Is a Caterpillar Eating Your Trees? Find out Which One
Which Caterpillar Is Eating Your Trees?
- 1 Which Caterpillar Is Eating Your Trees?
- 2 How to identify and control tent caterpillars, gypsy moths and fall webworms
- 3 How to Tell the Difference
- 4 What to Do If You Have an Infestation
- 5 Good Riddance
- 6 Help with caterpillar identification
- 7 Caterpillar identification help
- 8 How to send caterpillar identification requests
- 9 Is a caterpillar a pest or a health hazard?
- 10 caterpillar
- 11 caterpillar
- 12 Caterpillar
- 13 How to Get Rid of Caterpillars
- 14 Best Tent Caterpillar Control Methods
- 15 Other Common Caterpillars
- 16 Caterpillar Control Products
- 17 Best Organic Caterpillar Control
- 18 Greenhouse Gardening Organic Pest Control – Caterpillars
- 19 Organic methods to eliminate caterpillars in your greenhouse
- 20 What caterpillars are dangerous to crops?
- 21 Are there any beneficial caterpillars?
How to identify and control tent caterpillars, gypsy moths and fall webworms
- B.A., Political Science, Rutgers University
Three well-known caterpillars—tent caterpillar, gypsy moth, and fall webworm—are often misidentified for each other by homeowners that are having problems with swathes of defoliated trees. Caterpillars that defoliate trees in your home landscape can be invasive and sometimes require control measures.
How to Tell the Difference
Though the three caterpillars might look similar, these three species have distinct habits and characteristics that make it easy to tell them apart.
|Characteristic||Eastern Tent Caterpillar||Gypsy Moth||Fall Webworm|
|Time of Year||Early spring||Mid-spring to early summer||Late summer to fall|
|Tent Formation||In the crotch of branches, not usually enclosing foliage||Does not create tents||At the ends of branches, always enclosing foliage|
|Feeding Habits||Leaves the tent to feed several times per day||Younger caterpillars feed at night near treetops, older caterpillars feed almost constantly||Feed within the tent, expanding the tent as needed to enclose more foliage|
|Food||Usually cherry, apple, plum, peach, and hawthorn trees||Many hardwood trees, especially oaks and aspens||More than 100 hardwood trees|
|Damage||Usually aesthetic, trees can recover||Can completely defoliate trees||Usually aesthetic and damage occurs just before the autumn leaves fall|
|Native Range||North America||Europe, Asia, North Africa||North America|
What to Do If You Have an Infestation
Homeowners have a few options to control defoliation of trees due to caterpillars. The first option is to do nothing. Healthy deciduous trees usually survive defoliation and grow back a second set of leaves.
Manual control on individual trees includes hand removal of egg masses, inhabited tents, and pupa, and installation of sticky tree wraps on trunks to capture caterpillars as they move up and down trees. Do not leave egg masses on the ground; drop them in a container of detergent. Do not attempt to burn tents while they are on trees. This is hazardous to the health of the tree.
Various insecticides for tent caterpillars and gypsy moths are available at garden centers. Insecticides are divided into two general groups: microbial/biological and chemical. Microbial and biological pesticides contain living organisms that must be consumed (eaten) by the pest. They are most effective on small, young caterpillars. As they mature, caterpillars become more resistant to microbial pesticides. Chemical insecticides are contact poisons. These chemicals can have a potential impact on a variety of beneficial insects (such as honeybees), so they should be used wisely.
Spraying trees with insecticides is an option, too. Tent caterpillars are native and a natural part of our ecosystem and gypsy moths have «naturalized» in our forest communities. These caterpillars will always be around, sometimes in small, unnoticeable numbers. If dense concentrations of tent or gypsy moth caterpillars cause a decline in the trees’ health or threaten a garden or farm, spraying might be the best course.
However, using insecticides do have some drawbacks. It is not effective against pupae or eggs and is less effective once caterpillars reach 1 inch long. Nesting birds, beneficial insects, and other animals could be endangered by the use of chemical insecticides.
The good news about caterpillars is that their populations fluctuate and after a few years of high numbers, their populations usually drop.
Populations of tent caterpillars reaching highly noticeable levels run approximately on 10-year cycles and usually last 2 to 3 years.
Natural predators of caterpillars are birds, rodents, parasites, and diseases. Extremes in temperature can also reduce population numbers.
