What Do Tent Worms Eat

Eastern Tent Caterpillar

ENTFACT-423: Eastern Tent Caterpillar|Download the PDF version of this fact sheet

by Ric Bessin, Extension Specialist University of Kentucky College of Agriculture

The eastern tent caterpillar, Malacosoma americanum, is a North American insect that is a nuisance to both humans and animals. Populations change from year to year, with epidemics happening every few years or even more often. This bug is a nuisance in the late spring and early summer because of the defoliation of trees, the construction of unattractive silken nests in trees, and the presence of roaming caterpillars crawling over plants, sidewalks, and roadways. Eastern tent caterpillar nests are most usually seen on wild cherry, apple, and crabapple trees, but they can also be found on other trees such as hawthorn, maple, cherry, peach, pear, and plum.

Figure 1. An eastern tent caterpillar.

While tent caterpillars may almost completely defoliate a tree when they are in large numbers, the tree will typically rebound and produce a new crop of leaves. Nests, on the other hand, can constitute an eyesore in the landscape, particularly if they are exposed as a result of extensive defoliation. The silken nests, which are formed in the crotches of limbs, can grow to be rather substantial in size. As soon as the larvae begin to roam in search of safe havens to pupate, there is tremendous anxiety.

They are a nuisance and may cause a sloppy mess if they are squished on driveways, sidewalks, and patios, for example.

In general, insecticides are ineffective against fully developed larvae.

Fall webworm nests, in contrast to the tent caterpillar’s, are found at the extremities of branches, and their loosely formed webs include foliage, but the tents of the eastern tent caterpillar do not.


The eastern tent caterpillar overwinters as an egg in a mass of 150 to 400 eggs, which is the size of a grapefruit. In this case, the masses are covered with a glossy, black varnish-like substance and wrap branches that are approximately the size of a pencil or less in diameter.

Figure 2. Eastern tent caterpillar egg masses are wrapped around small twigs.

Overwintering as an egg mass of 150 to 400 eggs, the eastern tent caterpillar overwinters as a caterpillar. They are encircled by branches that are approximately the size of a pencil or smaller in diameter and are covered with a slick, black varnish-like substance.

Figure 3. An eastern tent caterpillar nest.

A row of oval blue dots on the sides of the caterpillars, which are black with a white stripe down the back, brown and yellow lines along the sides, and a black and white stripe down the rear. In order to consume the leaves, the larvae enlarge the web, which eventually grows to be a foot or more in length. They are fully developed and 2 to 2-1/2 inches in length after 4 to 6 weeks of development.

At this point, they begin to disperse from the nest in search of safe places in which to construct a cocoon on their own. Approximately 1 inch long and formed of tightly woven white or yellowish silk, the cocoon is linked to other items by a few coarser strands that run through it.

Figure 4. An adult male eastern tent moth.

The adult moth emerges from the cocoon around 3 weeks after the cocoon is laid. In coloration, the moth is reddish-brown with two faint stripes running diagonally across the forewings of each of its wings. Female moths mate and begin to deposit eggs on short branches after mating. The eggs will hatch in the spring of the following year. Every year, just one generation is produced.


  • Three weeks after the cocoon is formed, the adult moth emerges. Coloration: The forewings of the moth are reddish-brown with two faint stripes running diagonally across them. Female moths begin to deposit eggs on short branches after mating with another female. Those eggs will hatch out in the spring of the following year. Every year, there is just one generation.

Date of last revision: 11/19 CAUTION! The pesticides recommended in this book are only approved for use in Kentucky, United States of America. Some goods may not be legal to use in your state or nation, depending on where you live. It is recommended that you consult with your local county agent or regulatory authority before applying any pesticide listed in this article. As a reminder, ALWAYS READ AND COMPLY WITH LABELED INSTRUCTIONS FOR SAFE USE OF ANY PESTICIDE! Images courtesy of Ric Bessin, University of Kentucky Entomology, with the exception of the tent in the tree shot, which is courtesy of R.

Anderson, USDA Forest Service, copyright 1995.

All About Eastern Tent Caterpillars

The eastern tent caterpillar (Malacosoma americanum) may be the only bug that can be identified solely by the structure of its house rather than its appearance. These gregarious caterpillars reside in silk nests that they construct in the crotches of cherry and apple trees, where they may be seen in large numbers. Eastern tent caterpillars are sometimes mistaken for gypsy moths or even the fall webworm.

What Do They Look Like?

Caterpillars of the eastern tent species feast on the leaves of several popular decorative landscape trees, causing their presence to be a source of concern for many homeowners. In reality, they seldom cause enough harm to a healthy plant to cause it to die, and if you’re looking for an intriguing bug to see, this is the one to look for. Several hundred caterpillars live in a communal tent constructed in the crotch of tree branches, where they are protected from the elements. The eastern tent caterpillars, which are models of cooperation, live and work in peace with one another until they are ready to pupate.

They grow to be almost 2 inches long and have noticeable hairs down the sides of their bodies by the time they reach their last instar.

Broken lines of brown and yellow flow along the sides, accented by oval specks of blue in the center of each line.

They lack the vibrant colors of many other moths and look nearly dull in comparison.


Kingdom – Animalia Phylum – Arthropoda Class -InsectaOrder -LepidopteraFamily – Lasiocampidae Genus -MalacosomaSpecies -Malacosoma americanum Kingdom – Animalia Phylum – Arthropoda Class -InsectaOrder -LepidopteraFamily – Lasiocampidae Genus -M

What Do They Eat?

Cherry, apple, plum, peach, and hawthorn trees are among the plants where eastern tent caterpillars dine on the leaves.

When the caterpillar species Malacosoma americanum is in abundance, the enormous number of caterpillars can defoliate its host trees completely before moving on to less desirable plants to feed on. Adult moths only survive a few days and do not consume any food.

Life Cycle

Eastern tent caterpillars go through a complete metamorphosis, which includes four phases, as do all butterflies and moths:

  1. Eggs- In the late spring, the female oviposits 200–300 eggs, depending on the species. Caterpillars emerge from the egg mass in a few of weeks, but they stay dormant in the egg mass until the next spring, when new leaves grow. During the sixth instar larval stage, the sixth instar larva creates a silken cocoon in a secluded area and pupates within it. The pupal case is brown in color. Adult- Moths fly around in quest of mates throughout the months of May and June, and they only survive long enough to breed.

