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Corn
Earworm
(Helicoverpa zea) - Life Cycle
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Adults:
The adult is a yellowish-brown moth with a wingspan of 1 1/2 inches
(37 mm). The moth belongs to the same group as the common armyworm
moth, which it resembles. The moths vary in color; in general the
front wings are a light tannish brown, marked with dark gray irregular
lines and a dark area near the tip of the wing. The irregular lines
often shade into an olive green. The hind wings are whitish with some
irregular dark markings. The eyes are a light green color. |
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Eggs:
Eggs are laid at night, deposited individually on the underside of
leaves by the first generation or in the cornsilks by the second generation.
They are white, hemispherical in shape and about one-half the diameter
of a pin head. Depending on temperature, eggs hatch in 2-10 days. |
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Larvae:
The larvae has a tan head and is 1 1/2 inches (37 mm) long when fully
grown. Prominent alternating light and dark stripes run lengthwise
of the body. The larvae vary greatly in color from a light green or
pink to brown or nearly black and are lighter on the underparts. The
skin of the insect is somewhat coarse and has many small thorn-like
projections. The corn earworm larva should not be confused with the
European corn borer larva which seldom exceeds 1 inch (25 mm) in length
and is a dirty white color with dark brown or black head. |
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Pupae:
When the larvae are full grown they leave the corn ears and drop or
crawl to the ground where they burrow. The larva excavates a small,
smooth-walled cell, usually 3-5 inches in the soil, then transforms
into the resting or pupal stage. The moth will emerge 10-25 days later
depending on temperature. The development from egg to adult usually
takes about 30 days in midsummer. |
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Damage inflicted by corn earworm on corn
or on beans
Some information on this page
taken from Insects of Corn: Cornell Cooperative Extension factsheet
number 139VCFS791.00 authored by A. A. Muka.
©All material is protected
by Section 107 of the 1976 copyright law.
Copyright is held by Cornell University.
Maintained by Jason D. Plate. Last updated Mar. 8th, 2007.
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