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Erebidae and Noctuidae (Many species)

Definite tussock moth caterpillar, Orgyia definita. Photo: Pennsylvania Department of Conservation and Natural Resources - Forestry, Bugwood.
Scientific Name: 
Erebidae and Noctuidae (Many species)
Common Name: 
Tussock Moths
Growing Degree Days (GDD's): 
See individual species entries for more information.
Host Plant(s) Common Name (Scientific Name): 
Alder (Alnus spp.) (Acronicta americana; Halysidota tessellaris; Orgyia antiqua)
American elm (Ulmus americana) (Halysidota tessellaris)
Apple (Malus spp.) (Orgyia antiqua; Orgyia leucostigma)
Ash (Fraxinus spp.) (Acronicta americana; Halysidota tessellaris; Lophocampa caryae)
Aspen (Populus spp.) (Leucoma salicis)
Basswood (Tilia spp.) (Acronicta americana; Orgyia definita)
Beech (Fagus spp.) (Halysidota tessellaris)
Birch (Betula spp.) (Acronicta americana; Halysidota tessellaris; Orgyia definita; Orgyia leucostigma)
Blueberry (Vaccinium spp.) (Halysidota tessellaris; Orgyia definita)
Boxelder (Acer negundo) (Acronicta americana)
Cherry (Prunus spp.) (Orgyia antiqua; Orgyia leucostigma)
Chokecherry (Prunus virginiana) (Halysidota tessellaris)
Elm (Ulmus spp.) (Acronicta americana; Halysidota tessellaris; Lophocampa caryae; Orgyia antiqua; Orgyia definita; Orgyia leucostigma)
Fir (Abies spp.) (Orgyia antiqua; Orgyia leucostigma)
Grape (Vitis spp.) (Halysidota tessellaris)
Hemlock (Tsuga spp.) (Orgyia antiqua; Orgyia leucostigma)
Hickory (Carya spp.) (Acronicta americana; Halysidota tessellaris; Lophocampa caryae; Orgyia leucostigma)
Larch (Larix spp.) (Orgyia antiqua; Orgyia leucostigma)
Maple (Acer spp.) (Acronicta americana; Orgyia antiqua; Orgyia definita)
Oak (Quercus spp.) (Acronicta americana; Halysidota tessellaris; Leucoma salicis; Lophocampa caryae; Orgyia antiqua; Orgyia definita; Orgyia leucostigma)
Pine (Pinus spp.) (Orgyia antiqua)
Poplar (Populus spp.) (Acronicta americana; Leucoma salicis; Orgyia antiqua)
Rose (Rosa spp.) (Orgyia leucostigma)
Spruce (Picea spp.) (Orgyia antiqua; Orgyia leucostigma)
Sycamore (Platanus spp.) (Acronicta americana)
Viburnum (Viburnum spp.) (Orgyia antiqua)
Walnut (Juglans spp) (Acronicta americana; Halysidota tessellaris; Lophocampa caryae)
Willow (Salix spp.) (Acronicta americana; Halysidota tessellaris; Leucoma salicis; Lophocampa caryae; Orgyia antiqua; Orgyia definita; Orgyia leucostigma)
Witch hazel (Hamamelis spp.) (Orgyia definita)
Insect Description: 

Tussock moths are hairy caterpillars from various Lepidopteran families whose taxonomy changes frequently. In general, they are generalist feeders that feed on the foliage of both conifers and deciduous host plants. A few species of common tussock moths are discussed individually in this Guide, but many more are common to eastern North America. In this Guide, the pale tussock moth (Halysidota tessellaris), the satin moth (Leucoma salicis) and the white-marked tussock moth (Orgyia leucostigma) are discussed. The spongy moth (Lymantria dispar) and browntail moth (Euproctis chrysorrhoea) have caterpillars that are also considered tussock moths. Those insects will not be discussed here, but elsewhere in the Guide. Other common eastern species of tussock moth include but are not limited to: the American dagger moth (Acronicta americana), hickory tussock moth (Lophocampa caryae), rusty tussock moth (Orgyia antiqua), and the definite tussock moth (Orgyia definita). Host plant associations for those species are listed above (Wagner, 2005).

