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Catastega (Formerly Epinotia) aceriella

Maple trumpet skeletonizer larva and damage. Photo: John Ghent, Bugwood.
Scientific Name: 
Catastega (Formerly Epinotia) aceriella
Common Name: 
Maple Trumpet Skeletonizer
Growing Degree Days (GDD's): 
1388–2032, Base 50F, March 1st Start Date (Source: Robert Childs, UMass Extension and Cornell Cooperative Extension.)
Host Plant(s) Common Name (Scientific Name): 
Sugar maple (Acer saccharum) *Preferred host.
Beech (Fagus spp.)
Black oak (Quercus velutina)
Chestnut oak (Quercus montana)
Hawthorn (Crataegus spp.)
Red maple (Acer rubrum) *Preferred host.
Red oak (Quercus rubra)
White oak (Quercus alba)
Insect Description: 

The maple trumpet skeletonizer is a moth as an adult, and found throughout much of New England and parts of Canada. Adult moths are gray, 15 mm in length, and are present as early as April in the spring, and attracted to lights at night. Adult females will lay their eggs randomly on the undersides of host plant leaves in late June through mid July. Eggs hatch, and the larvae feed on the tissue between the larger leaf veins on the underside of the leaf, leaving a very thin layer of the upper leaf epidermis behind. Caterpillars are active from early-July to early-October. The caterpillar then spins silken webs on the underside of the leaf, folds it, and inside the fold creates a trumpet-shaped tube of silk and frass. Tubes may be approximately 5 cm in length. Caterpillars feed using the tube for protection and skeletonize the leaf beneath the webbing. Maple trumpet skeletonizer caterpillars are pale yellow-green with yellowish heads. At maturity, they can be up to 13 mm long. Once mature, the caterpillars drop to the ground and create a cocoon between two fallen leaves. 

Damage to Host: 

The undersides of sugar maple leaves are impacted by this insect, however it can feed on other hosts especially when maple is scarce. (May be confused for a similar species found on oak.) Larvae skeletonize and fold leaves and create webbing. The maple trumpet skeletonizer rarely requires management, however, even when populations are heavy because it causes this damage late in the growing season. Minor damage from this insect is common every year, however occasionally outbreaks will occur. Activity from this insect is rarely damaging to plant health.


Look for adult moths attracted to lights at night in April in the spring. Flip leaves over to look for caterpillars and the damage they cause from early-July to early-October. In particular, flip over any skeletonized leaves with only a thin layer of epidermis remaining on a section of the upper side of the leaf. Folded leaves can be pulled apart to look for the trumpet-shaped tubes of silk and frass found within.

Cultural Management: 

Infestations of maple trumpet skeletonizers can be reduced by raking and destroying or removing dropped leaves nearby impacted host trees in the fall. 

Natural Enemies & Biological Control: 

Populations of this native insect are often kept below damaging levels due to reported parasitoid activity, thus requiring no chemical management. The identity of the parasitoids or further information about other natural enemies such as predators or pathogens is currently unavailable. 

Chemical Management: 

Abamectin (NL)

Acephate (larvae) (NL)

Bifenthrin (NL)

Chlorantraniliprole (larvae) (NL)

Cyantraniliprole (larvae) (NL)

Cyfluthrin (larvae) (NL)

Flonicamid+cyclaniliprole (L)

Gamma-cyhalothrin (L)

Horticultural oil (L)

Indoxacarb (larvae) (L)

Lambda-cyhalothrin (larvae) (L)

Malathion (larvae) (L)

Neem oil (larvae) (NL)

Pyrethrin+sulfur (larvae) (NL)

Spinetoram+sulfoxaflor (larvae) (NL)

Spinosad (larvae) (NL)

Tebufenozide (larvae) (NL)


Chemical management of this insect is typically not necessary, and a best practice would be to tolerate its presence in ornamental landscapes. Active ingredients listed above are found in products labeled for use against “caterpillars” and “Lepidopterous insects”.

Active ingredients that may be applied systemically include: abamectin (injection), acephate (injection), chlorantraniliprole (soil drench), cyantraniliprole (soil drench, soil 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: .