Special Adaptations and Defenses

During the early spring months, when temperatures are more volatile, larvae emerge. The caterpillars dwell in large groups in silken tents that are meant to keep them warm during cold spells of weather. On cold or wet days, the broadside of the tent faces the sun, and caterpillars may congregate there to warm themselves. Each of the caterpillars’ three daily feeding expeditions begins with a thorough cleaning and replenishment of silk in their tent. In order to fit their growing size and to get away from the accumulating waste of frass, the caterpillars build additional layers to their body as they mature.

  1. As they move through branches and twigs in search of leaves to eat, they leave behind silk trails and pheromones that attract other insects to the area.
  2. Pheromone signals not only warn other caterpillars to the presence of foliage, but they also convey information about the quality of the food available on a certain branch of a plant.
  3. Whenever they sense a threat, the caterpillars leap to their feet and thrash their bodies about.
  4. When the caterpillars need to rest between feedings, they return to the shelter of the tent, which also serves as a protection against predators.

Where Do Eastern Tent Caterpillars Live?

It is possible for eastern tent caterpillars to infest the residential landscape, forming tents in ornamental cherry, plum and apple trees, among other species. It is possible that roadside stands of trees will produce adequate wild cherries and crabapples, and that dozens of caterpillar tents will embellish the forest border in this area. Because these early spring caterpillars need on the warmth of the sun to keep their bodies warm, tents would be unusual, if at all, to be seen in wooded places that were shaded.

Malacosoma americanum is a kind of bug that is indigenous to North America.


  • Caterpillar of the eastern tent. The Texas A&M University tent caterpillar is an Eastern tent caterpillar. T. D. Fitzgerald is at the University of Kentucky Agriculture Department. Stephen A. Marshal’s novel The Tent Caterpillars is set in a tent. Insects: A Natural History and Diversity of the Species

Tent Caterpillars – How do I get rid of tent caterpillars?

Wizzie Brown contributed to this article. Tent caterpillars attack a variety of broadleaf trees and shrubs, causing unattractive webs, or tents, to appear on the leaves. When their populations reach a critical mass, the caterpillars can defoliate trees, causing them to develop more slowly. They prey on ornamental and fruit trees, among other things. Early and correct identification of tent caterpillars, knowing their life cycle, and the use of suitable cultural or chemical management strategies are all essential for their eradication from the environment.

The eastern tent caterpillar, Malacosoma americanum, is the most troublesome of the four.

Life Cycle

Female moths lay their egg masses on tree trunks or tiny twigs throughout the late spring to early summer period (Fig. 1). The females of all Texas species, with the exception of the Sonoran tent caterpillar, utilize spumaline, a sticky, foamy substance, to “glue” the eggs to the bark or twigs of trees and shrubs. The spumaline also functions as a protective shell surrounding the egg mass, providing a firm, durable surface. During the majority of the summer, fall, and winter, egg masses linger on the branches of the trees.

  1. Eastern and western tent caterpillars begin feeding on these fresh leaves within a few days of their appearance.
  2. In most cases, the web is situated in the crotch of tiny limbs (Fig.
  3. Because the larvae wander away from their tents to feed on leaves, harm can occur even if the web is located a long distance away from the tents.
  4. These enormous, noticeable webs are created by the eastern and western tent caterpillars.
  5. The larvae molt, or lose their skin, multiple times throughout their development.
  6. The color pattern can also alter from instar to instar depending on the species.
  7. 3).
  8. Between feedings, dozens of caterpillars may assemble on these mats to wait for their next meal.
  9. Protected areas like as the web, under the bark, among dead plant material on the ground, within a curled leaf, or under the eaves of homes are all common locations for spiders to hide.
  10. Generally speaking, cocoons are loosely made of silk with a white or yellowish crystalline component dispersed throughout the whole thing.
  11. Tent caterpillars in their adult form are brown and yellowish moths with two diagonal patterns on the front wings of their bodies (Fig.

4). Their wingspans are around 1 inch in length. They are drawn to lights, like do other moths. A single generation of tent caterpillars occurs once a year in all species. Adults only survive for a few days, during which time they mate, lay eggs, and do not consume any food.


Tent caterpillars in its infancy are brightly colored and grow to be approximately 134 inches long when fully grown. The only lengthy hairs on their body are found around the sides and on the back. Individual species may be distinguished by the colors and patterns on their larvae. If you come across tents with larvae that do not fit the descriptions in Table 1, it is most likely that they are autumn webworm tents. Fall webworms may construct tents throughout the late summer and fall and can have numerous generations per year, depending on the species.


The degree of defoliation, unattractive webs, and nuisance caused by the caterpillars should be taken into consideration when developing a management strategy. It is possible that you may need to utilize a combination of cultural and chemical procedures to achieve the optimum results. Control over one’s culture. During winter pruning, look for egg masses, which show as swellings on tiny, naked branches and are a sign of infestation. When trees are pruned, the tent caterpillar eggs are frequently removed before they develop.

  • When you discover spider webs on twigs in the spring, prune them as soon as you notice them.
  • It is not suggested to burn the web or caterpillars since it is quite dangerous.
  • Remove the dead caterpillars from the ground and dispose of them.
  • Beneficial insects can help to lower the number of tent caterpillars.
  • Trichogramma species prey on the eggs of tent caterpillars.
  • Control through chemical means.
  • The use of insecticide is pointless if the tent caterpillars have been allowed to feed and develop to completion.

Tents are weather-resistant and will remain in the tree for an extended period of time until they are removed.

Early morning or late evening applications are recommended in order to concentrate the spray on the tents when the caterpillars cluster.

The species that may be sprayed with these oils will be listed on the label of the product.

Some organically generated goods contain active substances such as Bacillus thuringiensis (Bt)varietykurstaki, spinosad, or insecticidal soap, which are all derived from bacteria.

