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:
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 |
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 |
Regarding their activity, barklice tend to be more active in warmer months, and they might be considered a nuisance when present in large numbers.
However, they are mostly harmless and do not cause damage to plants or property.
Identifying and Managing Barklice
Distinguishing Features
Barklice can be found both indoors and outdoors.
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:
- Identify the infested area and regularly vacuum or clean it.
- Use a dehumidifier to reduce moisture, as booklice thrive in humid environments3.
- 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.
Barklice
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
- https://hgic.clemson.edu/factsheet/barklice/ ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7 ↩8 ↩9 ↩10
- https://content.ces.ncsu.edu/booklice ↩ ↩2 ↩3 ↩4
- https://uwm.edu/field-station/barklice/ ↩ ↩2 ↩3 ↩4 ↩5 ↩6
- https://extension.umn.edu/product-and-houseplant-pests/psocids ↩ ↩2 ↩3 ↩4 ↩5
- https://content.ces.ncsu.edu/barklice ↩
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39 Comments. Leave new
We’ve got these all over our maple tree in western NY State, as well. They are just gross to look at and we don’t even want to go near the tree. Is there anything we can do to get them to move along? Do we need to learn to live with them?
Thanks for your “Quick” response, perhaps I need a better spellcheck or spelling lessons. LOL
The booklice in my house have wings too but they still choose to hop rather than fly.
I am finding a ton of these around our house. Were these positively identified?
We have never had anyone refute our identification.
That is great information, well done and many thanks.
This also explains what they were feeding on. From my images, there did seem to be a kind of ‘scum’ on the leaves. I thought this might be pollen, but there were no blooms in the immediate vicinity. The area is very humid, with the stream, canopy of trees, hot sun and frequent rain, ideal conditions for fungal growth.
A month ago, I saw something small out of the corner of my eye, scuttering across the bark, but when I looked, I could not find. It was probably these. Now I know what to look for. I have searched for the ‘barklice’ again since and have not found them, but will keep looking.
So helpful. Thanks for time and effort. I do know how long this kind of research takes.
Dave
You are most welcome Dave. If you do any additional research and you discover a species name, please let us know so that we can update our posting. As you can imagine, we have considerably more “bugs” to track down than you do, and we did try for some time to identify the species, but alas, we had no luck.
That is great information, well done and many thanks.
This also explains what they were feeding on. From my images, there did seem to be a kind of ‘scum’ on the leaves. I thought this might be pollen, but there were no blooms in the immediate vicinity. The area is very humid, with the stream, canopy of trees, hot sun and frequent rain, ideal conditions for fungal growth.
A month ago, I saw something small out of the corner of my eye, scuttering across the bark, but when I looked, I could not find. It was probably these. Now I know what to look for. I have searched for the ‘barklice’ again since and have not found them, but will keep looking.
So helpful. Thanks for time and effort. I do know how long this kind of research takes.
Dave
my husband and I bought a renovated farm house in the southtown part of Montrose , pa. It was built in 1929, recently however, the beginning of may ,we started finding what looks like mouse turds [black] ones. we are avid clesaners and i have o.c.d.. they are single, and on the edges of carpet, on the kitchen table, tile in the bathroom. we were told they were weeveils, we checked our flour and pantry but to no avail. have looked at various bugs on your web site, plz hlp us!!! we need to cleen!!! answer our e-mail thank-u!
Please send images to Ask What’s That Bug?, a link on our website. We wouldn’t want to speculate without seeing images.
It’s my first time to encounter an insect like this. Is this poisonous or something? Please advice.
Barklice are benign, not dangerous.
They’re not springtails. They’re booklice (Liposcelis, Psocoptera), probably L. bostrychophila.
Thanks for the correction.
Yes I too have winged booklice that I have never seen fly, they look more like bark lice but apparently indoors means booklice.
They are harmless, just seal all food and throw away anything left open, especially flour and rice.
An outbreak will probably originate from open rice or flour and occur in warm humid weather.
Close inspection with a torch will soon locate at least one or two in most pantries and is a good way to find the source.
Empty cupboards outside and wipe down and wash everything before replacing.
Camphor and bay leaves are meant to repel.
Yes I too have winged booklice that I have never seen fly, they look more like bark lice but apparently indoors means booklice.
They are harmless, just seal all food and throw away anything left open, especially flour and rice.
An outbreak will probably originate from open rice or flour and occur in warm humid weather.
Close inspection with a torch will soon locate at least one or two in most pantries and is a good way to find the source.
Empty cupboards outside and wipe down and wash everything before replacing.
Camphor and bay leaves are meant to repel.
This is not a springtail, but a type of barklouse. I have noticed in the past that wingless or nymphal barklice can look a lot like globular springtails, but if you look closely at the photos you can see the reduced wings or wingbuds in this individual.
