What Do Western Tent Caterpillars Eat

Western Tent Caterpillar – Field Guide to Insects and Diseases of AZ and NM Forests

Hosts:Aspen, willows, cottonwoods, and mountainmahoganyFigure 46. Adult western tent caterpillar and egg mass.Symptoms/Signs:Western tent caterpillar is an early season defoliator with feedingdamages typically occurring between May and June. Symptoms includemoderate to complete defoliation of trees; large silken tents onbranches; and presence of larvae in and around the tents. Treesrepeatedly defoliated will have sparse foliage, minor branch dieback,and in some cases, tree mortality.Figure 47. Larva of western tent caterpillar.Maturelarvae are 4 to 5 cm long and vary widely in coloration. Their headsare blue to black and body color patterns are mixtures of black,orange, and blue. Larvae are usually quite hairy.Biology:Larvae overwinter as first instars insideegg masses glued around twigs. Larvae emerge from egg masses inspring and construct silken tents on branches that are used forshelter and molting during the daytime. At night, caterpillars feedoutside of the tents. As the larvae mature, they disperse and becomesolitary feeders. Moths emerge from cocoons and following mating glue egg massesto live twigs that are less than 2 cm in diameter.Figure 48. Tents of western tent caterpillar on aspen.Effects:Heavy defoliation of aspen for a number of years will cause growthloss and branch dieback. Some mortality may also occur during prolongedoutbreaks. Outbreaks, however, are generally short lived, generallylasting 2 to 3 years.Figure 49. Western tent caterpillar larvae and defoliation of aspen on the Carson NF, New Mexico.SimilarInsects and Diseases:Seefall webworm,large aspen tortrixand foliar diseases of aspen.References:3,16,24

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.

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.

  1. 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.
  2. They are not particularly gregarious, although they will leave pheromone trails leading to trees that have rich food sources.
  3. Below you’ll find a few of ways for distinguishing them from other species.
  4. 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.
  5. These tufts are absent in tent caterpillars.
  6. If the caterpillar you’re looking at doesn’t exhibit any of these characteristics, it’s most likely not a tent caterpillar at all.
  7. 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!

The western tent caterpillar, though unsightly, is mostly just an annoyance

Susan W. Clark contributed to this article. During this time of year, webby tents begin to develop on the branches of nearby trees. The tents herald the emergence of a defoliating insect pest known as the western tent caterpillar, Malacosoma californicum pluviale, which is responsible for the tents’ appearance. Despite the fact that the tents are eye-catching, the insects are largely a nuisance. “There is no portion of the tree’s life cycle that is detrimental to it,” said Weston Miller, a community and urban horticulture with the Arbor Day Foundation.

  1. After a year, the tent caterpillar’s life cycle comes to an end, with the eggs spending the winter in a Styrofoam-like egg case that is adhered to tree branches.
  2. They also construct the silken tents, which can hold a writhing mass of as many as 350 caterpillars at a time, according to legend.
  3. It takes two to three weeks after that for them to emerge as moths, ready to mate and deposit eggs for the next generation of butterflies.
  4. It is possible to remove the brown or gray egg masses by hand or by trimming throughout the winter months if you can identify them.
  5. Suppose an egg mass hatches in a little tree, Miller proposes that you cut the branch and place it in a basin of soapy water to sterilize it.
  6. Miller recommended visiting your local library or phoning your local pest control company to learn more about this bug.

The truth about tent caterpillars

Madrona Murphy has been a resident of the islands for 31 years, and this year has been the worst tent caterpillar infestation she has ever witnessed. According to Murphy, a botanist at the Kwiaht laboratory in Lopez, “people are always asking us what to do about them.” People want to know how to murder them, to put it more explicitly. An unwelcome visitor is the western tent caterpillar, which may be distinguished by its orange and black markings. It is estimated that periodic caterpillar outbreaks cause defoliation, slight limb dieback, and in some cases tree death according to the United States Fish and Wildlife Service (USFWS).

  • The weather and temperature have a strong influence on the frequency of these eruptions.
  • Despite its small size (it only measures four to five centimeters in length), this insect is known for spinning “tents” on the tops of branches.
  • Tent caterpillars in its early stages will typically consume all of the leaves on a single branch before moving on to the next.
  • According to Murphy, some caterpillars hatched late this year and may continue to feed until July.
  • Collman of Washington State University’s Extension Master Gardener Program in her essay “Biology and Control of Tent Caterpillars,” the good news is that caterpillars do not transmit diseases to people and do not bite.
  • According to WSU horticultural specialists, established trees can withstand at least 25 percent defoliation without suffering any negative consequences.
  • A highly infectious virus and a parasitic insect are among the natural enemies of caterpillars, which wreak havoc on plants that are vulnerable to their attacks.

