from Australia

Subject: What is this bug?
Location: Sydney
February 18, 2016 2:03 am
I see it everywhere in our place. On my laptop, spoon drawer, on doors.
It’s cream coloured and very small.
Help appreciated
Signature: Maryam

Dear Maryam,
This is a Booklouse in the family Liposcelididae, probably in the genus Liposcelis.  According to BugGuide they are found:  “worldwide and across NA; many spp. are now nearly cosmopolitan or otherwise widely spread through agency of man, mostly with stored products.”  They are basically harmless to humans, though when they are plentiful, they might render stored foods unpalatable. 

According to the Penn State Department of Entomology:  “Booklice, also called psocids, are not true lice. While they resemble lice in size and shape, booklice feed only on fungi or mold. If you find them in grain or other stored food products, it is an indication of high humidity which encourages mold growth.

In addition to food products, psocids may be found under wallpaper, in furniture, along the sides of windows or on window sills around potted plants. Booklice do not bite, transmit disease, or damage food or fabric, but they can be very annoying when present in large numbers.”

Letter 7 – Booklouse

Subject:  Bug on Lumber
Geographic location of the bug:  Minnesota
Date: 10/05/2017
Time: 01:10 PM EDT
Found hundreds of small bugs on a woodworking project in the garage.  I used a air compressor to blow off as many as possible but there are still some that are on my project. 

Any idea what these are and if they are destructive?  Any advise on removing them?  The best guess I have is that they are booklice.
How you want your letter signed:  Chris

Dear Chris,
This is a Booklouse and the presence of it and its hundreds of friends on your woodworking project is more an annoyance than a problem.  According to BugGuide:  “many spp. are now nearly cosmopolitan or otherwise widely spread through agency of man, mostly with stored products.”

Letter 8 – Barklice

Striped insect found in swarms
July 26, 2009
We have just recently found these little bugs in swarms on all of our trees, especially the cedar trees. We don’t see any specific damage being done by them. These are located in Syracuse NY. Please advise if these should be of concern?
Jamie
Syracuse NY 13209

Hi Jamie,
Thanks so much for writing to us before you decided to take drastic measures to exterminate these benign Cerastipsocus venosus, Barklice in the family Psocidae.  Generally when a large group of insects congregate on plants in this manner, they are feeding on the plant and potentially causing damage. 

These Barklice are feeding on lichens, not on your tree.  They are immature and adult Barklice are winged.  You may find images of adult Barklice on BugGuide.

Letter 9 – Booklouse

Subject: It was on the shower curtain – is it lice?
Location: Victoria, Canada
November 1, 2012 12:12 am
I’ve had an itchy head but can’t figure out if it’s lice (the nit comb comes up with nothing) or my shampoo. But recently I had a bath instead of a shower and had time to notice this bug on the shower curtain.

Sorry for the grainy photos – it’s the best I could do without a microscope! Can you tell me what it is? Is it lice?
Signature: Victoria, Canada

Dear Victoria,
This appears to be a Booklouse, and though it is related to the Parasitic Lice that infest people and animals, it is a harmless organism that is frequently found in homes.  They sometimes infest stored food products.

Letter 10 – Booklouse

Need help identifying this bug.
Tue, Nov 11, 2008 at 7:47 PM
Recently these little bugs started showing up in my basement bathroom. (It’s currently 11/11/08.) There are usually several in there at any given time. I have not seen them anywhere else in the house.

They may be in other parts of the basement, but the rest is carpeted with a light tan carpet, so the color of these bugs would blend right in if they are elsewhere in the basement.

I’ve tried vacuuming them (and the surrounding area) but within a day or so they’re back. They walk around (rather than fly) and usually don’t do much at all to get out of the way when I go to kill one. They can jump, but apparently only about an inch or so.

They are quite tiny. I shot these pics with a 105mm macro lens plus an extra 52mm extension tube. I placed a ruler in the second shot for size reference. The marks on it are 64ths of an inch.

I would very much like to know what they are, what troubles they might cause, and how to get rid of them. If possible, would prefer to find a way of dealing with the problem without using harsh pesticides.
Thanks in advance for the info.
Chris
Leesburg, Virginia

Hi Chris,
We are pretty certain this is a Booklouse in the order Psocoptera, but we recently misidentified a different insect thinking it was a Booklouse.  We will get a second opinion.  BugGuide indicates:  “Book lice are best known for feeding on the starch in book bindings.”

Letter 11 – Barklouse, not Globular Springtail

What is this Bug?
September 14, 2009
Dear Bugman, I have this most unusual bug in my downstairs (under the stairs bathroom). I apologise for the Quality of the pictures but it is so hard to get a picture of this bug as it is so tiny. You can see the scale from the last picture with the tap in it.
They seem almost transparent with a brown twinge and I only ever see one or 2 at a time. Usually on the sink or toilet but I have also seen them on the wall. The bathroom is small, quite cold usually and doesnt get a lot of light.
They move very slowly and seem a but unaware of my presence most of the time. They aren’t causing me any problem, more just curious as to what they are?
Thanks for your Help,
Regards,
Denis.
Dublin, Ireland

Hi Denis,
This is a Globular Springtail in the order Symphypleona and the class Collembola.  Springtails are primitive insects that are among the most numerous insects on our planet. 

They are often associated with dark damp areas.  When they are very numerous, they can become an annoyance in the shower and other indoor areas, but they are benign. 

They are thought to feed on molds, so a population explosion of Springtails may be symptomatic of a greater problem.

Correction by Eric Eaton
September 16, 2009
Daniel:
I think that “globular springtail” of September 14 is actually a wingless barklouse (order Psocoptera).  The two look extremely similar and I even have trouble telling them apart sometimes.  Still, I’d bet on this being a barklouse/booklouse.
Eric

Letter 12 – Barklice

Concrete bugs? Termites
May 1, 2010
Concrete bugs? Termites
• Your letter to the bugman    I recently noticed a big spot of bugs congregating on my concrete steps. I thought they may be termites, but do not see any wings. Also saw a collection of them all over a piece of lava rock.
Derek
South Florida

Hi Derek,
There are harmless immature Barklice in the genus Cerastipsocus, also called Tree Cattle.  Their presence on the concrete is a mystery.  They are generally found on trees where they eat lichen. 

You may compare them to images on BugGuide as well as read more detailed information on the University of Florida Horticulture website where they are identified as Archipsocus nomas.  When they are adults, they will have grown wings which hide the bold striped pattern of the nymphs.

Letter 13 – Booklouse from Singapore

Bug?
Location: Singapore
April 19, 2012 7:13 am
Hi recently i notice tiny moving black dots on my wall, they usually stay very still and they move when i shine my torchlight on them. Is this a pest?
Signature: Doesnt matter

Dear Doesnt matter,
This is a nicely detailed photo of a Booklouse.  Booklice in the family Liposcelididae are pictured on BugGuide.  According to Charles Hogue in Insects of the Los Angeles Basin: 

“Although it is a contributor to the allergens found in house dust and its feeding may do minor damage to book bindings and paper, the presence of the Book Louse is usually no more than an annoyance.” 

Letter 14 – Booklice

What is This?
Location: Glenview, IL
November 7, 2011 4:29 pm
Found these bugs on the outside of paper bags of wheat in our basement
Signature: Brittany Priz

Hi Brittany,
You have Booklice tiny insects that are often found in homes, especially damp cellars and garages.  According to Charles Hogue in his wonderful book Insects of the Los Angeles Basin: 

“The most common is the true Book Louse (Liposcelis bostrychophila), a cosmopolitan pest for the food industry, households, museums, and libraries. 

Although it is a contributor to the allergens found in house dust and its feeding may do minor damage to book bindings and paper, the presence of the Book Louse is usually no more than an annoyance.  Out of doors, this species lives on woody vegetation, on fungi in gournd litter, in soil, or in animal nests.”  See BugGuide for additional photos.

Letter 15 – Booklice in Indonesia

Bugs inside Milk Powder Cans
Dear Sirs,
We just searched websites for Booklice bug and found your website. We’re seeking a technical advice concerning bug contamination that recently found in our canned milk powder, made of tinplate metal can-packaging.

Kindly view the attached picture showing the bugs that might be Booklice bug, found inside the cans and suspected came from carton layers that are used to stack the empty cans on a pallet up to 2 meters can-stack height.

We use corrugated Carton layers with specification of Medium 100 triple layer, meaning that the top flute and bottom layer are made from ex recycle carton materials. Why Booklice bug loves to stay in carton layers; hope you can provide us some advices on how to overcome it.

What pest-control required to get rid of these bugs? Looking forward to your valuable advice; with kind regards,
Kristianto
Jakarta, Indonesia

Hi Kristianto,
First off, we agree that you have Booklice or Psocids, insects in the order Psocoptera, probably the family Ectopsocidae. They feed on starch which explains their presence in the cardboard.

They feed on sizing, paste and glue of book bindings as well. Your problem would seem to be how to prevent the Booklice from being transfered into the cans during the packing process. Sorry, we do not offere extermination advice. Booklice are in the order Psocoptera and are not true lice, nor do they harm people or bite.

They would much rather eat mold and fungi. Most Booklice are in the family Liposcelidae and you can find some additional photos on BugGuide. We also located a North Carolina University website that states:

“The presence of booklice can be quite an annoyance; however, they rarely cause significant damage to items. Most often, the damp conditions and developing mold or fungi have already caused the damage.” Large numbers of Booklice may be present in stacks of newspapers stored in damp places.