I would guess that this is probably (but not definitely) Psyllipsocus ramburii (http://bugguide.net/node/view/830096) which is a widespread domestic barklouse species. Another possibility is a nymph of Dorypteryx domestica, which you’ve had an individual of on this site before (http://www.whatsthatbug.com/2008/11/13/booklouse-2/). Both of these belong to the family Psyllipsocidae, which I can confirm from personal observations do jump.
We found several groups of these on the branches of our magnolia tree. This morning they were in pods, not moving. Some were molting. Yesterday at dusk they were streaming along a few of the branches like ants.
Perhaps they are on the move, searching for lichens elsewhere on the tree after depleting their food source.
Very helpful site
We just found another colony on the move here in Encinitas, California (North County San Diego). Unfortunately, we freaked out just as we did last year and killed all we could find! In my defense, they are super-creepy to look at, with a very sci-fi feel. We’ve made numerous attempts last year to find out what they were, but all the tree experts we contacted locally were baffled, even after we had collected specimens.
The little ones were being herded along our Ipe wood deck from a Jacaranda to our big Macadamia tree. The larger, winged ones, were definitely herding the little ones along, as if they were cattle. It turns out that that was the keyword, once I searched Google for “cattle bugs” I was looking at pictures of them within seconds. Sorry they’re dead. I expect they’ll be back – it’s happened a few times now. I will spread the word among my neighbors.
Their behavior does tend to seem more like that of a plant pest as opposed to the benign creatures they actually are.
We just found another colony on the move here in Encinitas, California (North County San Diego). Unfortunately, we freaked out just as we did last year and killed all we could find! In my defense, they are super-creepy to look at, with a very sci-fi feel. We’ve made numerous attempts last year to find out what they were, but all the tree experts we contacted locally were baffled, even after we had collected specimens.
The little ones were being herded along our Ipe wood deck from a Jacaranda to our big Macadamia tree. The larger, winged ones, were definitely herding the little ones along, as if they were cattle. It turns out that that was the keyword, once I searched Google for “cattle bugs” I was looking at pictures of them within seconds. Sorry they’re dead. I expect they’ll be back – it’s happened a few times now. I will spread the word among my neighbors.
I know, right? When you first see these bugs it is easy to imagine them swarming at *you*. Totally triggered an atavistic, visceral response in my wife and me.
We have been seeing these bugs crawling around the house, any idea what it is?
(Photo link): https://imgur.com/gallery/JfMi8
Appears to be a Springtail.
We have been seeing these bugs crawling around the house, any idea what it is?
(Photo link): https://imgur.com/gallery/JfMi8
I found some of these bugs of. My oak tree an concerned
My partner goes camping quite a bit. about 6 months ago, came back with a nasty huge rash on the side of his leg which has healed, went camping 2 more times, came back with the same type of itchy rash. Since that initial 6 months ago, we have noticed an increase of a very very tiny, fennel-looking (black to naked eye – off-white with an interior black line on body with a magnifier) all over our house inside and out, furniture, bed, floor, outdoor furniture, even at the bottom of our small pool. I do have pictures and have stickie rolled samples, but no one seems to know what they are. Tried DE-Food-grade, lemon oil, tried Borax – none seem effective, getting ready to try cedarwood oil / alcohol / water… Can you help?
We are unable to provide medical advice.
More specifically, this is a species of Dorypteryx (https://bugguide.net/node/view/457371; exactly which species can’t be distinguished from the photo). These cute little jumping barklice are most commonly found in association with humans; they’re probably cave and rock dwellers by origin.
Thanks so much for the genus identification. We were having trouble narrowing down the possibilities.
We have the same tiny insects in our (quite new) house.
From searching the Web I think those are “Dorypteryx longipennis”
https://species.wikimedia.org/wiki/Dorypteryx_longipennis
Searching for this name in the Google picture search shows mostly only insects looking exactly like that:
https://www.google.com/search?q=Dorypteryx+longipennis&tbm=isch&tbo=u
We have the same tiny insects in our (quite new) house.
From searching the Web I think those are “Dorypteryx longipennis”
https://species.wikimedia.org/wiki/Dorypteryx_longipennis
Searching for this name in the Google picture search shows mostly only insects looking exactly like that:
https://www.google.com/search?q=Dorypteryx+longipennis&tbm=isch&tbo=u
I think it’s Cerastipsocus trifasciatus
https://bugguide.net/node/view/145705
http://psocodea.speciesfile.org/Common/basic/Taxa.aspx?TaxonNameID=1197073
Thanks Cesar. The ranges of so many species represented on BugGuide extend well beyond North America.
I think it’s Cerastipsocus trifasciatus
https://bugguide.net/node/view/145705
http://psocodea.speciesfile.org/Common/basic/Taxa.aspx?TaxonNameID=1197073
What a great site. Just found my bug, thanks to you. The Tree Cattle. And, they are harmless. Thanks for the info.
I like the alternate name for these harmless insects, tree cattle.