The pale tussock moth, also sometimes called the banded tussock moth, is an eastern United States species that feeds on the foliage of deciduous trees and shrubs. The host list provided above is a combination of records from Johnson and Lyon (1991) and Wagner (2005). Adult moths are seen in June and July, with females laying egg masses on the underside of host plant leaves in July. The forewings of the adult moths are pale yellow-tan or cream-colored with a checkered pattern with darker bands; the thorax of the adult also possesses a pale orange stripe with thinner turquoise stripes on either side. Eggs hatch and caterpillars feed on host plant leaves beginning in mid-July. Caterpillars feed on the leaf tissue between leaf veins, and may be seen resting on upper leaf surfaces. Caterpillars are yellow/brown/tan and hairy, and active until the end of September. Caterpillars have noticeably longer black and white hairs (lashes) extending from either end of the body. Other related species of caterpillar in this same genus will have different colored lashes, and may be found on a more limited list of host plants. When fully mature, they may reach lengths of 1.2 to 1.4 inches. Caution: the hairs from the caterpillars as well as pupae may irritate the skin. Avoid handling. Note that children may be more susceptible to the hairs of these caterpillars, and more likely to experience rash symptoms following contact than adults. Luckily, for most, the rash caused by these caterpillars are usually short lived - but can be very itchy. Seek medical attention from a health care provider if necessary. This species overwinters in a hairy, brown/gray, round cocoon that the insect attaches to many different surfaces. (For example, host tree trunks/bark, fences, or in sheltered areas.) Specific details about the biology of this insect are not fully understood. A single generation typically occurs per year in New England, but two generations per year are reported in Missouri (Wagner, 2005).

The satin moth or white satin moth, Leucoma salicis, was introduced from Europe or Asia and first reported between Boston, MA and Hampton, New Hampshire in 1920. It has since spread throughout New England and additional locations in the US and parts of Canada. This insect is said to overwinter in the third instar (caterpillars pass through seven instars), either individually or in small groups. This occurs in a silken, cocoon-like bag attached to host plant trunks and branches. In the springtime, caterpillars leave their areas of hibernation to feed on nearby leaves. Fully grown caterpillars may be up to 2 inches long. Caterpillars spin a thin cocoon between leaves or between exfoliating or thick bark crevices. Pupae are dark brown/black and often in a thin, loose silken sack. Pupae also sport brightly colored, yellow setae (hairs) that make them quite attractive. Pupation begins by the end of June, and takes approximately 10 days to complete. Shortly thereafter, moths emerge and females lay egg masses covered in a frothy, white material from July – mid-August. Up to 400 eggs may be laid per mass. Eggs hatch sometime in August, and larvae will conduct feeding in August and September.

Satin moth caterpillars have a unique color pattern, which helps us distinguish them from others. The dorsal (back) side of the caterpillar is marked with 10-11 white, intersegmental spots as well as paired, red “setal warts”. The sides of the caterpillars are blueish gray. These caterpillars are known to the edges of waterways, woodlands, and forests from Canada to northwestern Connecticut and central New York. One generation occurs per year with mature caterpillars known in May and June. Host plants include aspen, poplar, and willow, the leaves of which are fed upon by the caterpillars of this species. While satin moth caterpillars are not noted to be of particular concern with regard to causing allergic reactions such as dermatitis, they are a type of tussock moth and do possess hairs, so they should not be handled and should be approached with caution particularly by sensitive individuals.

Finally, the white-marked tussock moth is native to eastern North America and parts of Canada. This species of tussock moth overwinters in the egg stage. Eggs are laid by females in groups of approximately 300 in a white frothy mass on the cocoon from which the female moth emerges. When temperatures warm in the spring and as host plant leaves are emerging, the eggs of the white-marked tussock moth hatch by approximately April until June. This depends upon location and temperatures. Young, newly hatched larvae will balloon to their host plants and skeletonize the leaves as they feed. As the caterpillars age and grow in size, they are capable of eating the entire leaf with the exception of the major veins and petiole. Fully grown caterpillars are approximately 1.22 inches long. These caterpillars are conspicuously colored - they have red/orange head capsules and a mostly yellow body with tufts of white to yellow hair. The tufts are found on abdominal segments 1 through 4 (four tufts total) and the caterpillars have a black stripe in the middle of their back that has a yellow stripe on either side. Caterpillars also have two bright red glands near the back-end. Once mature, the caterpillars pupate in a gray colored cocoon that they form, creating it with hairs from their bodies. Cocoons can be found on host plant twigs, branches, or the bark of the trunk. There may be 1-3 generations of the white-marked tussock moth per growing season, depending upon location and seasonal temperatures. Adult male moths are 1.0-1.2 inches in wingspan and gray/brown in color. Adult female moths are wingless, a drab white color, hairy, and only 1/2 inch in length. Caterpillars of this species may be common in the late summer when other species of caterpillar's activity has ended. 