The previously mentioned NCU website also gives the following advice; “Non-chemical management Reducing moisture and maintaining relative humidity below 50% will provide excellent control of booklice. Use a fan or dehumidifier to dry out damp rooms or other locations.

Repair any leaky plumbing. Try to determine and remedy the cause of any condensation around doors, windows, air conditioning units, or other areas. Eliminate any standing water.

Do not over-water houseplants. Reduce or eliminate potential harborage areas by sealing up cracks and crevices. Remove or dispose of items that could be harboring mold and fungi, such as old books, cardboard, papers, wallpaper, and food goods stored in damp conditions.

Those items that cannot be removed or disposed of should be stored in airtight plastic bags or containers in cool, dry, and well ventilated areas. Clean up any spilled food goods such as cereal or flour that could serve as a source for mold growth. “

Letter 16 – Tree Cattle

What is this cluster of bugs?
Location: Jacksonville FL, ( Northeast Florida )
March 27, 2012 1:12 pm
This tightly packed cluster of bugs were at the very base of a Crepe Mrytle tree trunk, where it was very smooth. Each bug was about the size of the head of a pin. When disturbed, they spread out but immediately regrouped.
This was taken March 27, 2012 in Jacksonville FL in a business/office park. It was about 80 degrees and sunny.
Signature: Kat

Hi Kat,
These are immature Barklice, commonly called Tree Cattle.  They are benign creatures that feed on lichen and they will not harm the tree though they resemble an infestation.  We believe the species is most likely Cerastipsocus venosus based on photos posted to BugGuide.

By the way – just found out what they were! ” Common Bark Lice ”  Species: Cerastipsocus trifasciatus
Kat

The two species look very similar.

Letter 17 – Booklice, NOT Globular Springtails

Subject: What is this tiny bug?
Location: Jacksonville, FL
November 23, 2015 9:08 am
Hello, I found these tiny, almost microscopic, bugs in my sink after being gone for the weekend. Any idea what they are?
Signature: Zb

Dear Zb,
You have Globular Springtails in the order Symphypleona and though they can be a nuisance when plentiful in the home, they are benign.  They are generally found in damp locations.  See BugGuide for additional information.

Correction:  Booklice
WE just received a comment with a correction.  We concur that these silhouettes are likely Booklice, Liposcelis bostrychophila, as pictured on BugGuide.

Letter 18 – Booklouse in Canada

Subject: Tiny insects
Location: Quebec, Canada
April 12, 2015 8:48 pm
Hi. I have been finding these tiny bugs in our new condo. I find them on baseboards, windowsills and around our electric breaker box. They are very small (1-4 millimeters, I would say), and are easier to spot with a flashlight. I have found about 50 of them over a 4 week period.
Signature: Concerned

Dear Concerned,
You are being concerned unnecessarily because of this Booklouse, probably a member of the genus Lipocelis based on this BugGuide image.  According to the North Carolina State University Department of Entomology: 

“Booklice feed primarily on microscopic fungi and mold. Therefore, they are most often found in damp, dark areas. Such places may include basements, crawlspaces, kitchens, leaky plumbing, unvented storage areas, and around over-watered houseplants.

They may also show up in recently built homes where they entered during construction and were enclosed in a wall after siding and sheetrock were installed. … Booklice are often associated with old books or other papers that are stored in damp conditions.

These conditions promote the growth of mold or fungi on the pastes and glues of book bindings. They may also be found in food goods stored in humid conditions that support mold development. While their presence can cause great annoyance, they rarely cause significant damage to items.”

Letter 19 – Tree Cattle

Subject: Insect infesting a crepe myrtle
Location: St. Augustine, FL
December 23, 2012 2:34 pm
I live in St. Augustine, Florida. Today (December 23) I noticed clusters of small, black insects on one of the two crepe myrtles in our back yard.

I took a picture to try to look it up online and I noticed another type (or possibly babies of the first?) of insect in the group. My parents and I want to know if this insect is harmless or if it’s something we should worry about.
Signature: Nicole

Hi Nicole,
You have Tree Cattle or Bark Lice.  They are benign creatures that will not harm your trees.  They feed on lichens that grow on tree,

Letter 20 – Booklouse in UK

Is this a bed bug?
Location: Chesterfield, England, UK
April 18, 2011 7:17 am
Hello bugman,
Me and my partner turned our house upside down when we thought we had bed bugs a couple of weeks ago.
Our only evidence was that I had seen what looked like a first instar bed bug on my trousers I’d left on the floor next to the bed, and he found a pearlescent egg on the base of our bed. I also had what looked like bed bug bites on me, but he had, and still has, nothing.

I’ve been to the doctor and been told that I do not have bed bug bites, it is a small oval shaped blister-like rash called pityriasis rosea.
Today however, I have just found another bug that looks like a very young bed bug; it was in a large carrier bag next to my bed.

We do think that it does look too slim and segmented to be a bed bug, it is not bulbous or translucent either.
Please please please can you help us, before we turn our room upside down again.
Signature: Kind regards, Hailey Winstone

Dear Hailey,
Due to the prevalence of media coverage regarding Bed Bugs in recent years, this very real concern has spawned unnecessary paranoia among the general public.  Every creature found in the bedroom is now a suspect. 

This is not a Bed Bug.  It is an innocuous Booklouse.  Booklice are often found in homes and they feed on the starch of book bindings and wallpaper glue, but they will not bite you or harm you in any way.  You can see BugGuide for additional information.

Letter 21 – Barklice

Big infestation of tiny bug on Western New York maple
July 31, 2009
Hi! We’ve got a silver maple tree which is just SWARMED with these tiny bugs with striped abdomens.

Each bug is about 1/8″ in length, and they gather in these densely-populated spots which are roughly 8 inches in diameter, and these spots are ALL over the tree.

Within each spot are HUNDREDS of the little bugs, and 2 or 3 slightly larger winged bugs, which are a little more ant-like than the little bugs.

So what the heck are they doing? Should I worry about the health of the tree and, conversely, our house since the large tree is right next to our house? We’ve lived here for 12 years, and never seen anything like this.
Worried in WNY
Niagara County, northwest corner of NY state

Dear Worried,
You will need to change your name to “Not Worried” because these Barklice, Cerastipsocus venosus, are perfectly benign. 

Though they congregate in large numbers, they will not harm your tree.  They feed on lichens and not on the tree, though the presence of lichens might be symptomatic of another problem on your tree.

Here is what the Texas A&M University Entomology website offers:  “Mouthparts are for chewing. Barklice feed on fungi, algae, dead plant tissues and other debris. Consequently, they are considered harmless and perhaps beneficial to the trees they infest.”

We love your scan of these Barklice because most photos we receive show the aggregations.  Your scan shows both the winged adult and the striped immature nymph.

Letter 22 – Tree Cattle: Barklice

Dark beetles on my tree
June 13, 2010
We live in Northern Virginia. We found these bugs on a tree in our front yard. Not sure the type of tree. They are in groups all over the tree. They remind me of herds of cattle. Each “herd” has 5-6 with wings. They are about 1/4 of an inch long, have dark greyish bodies and stripes. They look like they are snaking on the bark or on something on the bark. Please let me know if they are bad for my tree, thanks. Sorry for the bad pictures. Oh and it’s June.
Morgen
Woodbridge VA

Hi Morgen,
It is interesting that you compared these benign Barklice to herds of cattle because a common name for them is Tree Cattle.  The species is Cerastipsocus venosus and your individuals are wingless nymphs.  Adults have wings.  Though they seem like they might be damaging the trees, the feed on lichen growing on the tree and they will not harm the trees.

Letter 23 – Tree Cattle

Wondering what these insects are.
Location: Southeast Georgia
April 9, 2012 11:17 am
Curious what these insects are that group up on the sweet gum trees in my yard and if I should have them exterminated or leave them be?
Signature: James Pape

Hi James,
You have a colony of immature (striped) and adult (winged) Bark Lice, commonly called Tree Cattle.  They are benign creatures that feed on lichens, and they will not harm your tree.

Thanks for the info, I’ll be keeping those guys around and let other know.

Letter 24 – Booklouse found in wife’s hair

Subject: tiny bug?
Location: Pacific Northwest (urban)
January 17, 2016 12:34 pm
Found this in my wife’s hair the day after visiting a beautician.
I think it is too small to be lice. It’s super tiny, barely visible. The pic is 100x.
Thank you,
Signature: Payton

Dear Payton,
We have taken the liberty of removing your surname from this posting as we do not want to draw unnecessary attention to your wife and her hitchhiker. 

Though it is commonly called a Booklouse, and though it is classified with Biting Lice in the order Psocodea, Booklice are actually benign creatures that do not bite, but that may become a nuisance when they reach high population levels indoors. 

According to BugGuide, Booklice are found:  “worldwide and across NA; many spp. are now nearly cosmopolitan or otherwise widely spread through agency of man, mostly with stored products.”  You can compare your image to this BugGuide image of a Booklouse in the genus Liposcelis.

Letter 25 – Cave Barklouse from Germany

Subject: Insects in the balcony
Location: Berlin
July 28, 2015 11:27 am
Hi,
we have started having these insects since middle of May.
We live in the city, in a 5 story building, on the 3rd floor.
They are around 1 mm long and don’t bite.

We could see them in the balcony, crawling on the tiles specially in the evening, when the sun starts setting down and in the early night.
We have started seeing them too in the bedroom, only close to the window.
Any idea what they are?
Signature: Javier

Dear Javier,
We believe we have correctly identified your Cave Barklouse in the family Psyllipsocidae as Dorypteryx domestica thanks to images posted to BugGuide where it states they are found in “household habitats, food storage facilities.”