The additional risks that these caterpillars must contend with are far more subtle.

“The caterpillars are eaten from the inside out by the larvae,” Murphy explained.

If you use fire to control the bug, you should consult the Whatcom County gardening extension website to ensure that you do not do more damage to the tree.

Even if they seem horrible right now, most trees will recover on their own this year, according to the expert.

When the adult moths lay their eggs, which are somewhat bubbly gray crusts, they do so in late summer.

After the caterpillars hatch, according to Murphy, the next best approach for managing them is to spray them with insecticide.

Make arrangements to dispose of the afflicted branches by putting them in your compost pile, burning them, or soaking them in fresh or salt water.

According to some reports, islanders could spray the caterpillars with Bacillus thuringiensis, a bacterium that is deadly to caterpillars.

“Patience may be the best course of action at this time because the majority of caterpillars will cease eating in June and will leave the trees to make their cocoons,” Murphy explained.

The specialists at Washington State University’s Extension Service said that certain birds do eat on tent caterpillars, and that they can even be useful to plants.

In addition to providing healthy meals for tiny animals, pupae and moths are also consumed by birds and bats.

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.

See also:  How To Fold A Camping Tent


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.

  1. When you discover spider webs on twigs in the spring, prune them as soon as you notice them.
  2. It is not suggested to burn the web or caterpillars since it is quite dangerous.
  3. Remove the dead caterpillars from the ground and dispose of them.
  4. Beneficial insects can help to lower the number of tent caterpillars.
  5. Trichogramma species prey on the eggs of tent caterpillars.
  6. Control through chemical means.
  7. 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.

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.

Tent Caterpillars – Climate, Forests and Woodlands

The tent caterpillar’s “tent” can be as long as a foot in length or even longer. Figure 1. Photo courtesy of Tom DeGomez of the University of Arizona. A widespread defoliator of broadleaf deciduous trees, tent caterpillars are found on a variety of broadleaf species including poplar, ash, hawthorn, cherry, and apple. Due to the fact that they prey mostly on emerging buds and sensitive new leaves, they are most active in the spring and early summer. They are members of the genus Malacosoma, which contains multiple species, including the forest tent caterpillar (Malacosoma disstria), the Eastern tent caterpillar (Malacosoma americanum), and the Western tent caterpillar (Malacosoma occidentalis) (M.

They are native to North America and may be found all across the continent of North America.

Life Cycle

One of the most noticeable signs of this insect is a silken “tent,” or mat in the case of the forest tent caterpillar, that can be seen among the branches of a tree or on the ground (Figure 1). These tents can be a foot or longer in length, and they can accommodate dozens of larvae at a time. The larvae utilize the tent as a place to rest and as a means of shelter from predators and adverse weather conditions. An adult larva emerges from the tent on a daily basis to feed on the tree’s foliage for four to six weeks until it finds a safe place to pupate and develop into a cocoon.

Following mating, the female moth seeks out a suitable host tree and deposits egg masses containing 150 to 300 eggs, which are often arranged in a band around a twig or branch (Figure 2).

Every year, there is a new generation.

High Population Effects

Fig. 2: A tent caterpillar’s egg mass in its typical form. Featured image courtesy of Jeffrey W. Lotz, Division of Plant Industry, Florida Department of Agriculture and Consumer Services (FDACS) (DPI). In certain cases, tent caterpillar populations can get so large that they become a nuisance. Mature larvae (Figure 3) wander around in search of a safe area to construct their cocoons (see Figure 2). As the larvae wander over roads and pathways and make cocoons on protected surfaces, including on or within buildings when they locate a suitable access site, humans are likely to perceive a serious infestation when they do so in significant numbers.

The majority of trees can withstand the loss of their leaves and will leaf out again in the summer with a harsher, less appealing leaf than they had before.

While it is not well known if eastern tent caterpillars have had large economic consequences on forest or fruit output, they have been linked to the disease Mare Reproductive Loss Syndrome in Kentucky.

Controlling Outbreaks

The caterpillar larva of a tent is shown in Figure 3. Photo courtesy of Tom DeGomez of the University of Arizona. Because of a number of natural factors, nuisance-level populations will gradually diminish over time. Heavy defoliation as a result of overcrowding leads to malnutrition, which in turn causes the population’s numbers to decline. Weather conditions also play a role in tent caterpillar population control: cold weather that occurs immediately after the eggs hatch, as well as high spring temperatures, both kill huge numbers of tent caterpillars.