New York State Department of Environmental Conservation. Tent Caterpillars.
Help with caterpillar identification
Caterpillar identification help
As many as 40 identification requests and sightings are received a day from all over the world. Many of these are featured in the British Moth Caterpillar Gallery,
Other galleries featuring caterpillar sightings from Europe, Africa, Asia and South America are scheduled to be added. Many species of butterfly and moth have a wide distribution and found in more than one country.
Identification requests and photographs can be sent to Steve – email address [email protected] –
include LOCATION (country, province, state, county) – SEE BELOW other useful information to provide to help with identifications.
Your images are welcome and with your consent may be shared with others by adding to the appropriate countries caterpillar gallery with accreditation.
Please note that despite photographs and sightings being added daily there are many still awaiting processing and it can take time.
Consequently, although the majority can be identified from photographs, some can’t be without being reared through.
Knowing the size of a caterpillar can also help with identifications as many caterpillars dramatically change appearance as they grow, moult into another instar and prior to pupating.
In some countries the early stages of many species are under researched.
It may also be worth checking the latest news and caterpillar sightings to see if your caterpillar is featured.
Helpful information to send with your request
Date of sighting, location and habitat.
Photographs both from above and side on, if possible)
The size, colour and number of legs of the caterpillar.
If it was hairy or smooth skinned, any distinctive markings, bumps or tail extensions.
If it was on a particular plant.
How to send caterpillar identification requests
Identification requests and photographs can be sent to Steve – email address [email protected]
that whilst every effort is made to provide accurate identifications and information errors could occur.
Where sightings are of particular interest they may feature in latest sightings and on specific species pages or latest sightings , examples – Death’s Head Hawkmoth and Convolvulus Hawk-moth image.
Is a caterpillar a pest or a health hazard?
Most caterpillars are harmless and form a vital part in the food chain supporting many animals.
However, there are a few caterpillars that can cause severe damage to vegetables fruit crops, trees and shrubs.
These include caterpillars of The Large White and Small White Butterfly, often referred to as Cabbage Whites, which can cause severe damage to the Brassica family of vegetables.
Please also be aware that there are a few caterpillars that on occasions can become a health hazard.
The hairs of some caterpillars such as the Brown-tail Moth have hairs that can cause intense irritation.
Stinging slug caterpillars of the Limacodidae moth family are known in many countries for their urticating hairs. Some such as the Saddleback featured left and in the American caterpillar gallery cause painful skin reactions to many people in the States every year.
In general, and to be on the safe side, hairy caterpillars should be treated with caution and direct skin contact avoided.
See identification guide to some of the most frequently seen hairy caterpillars.
Other sections in our popular Illustrated Guide to British Caterpillars
Our caterpillar and larvae galleries
Copyright © 2010-2020 Wildlife Insight. All Rights Reserved. Images may not be used without the written permission of the photographer.
For image use enquiries please email [email protected] or click here to email Steve Ogden at Wildlife Insight.
Please note whilst every effort is made to provide accurate identifications and information errors could occur.
Do let us know if you spot any on the site.
the larval form of the butterfly.
The caterpillar feeds intensively, storing nutritive material for its subsequent development. After numerous moltings accompanying its growth, the caterpiller is transformed into a chrysalis. Caterpillars are principally phytophagous. More rarely, they eat wool, wax, and horny matter; there are predators and parasites as well. The body is vermiform and the mouth parts are adapted to nibbling. In addition to the three pairs of thoracic legs there are as many as eight pairs of “false” legs. Tubular spinning, or silk-secreting, glands, which open through a canal on the labium, are characteristic of the caterpillar. Upon contact with the air, these glandular secretions form a silk thread that is used in the construction of a cocoon, cementing leaves in the form of a little house, or in the preparation of a protective web. Some caterpillars live in the open and others live concealed. Some live in communities and build special nests, entwining the branches and leaves of trees with web. Processionary moths effect mass migrations in their search for food. Caterpillars that live in the open usually have a shape and color that harmonizes with their background (cryptic), some have bright coloration that demonstrates that they are inedible, and some strike a threatening pose in moments of danger. Pseudocaterpillars (for example, the sawflies) are distinguished from true caterpillars, having false legs on nine to 11 segments. More than 1,000 species of butterflies have been recorded in the USSR; their caterpillars damage field, orchard, and forest plants. The cocoons of the Chinese silkworm, the lappet moth, and several other silkworms yield valuable textile raw material; their breeding is an important branch of agriculture.