Letter 26 – Barklice

Clusters of tiny striped insects
July 27, 2009
On a walk with my dog outside my house, she began to sniff the trunk of a tree ~3′ off the ground. I went to investigate and found a series of insect clusters. They were each approximately 1/4″ long and have seemingly long antennae (roughly 2x their length).

They didn’t have wings from what I could tell, and had very straight alternating black and yellow striping on their bodies.
The photos I’m attaching are as close as my little point and shoot would allow me to go in macro mode, they’ll require a zoom to see more clearly
Steve
Upstate NY

Hi Steve,
Despite the name Barklice, and despite the large number on a tree, these Cerastipsocus venosus are benign.  They feed on lichen growing on the tree and are not injurious to the tree.  These are immature nymphs.  Adults have wings.

Thank you!  I just noticed a very similar submission on your site after doing a simple search for Barklice.
Your knowledge is invaluable.
Thanks again,
Steve Kreis

Letter 27 – Barklice, AKA Tree Cattle

What are these???
Location: St. Johns, MI 48879
July 26, 2011 3:03 pm
I have found clusters of these on almost all of my trees in our yard. Some of the the trees are dying 🙁 They fit the characteristics of the Emerald Ash borer, however do not look like any of the pictures I have found.

Some have black/clear wings, some don’t. The ones without wings have yellowish and black stripes. There are a few in each cluster that are white. ?????
Signature: Jessi

Hi Jessi,
This is an aggregation of Barklice, commonly called Tree Cattle.  They are benign creatures that feed on lichens and they will not harm your tree. 

The trees may be dying from other reasons, and dying trees might foster the growth of lichens, which your Barklice are feeding upon.  They are a symptom of a problem, not a cause.  Your photo shows winged adults as well as striped nymphs.

Letter 28 – Tree Cattle

Subject: WTB
Location: Olean, NY
July 24, 2013 7:17 pm
I took a photo of just one of the numerous clusters of unidentified insects just sitting in these clusters, not moving too much, on our magnolia tree. If you zoom in on the photo you can see two distinct looking insects, possibly the male and female?

We first noticed them about 3 days ago and they are still there, not doing much except huddling in these large masses. Can you tell me what they are and if they are dangerous? I live in Olean, NY.
Signature: Pat

Dear Pat,
These are Barklice, and they are sometimes called Tree Cattle.  They are benign insects that feed on lichens, and they will not harm your trees.  The striped individuals are immature nymphs and the dark individuals are winged adults.

Thanks so much, Daniel!  We’re relieved to hear they’re harmless critters.  You da man!  Thanks for the great vice you provide.
Patrick

Letter 29 – Booklice from Hawaii

Subject: Please help identify bug ASAP
Location: Maui, Hawaii
February 14, 2014 12:25 pm
I have 3 small children and worry if its something bad i found these little bugs on a wood little chest my son got from a yard sale
Signature: Jen

Hi Jen,
These appear to be Booklice, and they are benign, though if conditions are right, they can be numerous and a nuisance.  You can read more about Booklice on the Penn State University Entomology page where it states: 

“Booklice feed on molds and will overrun cereals and similar materials that support mold growth. Their presence, therefore, is a nuisance and can render some foods unfit.

The starchy paste of wallpaper and books also can support mold growth or may be attacked directly by booklice. Outside of annoyance, their damage is insignificant.”

Letter 30 – Booklice in Mexico

Subject:  Plague?
Geographic location of the bug:  Tamaulipas, MEXICO
Date: 11/04/2017
Time: 01:14 PM EDT
Hello, i called 3 diferent exterminators and any of them know what kind of bug are these, help me plase. They are in the walls and the roof of my house but they are infested parts of mdf wood in the furniture.

The structure of my house isnt of wood is all cement block, concret and stoff nothing of wood and insulating filler.  The weather is tropical and hot with a lot of humidity.  I hope you response as soon as posible good bless you…

How you want your letter signed:  My english its poor sorry about that i dont use an online traductor. Thx…. Agustin

Dear Agustin,
These are Booklice, and according to BugGuide, they are found:  “under bark, in ant nests, in homes” and “worldwide and across NA; many spp. are now nearly cosmopolitan or otherwise widely spread through agency of man, mostly with stored products.” 

According to Charles Hogue in Insects of the Los Angeles Basin:  “Although it is a contributor to the allergens found in house dust and its feeding may do minor damage to book bindings and paper, the presence of the Book Louse is usually no more than an annoyance.” 

According to DenGarden:  “Booklice are itsy, bitsy little bugs – about 1/16 ” long and they are not actually lice at all, so although they are harmless, they are still bugs. If you’ve got any dried out, or decaying plants, you might find these little critters enjoying a plant buffet, or they may even be lurking around your stored food.

The head and abdomen appear large, and the midsection is more narrow. Huge, compound eyes protrude from the sides of the head. They also have thread-like antennae that sweep backward toward the abdomen. Not all booklice have wings, but some do (usually the booklice that stay outside), and when they do, there are four of them – two smaller front wings and two larger back wings.

Most of the ones you will be hunting down should be wingless booklice.  Booklice really love paper, so you might find them on bookbindings, photographs, or even your wallpaper. You can look for them to thrive in a dark basement or storeroom, if you have one, and if you have a second home that you close up for part of the year, they have probably set up residence there as well.

If you live in an older, loosely-constructed home, there are probably a lot more booklice living there than people. You may need to invest in a good magnifying glass to see them, but they are there.”

Letter 31 – Aggregation of BarkLice

chilly bugs
Hey Bugman, these little critters were obviously chilly one morning. After the sun came out they were gone, then back the next morning. We are in West Tennessee.

Don’t know where to look them up since we have no clue what they are. Thanks. As always, love your informative site.
Richard

Hi Richard,
We wrote to Eric Eaton for help identifying your aggregation. Here is his response: “Wow! Spectacular images of barklice, order Psocoptera, family Psocidae. Also known as “tree cattle,” especially in the nymphal stage.

Some species create webbing on the bark, but I have never heard of them becoming pests. Pretty sure they feed on fungal spores and the like. Eric “

Letter 32 – Bark Louse

Completely Baffled as to Bug ID
Location: SE MIchigan
August 8, 2011 7:15 am
Dear Bugman: What have we found? My son and I discovered this small, unknown insect on the leaf of our tuberous begonia, hanging basket.
Neither of us have ever seen an insect like this before.

I don’t know where to begin to categorize it, so as to look it up. It’s face and antennae look similar to katydid & cricket species, and it measured not quite one half inch. But those dark window-paned wings have me baffled. It’s abdomen was chubby and striped.

At first I thought this might be a juvenile, or instar of some type. After taking many pictures, the insect leaped backwards off the leaf and flew down into the flower bed. Hoping you can put a name to this new find of ours.
Attaching L., R. and dorsal views of this intriguing little ”bug”.
Signature: Confused

Hi Confused,
This creature is a Bark Louse, Cerastipsocus venosus, and the scientific species name refers to the “window-paned wings” you describe.  We are not used to seeing solitary images of Bark Lice, and collectively, a group is sometimes referred to as Tree Cattle. 

Often our readers mistake them for a harmful species when a “herd” is found on a tree, but these benign insects feed on lichens and do not damage the trees.  This is a winged adult.  Nymphs have a boldly striped abdomen.  You can see photos and get more information on BugGuide.

Letter 33 – Barklice

Please help identify
I have been searching the internet, trying to figure out what kind of bug this is. I know it’s some form of a true bug, but cannot pinpoint the species. Is it harmful to my trees, etc.? Thanks for any help you can provide.

These are Barklice, and they are in the order Psocoptera. They are not harmful to your trees. According to Eric Eaton, they probably feed on fungus spores which might make them beneficial to your tree.

Letter 34 – Barklice

What is this bug
We live in Fairhope Alabama. We spotted these clustered adult and nymph(?) insects and have been unable to identify them online. Can you help us out?
John and Melissa Pershina

Hi John and Melissa,
What a spectacular image of Barklice in the order Psocoptera, family Psocidae. The last time we posted an image Eric Eaton said they are: “also known as Tree Cattle, especially in the nymphal stage. Some species create webbing on the bark, but I have never heard of them becoming pests.”

Letter 35 – Barklice

Bugs on our maple and oak trees
August 7, 2009
I noticed these dark patches on one of our maple trees. At first I thought it was patches of moss growing but when I looked closer, I saw that the patches were actually small bugs. I took a picture of the baby bugs and I have another of the adults with them.

I walked my property and found that these patches of bugs were located on ALL my maple and oak trees but not the dogwood or the ash trees… Are these bugs a danger to the trees and if they are, what do I need to do to get rid of them?
Michelle
Southeastern Michigan

Hi Michelle,
This seems to be a bumper crop year for Barklice, Cerastipsocus venosus, since we have receive so many letters in the past few weeks.  Barklice are benign insects that feed on lichens and will not harm the trees.

Letter 36 – Barklice

whats that bug website
Location:  conesus ny
August 23, 2010 7:26 pm
I guess i’m not quite sure how the site works I put a post up last week and was wondering it im just supposed to what to hear from you or am I suppose to keep checking the website…please advise…thank you Tom
Tom

Hi Tom,
We are not able to answer every letter we receive.  We randomly select letters that are submitted in the past 24 hours based in part on the promise of a good subject line.  We post as many letters as we are able to each day and we respond to other letters that we do not post.  After 24 hours, we only resort to posting old mail if we run out of new mail.  You didn’t inquire about the insect in your photo.  We cannot go back through old mail to verify any specific question you may have about these benign Barklice.  Barklice, despite looking like they might be doing damage to this tree, are really feeding on lichen and fungi.  These Barklice, Cerastipsocus venosus, are commonly called Tree Cattle.