  • In addition, numerous species of songbirds, as well as certain bats and small animals, prey on the eggs, larvae, and/or moths of the species.
  • If you have a small landscape, mechanical control can be accomplished by trimming off and destroying the tents in the early spring when caterpillar activity begins.
  • On smaller trees, egg masses can be trimmed during the winter months when they are visible, which is very beneficial.
  • Moth and butterfly larvae are killed by Bt, a naturally occurring bacterial bacterium that is found in the environment.
  • Nontoxic to people and other nontarget species such as bees and fish, as well as to the environment.
  • Using pesticides in situations where huge populations are difficult to manage is not always more successful than relying on natural causes or employing the mechanical control methods described above.

Other Considerations

Fig. 4: An adult forest tent caterpillar in its natural habitat. Photo courtesy of FDACS-Jeffrey DPI’s W. Lotz. Tent caterpillars (Figure 4) are not the same species as gypsy moths (Lymantria dispar), despite the fact that they may seem similar. Fall webworms (Hyphantriaspp.) are also seen in large numbers in several sections of the nation. These also construct tents in broadleaf trees, but they are only active in the late summer and early fall, whereas the other species is active all year. The fact that fall webworms defoliate trees late in the season means that they have a lower potential for causing significant harm.

In addition to the same problems and control techniques as for tent caterpillars, with the exception of the timing of application, the same issues and control methods as for autumn webworms apply as well.


Christopher Jones is a writer who lives in the United Kingdom.


“The Eastern Tent Caterpillar,” E.R. Day’s Eastern Tent Caterpillar, 2002. Publication 444-274 from the Virginia Cooperative Extension. W. T.E. DeGomez, T.E. DeGomez Aerial view of a tent caterpillar in Northern Arizona at 6000 feet elevation. 2009. Cooperative Extension of the University of Arizona. AZ1249. Publication number AZ1249. John F. Dill and C.A. Kirby, eds. Fact Sheets on Forest and Eastern Tent Caterpillars, published in 2010. Cooperative Extension of the University of Maine. Information about Pest Management Fact Sheet #5022.

  • Meeker, et al.
  • Hübner is a German word that means “horseman” (Insecta: Lepidoptera: Lasiocampidae).
  • The National Forest Health Monitoring Program was established in 2013.
  • 1987.
  • Annual Review of Entomology, vol.
  • 3, pp.

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.

See also:  How To Fold A Foldable Tent

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.

After three weeks, Malacosoma americanummoths are able to break away from their cocoons. They lack the vibrant colors of many other moths and look nearly dull in comparison. When examined closely, two parallel lines of cream may be seen across the wings, which are tan or reddish brown in color.


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.

  • 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.
  • 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.
  • Whenever they sense a threat, the caterpillars leap to their feet and thrash their bodies about.
  • 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.

The eastern tent caterpillar may be found across the eastern United States, as far west as the Rocky Mountains, and as far south as southern Canada. 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 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).

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.

  • Caterpillars of the western tent
  • A bunch of tent caterpillars on their way to feast off a tree
  • Caterpillar tent in the eastern hemisphere
  • A tent caterpillar nest with several caterpillars
  • In the United Kingdom, a tent caterpillar nest was discovered.

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

Malacosoma californicum – Wikipedia

Western tent caterpillar
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Lepidoptera
Family: Lasiocampidae
Genus: Malacosoma
Species: M. californicum
Binomial name
Malacosoma californicumPackard, 1864
  • The Clisiocampa californica (Packard) and the Clisiocampa californica (Packard) The species Bombyx pseudoneustria was described by Walker in 1865. Clisiocampa thoracica, described by Boisduval in 1868. Stretch (1881)
  • Clisiocampa fragilis var. perluteaNeumoegenDyar, 1893
  • Clisiocampa ambisimileDyar, 1893
  • Clisiocampa pluvialisDyar, 1893
  • Clisiocampa fragilisStretch (1881)
  • Clisiocampa musNeumoegenDyar, 1893
  • Clisiocampa fragilisStretch, 1881
  • Cl

The western tent caterpillar, Malacosoma californicum, is a member of the Lasiocampidae family of caterpillars. It is a caterpillar with a sting. The Western Tent Caterpillar may be found in southern Canada, western United States, and northern Mexico, among other locations. There are now six subspecies of M. californicum that have been identified. In their larval stage, western tent caterpillars are highly social and will spend a significant amount of their time with other caterpillars in silken tents that they build for themselves and their fellow caterpillars.