In order for the Bt kurstaki and spinosad to be taken up and consumed by the caterpillars, spray the plant well before applying the substance to the leaves.

Contact-kill insecticides such as insecticidal soap must be applied directly to the caterpillars in order for them to be killed.

See also:  How To Make A Civil War Tent

Some of these formulations operate when they come into direct contact with the pest, while others may have an oil-based component that is comparable to horticultural (petroleum-based) oils in their composition.

There are several long-lasting, synthetic pesticide solutions available that give quicker and longer-lasting control than most plant-derived insecticides while also working on all phases of the caterpillar’s life cycle.

Bifenthrin, cyfluthrin, esfenvalerate, fluvalinate, permethrin, lambda-cyhalothrin, indoxacarb, acephate, and carbaryl are all active chemicals to search for in a pesticide formulation.

Pesticide users are accountable for the impact pesticides have on their own plants or home goods, as well as any difficulties that may arise as a result of pesticide drift from their own properties to the properties or plants of their neighbors.

Also prone to change are the regulations governing the use of insecticides and pesticides. Always read and carefully follow the instructions on the product label for the most dependable instructions.


The author would like to express his gratitude to Bart Drees, Glen Moore, and Kim Schofield for their contributions to the review of this article. Bart Drees provided all of the photographs. Download a printer-friendly version of this publication by clicking on the following link: Caterpillars of the Tent »See more details about Gardening and Landscaping» Do you have a question – or do you require the assistance of an expert? Make contact with the appropriate county office.

The return of tent caterpillars: What’s it means for your yard?

Bud break does not just herald the advent of flowers and foliage; it also heralds the emergence of tent caterpillars from their cocoons. Troops of these caterpillars may completely cover tree branches with their silk tents in as little as a few weeks. Is it necessary for you to be concerned about them? Continue reading to find out! Caterpillar tents are a common type of western tent. These tents are commonly found in the bends of large branches on trees and medium-sized bushes, although they can also be seen on the ground.

  1. There are three species of tent caterpillar that may be found in Indiana: the Forest tent caterpillar (Malacosoma disstria), the Western tent caterpillar (Malacosoma californicum), and the eastern tent caterpillar (Malacosoma elatior) (M.
  2. All three species dwell in groups of anything from 40 to 200 individuals, and they remain together until just before they pupate, at which point they split off.
  3. They are not particularly gregarious, although they will leave pheromone trails leading to trees that have rich food sources.
  4. Below you’ll find a few of ways for distinguishing them from other species.
  5. If a tent caterpillar’s body is coated in fuzzy hairs, it is not a tent caterpillar; if it is smooth or spikey, it is not a tent caterpillar.
  6. These tufts are absent in tent caterpillars.
  7. If the caterpillar you’re looking at doesn’t exhibit any of these characteristics, it’s most likely not a tent caterpillar at all.

slate blue with a pair of black stripes, and C.



Elizabeth Barnes.

Hoff, C.

Hoff What exactly do they eat?

They are particularly fond of plants belonging to the Rosaceae family, such as cherry, apple, and chokecherry, among others.

What kind of harm do they cause?

Tent caterpillars typically defoliate only a few branches and are only actively feeding for a few weeks at a time.

However, if the tree is defoliated for a number of years in a row or is subjected to another stressor such as drought, it may suffer branch loss or even death.

If you decide that you want to get rid of tent caterpillars from your trees, you have a variety of choices to choose from.

Wait until the majority of the caterpillars have gathered in their tent before removing the tent from the tree and placing it in a bag to be frozen for later use.

Because their hairs might create an allergic response in some people, you may wish to use gloves when removing them off their tree.

If you believe you’ve discovered tent caterpillars but aren’t sure, please contact the author or post your find oniNaturalistorBugGuidefor ID assistance!

What Eats Tent Caterpillars?

A gigantic silk nest is constructed among the branches of trees by tent caterpillars. During the day, they leave the nest to eat on leaves, and they return to it at night to rest. They are protected from predators while in the nest, but after they leave the nest, they are preyed upon by a broad range of other creatures, including humans.

Bird Predators

Predators such as birds eat tent caterpillars as they are hatching from their eggs or when they are in the form of moths. Caterpillars are picked off the branches and leaves by songbirds. Tent caterpillars are eaten by a variety of birds, including robins, blue jays, red-winged blackbirds, and cardinals. In addition to ground dwelling birds such as wild turkeys picking off caterpillars when they crawl to the ground to pupate, the caterpillars themselves are preyed upon by a variety of predators.

Most of the time, birds devour them whole.

Insect Predators

Parasitic wasps attack both the egg and larval stages of the eastern and western tent caterpillars, causing them to die. Flesh flies prey on forest tent caterpillars, causing them to die. Depending on where the caterpillar eggs are laid, these parasites may lay eggs on the caterpillars themselves. As soon as the larvae hatch, they begin to devour the eggs or caterpillars from the inside out, as described above. Stink bugs, hornets, and yellow jackets are pests that attack many kinds of animals.

In addition to eating caterpillars directly by grasping them in their teeth, they also sting them and transport them back to their nests where they are devoured by the adults.

Mammal Predators

Caterpillars from tents are eaten by a few species of animals, including humans. While squirrels consume caterpillars that fall from tree branches, foxes and other large mammals (including white-footed mice and chipmunks) devour them as soon as they strike the ground, according to the National Wildlife Federation. The caterpillars and the moths will both be eaten by bats. Some species consume both the caterpillar and the moth in their whole, while others just consume the caterpillar and leave the moth wings behind.

Reptile and Amphibian Predators

Tent caterpillars are preyed upon by a variety of reptiles, including Eastern box turtles, garter snakes, copperheads, and skinks. Snakes and lizards are capable of climbing into trees in order to hunt for tent caterpillars, and they have even been seen to inside tents. It is possible that they will be eaten by water turtles if they fall into water. The tent caterpillar moths are preyed upon by a diverse range of frogs, including the wood frog and the American toad, among others. Tent caterpillar moths and caterpillars are consumed in their whole by reptile and amphibian predators.