How to Get Rid of Caterpillars
Updated — August 29, 2019 / Eric Ronning
As a child, I was fascinated by caterpillars (and I guess I still am). My brothers and I would tromp around the yard and the neighboring woods in the spring, mason jars in hand, and scour the foliage for caterpillars. Of course we had our mason jars stuffed with fun things for our captured caterpillars to do. There would be some nice grass in the bottom, a few leaves so the caterpillar would have a little something to snack on, and the obligatory stick for the little guy to crawl up on. It was excellent. And then after a couple days of captivity, if the caterpillar was still alive, we would usually tire of it and either use it as fish bait or spend some quality time with it and a magnifying glass.
As it turns out, I think that’s what my dad was hoping we would do with them. Actually, I think he wished we would have killed a lot more of them than we did. Once you realize just how destructive caterpillars can be, they sorta lose their magic. They can, and often do, destroy your vegetables like cabbage and tomatoes. They also like to munch on those fresh herbs you’ve been growing, and they might even enjoy some of your prized flowers for dessert.
If tent caterpillars are your enemy (you know, the ones that spin and live in a huge web mass in your trees), they can, in extreme cases, completely defoliate a tree. In this article, my primary focus will be on how to get rid of tent caterpillars. However, many of the suggestions, especially the ones at the bottom of this page, will work very well for getting rid of caterpillars of any flavor.
Best Tent Caterpillar Control Methods
Say what? Yeah, let’s just call it BT. This is simply the number one thing you can do to get rid of caterpillars. It is a bacteria that infects and kills caterpillars by destroying the lining of their guts. The great thing is it only kills caterpillars, which means there are no innocent bystanders that get wasted in the process. Since BT must be ingested to work, it is applied to foliage as a spray. BT is available online or at any garden shop. Make sure to get BTK. The “K” stands for kurstaki. You can get Bacillus Thuringiensis from Amazon for a good price.
Find a good long stick.
Maybe the most common way to get rid of caterpillar nests is to simply use a long stick to scrape the thing out. Just poke the stick into the nest and start spinning and scraping. It will work much better for you if you pound a few nails into the stick. In fact, if you have one, use an old broom handle. You will want to do this in the early morning or in the late evening so you will be sure that they are in their nests. Dispose of them however you wish, though it is satisfying to burn the stick you used to scrape out the nest.
Slash and burn.
Another good method for caterpillar control is cutting down their nests and burning them. Use pruning shears, a hand saw, or a chain saw to disconnect the branches with the tent caterpillar nest on them from the rest of the tree. Pull the branches down to the ground and pick your favorite incineration method. We always used an empty aluminum garbage can, a bottle of charcoal lighter fluid, and a match. If you don’t feel like using fire, just stomp on them for awhile.
Manual caterpillar pest control.
This is another one of those methods to control caterpillars that will work for absolutely any type of pest caterpillar you find. However, I wouldn’t advise it for the squeamish. Grab yourself an empty ice cream pail, coffee can, or whatever else you can find, fill it about half way up with water, squirt about a quarter cup of dish soap in it, and start picking. Just use your fingers to pluck caterpillars off of plants and toss them into the bucket to drown. Look very carefully for them. They oftentimes hide on the undersides of leaves.
Get rid of tent caterpillar egg masses.
This is actually easier than it sounds. The egg masses of tent caterpillars are pretty easy to identify. See right. In the winter, go outside with a good sharp knife and search every tree you can see for the little egg masses. They can be on trunks or branches. When you find them, scrape them off and destroy them. You may also wish to bring a pair of shears with you, too, as sometimes it’s easier to just snip the branch off.
Other Common Caterpillars
Parsley worms are commonly found munching on your parsley and other plants like dill, fennel, carrots, Queen Anne’s lace, and parsnips. They are know as black swallowtail butterflies as adults. See the bottom of this page for caterpillar control products.
Cutworms are found frequently eating the stems of asparagus, cabbage, carrots, corn, and tomatoes, to name a few. They are the larvae of night-flying moths of the Noctuidae family. Check out the bottom section of this article for products for controlling caterpillars.
Gypsy Moth Caterpillars.
