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Halysidota tessellaris

Pale tussock moth caterpillar. Photo: Bruce Watt, University of Maine, Bugwood.
Scientific Name: 
Halysidota tessellaris
Common Name: 
Pale Tussock Moth (Banded Tussock Moth)
Growing Degree Days (GDD's): 
192–298, Base 50F, March 1st Start Date (Source: Robert Childs, UMass Extension.)
Host Plant(s) Common Name (Scientific Name): 
Alder (Alnus spp.)
American elm (Ulmus americana)
Apple (Malus spp.)
Ash (Fraxinus spp.)
Beech (Fagus spp.)
Birch (Betula spp.)
Blueberry (Vaccinium spp.)
Boxelder (Acer spp.)
Chestnut (Castanea spp.)
Chokecherry (Prunus virginiana)
Grape (Vitis spp.)
Hackberry (Celtis spp.)
Hazel (Corylus spp.)
Hickory (Carya spp.)
Oak (Quercus spp.)
Siberian elm (Ulmus pumila)
Sycamore (Platanus spp.)
Walnut (Juglans spp.)
Willow (Salix spp.)
Insect Description: 

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). Other species of tussock moths discussed in this guide include the white-marked tussock moth (Orgyia leucostigma).

Damage to Host: 

This species of native tussock moth 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.)

Monitoring: 

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

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.

Natural Enemies & Biological Control: 

Birds are not great predators of these 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).

Chemical Management: 

Acephate (larvae) (NL)

Azadirachtin (NL)

Bifenthrin (NL)

Carbaryl (L)

Chlorantraniliprole (NL)

Chlorpyrifos (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)

Notes: 

Chemical management of this species is typically unnecessary. 

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

When used in nursery settings, chlorpyrifos is for quarantine use only.

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: https://www.mass.gov/pesticide-product-registration .