Avoid touching white-marked tussock moth caterpillars or their cocoons: they may cause allergic reactions, especially if their hairs come into contact with sensitive skin (ex. back, stomach, underside of arms) (Wagner, 2005). Contact dermatitis (itching) as a result of interacting with these insects has been reported from schools and daycares. Teach children how to identify and avoid handling cocoons and caterpillars. These caterpillars have urticating (irritating) hairs. Welts may appear on the skin within minutes, but subside the next day; however itching can last for several days depending upon the sensitivity of the individual. 

Damage to Host: 

Host plants and the damage caused depend upon the species of tussock moth involved. See the above host plant list for potential tussock moth species herbivores. 

The pale tussock moth is a species of native tussock moth which has caterpillars that are generalist feeders on many deciduous trees and shrubs. Caterpillars feed on host plant leaves between the veins. This species may be more common in northern New England. Usually, populations do not reach outbreak levels where significant defoliation occurs. These caterpillars may be more important as a curiosity, or because of the potential for the hairs of the caterpillars or their cocoons to cause an itchy rash. (As stated above, avoid handling those life stages.)

Current season satin moth caterpillars skeletonize leaves until early fall or first frost, then move to their winter hibernation location. Foliage of white poplar, willow, and other Salicaceous plants may be fed upon, including shade trees and ornamentals. Occasionally found on aspen and oak. Feeding in the spring occurs on newly developed host plant leaves. Historically, outbreaks of this insect have occurred, although they are not frequently experienced in Massachusetts in recent years. If an outbreak occurs, severe defoliation can weaken trees and mortality is possible, however trees are often able to survive. 

The white-marked tussock moth can appear frequently throughout the Northeast. It may cause problems for several years when population outbreaks occur, and then almost vanish from that area, only to return years later. White-marked tussock moths may be occasional pests of Christmas tree farms. Usually, however, large trees can tolerate feeding by these insects and chemical management options are unnecessary. They may be an issue for smaller ornamental trees and shrubs.


Adult pale tussock moths may be attracted to artificial light traps at night. Visually monitor for the presence of caterpillars. Avoid handling with bare skin if found.

The sex pheromone 3Z-cis-6,7-cis-9,10-diepoxyheneicosene (Gries et al., 1997) called leucomalure (Muto and Mori, 2003) is available to capture male satin moths in baited traps. Black light or mercury vapor light traps are also attractive to the moths, that are most active at night. Visual monitoring of susceptible host plants experiencing defoliation is also helpful in scouting for caterpillar activity. Often, annual populations of this insect exist below severely damaging levels and may be observed at the same location annually. For example, in Beartown State Forest (Monterey, MA) a population of white satin moths has been observed on Populus spp. in 2020, 2021, and 2022.

Sex pheromones produced by the adult female white-marked tussock moth (who is wingless) to attract the winged males have been identified by researchers. The pheromone is:  (Z,Z)-6,9-heneicosadien-11-one (Z6Z9-11-one-21Hy) (Grant et al., 2006). However, to make it stable for field and trapping use, researchers have experimented with a pheromone "precursor", which they have identified as: (Z,Z)-6,9-heneicosadien-11-one ethylene ketal. Field tests in 2004 and 2005 showed that sticky traps fitted with an autonomous pump delivering the ketal (0.1-1 microg/microL in heptane) at 10 microL/hr to a cotton pad soaked with the hydrolyzing solution were attractive to male white-marked tussock moths (Grant et al., 2006). Visual monitoring for these insects can include searching susceptible host plants for cocoons (be careful not to touch them as they contain the hairs of the caterpillars), overwintered frothy egg masses on the cocoons, and the caterpillars themselves any time between approximately April (young larvae) through the late summer.

Cultural Management: 

Pale tussock moth caterpillars typically do not cause significant damage to overall host plant health. Therefore, management of these insects is likely not necessary. If you choose to manually remove caterpillars or pupae, do so with gloved hands to avoid contact with the hairs, which may cause an annoying, itchy rash.

As with spongy moth, sticky bands have been suggested as a possible means of managing the satin moth on individual trees. It is uncertain how effective this will be on an individual host plant at preventing defoliation. It is suggested that they be placed in the tree in the spring, to capture any wandering caterpillars that overwintered. Egg masses may also be manually scraped off tree trunks whenever found.

