Erebidae and Noctuidae (Many species)

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.