Letter 37 – Barklice

Subject: Small red bugs with black stripes
Location: Nelson, New Hampshire
July 17, 2013 7:19 pm
Dear Bugman,
These small critters were found on my mother-in-law while canoeing in a pond this past Monday, July 15th 2013 in Nelson, New Hampshire. After brushing against some leaves from a nearby tree these bugs were found on her shirt. They are very small. You can compare their size with the clothe stiching. I have scoured over photos from insect guides and the internet and I cannot figure out what these are. Nymphs? Ants? Aphids? I’m stumped.
Signature: Stumped

Dear Stumped,
These are Barklice, benign creatures that you may read about on BugGuide, which states:  “barklice are always found outdoors, and occupy a wide variety of habitats; booklice often live in homes” and “Barklice feed on lichens and fungi on tree bark, booklice are best known for feeding on the starch in book bindings.”  They look very similar to this member of the genus Ectopsocus which is pictured on BugGuide and was also found in New Hampshire.

Letter 38 – Barklice

Subject: Black Bug ID
Location: Florence, Alabama
October 29, 2013 5:48 pm
My daughter photographed this bug. It has a very clear pattern on its back, like a decorated suit coat.
Signature: Jerry Owen

Hi Jerry,
These are Barklice and they are commonly called Tree Cattle because they form colonies on trees.  They are benign creatures that feed on lichens and they do not harm the trees.

Daniel Marlos,
My daughter lives in Alabama and I in Mississippi.  But she got me an insect book for Father’s Day, and with the PC, we stay in touch.
And I thank you.
Jerry W. Owen
Ripley, MS

Letter 39 – Barklice

Subject: Wtb?
Location: Delaware
June 28, 2014 5:35 am
I have found a swarm on my oak tree in delaware. I’m attaching a video and photo. Should I try to get rid of them? They look harmless but I don’t want to lose my tree that is holding up the treehouse.
Signature: Robin

Hi Robin,
As you have surmised, these Barklice, Cerastipsocus venosus, are harmless, despite the alarming appearance of being an infestation.  Barklice, also called Tree Cattle, feed on lichens and they are benign, hence they will not cause harm to the tree or the folks using your treehouse.

Thank you! That was very informative and helpful!

Letter 40 – Barklice

Subject: can’t indentify insect
Location: South Texas
April 17, 2015 3:32 pm
Hello,
I live in West Columbia Texas and found these bugs outside. I’ve searched for an hour and cannot find what it is. Help?
Thanks
Signature: Travis

Dear Travis,
These Barklice, Cerastipsocus venosus, are benign creatures that feed on fungus and lichens.  They are generally found living on trees, and though they do not damage the trees, they might be a sign that the tree has health problems causing the growth of fungus that the Barklice are feeding upon.  Barklice are commonly called Tree Cattle.

Letter 41 – Bug of the Month May 2015: Tree Cattle

Subject: Fly?…
Location: Houston
April 30, 2015 10:58 am
Hello bugman,
I noticed a large cluster of flying bugs of some sort on my tree today. 2 groups. From a distance they appear black, like large gnats? Up close they’ve got 6 legs it appears, long antennae, and wings.

The wings are a very detailed combination of black and gray colors, outlined in white with a white solitary spot. Very beautiful looking up close. Just not sure if these are invasive /destructive to my tree/garden and wanted to check what they were.

The closest thing I’ve been able to find is a picture winged fly but there are so many I wasn’t sure. I have a video as well if you’d like it. You’re help is truly appreciated!
Signature: Alma

Dear Alma,
These benign Barklice, Cerastipsocus venosus, might appear alarming when they are seen clustering on a prized tree in the yard, but gardeners have no cause for alarm.  Barklice feed on lichens, and they will not harm your tree.  Barklice are sometimes called Tree Cattle. 

Your image is of winged adults.  Wingless Barklice nymphs are boldly striped.  We just realized it is the first of May and we need to select a new Bug of the Month, so we have selected your excellent image of Tree Cattle as the featured posting of the month.

You guys are AWESOME! I can’t thank you enough for your help and information!!!  I’m a huge science fan so I love exploring and trying to figure out what things are. I also know how busy you guys must get, so I will definitely be helping with a donation.

I also let people know about your site when they are trying to figure out bugs. If you ever need help for rebranding/redesigning let me know (I’m a professional graphic designer). I’m happy to help if you need it!
You have a great weekend!
Alma Soto

Thanks for the offer Alma.  We got our start many years ago on the now defunct American Homebody site, and we still prefer our homey look to the more high tech sites.

I can most certainly understand and respect that!
For what you guys do… It actually works.
Again thank you guys so much for your help, and prompt response.

i’ve made sure to tell all my friends about you guys, and have already tweeted you out. 🙂 you guys have helped me before I remembered for a bug I experienced when we lived on job assignment on Venezuelan Penninsula that they call pachaco – it was

I found out thanks do you guys a Solifugae (all I could remember was that their body looked like a cross between an ant, spider and an earwigi- they were fierce looking, fast, and scared the living daylights out of me). so again, thank you guys for all you do!
Alma

Letter 42 – Barklice

Subject: Question from my 5-year old son
Location: Florida
June 3, 2015 12:42 pm
Dear Bugman,
We saw these bugs on a tree. It was in our yard. What are they? We live Florida. Winter park. We saw them yesterday.
(Mom who typed this adds: They were swarming in several locations on that tree. They were all about the size of a kid’s fingernail. No flying just grouping together. Hadn’t seen them there before.

My son really loves bugs and our goal this summer, being fairly new to florida, is to find and identify as many as we can. We couldn’t find these in a guidebook. Pic attached! THank you I advance!)
Signature: From Declan

Dear Declan,
These immature Barklice, Cerastipsocus venosus, are commonly called Tree Cattle, and though they may look like an injurious species, they are actually quite benign, feeding on lichens that grow on the trees and not in any way harming the trees themselves.  Adult Tree Cattle have wings.  You can read more about Tree Cattle on BugGuide.

Letter 43 – Barklice

Subject: Barklice?
Location: Greenville, SC
September 13, 2015 3:47 pm
Hello,
I recently discovered a large grouping of insects on one of my trees. The insects are very small and are grouped very tightly together. I would estimate that there are 300-400 insects in this group that I sent a picture of.

Apon further investigation I noticed this one grouping was just the tip of the iceberg. From standing at the bottom of the tree I can see about 20-25 additional grouping. In other words the tree is infested with these insects.

I am affraid they are killing the tree. I searched the Internet and found a Barklice that look very similar to the insect on my tree. Can you please tell me if this is a Barklice and what I should do to remove it? Thank you very much. I greatly appriciate your help.
Signature: Jason Buckley

Dear Jason,
These are indeed Barklice or Tree Cattle, and they are benign insects that feed on lichens.  They will not harm your tree, however, their presence because of large amounts of lichen and fungus on the tree may signal that the tree is compromised, though not because of the Barklice.  Your individuals look like Cerastipsocus trifasciatus based on images posted to BugGuide.

Daniel,
Thank you very much. I will leave the these insects alone and have someone inspect the health of our tree asap. We greatly appreciate your help.
Thank you,
Jason Buckley

Letter 44 – Barklice

Subject: please help me, I’ve looked everywhere. ..
Location: South Central Pa
July 14, 2017 6:29 pm
I found these on a Crabapple tree…. my 8 year old son and I have been poring over pictures to find out what they are… we are in south central Pa, and it’s in July. ..
Signature: Renee and J

Dear Renee and J,
Home gardeners are often quite alarmed when they find large colonies of winged adult and wingless immature Barklice on their trees.  Barklice are commonly called Tree Cattle. 

There is no cause for concern.  Barklice will not harm the trees.  According to BugGuide, they eat:  “accumulations of fungi, algae, lichen, dead bark and other materials that occur on tree trunks and large limbs.”

Letter 45 – Barklice

Subject:  What’s this bug/insect?
Geographic location of the bug:  New Jersey Pine Barrens
Date: 10/01/2017
Time: 11:07 AM EDT
A friend of mine in NJ found these on her shed in the Pine Barrens.  It’s a wooded, swampy, sandy area that is densely populated with many trees including oaks and pines of all sorts
How you want your letter signed:  Curios creature that

Dear Curios,
We often receive identification requests for Barklice that are found in large numbers on trees in lawns.  Though they appear as though they are harmful to the trees, Barklice actually feed on lichens and they do no harm to the trees.  Barklice are commonly called Tree Cattle.

Letter 46 – Barklice

Subject:  Bugs in tree
Geographic location of the bug:  Tampa fl
Date: 02/11/2018
Time: 05:16 PM EDT
Your letter to the bugman:  Found these bugs on a live tree in our back yard. What are they please?
How you want your letter signed:  Miranda

Dear Miranda,
These benign insects are in the family Psocidae, and they are commonly called Barklice.  Based on this BugGuide image, we are relatively certain your species is Cerastipsocus venosus. 

Barklice frequently form large aggregations of both winged adults, and brightly patterned wingless nymphs as they feed upon, according to BugGuide, “accumulations of fungi, algae, lichen, dead bark and other materials that occur on tree trunks and large limbs,” leading to the common name Tree Cattle.

