Lace bugs are small, inconspicuous insects that feed on plants, potentially causing damage to trees and shrubs. These pests can be found on various plant species, with some common types including the azalea lace bug, andromeda lace bug, and rhododendron lace bug, as well as those that attack shade trees such as sycamore, hawthorn, elm, walnut, oak, willow, poplar, birch, and basswood trees source.
To protect your garden from lace bugs, you should start checking for them in late spring or early summer source. Examine susceptible plants about once every two weeks, paying close attention to any that have had previous infestations. By staying vigilant and implementing effective preventative measures, you can minimize the damage caused by lace bugs and maintain a healthy garden environment.
Lace Bug Basics
Appearance and Biology
Lace bugs are small insects belonging to the family Tingidae within the order Hemiptera, making them a type of true bug. Their most distinctive feature is their transparent, lace-like wings, which are adorned with intricate patterns and often have spines along the edges. Here’s an overview of their characteristics:
- Adults typically measure between 2-5 mm in length
- Wings are held flat over the body, creating a rectangular shape
- Nymphs are smaller, wingless, and covered in spines
Lace bug biology involves a life cycle that includes eggs, nymphs, and adults. Female lace bugs lay their eggs on the undersides of leaves, where they spend the winter. By early spring, eggs hatch and nymphs emerge to start feeding on the host plant.
There are several species of lace bugs that are commonly found on various plants. Two examples include the azalea lace bug (Stephanitis pyrioides) and the hawthorn lace bug (Corythauma ayyari). These species are known for causing damage to their host plants by feeding on the leaves, leading to discolored, stippled foliage.
Here’s a comparison table highlighting the differences between these two common species:
|Species||Host Plants||Physical Characteristics|
|Azalea Lace Bug||Azaleas, rhododendrons||Oval-shaped, 3-4 mm, dark brown|
|Hawthorn Lace Bug||Hawthorns, cotoneasters, pyracantha||Elongated, 3.5-4 mm, light brown|
Both azalea lace bugs and hawthorn lace bugs share similar lifecycle stages and cause similar types of damage to their respective host plants. However, the specific plants they target and their physical differences help distinguish them from one another.
Plant Damage and Infestation
Plants at Risk
Lace bugs are known to feed on the undersides of leaves in a variety of plants, including deciduous trees and shrubs. Some common host plants for lace bugs are:
Signs of Infestation
Lace bugs use their needle-like mouthparts to suck sap from the foliage of their host plant. This feeding can cause:
- Yellow or white discoloration of leaves
- Stippling pattern on the leaf surface
- Premature leaf drop
In severe infestations, the overall health and vigor of the plant may be affected.
Preventing Premature Leaf Drop
To prevent premature leaf drop and maintain plant health, consider the following methods:
- Proper Cultural Care: Providing the right growing conditions allows host plants to be more resistant to lace bug infestations.
- Natural Predators: Encourage the presence of lace bug predators, such as ladybugs and spiders, to help control their population.
- Inspection: Regularly check the undersides of leaves for signs of lace bug presence, and take action if necessary. This may include the use of pesticides or other control methods.
Please keep in mind that tolerating some lace bug damage is often more beneficial than resorting to extreme measures, as it can prevent the imbalance of natural predators and the environment.
Life Cycle and Seasons
Spring and Summer Behavior
Lace bugs have a distinct life cycle that spans over multiple generations each year. In spring and summer, females lay tiny, oblong eggs on the leaves of host plants, such as azaleas or avocado trees 1. The eggs hatch into small, wingless nymphs that feed on the leaves and develop through several instars before reaching adulthood 2. During these seasons, lace bug populations can increase rapidly, causing significant damage to their host plants 3.
Some common traits found in lace bugs during spring and summer:
- Female lace bugs lay eggs on leaves
- Nymphs are wingless and feed on leaves
- Multiple generations can occur in a single season
In North America, lace bugs usually overwinter in the egg stage, which ensures their survival during the colder months 4. By spring, the eggs will hatch, and the new generation of lace bugs will begin feeding on their host plants’ foliage, continuing their life cycle 5.
Below is a comparison table for lace bug behavior in spring-summer and winter seasons:
|Season||Lace Bug Behavior|
|Spring-Summer||Female lace bugs lay eggs; nymphs feed on leaves; multiple generations|
|Winter||Lace bugs overwinter in egg stage|
Natural Predators and Control
There are several beneficial insects that act as natural predators for lace bugs. Some of the key predators include:
- Assassin bugs
- Pirate bugs
- Jumping spiders
These predators feed on lace bug eggs, nymphs, and adults, helping to limit their population in gardens. In addition to these insects, other natural enemies such as green lacewing larvae and mites can also help control lace bug populations.