Tent caterpillar – Wikipedia

Tent caterpillars
Eastern tent caterpillar,Malacosoma americanum
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Lepidoptera
Family: Lasiocampidae
Subfamily: Lasiocampinae
Genus: MalacosomaHübner, 1822
About 26, including:
  • The eastern tent caterpillar (Malacosoma americanum)
  • The western tent caterpillar (Malacosoma californicum)
  • The ground lackey (Malacosoma castrense)
  • And the ground lackey (Malacosoma castrense). Malacosoma disstrium, the forest tent caterpillar
  • Malacosoma neustrium, the lackey moth
  • Malacosoma disstrium, the forest tent caterpillar

Tent caterpillars, sometimes known as moth larvae, are medium-sized caterpillars that belong to the genus Malaco and are members of the family Lasiocampidae. Twenty-six species have been identified, six of which are found in North America and the remaining twenty-six in Europe and Eurasia. Some species are regarded to have subspecies in addition to the main species. Because of their proclivity for defoliating trees, they are frequently referred to as pests. They are among the most gregarious of any caterpillars, and they display a variety of interesting activities.

A single large tent is typically occupied throughout the larval stage by some species, such as the eastern tent cattter,Malacosoma americanum, and the caterpillar of the small eggar moth,Eriogaster lanestris, whereas others construct a series of small tents that are sequentially abandoned by others (for example, the eastern tent caterpillar,Malacosoma americanum).

Unlike tent caterpillars, which construct their tents in the nodes and branches of a tree’s limbs, fall webworms construct their webs at the extremities of the limbs, encircling leaves and tiny branches.

Life cycle

In the following description of the tent caterpillar life cycle, the eastern tent caterpillar, which is the most well-known species, is used as a model. The specifics of the life cycles of other animals differ only little from one another. It is during the early spring season, when the leaves of their host trees are just beginning to emerge, that tent caterpillars hatch from their eggs. The caterpillars begin constructing their tent as soon as the gates close. The tent is built in such a way that it is shielded from the light in the early morning.

  • Studies have indicated that digestion cannot take place when the body temperature of a caterpillar is less than around 15 degrees Celsius (59 degrees Fahrenheit).
  • Caterpillars may regulate their internal body temperatures by traveling from one compartment to another within their body.
  • On frigid but sunny spring mornings, it is not uncommon to find that the temperature of the aggregate is as much as 30 degrees Celsius (54 degrees Fahrenheit) higher than the temperature of the surrounding air.
  • Due to the fact that tent caterpillars’ digestive physiology is oriented to young leaves, they must feed multiple times per day in order to finish their larval development before the leaves of their host trees grow too old for them to consume, which forces them to feed several times each day.
  • The caterpillars return to the tent immediately after eating and congregate in the sunshine to aid with the digestive process.
  • The forest tent caterpillar, on the other hand, is a nomadic forager who constructs a succession of temporary resting spots during the course of its larval growth, unlike the other caterpillars.
  • Caterpillars migrate out from the tent in search of food, leaving a pheromone trail behind them as they pass over the branches of the host tree, which they use to find food.

If a caterpillar finds food and consumes it until it reaches full maturity, it will return to the tent, leaving a recruiting trail that will attract other hungry tent mates to the location of the food source.

The chemical recruiting trail of the eastern tent caterpillar is very similar to the pheromone trails used by ants and termites to notify their nest mates to the discovery of food sources in their environment.

Because of this, a colony of caterpillars generates vast volumes of fecal pellets on a regular basis.

The audio illusion of rain is created by fecal pellets falling from trees where caterpillars are feeding, creating the aural illusion of rain.

It is believed that the final instar eats around 80% of the total amount of food consumed by a larva over its entire life cycle.

Caterpillars grow at a quick rate, and their larval development is usually completed in seven to eight weeks on average.

They become fully grown adults around two weeks after that.

Mating normally takes place in the early evening, and the mated female, who is already heavily loaded with eggs, oviposits the whole clutch of eggs later that evening.

Spumaline has a hydrophilic property, which means it protects the eggs from becoming dry.

The female moth dies shortly after laying her eggs, despite the fact that the male can survive for a week or more.

Embryogenesis occurs shortly after the egg mass is implanted in the uterus.

Thesepharatelarvae are kept safe within the shells of the eggs until the next spring, when they hatch.

Because they are very freeze-tolerant, pharate larvae may survive temperatures as low as -40 degrees Celsius (40 degrees Fahrenheit) in northern climates.

The forest tent caterpillar, which is the most well-known of the epidemic species, is responsible for the outbreak.

Despite the fact that these outbreaks do not follow real cycles in the sense that they occur at regular intervals, outbreaks have been observed in some particularly vulnerable places every 10 years or so on average.

Parasitoid infestations and illness are among the factors that put epidemics to a stop.

Trees that have been defoliated by caterpillars will normally refoliate and will not suffer any long-term consequences.

Trees or sections of trees may, in certain situations, be destroyed after multiple seasons of recurrent defoliation, but this is not always the case. This occurred as a result of forest tent caterpillars defoliating sugar maples that were already stressed as a result of the recent drought.