Letter 47 – Barklice

Subject:  Strange bug
Geographic location of the bug:  Beaufort, NC
Date: 05/29/2018
Time: 07:06 AM EDT
Your letter to the bugman:  We have recently seen these bugs on a crepe murtle tree
How you want your letter signed:  Curious

Dear Curious,
These are benign Barklice, commonly called Tree Cattle.  They will not harm your tree. 

Letter 48 – Barklice

Subject:  Wood boring bug?
Geographic location of the bug:  Berlin Center Ohio
Date: 07/24/2019
Time: 11:07 PM EDT
Your letter to the bugman:  My friend found these on her grandchildren’s swing set wooden post. She wants to know what they are? And if they are poisonous or a danger to her grandchildren. I’ve search every where and can not find anything. She told me that they don’t fly or jump because one of her grandchildren sprayed them with a water gun and they crawled away extremely fast.
How you want your letter signed:  MissMiss91

Dear MissMiss91,
These are benign Barklice, and they will not harm your friend’s grandchildren, nor will they destroy the swing set as they are not wood boring insects.  They are often found on the bark of old trees and on old unpainted fences and other wooden structures where they feed on lichens.  Barklice are commonly called Tree Cattle.

Letter 49 – Barklice

Subject:  bug
Geographic location of the bug:  sussex- county
Date: 08/30/2021
Time: 05:02 PM EDT
Your letter to the bugman:  They are located on my maple tree in groups thur out the tree. Attaching a picture–Thank you for taking your time out to let me know
How you want your letter signe:  David

Dear David,
We suspect you mean Sussex County, New Jersey.  Because of their large numbers, these Barklice look like they pose a threat to your tree, but they are actually quite benign.  They feed on lichens, not on the tree.

Letter 50 – Barklice and Azalea Lace Bug

Mystery bug on red cedar
November 16, 2009
These pictures were in Eastern Long Island in August. They were on eastern red cedar in a “grove”. Trees had cedar quince rust, even on trunks. I think they may be involved in disease spread. Move very fast in “herd” like fashion. Third image is azalea lacebug, thought you might be interested..it shows the helmet and cowl fairly clearly!
Dr. Andy
Bridgehampton, NY (Long Island)

Dear Dr. Andy,
The Barklice you wanted identified are perfectly harmless.  They are sometimes called Tree Cattle.  The pictured individuals are immature and the adults will have wings.  Thanks for also including the photo of the Azalea Lace Bug.

Letter 51 – Barklice found on Fence

Subject: Swarms of Bugs on my Fence in Kentucky.
Location: Louisville, Kentucky
June 25, 2015 9:44 am
All,
I woke up this morning and saw several swarms of the attached bugs on my fence in Louisville, KY. Any ideas what this is?
Signature: Rick L

Dear Rick,
These benign Barklice or Tree Cattle are generally found feeding on lichens and fungus on trees, and because of their numbers, they alarm gardeners.  They are perfectly harmless.  Finding them on a fence is unusual, but if you used untreated wood, fungus and lichen might be growing on the fence.

Letter 52 – Barklice from Panama

Subject:  What are these bugs
Geographic location of the bug:  Chiriqui province Panama
Date: 03/25/2018
Time: 12:55 PM EDT
Your letter to the bugman:  This group of insects were high up in a Cecropia tree. Some appear to be winged and others have what looks like long rear legs.
How you want your letter signed:  Linda Scott

Dear Linda,
These are Barklice or Tree Cattle in the insect order Psocoptera, and though we were not able to locate any similar looking species from Panama or surrounding countries, we did locate this somewhat similar looking individual from Bolivia on FlickR.

Daniel,
Thank you for your help. The photo was poor quality due to the bugs being so high in the tree so I am amazed that you could id it so quickly. I will study what you sent.

I am curious about the winged bugs that were with the ones with large hind legs, the winged ones seemed to be herding or at least following the others.
Thank you for your website.
Linda Scott

Hi again Linda,
The winged individuals are adults, and the immature individuals have not yet developed wings.

Letter 53 – Barklice or Tree Cattel

Subject: Unknown group of bugs
Location: Coastal NC
May 28, 2016 4:55 am
We live on the mainland of Holden Beach, NC. I have never seen this bug but all of a sudden this week I have noticed several clusters of bugs on several of my live oak trees. It is May 28th.
Please help me to identify these creatures. Some clusters are smaller than others. Do I need an exterminator and will they destroy my trees? Some of these clusters are like 8×8 inches. This is creeping me out, I’m not a bug lover, just a bird lover, but yet I havent seen any birds eating them. I wish they would.
Thank you!
Signature: Loretta

Dear Loretta,
These benign Barklice are sometimes called Tree Cattle because of the large aggregations of winged adults and wingless nymphs that they form on trees with lichen growth. 

They feed on the lichens, and they do not damage the trees.  Though we are responding to you on the day you submitted your request, we will not be posting your submission until mid-June while our editorial staff is away from the office.

Thank you Daniel!  I did look at your description of Barklice earlier, but just wasn’t sure.  So glad I asked.  Thank you for your quick response.
Have a good weekend.
Loretta

Letter 54 – Barklouse

Subject:  whats that bug
Geographic location of the bug:  greece athens area
Date: 01/28/2018
Time: 03:18 PM EDT
Your letter to the bugman:  Hi we found some of these bugs in our bathroom
Do you know what is it and if it is dangerous or needs treatment
Regards
How you want your letter signed:  VP

Dear VP,
This looks to us like a benign Barklouse in the order Psocodea.  In our opinion, treatment is not necessary, though when plentiful, Barklouse might be a nuisance.

Letter 55 – Barklouse from the UK

Unknown Baby Bug
Location:  UK (Southampton)
October 16, 2010 7:44 pm
I’m trying to work out what this bug is. It’s (presumably) a baby, and measures in at about 1 or 2mm.

We are currently having an infestation of silverfish in the property, but this doesn’t really seem to look like one to me (and there have been quite a few of these little ones crawling around), plus it appears to have wings. Any suggestions would be greatly appreciated.
Signature:  Geoff Merrett

Hi Geoff,
Though it is small, this Barklouse in the order Psocodea is a winged adult.  Since your specimen is from the UK, we did not expect to be able to find a match on BugGuide which is devoted to North American species, however, the Cave Barklice in the family Psyllipsocidae has some individuals posted to BugGuide that look very similar to your specimen, especially Dorypteryx domestica.

Letter 56 – Mystery Insect from Slovenia may be Barklouse or Maimed Beetle

Mysterious insect!
Location: Slovenia
October 31, 2011 10:57 pm
http://imgur.com/a/SQe1O
These photos were submitted by a friend. The only info I have is that it’s from Slovenia.
I am thinking it is a beetle with the elytra missing due to a cruel individual pulling them off or due to a genetic mutation. Maybe Chrysomelidae?
What do you think?
Signature: Joseph_P_Brenner

Dear Joseph,
We agree that this insect is quite beetle-like, but we haven’t a clue as to its identity.  We are posting your photos in the hope that we will be able to provide you with an identification.

We are also planning on contacting Eric Eaton for assistance.  The closeup of the head should be very helpful.

Eric Eaton has a suggestion
Hi, Daniel:
My gut reaction is that this is some kind of barklouse, order Psocodea.  Beyond that I have no idea.
Eric

Thanks, Daniel.
My buddy got in touch with Dr. Vassili Belov and Dr. Belov thinks it’s Malthodes or Malthinus with the elytra amputated.  I think he is correct.  Definitely looks like one of those 2 soldier beetle genera.
Thanks again!

Letter 57 – Benign Barklice succumb to annihilation

Subject: On Crepe Myrtle Bark
Location: Auburn Alabama
March 6, 2016 3:37 pm
Found this on crepe myrtle tree whilst pruning today–they traveled together in 20-30 bug groups, moving then stopping on the bark. What is this?
Signature: Bob Alabama

Dear Bob,
These are benign Barklice.  Home gardeners may find the presence of aggregations of Barklice or Tree Cattle as they are commonly called, alarming because generally insects found in large groups on plants are injurious, Barklice will not harm your crepe myrtle tree. 

Barklice feed on lichens on tree bark and fence posts.  We hope future encounters do not meet with Unnecessary Carnage because it appears the Barklice in your image have succumbed to pesticide spray.

Letter 58 – Book Lice

>Can you help identify Small fly like bugs/insects
Hi Lisa Anne and Daniel,
Noted on the site you’ve had some internet issues and resubmitting wasn’t a bad idea. Realy incredible that you get circa 100 requests a day, WOW!

Keep up the good work, I realy like this site it’s already helped me identify quite a few bugs :o) Pity you get the “Nasty readers” but the award is good idea, should put them to shame. Kind regards,
Willem

(12/04/2007) Can you help identify Small fly like bugs/insects
Hi Bugman,
I was wondering if you could help me with identifying these little fly like bugs or insects. You ‘ll find top, botom and side views attached. Though they have wings they don’t fly.

When you approach them they jump around, about 5 cm high, and only about 3 times max, they seem to get exausted quite quickley. They are about 1 to 1.5 mm in length. They are about everywhere in my appartment though not in great numbers, one or two tend to show up here and there (though they are difficult to see).

Any idea what they are living of? location: Brussels, Belgium. Love the site! Its well made and accessible 🙂 Thanks in advance, Kind regards,
Willem

Hi Willem,
These sure look like Book Lice to us. Book Lice are in the order Psocoptera and they feed on sizing, paste and glue in book bindings. They may infest homes. We believe your specimens are in the family Ectopsocidae based on images posted to BugGuide.

