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INSECT AND MITE PESTS
Adult GFW are dark grey to brown moths resembling cutworm moths. Eggs are white to cream colored and oval. They appear slightly flattened when viewed from the side. GFW larvae are green with the shade varying from very light to dark green. The body is normally covered with yellow "speckles". Worms will also have a white to yellow stripe down the middle of the back and one on each side.
Depending upon the species, GFW may overwinter as eggs, or pupa. But, most all worms appear at about the same time in the spring, feeding first on young foliage much like leafrollers. Later developing worms feed on small fruit.
Pupation occurs about late May to June. Adults fly all summer but egg laying will not normally occur until late summer. The most common species have only one generation per year.
GFW will feed upon leaves but the most important damage is feeding upon young fruit. Feeding may be only a few bites or they may eat the whole fruit. Because feeding occurs so early in the season, damaged fruit will be severely misshapen when expansion is complete. The damaged area will often be covered with a heavy russet.
SCOUT: Jar five scaffold limbs with a padded stick. Catch and examine the insects on a beat cloth. Examine 100 fruit clusters for green fruitworm larvae.
RECORD: The number of green fruitworms per 100 fruit clusters. When sampling with a beat cloth, mark that entry on the scout form with a "BC".
ACTION THRESHOLD: Ten green fruitworm larvae per 100 fruit clusters.
Apple IPM web site created by Kerry Kirk - 2001 - Send questions or comments to Patty Lucas