Gypsy moth caterpillars are found most commonly in and dangling from trees and shrubs. They eat foliage primarily at night but can be seen during the day. See the bottom section of this page for some products to help you get rid of caterpillars.
Caterpillar Control Products
While I do feel strongly that BTK (mentioned above) is the best thing you can use to get rid of caterpillars, there are many other types of caterpillar pest control products available that work very well for almost any type of caterpillar. Neem oil is one of these. It is a natural oil derived from the neem tree that not only can be used as an insecticidal soap to kill caterpillars immediately, but it also tastes so bad that when sprayed on things caterpillars eat, they would rather starve than ingest anything sprayed with it.
Pyrethrins are another common and effective way to get rid of caterpillars. We write about pyrethrins in our piece on how to get rid of maggots, and several other how-to guides. They are generally found in spray form. Look for brands like Take Down and Rotenone-Pyrethrin Spray. Insecticidal soaps are another way to go. These work not only by dissolving the protective layer, or “cuticle,” of insects, they also destroy cell membranes causing cell contents to spill out. Look for brands like Safer Insecticidal Soap (which you can get at Amazon) and Garden Safe. Be careful using pyrethrins, and use them sparingly. They kill bees, and we do not advocate killing bees.
Many people take a preventative approach and spray their trees with dormant oil in the winter or early fall. This is a thick, plant-based oil that, when sprayed liberally on trees, engulfs and suffocates the insects that are lying dormant in the bark. Look for brands like Eco-Oil and All Seasons Horticultural & Dormant Spray Oil. One last thought: if you don’t feel like spraying anything or you are looking for something to use in addition to your spray, use a trunk band. Using duct tape or aluminum foil, construct a band around the trunk of the tree, and coat it with something sticky like petroleum jelly or, better yet, Tree Tanglefoot Pest Barrier.
Best Organic Caterpillar Control
Many birds are happy to eat caterpillars, so do whatever you can to attract more birds to your yard. Put up feeders, houses, nesting shelves, and birdbaths. It’s also a good idea to get yourself some chickens. They’ll nab and eat pretty much anything that moves. Also, hey! Eggs!
Generally speaking, if you leave paper wasps alone, they’ll leave you alone. Unless you’re too scared or someone in you family is allergic, permit paper wasps to set up shop in your yard. Turns out they are quite happy to eat soft-bodied insects like caterpillars.
You can kill lots of gypsy moth caterpillars simply by wrapping your tree trunks with a band of burlap bags. Since these caterpillars like to hide during the heat of the day, they will find their way into and under the burlap bags, making it very easy for you to kill lots of them quickly.
Greenhouse Gardening Organic Pest Control – Caterpillars
Table of Contents
Caterpillars can be harmful, and not each of them turns out to be flying like Monarchs. Do a little research. Determine what sort of caterpillars you have. Gypsy Moth and Redhumped caterpillars are the actual pests. They can strip leaves in a short time. Keep reading to find ways to organically control caterpillars in your greenhouse.
Caterpillars are the larvae of moths and butterflies. The term also describes the larvae of other insects such as sawflies. Most caterpillars are herbivorous, though about 1% of them are insectivorous.
The most distinctive features of caterpillars are their hairy, segmented bodies, three pairs of legs, and five pairs of prolegs. They move as if they are measuring the length of their track. These crawlers are voracious feeders that can easily strip your greenhouse plants of all their leaves and in the process, leading to reduced plant vigor.
Organic methods to eliminate caterpillars in your greenhouse
Use one of the following organic pest control methods in your greenhouse quickly before they ruin your harvest.
Use Bacillus thuringiensis (Bt.)
This free occurring bacterium lives in the soil and is effective in eradicating caterpillars. During sporulation, it produces delta endotoxins (pore-forming toxins) that are harmful to caterpillars and other pests. The dilution percentages carrying the bacteria may vary depending on the plant you are preparing to spray. Read thoroughly and understand the manufacturer’s directions for blending and applying pesticides.
Bacillus thuringiensis or Bt. is a bacterium that is not poisonous to humans and mammals but it is lethal to some insects like caterpillars when ingested. The EPA and various scientific organizations have found that Bt and engineered Bt-crops are not fatal to humans. It is typically found on the leaves and in soil worldwide. It has been used commercially in organic and traditional agriculture for more than fifty years.