We don’t get nearly as many letters per day in the winter as we do in the summer, but we still cannot answer every letter we receive. Thanks for being patient.

(12/22/2007)
Hi Brilliant! Thanks to you I’ve now narrowed their identification down to: Dorypteryx domestica. Kind regards
Willem.

Letter 59 – Booklice

Bugged in Seattle
Hello,
These miniscule little buggers have infested my flour and grain boxes, getting into the new boxes of corn flour, wheat flour, and oatmeal within days of bringing them home. Also they liked to hid under the spice bottles, but didn’t seem to get inside any of them.

They are 1mm long and look like ants under a 10X hand scope. Attached are photos, sorry they are not great, but they are tiny little rascals. What are these bugs? And more importantly, how do we get rid of them? Please find attached 10X microscope photos of the bugs mentioned below.

I do not believe they are springtails, although you are right that they do resemble them. They are definately not immmature cockroaches, as they never get bigger than 1.0mm long. I have attached a photomicrograph of a springtail as well for direct comparison.

These are one milimeter long and slightly less than 0.5mm across and resemble little ants. When disturbed they appear to fall on their backs and “play dead”. At times they appear to “jump” but not very far 1-2cm, almost like a piece of small plastic being repelled by static electricity.

We live in Seattle and they have attacked all our grains and interestingly, when I visited my parents in Ohio, they also had the same bugs in their oatmeal and grain boxes. Hope this additional info and photos help you to identify these bugs.
Cheers,
Kyle Horner

Hi again Kyle,
Thank you for sending the much improved images. These are Booklice, also known as Psocids. According to Hogue: “The most common [species] is the true Book Louse, Liposcelis bostrychophila, a cosmopolitan pset for the food industry, households, museums, and libraries.”

Letter 60 – Booklice

What the…
Hello,
I live on the Oregon coast in Coos Bay. We are beginning to find these little bugs all over our house. What are they and what can we do about them? Here it sits on tape next to a dime.
Richard Hinkel

Hi Richard,
We needed to turn to Eric Eaton for help and here is his response: “This is actually a booklouse, order Psocoptera, family Liposcelidae most likely. Neato. Just keep it away from my insect collection:-) Eric ” According to Audubon: “Book lice are wingless and sometimes infest houses, where they feed on the sizing, paste, and glue of book bindings.”

Letter 61 – Booklice

Subject: Need identification
Location: 44.703093,-63.610989
January 5, 2017 10:59 pm
Being having crawling sensations on me for the last two years.
Sorry for the bad pictures i had to put transparent tape over it.
I got this when i stop at Burnside motel in Dartmouth NS.
Signature: Celine

Dear Celine,
This is a Booklouse in the family Liposcelididae, and according to BugGuide they are found:  “worldwide and across NA; many spp. are now nearly cosmopolitan or otherwise widely spread through agency of man, mostly with stored products” and their habitat is “under bark, in ant nests, in homes.” 

According to Penn State Department of Entomology:  “Booklice, also called psocids, are not true lice. While they resemble lice in size and shape, booklice feed only on fungi or mold. If you find them in grain or other stored food products, it is an indication of high humidity which encourages mold growth.

In addition to food products, psocids may be found under wallpaper, in furniture, along the sides of windows or on window sills around potted plants. Booklice do not bite, transmit disease, or damage food or fabric, but they can be very annoying when present in large numbers.” 

The site also states:  “Booklice feed on molds and will overrun cereals and similar materials that support mold growth. Their presence, therefore, is a nuisance and can render some foods unfit. The starchy paste of wallpaper and books also can support mold growth or may be attacked directly by booklice. Outside of annoyance, their damage is insignificant.”

Letter 62 – Booklice on Silk Sweater

Hi. These were crawling all over a silk sweater. What are we dealing with? Here’s another one we caught. (We froze the sweater.) This one is “undamaged”, but not very focused. These things are on the order of 100 microns wide
Thanks.

You have Booklice. According to Hogue they are known as book lice or paper lice: “becaues they are so commonly found scurrying over books and newspapers, especially those stored in damp cellars and garages.” He goes on to write that they are “a cosmopolitan pest for the food industry, households, museums and libraries.”

Letter 63 – Booklouse

Subject: Psocid?
Location: Presque Isle, Maine
August 30, 2012 9:08 am
Hi there!
All of a sudden (about a month ago), they showed up! Went to use my Food processor and the bowl was crawling with a bunch of them. Yuck!! I checked around in the closet and found a bunch more on platters and in canning jars I keep in there as well. I am a clean person and this has me freaked out!

Being a knowledge hound and wanting to know what they are, I took a photo and proceeded to look at image after image online to find one like it.
And I think I did! So I am asking you to confirm that the TEENY-TINY critter I photographed is what I think, a psocid, and that it will not harm the people, dog and cats that all live here.

I intend to freeze the dog food that is also stored in that closet to kill off any that may be in there. NOTE: No other food is stored in there typically. I had some potatoes in there but threw them away a couple weeks ago and the closet isn’t near any water sources like sink or drains.
Signature: Gratefully, Creepy-crawled

Dear Creepy-crawled,
Though your photo is quite blurry, it does appear to be a Booklouse or Psocid.  Your excellent description confirms what the photo does not reveal. 

You are correct that Booklice or Psocids are harmless, though they can be a nuisance if they are plentiful, as you learned firsthand.  More information on Psocids is available on BugGuide.

Letter 64 – Booklouse

Subject: household bug, a few living in my computer… nothing to worry about?
Location: Oakland, California
March 30, 2017 5:37 pm
Hello, bugman! Thank you from the bottom of my heart … and floorboards? … for all that you’re doing to ID bugs.

These little mites might be harmless, as I haven’t seen a single bite yet, but there are many dozens of them every month crawling along the wooden floorboards of my apartment in Oakland, California.

A few appear on my computer from time to time. What do you think? Harmless?
Signature: David

Dear David,
Though they are quite small, this is not a Mite.  It is a Booklouse, an innocuous creature that could become a nuisance if they get plentiful.  According to the North Carolina State University Department of Entomology: 

“The presence of booklice can be quite an annoyance; however, they rarely cause significant damage to items. Most often, the damp conditions and developing mold or fungi have already caused the damage.” 

Letter 65 – Harmless Barklice in Play Fort

Subject: What is this?
Location: Ocala, Florida
January 11, 2016 2:24 pm
I just found these tiny little bugs in my boys play fort! I have no clue if they are harmful or what I should do. Please help me! I’m also in FL
Signature: Lauren

Dear Lauren,
You have no cause for concern.  These are immature Barklice, and they are usually found on trees where they feed on lichens growing on the bark.  There must be lichens growing on your boy’s fort.  Barklice are frequently called Tree Cattle, but in your case, we would have to call them Fort Cattle.

Letter 66 – Immature Barklice or Tree Cattle

Hornet with no Wings?
Location: California
August 15, 2011 5:00 pm
a Friend of mine found these on another friends front trees. They appear to be some kind of wingless wasp/hornet.
Signature: Thanks, Craig

Dear Craig,
These are immature Barklice in the family Psocidae, and they look remarkably like Cerastipsocus venosus, a species that is commonly collectively called Tree Cattle. 

They are benign creatures that feed on lichens and they will not harm the tree, though homeowners are often startled to find large numbers on mature trees.  When they mature, they will have wings that cover the strikingly striped abdomens.

Here is a photo from BugGuide that shows a large number of nymphs and adults together.  What we find unusual is that BugGuide does not have any sightings west of Texas, though it is indicated on BugGuide that they are “widespread.” 

Eric Eaton concurs, and offers a suggestion
Daniel:
I believe you are correct.  You might ask the contributor if he/she would not mind periodically taking images of these.  Might be easier to identify the adult version whenever they graduate to that stage.
Eric

Letter 67 – Immature Tree Cattle

Subject: What are these
Location: 01267
July 24, 2015 3:57 pm
These bugs where at the base of a old blue spruce tree in Williamson ma 01267.
zoom in to see the bee like markings.
Thank you
Signature: Jesse Wirtes

Dear Jesse,
This is probably the most amazing aggregation of immature Barklice or Tree Cattle we have ever seen.  Barklice are benign creatures that feed on lichens and fungus on tree bark.  Though they do not harm the tree, they might be symptomatic of an ailing tree.  Adult Barklice have wings.

Daniel,
Thank you!
The photo was just a small part of the mass that was around and on the tree.
Jesse

Letter 68 – Isopods

Help! I have just found your website which I hope will be my saviour. I have a wee problem here in my flat in Edinburgh. This “problem” is a brown creepy crawly thing which seems to like catfood. Whenever I put the catfood back down on the floor for the cats these things seem to put in an appearance.

They seem to be more nocturnal, appearing after dark, so that I find them only when I go into the kitchen at night – and there they are hoovering up the cat food that the messy little eaters have spilt on the floor (cats have no table manners!). There are loads of them and despite me cleaning the floor with bleach several times a week, they reappear with annoying regularity.

They are brown on top and whitish underneathand appear to be ridged making them look a bit maggoty. They have legs and can be various sizes – up to 2cm long. What are these things and more importantly how do I get rid of them. They must be “nesting” under the floorboards as there is nowhere else they can be coming from. I have tried moving the cats food to other parts of the kitchen but they always seem to find it. URGH!!!

