The oriental fruit moth is an important pest of peach varieties which mature fruit in late June or July. Some damage to plum tree twigs may occur, but the fruit is not attacked.
In the spring, injury is largely confined to the growing tips of twigs, into which the larvae burrow. As a result, the terminals die and heavily infested trees appear bushy and stunted. Larvae of succeeding generations attack peach fruits, frequently entering through the stem so no external evidence of injury is apparent. They also may enter where two peaches are in contact or they enter the sides of individual fruits. Infested peaches break down rapidly in shipping and are unfit for consumption because of extensive internal damage.
Adults of the oriental fruit moth are gray with dark-brown bands on their wings. The mature larvae are about 1/2 inch long. They become active when disturbed, crawling rapidly over the fruit surface. They may be distinguished from curculio grubs by their pinkish color and the presence of distinct legs. Also, plum curculio feeding in the fruit leaves little frass and debris, while the oriental fruit moth is an extremely messy housekeeper.
The winter is passed in the larval stage in a cocoon under the bark, in dried fruit or in ground debris. Following pupation in the spring, the adults emerge and deposit flat, whitish eggs on leaves and twigs shortly after peaches bloom. The larvae feed in the succulent new growth of the twigs. In the summer, when tender growth is no longer available, the larvae of later generations attack the fruit, feeding around the seed. If succulent growth and fruit are absent later in the summer, a “suicide” generation probably occurs, since the larvae cannot find food satisfactory for their development. Consequently, only a few survive and damaging infestations rarely occur the following year.
Injury may be severe in orchards where apples, pears or late-maturing peaches are grown, since egg-laying of later broods is concentrated on these fruits. In years of abundant summer rainfall, succulent twigs of fruit trees and ornamental shrubs such as photinia may be attacked in the fall
Suggested Control of Oriental Fruit Moth in Peaches
Since larvae feed in protected situations, time sprays to control the moths when they are depositing eggs and the young larvae immediately after hatching.
An application of an insecticide at shucksplit followed by another 2 weeks later, prevents extensive injury. If the infestation is unusually severe, another application 3 to 4 weeks before harvest may be required.
Pheromone traps baited with oriental fruit moth lures are available and are an excellent tool to determine when moths are present in the orchard.
Commercial producers may refer to TAEX publication B-1689 Insect and Disease Control of Peaches, Apricots, Nectarines and Plums, for insecticide, rates and remarks. Homeowners please refer to TAEX publication B-5041 Homeowner’s Fruit and Nut Spray Guide.