Plant coverings can efficiently shield your plants from caterpillars. Place the cover above the crop. This approach is not suitable for crops that demand pollination.
Practice crop rotation
Growing crops, in turn, is an effective strategy in controlling caterpillar infestation in greenhouses. For instance, after good harvest of tomatoes, you may consider planting coriander.
To intimidate and distract caterpillars, do not grow plants in the related species collectively in the very place every year. You can alternate your rows of greens or rotate crops throughout your greenhouse each season.
Beneficial insects and birds
Ducks and chickens enjoy feeding on caterpillars, so do praying mantises. You can invite your hens into the greenhouse so they can help with biological control. If you live in an environment that has praying mantises then these too can help. You can encourage birds to perch around your greenhouse by building feeding areas. Although it is a slower method than spraying, promoting a variety of wildlife to visit your greenhouse is a beneficial long-term tactic for defeating caterpillars and other pest invasions. Note: You will obviously need enough escape openings so that birds can easily find their way out. If you only have a small door and a roof vent, don’t invite birds, as they might get trapped.
Natural pesticides are better since they have fewer side effects. These pesticides are made from plants. It breaks down quickly, unlike synthetic chemicals. Some are organic techniques that are very helpful in combating pests.
Sage, peppermint, mugwort and lavender, all produce scents that repel caterpillars effectively. Therefore, consider planting one or two of these plants when setting up your greenhouse. These home remedies are effective repellents.
Garlic has a naturally acidic essence that can eliminate caterpillars. Combine two cups of water including two spoons of garlic powder in a spray bottle. Add a spoon of dish soap. Sprinkle the solution to the affected area.
Hot pepper is another natural caterpillar repellent. Crush and dash some hot peppers throughout your garden. You may also create a chili spray formula by combining two cups of water, two spoons of hot pepper powder, and a spoon of dishwashing soap. Sprinkle it on your plants. You can spray the solution every couple of weeks or after a rainfall.
Neem oil is a natural insecticide. It is formulated using essences from its seeds. Organic sprays carry bacteria that tackle the pest but are not toxic to humans and pets. Neem oil is lethal to bees. Spray it after dusk when the bees are no longer active.
You can patrol the greenhouse either during the day or at night and handpick caterpillars off the plants. Use burlap for your fruiting trees. Wrap the trunk with a burlap. The caterpillars will surely crawl under it when they need shade. Once they are all there, you can remove the burlap and handpick them. Consider relocating the picked caterpillars to some location where they will cause little damage.
When you notice just one caterpillar, inspect your plant for more which may be on a different leave or plant. Take off all the caterpillars you can see, place them somewhere far away, or crush them. Pick off the entire leaf and destroy it if your plant has more leaves. Repeat it every day. Handpicking may not be as effective as other methods but it is definitely a way to reduce or eliminate these caterpillars.
What caterpillars are dangerous to crops?
Gypsy moth is an invasive caterpillar. They are commonly known as the exfoliator pest. They tear the leaves of a plant. You will see them feeding on apple, oak, and willow trees. The adult caterpillar will eat the leaves from the outer side inwards and leave almost nothing. The young ones will penetrate small openings in the middle of the leaves they eat.
The Redhumped caterpillar usually eats leaves. It feeds on plum, apple, walnut, cherry, and other deciduous trees and plants. Newborn caterpillars generally feed side-by-side in clusters. They will chew the lower leaf part. Then they will manage to disperse as they develop and sustain themselves in smaller groups or independently.
Skeletonized leaves are the most common outcome. Insecticide applications can be used only if there are a lot and their damage is unbearable. Biological control can also help manage these kinds of invasion. Spot pruning is effective if there are a few of them.
Are there any beneficial caterpillars?
Some caterpillars are beneficial insects. They will become butterflies or moths, which are essential pollinators. If you notice some caterpillars in your garden, remember that only a few species are the actual pests.
One of the most noticeable is the Monarch.
. They only consume milkweed and they mean no threat to your plants. As a matter of fact, gardeners are doing their best to attract them.
A friendly caterpillar called Cecropia poses no risk to your plants. It is roughly as long and thick as your finger with neon green and multi-colored spiked knobs. Thankfully, the spikes are not harmful when touched. They have plenty of hunters that is also another reason why they don’t usually become a pest. The adult caterpillar has no functioning mouthparts, so its only purpose is to mate.