I am at my wits end and would like to get rid of these things before the poor cats go mad trying to work out where I have decided to put their food this time. I don’t think they enjoy this game very much! Your help and advice on how to eradicate these pests from my home PERMANENTLY would be hugely appreciated.
—Lesley

Dear Lesley,
From the time mankind has lived in caves, we have been annoyed by household pests. In his usual charming manner, Hogue writes in his chapter on household pests: “Unwelcome guests within our homes, stealing our food and wrecking our possessions, and sometimes repaying us with bites and stings–these are the insect pests. …

A need for shelter, food, or a nesting place, attraction to lights, or perhaps the enticement of shade and food odors–and not a conscious desire to bother us–bring these guests to our door. In spite of screening, entry is easy for most insects: their small size permits them to squeeze through small cracks in the flooring, around baseboards, and under doors and through other imperfections in construction.”
With that said Lesley, no matter what you do, you will have household intruders. Regarding the identification of your brown creepy crawly thing, I suspect pill bugs or sow bugs.

They are not true insects, but rather members of the order Isopoda and the subphylum Crustacea. Pill bugs are so called because of their habit of rolling into a little ball. Sow bugs are generally larger and cannot roll themselves up into a ball. Sow bug can grow as large as 15mm.

They are nocturnal, omniverous and can be very numerous, sometimes experiencing population explosions. They are generally found outdoors in the garden, but they will take refuge inside the home, especially when it is dry.

I would guess that you feed your cats near a water source, and a leaking pipe with the resulting rotting wood, could well be the reason the ispods have taken up quarters in your flat. Because of their distasteful secretions, these isopods are eaten by few predators. A notable exception is the sow bug killer, a dysderid spider, Dysdera crocota.

Letter 69 – Middle Barklouse from Alaska

ID help
Location:  Juneau, Alaska
July 20, 2010 12:14 pm
This little guy (a cm long or so) was crawling on my hand. I have never seen anything like it befofe. It’s summer in Juneau, Alaska.
Shadoe

Hi Shadoe,
We matched your images to a posting on BugGuide of a Middle Barklouse, Mesopsocus unipunctatus.  The BugGuide information page does not provide much information.

Letter 70 – More Tree Cattle in San Diego

Subject: Bug identification needed
Location: San Diego
May 27, 2013 8:43 pm
Found these bugs on a ficus tree trunk in San Diego, CA. There was one group of the bigger bugs, and anther group with a few of the large bugs that seemed to be herding the little striped bugs. The bigger bugs were about 1/4” long, maybe less.
Can you tell me what they are, and what they are doing.
Signature: Stan

Hi Stan,
This is our second posting this week of an aggregation of Barklice from San Diego.  We are not certain of the species because this looks like an allegedly eastern species, Cerastipsocus venosus, that are commonly called by the Tree Cattle.  Tree Cattle are benign insects that feed on lichens and pose no threat to the tree, garden or gardener. 

We don’t know if the eastern species has been accidentally introduced to the west, if this is a heretofore unknown species or if there is just little documentation on the presence of this insect in Southern California.  Time will no doubt provide some revelations.

Letter 71 – Mystery from Alaska: a Barklouse

Help from Alaska
Hi Folks!
Well, I think that I am fairly conversant on local bugs but this one has got me and our local pro scratching our heads. I found it on a garbage can in a park in the Kenai Peninsula, AK. It is about 3mm long. Any ideas? Keep up the wonderful work that you do!! Cheers and we are Thankful for you guys!
DeWaine Tollefsrud
www.arcticstarstudios.com

Hi DeWaine,
We weren’t real sure about this critter, and entertained the thought that it might be a ground beetle, but Eric Eaton set us straight. Here is what he concludes: “Hi, Daniel: Wow, the image is of some kind of barklouse, order Psocoptera. Wish I could be more specific! It might even be a wingless adult, rather than a nymph. Eric”

Letter 72 – Nicest Anagrammatical Subject Line in a long time: Insect is Booklouse

Unknown very tiny incest in kitchen cuboard
Location:  Winnipeg Manitoba
September 2, 2010 2:11 pm
My wife found these tiny incests in the kitchen cuboard mostly where she keeps crackers,grains,cereals,but not limited to there. Size is less than .5mm,width much less.

Very hard to see because of size unless they move, very hard to get a picture even at my macro setting. Look like tiny wood fibres till they move. They move around individually.What are they and what will remove them from the cuboards and keep them out?
Signature:  Freddio

Hi Freddio,
Since you used it twice, we figured your anagrammital play in the subject line was designed to get our attention and it worked.  This appears to be a Booklouse, Liposcelis bostrychophila, considered by BugGuide to be a “Common domestic species.”  

Booklice get their name because they are often found eating starch in book bindings, though they will also feed on starchy food products in the pantry.  BugGuide has a nice photo of Booklice feeding on oatmeal.

AskTheExterminator offers some good advice on Booklice control without pesticides, beginning with reducing the humidity in the cupboard area and not storing any foods longer than six months.  Kiwicare offers similar advice. 

We posted a letter last autumn that has many great citations.  We will be tagging this as a household pest, though in our opinion, in small numbers they are probably benign and even inevitable in even the cleanest of pantries.

Thanks for your “Quick” response, perhaps I need a better spellcheck or spelling lessons. LOL

Letter 73 – Probably Barklice from Indonesia

Subject: Bug identification
Location: Bandung, Indonesia.
April 7, 2014 2:20 pm
North west Bandung, Indonesia.
Adjacent to a small stream. Altitude 1000m. Towards end of wet season.
Location – Lat: -6.8468, Long: 107.5815
Found feeding on a leaf, but not on the leaf itself, some kind of deposit. When I disturbed the leaf, the bugs did not take flight, just scrambled about.
Size – small, about 6mm long.

My first thought was a fly, but the antennae don’t seem right. Also there is no visible ‘drumstick’. A group of 3 ocelli are visible, so this rules out moth. The bugs were not bothered by my intrusion, so this rules out wasps. The eyes are small, indicating a nocturnal bug. The time was 09:11 (dawn 05:30).
Hope you can help.
Dave
Signature: Vodkaman

Dear Vodkaman,
These creatures resemble North American Barklice in the suborder Psocomorpha, and armed with that information, we did locate a similar looking Barklouse image on the Potokito Myshot Blog, but we have not been able to locate any other images to substantiate our supposition. 

That individual, which is not an exact match to your images, is classified as:  “Suborder : Psocomorpha, Infraorder : Caeciliusetae, Family : Caeciliusidae – Lizard Barklice, Genus : Valenzuela.”  According to BugGuide:  “Barklice feed on lichens and fungi on tree bark.”  We will try to do additional research on your request.

Letter 74 – Tropical Barklouse, we believe, from Singapore

Subject: Curious bug to be identified
Location: Singapore
January 9, 2014 2:42 am
Hi guys,
My friend recently found this bug in his Drosophila culture bottle and we are curious in its identity and, perhaps, why is it doing in that bottle. Random chance or looking for food?

The body length of this bug is around 1mm. Got a few images with the microscope and it does look odd to us. Can’t even be sure if it is a Dipteran, as its hind wings are not completely absent (Image 3, though it may be a bit hard to see).
Looking forward to your reply. Thank you.
Regards,
Nsh
Signature: Nsh

Dear Nsh,
We hope you are content with a tentative identification to the Order level.  We believe this is a Psocid in the order Psocodea, a group that includes Barklice, Booklice and Parasitic Lice.  You can find many examples on BugGuide. 

We would eliminate the subgroup that includes the Parasitic Lice, but we cannot say for certain if this is a Booklouse or a Barklouse.  According to BugGuide:  “barklice are always found outdoors, and occupy a wide variety of habitats; booklice often live in homes” and “Barklice feed on lichens and fungi on tree bark, booklice are best known for feeding on the starch in book bindings.” 

Since there is probably starch in your friend’s Drosophila culture bottle, a Booklouse would be a likely candidate, however BugGuide does not picture any winged Booklice from the family Liposcelididae. 

Your photos are excellent and we are sure an expert will have no trouble providing a more specific identification, however our staff is not capable of that task.  If pressed for a more focused identification, we would guess this might be a Tropical Barklouse in the family Amphientomidae, based again on photos posted to bugGuide. 

We do not believe your friend needs to worry about this Psocid infesting the culture, though it would be curious to know how this little guy ended up there in the first place.

Letter 75 – Tree Cattle

bug ID
I’m not sure what this is. Found them on an oak tree in my yard. In Houston, TX. Thanks
James Benton

Hi James,
These are Bark Lice, Cerastipsocus venosus, but we like the common name Tree Cattle. The immature Tree Cattle are boldly striped black and yellow creatures without wings. Tree Cattle will not harm your trees as they eat lichens and fungus.

Letter 76 – Tree Cattle

What on earth?
Hey Bugman.
Your site has become a favorite of mine lately. Who knew there were so many weird bugs in South Georgia? I have found most of them fairly quickly. These were on a tree locally known as a swamp maple. We’re about 20 miles inland from the mouth of the Savannah River.

They were moving in a cluster from the ground up, stopping and re-grouping at knots and dark spots on the bark. They are about three eighths of an inch long. Tan striped box elder bugs??? Really curious what they are and what they are doing….kind of looks like moving a queen or something.

(Also happy to finally get a decent photo of a bug to ask about! I have blurry bad shots of bordered leaf bugs, cicada killers, winged ant lions, and a couple of whatzits! Macro is new to me) Thanks,
Cleo

Hi Cleo,
These wonderful insects are known as Tree Cattle or Bark Lice. Though they might appear to be harmful insects, they are actually quite beneficial. T

hey feed on debris found on the trunks of trees including lichen, moss, algae, fungi, spores, pollen and possibly the remains of other insects. The larger winged insect in your photo is the adult and the others are immature numphs.

