The summer fruit tortrix (Adoxophyes orana) is a serious pest of apple, pear, apricot, cherry, peach, plum and other fruit trees.
Life cycle and appearance of Summer fruit tortrix
The summer fruit tortrix (Adoxophyes orana) has two generations per year, under favourable conditions, a third generation may appear. Adults are present in late May and June for the first generation, in July through September for the second generation, and in October for the third. Flight times vary with latitude and climatic conditions.
Females lay eggs in masses of up to 150 individual eggs primarily on leaves. First instar larvae hatch in 8-20 days and feed beneath a silk web on the underside of a leaf. Later instars feed inside rolled leaves or web leaves to fruit and feed on the fruit surface. The larvae complete five instars and pupation occurs in the final larval nest. Second or third instar larvae of the last generation hibernate until spring and complete development by feeding on buds and young leaves.
The adult females have a wingspan of 18-22 mm. The forewings are greyish brown to orange brown with dark markings and often reticulate; the hindwings are grey. Adult males are slightly smaller and have more distinctly marked forewings. The eggs are lemon yellow. Larvae are up to 20 mm long, yellowish green, olive green or dark green with an ochre-coloured head and the pupae are 10-11 mm long an dark brown.
Larvae feeding on mature fruits, especially on apple and pear, remove the skin and graze shallowly into the fruit flesh to form large irregular patches. These feeding areas become an even russet colour and the fruits may become unmarketable. Damage to the surface of developing plums may result in considerable weeping and the blemished fruits are also unmarketable.
Damage to leaves is usually not important but loss of buds in spring can be significant.