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Bell-shaped appearance of adult oak leaftier
USDA Forest
Service
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Oak leafroller damaged red oak leaves
USDA Forest Service
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The oak leaftier, Croesia semipurpurana (Kearfott), and the
oak leafroller, Archips semiferanus (Walker), are important
Tortricidae moths in a complex of native species feeding in the early
spring on oak foliage throughout the forests of Eastern North America.
Outbreaks periodically develop with frequent and severe defoliation
resulting in tree mortality. The last outbreak during the 1960's and
1970's covered large areas of Connecticut, Massachusetts, New York,
Pennsylvania, Virginia, and West Virginia.
Either moth species may dominate during an outbreak
depending upon which oak species are present. Oak leaftier caterpillars
(larvae) tend to favor red, scarlet, black, and pin oaks; whereas, oak
leafroller caterpillars feed not only on red and scarlet oaks, but also on
chestnut and white oaks commonly found along ridgetops.
Resting adults of both species hold their wings in a
characteristic bell shape. The adult wingspan of the oak leaftier is
smaller (0.5 inch) than the oak leafroller (0.9 inch). Adults of both
species are distinctly marked. The oak leaftier is yellow with a large,
violet to brown front wing; the oak leafroller is creamy brown and gray
with a darker oblique band across its front wing.
Despite their small size, larvae of both species, if
abundant, can severely defoliate an oak tree. Newly hatched oak leaftier
larvae enter opening buds and eat immature leaves. This feeding habit can
destroy most new growth. Surviving leaves are deformed and riddled with
holes. Oak leafroller larvae feed from leaves webbed together or rolled at
the edges into shelters.
Larvae of both species exhibit various colors and markings
as they mature. Immature larvae are several shades of green with a dark
head capsule and thoracic shield and cannot easily be identified to
species until they are mature. Mature oak leaftier larvae (left-facing)
are 0.5 inch long with both a dark eye patch and a bar on the side of the
head, and dark legs. Mature oak leafroller larvae (right-facing) are 1.2
inch long with either a dark eye patch or a dark bar on the head, and pale
legs.
Information provided by the USDA
Forest Service
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