Letter 77 – Tree Cattle

Herd of insects
This was taken Sept 13th, 2007 at about 6:00 pm in central Virginia on a maple tree. The insects were a half inch long and kept together in a herd. My daughter separated one for a closer look and when we put it back and it realized it’s herd was there, it ran back into the group like a baby duck. Thanks
J.

Dear J,
We love the way your descriptive letter supports the common name of Tree Cattle which we just discovered. Commonly known as Bark Lice, these communal insects are not injurious to trees. We just located a website that mentions the other common name, Tree Cattle. The site also quotes and article by Larry Williams, which state: ”

The tiny insects that make the webbing are called psocids (pronounced so-cids). They have numerous common names including tree cattle and bark lice. Basically, they feed on lichen, moss, algae, fungi, spores, pollen and possibly the remains of other insects found on the tree’s bark.

As a result are sometimes referred to as bark cleaners. ” Your specimens appear to be the genus Cerastipsocus as evidenced by BugGuide.

Letter 78 – Tree Cattle

Unnambed bug on trees – Good or bad?
Location: 45.120367,-79.566593
August 1, 2011 1:45 pm
Suddenly found these on several trees in our front yard near a lake in Muskoka.
Found down low at ground level, or a few feet off the ground on both mature cedars and pine.
Mostly still unless disturbed (by gathering a specimen) and then move as a school / herd away from the disturbance.
Larvae or mature?
Good or bad?
Leave or eradicate?
Signature: Wondering in Muskoka

Dear Wondering in Muskoka,
What we especially love about your submission, in addition to the truly awesome photograph, is your marvelous description of this immature Bark Louse, Cerastipsocus venosus, when it is in company with the rest of its aggregation.  You described them as a herd, and another common name for Bark Lice is Tree Cattle. 

They are harmless creatures that feed on lichens, but since lichens are generally associated with old trees that might be in decline, folks without the proper information might be inclined to blame the Tree Cattle for the death of a large tree.  We have already indicated that the individual in your photo is an immature nymph.  Adults are interesting insects with black wings with white veins.

Letter 79 – Tree Cattle

Subject: boxelder bugs?
Location: Charleston, South Carolina
June 25, 2012 9:40 pm
Hi,
I was wondering if you could identify this. There were about 35 of them in a cluster on a barkless tree, eating lichen growth. Very small, about a quarter inch long each. I thought they might be young boxelder bugs, but the color and markings are wrong.

Now I’m thinking some variety of plant bug. They resemble fireflies as well, and seem to have a whitish abdomen (or are those white wing markings? hmmm), but the ant-shaped head is throwing me off. Any help would be appreciated.
Thanks,
Signature: Scott Matheson

Hi Scott,
These are Bark Lice in the genus Cerastipsocus, commonly called Tree Cattle.  They are benign creatures that feed on lichens and they do not harm the trees even though their mass aggregation would tend to imply otherwise.  See BugGuide for a matching photo of Bark Lice.

Letter 80 – Tree Cattle

Subject: True Bug Colony?
Location: Coastal San Diego County
May 22, 2013 6:24 pm
Found these in my neighbors back yard…
Signature: SJD

Dear SJD,
Though this resembles a Hemipteran aggregation, it is actually a colony of Barklice or Tree Cattle.  The look to us like Cerastipsocus venosus which BugGuide identifies as an eastern species, though the genus is reported from Arizona. 

We have not been able to substantiate any California sightings in our quick search, so they might have been accidentally introduced to your area. 

Barklice are benign creatures that feed on lichens and they will not harm trees and plants.  Adults are winged and nymphs are boldly striped.

Letter 81 – Tree Cattle

Subject: Group of small greenstriped bugs on a tree
Location: Fredericton, New Brunswick Canada
August 9, 2014 7:59 pm
I found this group on bugs all grouped together on a tree in my yard. I thin its an ash or an oakWhat are these bastards?
Signature: Jonathan Bowie

Dear Jonathan,
Since neither the church nor the state recognizes marriage between “bugs” or any other lower beasts for that matter, these Barklice or Tree Cattle cannot have been conceived out of wedlock. 

Though they look potentially problematic, Tree Cattle are benign creatures that feed on lichen and fungus, and they will cause no harm to your trees, neither ash nor oak nor any other species.

Dear Daniel,
Please excuse my late reply. Many thanks for this information!
Have a great weekend,
Jonathan Bowie

Letter 82 – Tree Cattle

Subject: Creepy Tree Bugs
Location: Abingdon, Virginia
September 20, 2014 2:29 pm
My 7-year-old was climbing a dogwood tree in our front yard when she suddenly started shrieking. She said there were bugs everywhere, and there were stains on her shirt where she had squished several.

Once I got her down, I examined the tree and found this pile of little beasties. It is mid-September, and we are in the mountains of Southwest Virginia. She has climbed this tree in all seasons, but we haven’t seen these bugs before.

They freaked her out pretty bad. What are they? Also, are they harmful? Thanks!
Signature: Staying Out of Trees for Awhile

Dear Staying Out of Trees for Awhile,
We hope we can mitigate any trauma your daughter experienced because of her encounter with these Bark Lice, Cerastipsocus venosus. 

Let her know that Bark Lice, which are sometimes called Tree Cattle, are benign creatures that are not harming the tree, though their presence might be symptomatic of a tree health issue. 

Bark Lice feed on lichens and fungus, and sometimes older trees have fungus and lichens present.  The Bark Lice will not bite or otherwise harm humans.  See BugGuide and this University of Florida pdf for additional information on Bark Lice.

Letter 83 – Tree Cattle

Subject: Beetle w/ yellow horizontal stripes

Location: Little Rock, AR US
October 29, 2014 8:45 am
I cut down a small dead tree in our yard the other day and these little beetles were everywhere. they’d swarm together in groups and make their way up and down the tree after i disturbed them.
Signature: Tim

Dear Tim,
These are not beetles.  They are benign, immature Bark Lice, commonly called Tree Cattle.  They are often associated with dead and dying trees because they feed on lichens and fungus, but they do not harm living trees.  Mature Bark Lice have black wings that cover the striped bodies.

Daniel,
Thank you so much for taking the time to reply, I really appreciate it.
I left the critters alone.  Wasn’t sure if they were the cause of the problem or not, but it’s nice to know they weren’t.
It was interesting, watching them scurrying around on the tree in large, but  separate groups.
Thanks again for taking the time to answer my question and help in identifying them.
-=tim

Letter 84 – Tree Cattle

Subject: Mystery bugs
Location: St Petersburg, FL
April 10, 2016 5:30 pm
Hi— while walking my dog the other day I came across a swarming group of insects on the side of a small tree in the early morning, which included the nymphs.

When I returned an hour later to take more photos, they had entirely disappeared. I posted a picture on Instagram and many people were interested in knowing what they could be.

An online friend had posted a picture from Tennessee that showed the nymphs w/o any adults. I live in the Tampa Bay Area. Do you have any idea what they are? Many thanks for any help you can provide!
Signature: KARBARG

Dear KARBARG,
These benign insects are Barklice or Tree Cattle, Cerastipsocus venosus.  The feed on lichens and do not harm the trees upon which they are found.

Many, many thanks for identifying them. I spotted three more groups this morning on another oak in the neighborhood. I’m very happy to share this information with my Instagram friends ???

Letter 85 – Tree Cattle

Subject: Bugs on crape myrtle
Location: Baton Rouge, LA
June 11, 2016 8:48 am
Can you tell me what this is? Just noticed while cutting grass.
Signature: Cody

Dear Cody,
These are Barklice or Tree Cattle.  They are benign creatures that do not harm the tree as they feed on lichens that frequently grow on older trees.  Your image contains mostly striped nymphs, though if you look closely, you will see a few winged adults.

Letter 86 – Tree Cattle

Subject:  Insect on Carpinus caroliniana
Geographic location of the bug:  Dekalb County, IL
Date: 07/18/2018
Time: 03:56 PM EDT
Your letter to the bugman:  Never seen this on my prairie.
How you want your letter signed:  Jack Pizzo

Dear Jack,
We hope our response was not too late to save these benign Barklice or Tree Cattle.  Generally when insects congregate like this, they are plant pests, but Tree Cattle will not harm your tree.  They feed on lichens.

Letter 87 – Tree Cattle

Subject:  Bugs on crape myrtle
Geographic location of the bug:  Virginia
Date: 10/01/2021
Time: 06:30 PM EDT
Your letter to the bugman:  Found these bugs swarming all over our crape myrtles. What are they and how do I get rid of them?
How you want your letter signed:  Deb Hammond

Dear Deb,
These are Barklice which are commonly called Tree Cattle and they are benign.  They feed on lichens and they will not harm your crape myrtle.  We do not provide extermination advice.

Letter 88 – Tree Cattle we believe

Insect Colony on Pine Tree
Location: Millville, PA
July 16, 2011 1:45 pm
It’s a hot July day in central PA. I discovered several colonies of a tiny insect on a pine tree. Each colony had hundreds of bugs. About 1/8” long, the predominant color is a series of yellow-gold stripes across the back.

The body looks gray or black. There are long antennae that are pointed at the ends. They don’t seem to fly. Would like to know what this is, and if it is bad for our tree!
Signature: alice

Dear alice,
We cannot make out the detail in your image, but we suspect these are benign Tree Cattle, a common name for Bark Lice that we really like.  They feed on lichen growing on the tree and they will not harm the tree.  See this posting from our archive to compare:  2010/06/13/tree-cattle-barklice/