If overwintering egg masses on spent white-marked tussock moth cocoons are found, they can be removed and destroyed. Avoid direct handling or touching the cocoons; wear gloves and appropriate clothing. Wash any clothing that comes into contact with the cocoons separately. Cocoons contain the irritating hairs of the caterpillars and can cause allergic reactions.

Natural Enemies & Biological Control: 

Birds are not great predators of pale tussock moths, as they avoid feeding on their distasteful hairs. Some caterpillars may be seen missing their longer hairs or lashes or other hairs following attention from a bird still learning to avoid them. Adult moths are also reported to be distasteful to birds and bats (ex. Eptesicus fuscus) that would otherwise try to eat them due to chemical defenses of the moths. Additional insect parasitoids of the pale tussock moth may exist, but are likely poorly studied. At least 9 different Braconidae (parasitoid wasps) are noted for Halysidota tessellaris (Barbosa and Caldas, 2003).

Many of the native and introduced parasites of the spongy moth (Lymantria dispar) will also kill satin moths (white satin moths). These include the parasitic fly, Compsilura concinnata, and a species of wasp, Eupteromalus peregrinus (Johnson and Lyon, 1991). Pathogens have been reported as able to kill the satin moth, including but not limited to: a multicapsid nucleopolyhedrovirus, and two fungi: Paecilomyces spp. and Hirsutella gigantean. At Beartown State Forest in Monterey, MA, adult moths were observed predated upon by birds. The birds fed upon the moths, leaving behind only their wings as evidence of their feeding.

Birds may be significant predators of the older white-marked tussock moth caterpillars. Mortality of younger-instar caterpillars may be due to the inability to find a suitable host plant when initially ballooning to disperse. Predation of young larvae can also occur by invertebrate predators. Larger ground beetles and Polistes spp. wasps have also been reported to predate upon these caterpillars. Caterpillars in the Orgyia genus are known to be infected by nuclear polyhedrosis viruses and cytoplasmic polyhedrosis viruses. If killed by these pathogens, they hang from the substrate limp, attached by their prolegs (in a shape similar to the spongy moth, Lymantria dispar, caterpillar when it is killed by an NPV virus). An abundance of tachnid fly parasitoids (Arnaud,1978) as well as braconid, ichneumonid, eulophid, pteromalid, and scelionid wasp parasitoids (Krombein et al.,1979) have also been reported for the white-marked tussock moth. Typically, the natural enemies of the white-marked tussock moth keep their populations at manageable levels.

Chemical Management: 

Abamectin (NL)

Acephate (larvae) (NL)

Azadirachtin (NL)

Bifenthrin (NL)

Carbaryl (L)

Chlorantraniliprole (NL)

Chlorpyrifos (larvae) (N)

Chromobacterium subtsugae (NL)

Cyfluthrin (larvae) (NL)

Emamectin benzoate (L)

Gamma-cyhalothrin (larvae) (L)

Indoxacarb (L)

Isaria (paecilomyces) fumosoroseus (larvae) (NL)

Lambda-cyhalothrin (larvae) (L)

Neem oil (NL)

Spinetoram+sulfoxaflor (N)

Spinosad (larvae) (NL)

Tebufenozide (NL)


Active ingredients that may be applied systemically include: abamectin (injection), acephate (injection), azadirachtin (injection, soil drench), chlorantraniliprole (soil drench), emamectin benzoate (injection), and neem oil (soil drench).

Make insecticide applications after bloom to protect pollinators. Applications at times of the day and temperatures when pollinators are less likely to be active can also reduce the risk of impacting their populations.

Note: Beginning July 1, 2022 neonicotinoid insecticides are classified as state restricted use for use on tree and shrub insect pests in Massachusetts. For more information, visit the MA Department of Agricultural Resources Pesticide Program.

Read and follow all label instructions for safety and proper use. If this guide contradicts language on the label, follow the most up-to-date instructions on the product label. Always confirm that the site you wish to treat and the pest you wish to manage are on the label before using any pesticide. Read the full disclaimer. Active ingredients labeled "L" indicate some products containing the active ingredient are labeled for landscape uses on trees or shrubs. Active ingredients labeled "N" indicate some products containing the active ingredient are labeled for use in nurseries. Always confirm allowable uses on product labels. This active ingredient list is based on what was registered for use in Massachusetts at the time of publication. This information changes rapidly and may not be up to date. If you are viewing this information from another state, check with your local Extension Service and State Pesticide Program for local uses and regulations. Active ingredient lists were last updated: January 2024. To check current product registrations in Massachusetts, please visit: .