  • Based on the life cycle and appearance of the eastern tent caterpillar, which is the best-known species, the following description of tent caterpillar life cycle is provided: Details of other species’ lives are only slightly different from ours in terms of specifics. It is during the early spring season, when the leaves of their host trees are just beginning to open, that tent caterpillars hatch from their eggs. It is not long after they close that the caterpillars build their tent. Building the tent at a location that is shaded from the early morning sun is an excellent idea! Since the caterpillars must bask in the sun to raise their temperatures beyond that of the chilly ambient temperatures that prevail in early spring, the location of the tent is crucial for their survival. The body temperature of a caterpillar must be greater than 15 degrees Celsius (59 degrees Fahrenheit) for digestion to take place, according to scientific evidence. In this tent, the layers of silk are divided by gaps, and the temperature in each compartment differs significantly from the rest of the structure. A caterpillar’s body temperature may be adjusted by switching from one chamber to another. The birds usually congregate in a close cluster just beneath the surface of the tent that is illuminated by the sun on cold mornings. Even on frigid but sunny spring mornings, it is not uncommon to find that the aggregate’s temperature is as much as 30 degrees Celsius (54 degrees Fahrenheit) higher than the surrounding air temperature. After a while in the spring, temperatures may become excessive at midday, causing the caterpillars to seek refuge on the shaded outer surface of the tent to cool themselves down. Due to the fact that tent caterpillars’ digestive physiology is tuned to young leaves, they must feed several times per day in order to complete their larval development before the leaves of their host trees become too old for them to eat, which forces them to feed several times per day during their larval development. After leaving the tent in large numbers to forage for food, caterpillars go to distant feeding places in a group. After eating, the caterpillars immediately return to the tent and congregate in the sunshine to aid with the digestion process. Foraging for eastern tent caterpillars takes occurs in the middle of the night. A migratory forager and temporary resting site establisher, the forest tent caterpillar is an exception to this rule. During the course of its larval development, the forest tent caterpillar visits a number of different temporary resting sites. According to research, eastern tent caterpillars recruit their tent mates to go on food hunts with them in order to locate food. In their hunt for food, caterpillars migrate out from the tent and over the branches of the host tree, leaving a pheromone trail behind them. In order for caterpillars to return to the tent, chemical exploring trails must be laid down. After finding and eating enough food to replenish its energy, a caterpillar returns to its tent, where it leaves a recruiting trail that attracts other hungry tent mates to the food it has discovered and eaten. Even though the chemical composition of the pheromone has been identified, it is still unknown how the exploration and recruiting pathways differ from each other. The chemical recruiting trail of the eastern tent caterpillar is very similar to the pheromone trails used by ants and termites to notify their nest mates to the finding of food sources in their environments. Tent caterpillars empty about half of the energy they consume as fecal pellets, which is believed to be due to the high concentration of nondigestible components in leaves. This results in an enormous amount of waste being produced by a single colony of caterpillars (fecal pellets). The presence of the forest tent caterpillar is most visible during outbreaks of the pest. The aural illusion of rain is created by fecal pellets falling from trees where caterpillars are feeding, creating the sound of rain. There are five to six larvalinstars in the life cycle of a tent caterpillar. A larva’s last instar is believed to eat around 80% of all the food consumed by the animal throughout the course of its entire life cycle. As a result, it is not uncommon for populations of forest tent caterpillars to go undetected until the final instar, when their eating causes considerable defoliation of tree foliage. It takes seven to eight weeks for a caterpillar to evolve from a caterpillar to a fully fledged larval form. In order to spin their cocoons and defend themselves from predators, the caterpillars leave their natal tree when they are fully grown and seek shelter on the ground or beneath the eaves of buildings. They become fully functional adults around two weeks after that. The female moth secretes an apheromone shortly after emerging from the cocoon, which attracts the attention of males in the vicinity. Mated females normally oviposit their complete complement of eggs later that evening, after mating has taken place in the early evening and the female has become fully loaded with eggs. Using a frothy substance known asspumaline, the eggs are arranged around the perimeter of a branch and coated with it. Water-loving spumaline keeps the eggs from drying up and becoming brittle. The coating also serves as a protective layer, reducing the likelihood that parasitic wasps will be able to infect the eggs. The female moth dies shortly after laying her eggs, despite the fact that the male might survive for a week or more. As a result, the whole adult life of a girl may be completed in less than 24 hours. Embryogenesis begins shortly after the egg mass is laid down. Small larvae can be discovered within each egg mass within three weeks or so of hatching. It is not until the next spring that thesepharatelarvae are released from their cocoons. This means that the insect’s enclosed larvae are now considered to be the most resilient of its several developmental phases. Because they are very freeze-tolerant, pharate larvae may survive temperatures as low as -40 degrees Celsius (40 degrees Fahrenheit) throughout the winter in northern places. The population dynamics of tent caterpillars are boom-or-bust. It is the forest tent caterpillar, which is the most well-known of the outbreak’s species. During outbreaks, the caterpillars can become so numerous that they are capable of defoliating tens of thousands of acres of woodland in a single night. Despite the fact that these outbreaks do not follow genuine cycles in the sense that they occur at regular intervals, outbreaks have been observed in some particularly vulnerable places every 10 years or more, according to the World Health Organization. For more than two to three years, caterpillars are rarely found in large quantities in outbreaks. Parasites and illness are two factors that might bring an outbreak to a conclusion. Occasionally, caterpillar populations fail due to starvation, which occurs when trees are totally defoliated before the caterpillars are fully matured or when the quality of host leaves deteriorates to the point where they are no longer appetizing to the caterpillars themselves. Trees that have been defoliated by caterpillars will normally refoliate and will not suffer any long-term effects. The death of trees or sections of trees may occur in some circumstances following repeated defoliation over a number of seasons, though. When forest tent caterpillars defoliated sugar maple trees that were already stressed from the drought, this resulted.

See also

  • Fall webworm is a North American moth whose larva weaves webs similar to those of the fall webworm.


  • Terrence D. Fitzgerald is a writer and editor who lives in New York City (1995). The Caterpillars of the Tent Cornell University Press, Ithaca, New York, ISBN 9780801424564
  • Fitzgerald, Terrence D., “Social Caterpillars,” Cornell University Press, Ithaca, New York, ISBN 9780801424564

External links

  • Savela, Markku, “MalacosomaHübner,” in Savela, Markku, “MalacosomaHübner.” Lepidoptera, as well as a few other types of life. retrieved on 1st July, 2019

Eastern Tent Caterpillar Moth

Two light-colored stripes cut across the forewing of the adult eastern tent caterpillar moths distinguish them from other moths. The center band between the two lines might be lighter or white in color at times. These moths are similar in size to others in their family, and they have thick, lengthy scales that give them the appearance of being fuzzy. Feathered antennae are found on both males and females. Females are lighter and more golden in color, as well as bigger and more rounded in their wings.

  1. They live in groups in “tents” formed of numerous silken threads in the crotches of host trees, which they construct from the strands.
  2. The inside of the head is dark.
  3. disstria) has black (rather than pale) lines on the forewings, but the forest tent caterpillar (M.
  4. The larvae do not have a continuous line down their backs; instead, there is a light-colored mark on each segment down their backs, with the form of each mark resembling a keyhole, shoeprint, or bowling pin on each segment.
  5. Instead, they merely construct silken mats and recommendations on tree trunks and branches to direct them to and from feeding areas and group meeting areas.