Adults emerge in the late summer to copulate and deposit eggs, and they are followed by their young.

Eggs will be laid during a period of inactivity throughout the winter and hatch the following spring.

Severe outbreaks can result in defoliation of host trees; however, the damage to plants is limited, and the majority of trees will regrow their leaves within a few weeks.


The pre-pupa stage of the Western Tent caterpillar is 4-5 cm in length. A longitudinal orange stripe runs lengthwise across the body of the caterpillars, which are black, grey, or white in color. There are blue-white lines on each segment, and dispersedsetaeextruding from the body are seen between the lines. Pupae are 2-2.5 centimeters in length and range in color from reddish-brown to black. During development, pupae create a white silky cocoon that is dusted in white and yellow. Adults have a wing span ranging from 3.5 to 5 cm.


Western tent caterpillar larvae are generalist herbivores that eat on a wide variety of plant materials. Diet preferences, on the other hand, are highly reliant on one’s geographical region. The larvae will select to feed on the leaves of the tree in which the female has deposited her eggs. Among the most often encountered host plants on which caterpillars prey are the leaves ofstonefruittrees. The larvae, on the other hand, will feed on a wide variety of different types of treefoliage. Adult moths do not feed and can only survive for 1–4 days without water.


Western tent caterpillars are ectothermic, which means that they do not generate their own body heat and are consequently significantly impacted by the temperature of their surroundings. Thermal regulation is supposed to take place when larvae bask in the sun and congregate in small groups to raise their body temperature. Caterpillars’ growth can be sped up by raising their body temperature throughout the day.


Caterpillars in their first instar are social and like to live in groups in silken tents. In order to prevent predators, raise the warmth, and forage for food, caterpillars congregate in large groups. Caterpillars grow in size and require more food during the late instars, resulting in a solitary behavior during the later instars.

Caterpillars are self-sufficient in their feeding and do not require cover in tents. A defense strategy, caterpillars flip their heads in reaction to the sound of fly parasites in their environment.


Moths will begin to mate in the middle of summer. For females, there will be a lot more male-on-male competition. Females are polyandrous, which means they deposit a clutch of eggs that are fertilized by numerous men. It is customary to lay a single band of eggs around the circle of the branch’s diameter. A single egg band may hold hundreds of eggs in its midst. FemaleM. californicum with a significant egg mass


The nuclear polyhedrosis virus (NPV) is an insect-borne virus that mostly affects butterflies and moths, but can also harm other insects. NPV has been demonstrated to reduce fitness and even cause mortality in some cases. The bodies of larvae that perish as a result of NPV become thin and liquidy in appearance. It has been demonstrated that higher temperatures enhance the frequency of this virus. NPV can be passed on from parent to child or between persons who have come into personal touch with one another.

NPV infections do not always result in the death of the caterpillar, and survival rates are significantly higher in late instar caterpillars.


When the population sizes of larvae reach their maximum levels, outbreaks are a consequence. Population breakouts of the western tent caterpillar occur in cycles every 6–11 years, according to the National Geographic Society. Severe outbreaks can result in the defoliation of host trees; nevertheless, the majority of trees will regrow their leaves within a few weeks. Outbreaks of the western tent caterpillar have the potential to cause widespread defoliation of trees. Many people believe that the caterpillars become an issue when they reach epidemic population numbers.

The most successful human suppression of western tent caterpillars occurs when humans intervene before a large population of the caterpillars has developed.

However, it is considered that the NPV plays the most important role in the boom-and-bust cycle of population outbreaks.

As the population of western tent caterpillars grows, the prevalence of the illness grows as well, resulting in a population crash as a result.


It is well known that western tent caterpillars have substantial ecological interactions with the plants that they feed on. The time of caterpillar egg hatching is carefully coordinated with the time of bud burst on the host plant to guarantee that early instar larvae are able to feed on the leaves of the host plant. Caterpillars, on the other hand, can hatch up to two weeks before or after the tree’s buds have burst, depending on the species. The consequences of climate change are projected to cause a phenological asynchrony between the host tree and the western tent caterpillar, which will be characterized by an advance in the time of larval emergence of the caterpillar.

Because caterpillar larvae are resistant to famine, it does not appear that this has a substantial impact on their fitness as caterpillars.


