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INSECT AND MITE PESTS
The Fruit-Tree leafroller (FTLR) is a native pest occurring in the northern half of the United States. The adult is a brown moth slightly larger than the codling moth. Slender light markings will appear in various patterns across the front wings. The larva is a slender worm, pale green in color. The head is black and a black spot will appear just behind the head. The larva may reach 3/4 in. in length.
The insect overwinters in the egg stage. Hatching will occur about the time buds begin to open. Larvae feed on buds, blooms, leaves and fruits. In June full grown larva transform into pupae, inside folded or rolled up leaves. Moths appear in about two weeks, lay their eggs, and die. Only one generation occurs each year.
The Oblique-banded leafroller (OBLR) is somewhat less important than the Fruit-tree leafroller. Adults are brown with three dark bands on the front wings. Wingspread is about one inch. Larva are small and green with black heads.
Overwintering occurs as partially grown larva inside tightly woven cases, on the host trees. During spring, larvae emerge and continue feeding until late May. Pupation occurs and adults will emerge in June. One or two generations may occur. Damage is done by young larva mining the leaves, with larger larva feeding inside rolled up leaves.
Red-banded leafroller (RBLR) is generally a problem north of the Ohio and east of the Mississippi Rivers. However, they are at times a problem in Kentucky. Adults are brown, about the size of the codling moth, and have broad reddish bands on each forewing. Larva are green, slender and will reach a length of about 2/3 in.
Winter is passed in the pupal stage. This pupa will generally be found in a silken cocoon, in detritus at the base of host trees. Moths emerge in the early spring, and lay their eggs in clusters on the bark of host trees. The first generation larva will emerge and begin feeding at about petal-fall. Up to four generations may occur each season.
SCOUT: Leafroller populations will be sampled by both tree examination and pheromone trap. Therefore, you may have two entries for each species on the scout form, one for the number of live larvae found and a second for the number of adults captured in pheromone traps. Mark your entry on the scout form for trap catch with a "PT". Pheromone trap catches will indicate when to monitor carefully for the larvae.
RECORD: The number of larvae/100 leaves or fruit clusters. Record the number of moths in each trap (mark this entry with "PT").
ACTION THRESHOLD: An average of 4 larvae per 100 leaves or fruit clusters. See Appendix 4 by species for information on pheromone trapping.
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