Introducing Predators to Your Garden
To attract and maintain beneficial insects in your garden, it’s essential to create a suitable habitat. Some ways to do this include:
- Growing a variety of flowering plant species
- Providing partial shade for shrubs that are not adapted to full sun
By providing a diverse and suitable habitat, you can increase the abundance of natural predators in your garden to help control lace bug populations. When using chemical control methods, choose nonpersistent, contact insecticides to minimize adverse effects on beneficial predators and parasites.
|Assassin bugs||Lace bugs|
|Pirate bugs||Aphids, thrips|
|Jumping spiders||Various pests|
|Green lacewing larvae||Aphids, mites|
Remember, while attracting these natural predators can help control lace bug populations, no single method can guarantee complete eradication. Combining various control methods with a healthy garden environment will yield the best results.
Lace Bug Management
Proper care for plants is the first line of defense against lace bug damage1. Some practices include:
- Providing ample shade for plants sensitive to full sun
- Ensuring good soil drainage and aeration
- Planting in ideal conditions to encourage healthy growth
Additionally, regularly inspecting plants for early signs of infestation can help prevent severe damage.
Beneficial insects, like ladybugs and lacewings, can help control lace bug populations2. Encourage these natural predators by:
- Planting flowers that attract them
- Avoiding broad-spectrum insecticides that kill beneficial insects
Insecticidal soap is another organic option for treating lace bug infestations. Apply it during the growing season, targeting the undersides of leaves, where lace bugs feed3. Use a garden hose with a water spray nozzle to dislodge lace bugs from leaves as a mechanical method.
When organic methods are insufficient or infestations are severe, chemical control may be necessary4. Some chemical options include:
- Horticultural oils, which can be applied to bark crevices where lace bugs overwinter
- Insecticides, like cyfluthrin or permethrin
Keep in mind that these chemicals can be harmful to bees and other beneficial insects. Apply them carefully and, if possible, during times when bees are less active5. Here’s a comparison table of the treatments discussed:
|Cultural Practices||Preventative, non-invasive||May not work against severe infestations|
|Organic Treatments||Environmentally friendly, gentle on plants||May not be effective on some lace bug species|
|Chemical Control||Effective for severe infestations||Harmful to bees and beneficial insects|
Over the years, our website, whatsthatbug.com has received hundreds of letters and some interesting images asking us about these insects. Scroll down to have a look at some of them.
Letter 1 – Lace Bugs reported to bite gardener
Bugs in our bushes
Location: Chattanooga, TN
September 17, 2011 12:26 pm
My wife found these bugs when she was trimming our bushes. They bit her and were very painful. I have never seen these insects before. To me, they look like tiny formula 1 racecars. They were very small.
You have Lace Bugs in the family Tingidae. There are many similar looking species, but your individual looks close to the Hawthorn Lace Bug, Corythucha cydoniae pictured on bugGuide. The information page for the family on BugGuidesays nothing about them biting, but it does indicate they “Feed mainly on leaves of trees and shrubs, causing yellow spotting and sometimes browning and death of the leaves.” Many plant feeding Hemipterans are capable of biting humans since they have mouths designed for piercing and sucking, however, most of these True Bugs and other Hemipterans do not feed off of humans.
Letter 2 – Lace Bug
Subject: New bug outside
Geographic location of the bug: Northeast Pennsylvania
Time: 03:22 PM EDT
Your letter to the bugman: Hello,
We found this bug recently after getting wood from our wood pile, now we are finding them all over our yard and pool deck. They appear flat, can be squished, move easily over skin, seem to like wood, are very small, brown and seem to almost be one piece as opposed to having legs.
How you want your letter signed: Tom
This is a Lace Bug in the family Tingidae, and though your image is lacking in clarity, it appears it might be an Elm Lace Bug which is pictured on BugGuide, or a Cherry Lace Bug which is also pictured on BugGuide. Of the genus that contains both, Corythucha, BugGuide notes: “Leaf feeders, most species have restricted food preferences” and “Some are considered pests.”
Letter 3 – Lace Bug on Cannabis
Subject: Bug on Cannabis
Geographic location of the bug: Mount Washington, Los Angeles, California
Time: 02:19 PM PDT
Your letter to the bugman: Dear Bugman,
While inspecting my maturing marijuana buds in anticipation of harvest, I noticed this solitary insect on one of my bugs. Can you identify it for me?
How you want your letter signed: Constant Gardener
Dear Constant Gardener,
This is a Lace Bug in the family Tingidae, and according to BugGuide: “Feed mainly on leaves of trees and shrubs, causing yellow spotting and sometimes browning and death of the leaves.” We did find a posting on Invasive.org of a Lace Bug and eggs on marijuana, and it contains the caption: “Adult lace bug and eggs on the underside of a hemp leaf. Note: The nymphs failed to establish on the plant. ” The University of California Pest Management System does not mention Cannabis as a host plant.
Letter 4 – Lace Bugs
What the…. My neighbor “captured” these THINGS which were crawling around by the hundreds on one of her bushes! I can’t find a picture that even vaguely resembles these THINGS. Sorry about the tape. I didn’t want them to get away.
These are Lace Bugs in the family Tingidae. They most resemble a species on BugGuide, Corythucha associata.