Eliminating Tent Worms – Tent Caterpillar Home Remedy Solutions

The forewings of adult eastern tent caterpillar moths are dark, with two light-colored bands running across them. It is possible to have a lighter or whiter center band between the two lines in some cases. These moths are medium in size, and their thick, lengthy scales give them the appearance of being hairy, just like the rest of their family members. Feathered antennae are seen on both males and females. Females are lighter and more yellowish in color, and they are bigger and have more rounded wings than their male counterparts do.

  • A number of them will gather and build “tents” in the crotches of host trees, which will be built out of numerous silken threads.
  • A black cloud hangs over the head of the protagonist.
  • disstria) has black (rather than yellowish) lines on the forewings, but the forest tent caterpillar (M.
  • Similar species: The larvae do not have a continuous line down their backs; instead, there is a light-colored mark on each segment down their backs, with the form of each mark resembling a keyhole, shoeprint, or bowling pin on the back.

In addition, the communal larvae of that species do not construct tents as a kind of protection. As an alternative, they merely construct silken mats and recommendations on trunks and branches to direct them to and from feeding areas and group meeting spots.

About Tent Worms

Tent caterpillars are commonly mistaken with autumn webworms, although they are very distinct creatures. Tent worms are most active in the early spring, whereas webworms are most active in the late summer and early fall. Tent worms build their tent-like nests in the forks of branches, whilst webworms build their web-like nests at the extremities of branch forks. Fall webworms construct nests that include foliage or leaves as well as their own bodies. Tent caterpillars, on the other hand, do not.

They will, however, build their nests in ash, willow, and maple trees as well as other species.

Large colonies, on the other hand, can cause severe defoliation of trees because they feed on the leaves.

Tent caterpillars may also graze on neighboring plants, according to the USDA.

Tent Caterpillar RemovalTent Caterpillar Home Remedy

It is frequently possible to pluck out the tent caterpillar nests or egg cases by hand when tent caterpillar removal is required. When the leaves fall off the trees in the fall, egg cases are plainly seen. Larger nests may be removed by looping them around a stick, or they can be pruned out and disposed of in the trash. The optimum time to remove tent caterpillars from their nests is in the early morning or late evening, when they are most likely to still be in the nest. The introduction of natural enemies, such as different species of parasitic wasps, can also aid in the reduction of tent worm populations.

How to Kill Tent Worms

When it comes to getting rid of tent caterpillars, sometimes the only option is to kill them. While tiny infestations may be controlled by dumping the nests into soapy water, contact pesticides are the most effective method for controlling bigger populations. Bacillus thuringiensis (Bt) is the most effective of the bacteria types. Because this is a selective pesticide, it only kills tent caterpillars while staying safe for use around other animals. Directly spray the foliage and tent worm nests with the product.

The beauty of your trees will be restored in a short period of time.

Forest tent caterpillars

Throughout Minnesota, forest tent caterpillars prey on a variety of broadleaf trees and plants, including quaking aspens, balsam poplars, basswoods, oaks, ashes, birches, alders, and fruit trees, among others.

  • The feeding damage caused by these caterpillars causes the development rate of deciduous trees to slow down. When forest tent caterpillars defoliate their target trees, they may cause damage to other adjacent plants as well. On vegetables, fruit trees and other tiny fruits, as well as nursery crops, there is evidence of damage
  • When they are discovered in close proximity to buildings or on roads, they become a nuisance.

The forest tent caterpillar (Malacosoma disstria) may be found throughout most of the United States and Canada, where hardwood trees can be found in dense stands of foliage.

Red maple and conifers, such as pine and spruce, are among the plants on which this caterpillar is less likely to feed. Larvae of the forest tent caterpillar

How to identify forest tent caterpillars

  • Two inches long, primarily blue and black in color, with a row of white, footprint-shaped marks on the back and a dense covering of hairs along the edges of their bodies.

Adult moths

  • Moths are nocturnal and drawn to lights at night
  • They emerge from their cocoons around two weeks later, in mid-July
  • And they have a short lifespan.

Moths are nocturnal and drawn to lights at night; they emerge from their cocoons around two weeks later, in mid-July; and they have a long lifespan.

Life cycle of forest tent caterpillars

Aspen leaves begin to open in early to mid-May, which coincides with the emergence of larvae (caterpillars) from egg masses on the aspen tree.

  • Over a period of five to six weeks, aggressively feed on aspen and other broadleaf trees a silken mat that is hardly discernible where caterpillars congregate on the tree’s trunk and branches

As the month of June approaches, older larvae begin to roam about trees and other vegetation in search of food, causing harm to adjacent plants.

  • By the end of June, fully grown caterpillars are searching for safe havens to spin silky cocoons
  • By the middle of July, adults have emerged from their cocoons
  • Adults live for about five days and lay 100 to 350 eggs in gray, cylindrical masses surrounding small twigs
  • By the end of August, the caterpillars have hatched.

The eggs survive the winter, and the larvae that emerge from the eggs the following spring. Every year, just one generation is produced. The forest tent caterpillar is responsible for some defoliation.

Damage caused by forest tent caterpillars

Generally, feeding by forest tent caterpillars does not cause deciduous trees to die since they may develop another set of leaves during the same season in which they were fed. Healthy trees may withstand two to three years of intensive defoliation in a row if they are in good condition. Trees may be felled for the following reasons:

  • If the same tree has been significantly defoliated for four or more years, it is considered to be diseased. When trees are under stress, such as during a drought, they might die.

The forest tent caterpillar has completely defoliated the woodland.

Forest tent caterpillars as a nuisance

Maturity larvae can be seen on buildings and in yards when they are searching for a safe haven to lay their eggs.

  • When mature larvae are on the prowl for safe havens, they can be found on buildings and in yards.