  • Malacosoma californicum ambisimile (Dyar, 1893)
  • Malacosoma californicum californicum
  • Malacosoma californicum fragile (Stretch, 1881)
  • Malacosoma californicum lutescens (NeumoegenDyar, 1893)
  • Malacosoma californicum plu


  1. ^ab Ciesla, William
  2. Ragenovich, Iral
  3. Ragenovich, Iral (2008). “Western Tent Caterpillar,” as it is known in the trade. Franklin, Michelle
  4. Myers, Judith
  5. Cory, Jenny
  6. Forest InsectDisease Leaflet.119: 1–8
  7. Franklin, Michelle
  8. Cory, Jenny (2014). In a study published in Science, “Genetic Similarity of Island Populations of Tent Caterpillars through Successive Outbreaks” was examined. In PLOS ONE, 9(5), 325–330, doi:10.1371/journal.pone.0096679.PMC4032236.PMID24858905
  9. Abcd, abcd Heather Kharouba, Marc Vellend, Rana Sarfraz, and Judith Myers are among those who have contributed to this work (2015). “The Effects of Experimental Warming on the Timing of a Plant-Insect Herbivore Interaction,” a paper published in the journal Ecology and Evolution. doi: 10.1111/1365-2656.12328.PMID25535854
  10. Journal of Animal Ecology, volume 84, number 3, pages 785–796. Russel Mitchell is the author of this work (1990). On Bitterbrush and Currant in Central Oregon, we studied the seasonal history of the Western Tent Caterpillar (Lepidoptera: Lasiocampidae) on the leaves of the plant. In: Journal of Economic Entomology, Vol. 83, No. 4, 1492–1494, doi: 10.1093/jee/83.4.1492
  11. Moore, Lynn
  12. Eng, Rex
  13. Myers, Judith (1988). “Western Tent Caterpillars Prefer the Sunny Side of the Tree, but Why?” asks the author of the article. JSTOR3565313
  14. Abcdef
  15. Oikos.51(3): 321–326.doi: 10.2307/3565313.JSTOR3565313 “Population variations of western tent caterpillars in southern British Columbia,” Judith Myers’s dissertation from 2000. The Journal of Population Ecology 42: 231–241, doi: 10.1007/pl00012002.S2CID14703541. Barnes, Elizabeth
  16. Gosnell, Sarah
  17. Hallagan, Claudia
  18. Otten, Keelia
  19. Slayter, Lainey
  20. Murphy, Shannon
  21. (2016). A study of the Western Tent Caterpillar (Malacosoma californicum) on two common host plants, including a new host plant record, was published in the journal Entomology. 277–282 in Journal of the Lepidopterists’ Society, vol. 70, no. 4, doi: 10.18473/lepi.70i4.a5.S2CID4957934, and abcd Leonardo Frid and Judith Myers are the authors of this article (2002). Malacosoma californicum pluviale and Infection by Nucleopolyhedrovirus.Ecological Entomology.27(6): 665–673.doi:10.1046/j.1365-2311.2002.00460.x
  22. Safraz, Rana
  23. Myers, Judith. “Thermal Ecology of Western Tent CaterpilalrsMalacosoma californicum pluviale and In (2013). “Long-Term Life-History Consequences and Disease Resistance of Western Tent Caterpillars in Response to Localized, Herbivore-Induced Changes in Alder Leaf Quality.” Ecological Entomology.38: 61–67.doi: 10.1111/j.1365-2311.2012.00404.x.S2CID86568249
  24. Michelle Franklin, Carol Ritland, Judith Myers, and Jenny Cory are among the authors of this article (2012). “Multiple Mating and Family Structure of the Western Tent Caterpillar, Malacosoma californicum pluviale: Impact on Disease Resistance.” Malacosoma californicum pluviale is a caterpillar that lives in California. Jenny AbCory and Judith Myers were published in PLOS ONE on May 5, 2012, with the doi:10.1371/journal.pone.0037472.PMC3360058.PMID22655050 (2009). Disease resistance in cyclic populations of western tent caterpillars differs within and between individuals, as demonstrated by a study that tested the “disease defense theory.” Publication: Journal of Animal Ecology, vol. 78(3), pages 646–655, doi:10.1111/j.1365-2656.2008.01519.x, PubMed ID: 1920564
  25. In “Intervening in pest outbreaks: simulation experiments with the western tent caterpillar,” Thompson et al. (1981) cite Vertinsky et al. (1981) as well as Wellington (1981). 23: 27–38.doi: 10.1007/bf02514091.S2CID7798127
  26. Researches on Population Ecology.23: 27–38.doi: 10.1007/bf02514091.S2CID7798127

External links

  • OnM is a page on Bugguide.net. californicum
  • Page onM on the iNaturalist.org website. californicum
  • M.’s YouTube video may be seen here. Larvae of the californicum were discovered near Saint Mary Lake in the East Kootenays of British Columbia.

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