Letter 5 – Lace Bugs
Subject: Help tree is covered
Location: Woodlawn TN
August 29, 2015 10:44 am
We have a tree covered with white flying bugs! I went to cut limbs today and it was like snow coming down! Hundreds of it these flying about! If you didn’t know my truck was white you would like it was with these bugs! Thanks for you time!
You have Lace Bugs in the family Tingidae, and according to BugGuide, they: “Feed mainly on leaves of trees and shrubs, causing yellow spotting and sometimes browning and death of the leaves.”
Letter 6 – True Bug Nymph on Marijuana Leaf in Hawaii might be Lace Bug
Subject: Mystery bug
Location: North Shore, Maui, Hawaii
February 20, 2016 6:54 pm
Aloha folks, You guys were so helpful the last time that I thought I’d give it another go.
I found this guy on the underside of a Cannabis sativa fan leaf (legally grown). I’m not sure if the black spots surround it are fecal matter, but some of the black spots on the bug almost looked like babies. Any help is much appreciated.
Signature: Greg Hansen
This is an immature True Bug, and nymphs can be very difficult to correctly identify. Our initial guess is that this appears to be an immature Lace Bug in the family Tingidae. According to BugGuide, they: “Feed mainly on leaves of trees and shrubs, causing yellow spotting and sometimes browning and death of the leaves.” Beetles in the Bush has some nice images of immature Lace Bugs. Aloha Arborist Association has a similar looking image of the Cotton Lace Bug, with a list of plant family hosts, but Cannabaceae is not listed. Perhaps your Lace Bug is a different species, or perhaps the information on plant host families is incomplete.
Thank you so much Daniel! You are a saint! I really appreciate your help and expertise.
Letter 7 – Unknown Hemipterans are Immature Lace Bugs
Bug ID help Requested
These were observed last month, on the leaf undersides of a birch sapling, in S.W. Hillsboro County ,New Hampshire . Are they maybe Aphids ??. There were large groups of them on the underside of many leaves. Hoping you can help me, as I have spent countless hours searching your site, the internet and even the book "Field Guide to Insects of N.A." by Eaton and Kaufman, which I bought last weekend. I took some fairly accurate measurements of them, on a ( US ) one cent for size comparison. Small bug is on Lincoln ‘s chin. Measurements from Precision 7X Magnifier with Measuring Plate. Large Bug: .075 long x .050 wide (1.9mm x 1.27mm) Small Bug: .050 long x .025 wide (1.27mm x .635mm) I still am not sure if these are aphids. By the way, WTB is a really great site !!
Thanks for any help or insight you can provide.
Other than knowing that these are Hemipterans, we are stumped. We have contacted Eric Eaton for assistance. Your photos are quite detailed, and your written account is quite thorough, so we are fully confident that Eric will either provide the answer, of know who to contact for the answer.
The tiny hemipterans are, in all likelihood, nymphs of a lacebug, family Tingidae. I’ll get a friend of mine, who is a lacebug expert, to confirm this. The image with multiple individuals is clearly a collection of shed exoskeletons left behind after molting:-) Many insects seem to have synchronous molts like this. Keep up the great work, don’t be afraid to refer folks over to Bugguide, as we’ve got lots of people who can ID stuff, do it pretty quickly, and correctly most of the time. We will accept images of insects from elsewhere, too, they just would not stay in the guide permanently. Might relieve some of your burden?
Here is Laura Miller’s answer. She is a leading authority on lacebugs.
Good to hear from you. I don’t understand exactly what you want me to do about the “reply to all”. But I can tell you the answer here anyway. They sure are lace bug nymphs and the second set of pictures are lace bug exuvia. If he is seeing them on birch, they’re either Corythucha heidemanni or C. pallipes but at least I’m sure they’re Corythucha sp. Cheers,
Letter 8 – Walnut Lace Bug, we believe
Subject: Small box-like fly?
Geographic location of the bug: Western Pennsylvania
Time: 12:02 AM EDT
Your letter to the bugman: Hi! Just yesterday, this odd tiny, clear/brown fly landed on my hand. The bottom half of the wings are totally square. The pattern sort of makes it look like a lobster? I’ve never seen one of these before in any season, not just summer, so I’d love to know what it is! I know it’s a little hard to see, I didn’t want to get too close without scaring it away.
How you want your letter signed: Bugfriend
Perhaps this Lace Bug in the family Tingidae was attracted to your festive nail finish. We believe, based on this BugGuide image, that it is a Walnut Lace Bug, Corythucha juglandis. According to BugGuide: “Both adults and nymphs are found together on the lower surfaces of walnut leaflets where they suck the sap from the leaves. More than 100 nymphs and adults may be present at one time on one leaflet. Areas where they have fed are easily recognized because of cast skins, excrement, and dark, discolored patches of leaf. The upper leaf surface is stippled with tiny white spots that give the upper leaf surface a whitish appearance. Leaves of heavily infested trees may turn brown and fall off.”