Scophaga aldrichi is a huge gray fly that preys mostly on forest tent caterpillars. When enormous numbers of forest tent caterpillars are discovered, the fly’s population grows exponentially. This fly does not bite and is completely harmless; yet, it is a nuisance since it will settle on any item, including people, and may cause irritation. This bug is critical in putting a stop to a forest tent caterpillar infestation on a natural basis.

How to protect your trees from forest tent caterpillars

  • The population of forest tent caterpillars is reduced by a cold or damp spring, hunger, and viral illness. In order to destroy caterpillar eggs, larvae, and pupae in a forest tent, wasps and flies must be allowed to flourish within the tent. A good example is the giant gray fly, Sarcophaga aldrichi, which is endemic to Minnesota and is considered a pest.

Remove eggs and caterpillars as you see them

  • Remove and destroy egg masses that have accumulated on the limbs of tiny trees before the eggs hatch the following spring. With a stiff brush, remove caterpillars and cocoons from the outside of houses, picnic tables, and decks. Using a water spray, knock caterpillars from their perches. Care should be taken not to crush too many caterpillars as this might cause smearing and marking on some paints.

Using pesticides

Pesticides, in addition to physical measures, may be effective in the control of larvae. Pesticides should be used while larvae are little (1 inch or less in length), which is often in early to mid-May. Larger larvae are more difficult to destroy, and they can continue to defoliate trees even after insecticides have taken their toll. Some of the choices that are accessible are as follows:

  • Bacillus thuringiensis (commonly known as BT), a microbial pesticide derived from a bacterium, is both efficient and friendly to the environment. Additionally, insecticidal soap, spinosad (a microbiological pesticide), and azadirachtin (a botanical pesticide) are among the pesticides that help to conserve beneficial insects. A number of chemical insecticides, including acephate, bifenthrin, carbaryl, cyfluthrin, esfenvalerate, fluvalinate, lambda-cyhalothrin, malathion, permethrin, and phosmet, have been developed to combat these pests.

When selecting a pesticide, take sure to read the label carefully because the active components are written in small type.

Forest tent caterpillars in wood lots

Birds, rodents, and even bears consume the caterpillar larvae of the forest tent caterpillar in wooded areas. Control actions should only be performed in the event of severe defoliation over a period of several years. In wooded regions, resort areas, and campsites where huge areas may require treatment, the following procedures should be followed:

  • Aerial pesticide spraying by aircraft is the most efficient, effective, and cost-effective approach available
  • Nevertheless, spraying should be avoided where gusts threaten to carry the pesticide over open water or other sensitive locations. Treatment of an extra strip about 400 feet wide next to the region should be performed when spraying in residential or recreational areas. The presence of this barrier strip prevents caterpillars from migrating.

The pesticide BT is recommended because it is non-toxic to humans, birds, or beneficial insects, and it is typically used first in aerial spray programs because of this property. Diflubenzuron should not be used near wetlands or bodies of water since the pesticide has the potential to harm aquatic insects and other arthropods. DISCLAIMER: The mention of a pesticide or the application of a pesticide label is solely for educational reasons.

Always read and follow the pesticide label recommendations that are connected to the pesticide container that you are currently working with. Keep in mind that the label is the law. In 2018, a review was conducted.

Tent caterpillars – Canada.ca

The pesticide BT is recommended since it is non-toxic to humans, birds, or beneficial insects, and it is typically used first in aerial spraying programs because of this safety feature. You should avoid using diflubenzuron while you are near wetlands or bodies of water, as this herbicide may harm aquatic insects and other aquatic arthropods. DISCLAIMER:Any mention of a pesticide or the application of a pesticide label is only for educational reasons. Never deviate from the pesticide label instructions that are affixed to the pesticide container that is being used.

In 2018, the situation was reviewed.

  • Adormant oil spray on sensitive trees in late winter can be used to suffocate caterpillar eggs before they hatch in early spring if you have a caterpillar infestation. Dried eggs, mites, scales, and other insects can be controlled by applying dormant oils to fruit trees over the winter. If dormant oils are not used properly, they can cause damage to plants, so make sure to read and follow all package recommendations. There are a variety of additional pesticide products that have been approved for the management of tent caterpillars. If the tent is within reach, use a stick to pry it open and spray the insecticide into it while it is still open. When spraying in the evening, it will be most successful, because the caterpillars return to their nesting location at night.

Fall webworm & Eastern Tent Caterpillar [fact sheet]

Obtaining a Downloadable Resource In addition to fruit, the autumn webworm (Hyphantriacunea) and the Eastern tent caterpillar (Malacosomaamericanum) eat on trees in woodlands and shadows. Orchards that are frequently treated with pesticide to combat codling moths and other pests have little need for them in terms of economic value. They can, however, be regarded a serious pest in nurseries and landscaping due to the unattractive webs they create. A common misconception is that the fall webworm is the same as the Eastern tent caterpillar.

For its part, the Eastern tent caterpillar’s web is densely packed into the forks and crotches of trees; the larvae do not feed within their webs, but instead cluster there at night and during wet weather.

Caterpillars of the eastern tent Image courtesy of Marie-Eve Jacques


Fall Webworm: When fully developed, the larvae measure around 1 1/2″ in length. Depending on the species, they may be yellow with dark stripes and dots or a drab blue black without any yellow. Their bodies are covered with hair, and their heads are dark in color. Adult moths have a wing span of around 1 1/2 inches. Their hue is almost completely white. The Eastern Tent Caterpillar has scant hairs and grows to be around 2 inches long when fully developed. A white stripe runs down the middle of the back of the animal, and it is painted black with white and blue patterns.

Life Cycle

Each year, a new generation of fall webworm is produced, but it is not particularly synchronized. The insects hibernate as pupae in the soil during the winter. The adult moths emerge from the earth throughout the months of June and July. In July, the females begin laying their massive clutches of eggs. The eggs begin to hatch towards the middle of July. The larvae eat within the web for a month or more before crawling down the tree and constructing a cocoon, where they will eventually pupate.

The insects overwinter as egg masses on twigs, and they hatch in April after spending the previous winter as egg masses.

As the larvae grow and mature, more layers of the tent are erected.

The females lay masses of eggs in bands around twigs, which are then eaten by the males.

