Winter Moth
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Scientific
Name: Operophtera brumata
Common Names: Winter Moth
Known
Hosts:
Many deciduous plants are hosts for the winter moth
including oaks, maples, basswood, white elm, crabapples,
apple, blueberry, and cherry.
| Key
ID Features: |
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Adult moths emerge
in late November and can be active into January
under the right weather conditions. |
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Females are small (8mm), gray,
and wingless. They can be found crawling up tree
trunks, sides of houses and other vertical surfaces.
(Figure 1) |
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Males are small (wingspan
of 20-25 mm) and light brown to tan in color. The
wings of the male have a fringed appearance along
the hind margins. (Figure 2) Large numbers of males
are attracted to lights at night. |
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After mating females lay egg
clusters on tree trunks and branches, under lichens
and bark scales, and in bark crevices. The eggs
are pale green at first but turn reddish orange.
(Figure 3) |
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Larvae are pale green caterpillars
with a white stripe running down each side of the
body. They have two pairs of prolegs (Figure 4) |
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Larvae are loopers or inchworms
that grow to be about 1 inch long at maturity. |
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Larvae will feed until mid-June
when they migrate to the soil to pupate. (Figure
5) |
| Description
of damage: |
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Larvae appear
as early as March. Eggs hatch when temperatures
average around 55F. |
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Young larvae tunnel into buds,
especially the flower buds of fruits, and feed inside
buds. Once the bud has been devoured the larvae
will move to another bud to feed. (Figure 6) |
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Older larvae feed on foliage.
(Figure 7) |
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In areas with large infestations
winter moth larvae can completely defoliate host
plants. |
Similar species:
The winter moth looks very similar to the fall cankerworm (Alsophila pometaria) in both adult (Figure 8) and larval (Figure 9) stages. The related bruce spanworm moth (Operophtera bruceata) looks almost identical to the winter moth at all life stages (Figures 10, 11, 12). Mixed populations of these species occur in Massachusetts. Spring cankerworm (Paleacrita vernata) larvae are present at the same time in the spring as the fall cankerworm and winter moth larvae.
Summary of caterpillar pests prevalent in MA and how to identify and manage them, from UMass Extension
http://extension.umass.edu/landscape/fact-sheet-categories/insects-and-mites
Catepillar identification guide: Discover Life Organization
http://www.discoverlife.org/mp/20q?guide=Caterpillars
Bruce spanworm, Operophtera bruceata / Winter moth, Operophtera brumata
Ministry of Forest and Range, British Columbia, Canada
http://www.for.gov.bc.ca/hfp/publications/00198/winter_moth.htm
Fact sheets and references:
UMass Extension Fact Sheets on Winter Moth
Winter Moth Overview 2011
http://extension.umass.edu/landscape/fact-sheets/winter-moth-overview
Identifying and Managing the Life Stages of Winter Moth
http://extension.umass.edu/landscape/fact-sheets/winter-moth-identification-management
Winter Moth Project-Biological Control in MA: UMass Amherst
http://www.newtontreeconservancy.org/documents/Elkinton%20handout%201%20031510.pdf
http://www.umass.edu/newsoffice/article/umass-amherst-entomologists-begin-control-winter-moth-infestation-eastern-massachusetts
Winter Moth Pest Alert - Cooperative Agricultural Pest Survey, New York
http://www.agriculture.ny.gov/CAPS/pdf/Winter%20Moth%20Pest%20Alert.pdf
last reviewed December 22, 2014 |