The larvae of the fall webworm. Photograph courtesy of Ward Upham of Kansas State University. The larvae of the eastern tent caterpillar. Marie-Eve Jacques is credited with this photograph. The larvae of the eastern tent caterpillar. Photograph courtesy of Marie-Eve Jacques.


  • It is possible to limit the requirement for therapy by monitoring for and eliminating tent caterpillar egg masses. It is critical to discover webs of either insect as soon as possible in order to avoid significant defoliation. Destroy nests by trimming or removing them manually (a stick can be placed into huge webs and then twisted to remove the webs). Biological Control – A variety of natural enemies, including birds, small animals, insect predators, spiders, and parasitic wasps, keep the numbers of both the autumn webworm and the Eastern tent caterpillar under control. When the humidity and temperatures are just right, a naturally existing virus and a fungus can multiply to the point where they kill large numbers of caterpillars of both species. When dealing with either pest, biological pesticides based on the Bacillus thuringiensis (Bt) bacteria should be employed, and they should be administered as soon as the tents are spotted while the larvae are still young. Chemical Control – Use pesticides to control infestations that are difficult to reach or when populations are large. In order to receive particular pesticide recommendations, contact your county’s Agricultural Field Specialist.

Egg mass of the eastern tent caterpillar. Photograph courtesy of Alan T. Eaton. The Eastern tent caterpillar is responsible for the defoliation. Photograph courtesy of Marie-Eve Jacques. Stop! Ensure that you thoroughly read the label on every pesticide bottle before to utilizing the item. Pesticides must only be used in the manner specified on the label in order to be in conformity with the law. The continuous registration of all pesticides described in this book is conditional on their ongoing use.

New Hampshire rules require that empty containers be disposed of in an appropriate manner.

How to Get Rid of Tent Caterpillars

Tent caterpillars are the larvae of various moth and butterfly species (mentioned below), which are referred to as a group by their common name. These caterpillars, which are found throughout most of the United States and Canada, reproduce quickly and have the ability to defoliate a significant number of deciduous trees and shrubs in a short period of time. These pests are frequently seen on wayside trees and in abandoned orchards. Aside from defoliation, the larvae build big unattractive webs, or tents, in the crotches of tree limbs, which are difficult to remove.

Despite the fact that tent damage is ugly, infestations of insects seldom endanger the life of trees.


The Eastern Tent Caterpillar (Malacosoma americanum) is a species of caterpillar that may be found east of the Rocky Mountains and north into southern Canada. In their full developed state, caterpillars are sparsely hairy and black in appearance, with a row of pale blue markings on either side of their bodies. They may be distinguished by a white stripe running down the middle of their backs, which helps to identify them. Adults are reddish brown moths that are 1-1/2 inches in length and have two white stripes running diagonally across each forewing.

  1. The Western Tent Caterpillar (Malacosoma californicum) is a pest that may be found in the northern and western regions of the United States as well as in adjacent Canadian territory.
  2. Approximately 1-1/2 inches in length, adult moths are orange-brown in color with two faint yellow lines on the underside of the wings.
  3. Malocsoma disstria is a forest tent caterpillar that may be found across the United States and Canada anywhere hardwoods can be found in the forest.
  4. americanum are similar in appearance to the adult, but instead of a solid line running down their back, they have a series of keyhole-shaped white dots.
  5. Wild cherry, aspen, maple, oak, and hawthorn are among the plants that serve as hosts.
  6. Webworms are known to feed on over 85 different types of trees and are found across North America and Mexico.
  7. One-inch-long caterpillars are coated with long hairs and range in color from yellow to green, with a black stripe along the back and a yellow stripe on each side of the body.

The color of their heads is either red or black. Adult moths (1 inch in length) are pure white in color with black markings on the wings, which are characteristic of the species.

Life Cycle

The egg stage is where the majority of tent caterpillar species overwinter. Egg masses ranging in color from dark brown to gray and holding 150 to 400 eggs are adhered to the short twigs of trees and bushes. Hatching takes occur around the time when leaf buds begin to open, which is normally in the early spring months. They are social creatures who quickly build silken tents, which they use as a haven during the early morning and evening hours, as well as during rainy spells, to protect themselves from the elements.

The larvae reach full maturity around six weeks after hatching and five instars following that time period (up to 2 inches long, sparsely hairy).

Adult moths emerge around two weeks later and deposit the overwintering eggs within a short period of time.

Note: When larvae begin to travel to sheltered regions in order to pupate, they can become a nuisance.

How to Control

  1. Prevent the larvae from starting to eat by scraping off and discarding overwintering egg masses and tearing the protective tents out by hand before they start to feed. With this method, you may restrict caterpillar mobility and deny them access to eating locations. Sticky Tree Bands or Tree Tanglefoot Pest Barrier are two options for preventing pest infestations. The naturally occurring soil-dwelling bacteriumBacillus thuringiensis, often known as Bt-kurstaki, is highly powerful against all species of inch worms. At the first indication of damage, use a spray that is simple to apply to knock out the worms and safeguard the foliage. It is safe to use BTKsprays near dogs and children since they do not damage honey bees or birds
  2. Spinosad, a biological substance developed from fermentation, is also extremely useful in a variety of applications. In fact, it’s the active ingredient in Monterey Garden Insect Spray, a product that has been classified as organic by the United States Department of Agriculture’s National Organic Program and listed for organic use by the Organic Materials Review Institute
  3. AzaMaxcontains azadirachtin, which is the key insecticidal ingredient found in neem oil. This very powerful spray interferes with the growth and development of nuisance insects while also acting as a repellant and anti-feedant. In addition to being non-toxic to honey bees and many other helpful insects, it should only be used as a last resort for dealing with bug infestations. Natural pesticides, which are derived from plants that contain insecticidal qualities, have less adverse side effects than synthetic chemicals and degrade more quickly in the environment.

Note: Although more than 80 species of predators and parasites have been identified in the United States, none of them are now available for purchase on the market. During the majority of the year, these insects serve a crucial role in keeping pest populations under control. As a result, extreme caution must be exercised while spraying pesticides in order to avoid causing harm to these important species.

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