Quick Facts

  • Emergence of the adults corresponds to apple stages
  • Mating and oviposition occur in the evening, when temperatures are around 13°C
  • Two generations per year

Species Facts:

Young caterpillars of the Summer Fruit Tortrix Moth, Adoxophyes orana, hibernate in cocoons under a piece of dead leaf or bud scale. They are yellow green in color and emerge from cocoons between bud burst and green cluster growth stages. The caterpillars burrow in to fruit buds and then blossom trusses, before webbing leaves together on young shoots. Pupae are formed in the webbed leaves.

Light brown adult moths emerge during June and July, the females laying batches of around 100 eggs on leaf surfaces. Each egg batch is yellow green and appears waxy. Further caterpillars develop in July and August, giving rise to a second generation of moths during August and September. Young caterpillars produced from the eggs laid by this generation of adults molt once or twice then hibernate. Fruit damage is caused by large caterpillars feeding through July and August.

The summer caterpillars appear at the end of June and attack the leaves at the tips of the stems, and then the leaves lower down. When the leaves attacked are in contact with fruit, the caterpillar will also graze its upper epidermis (irregular pattern) and occasionally dig roundish holes (3 to 6 mm deep).

The 2nd-generation adults appear in August-September, mate and lay eggs. The autumn caterpillars eat the leaves and gnaw the fruit. They then seek a hiding-place to overwinter in. When the summer is hot, growth may continue and give rise to moths which die without reproducing.

The 2nd generation of larvae overwinters in a loosely woven cocoon in the crook of a forking twig, bud axil, in a leaf or in a crack in the bark. It becomes active again at the end of winter apple-tree, penetrating the buds and, by means of silken thread, attaches the leaf tips and buds together. It eats the small outer leaves and floral parts, sometimes attacking a number of blossom trusses. Some larvae hang down on the end of silken threads, and may then be dispersed by the wind, occasionally over long distances.

Portions of this article courtesy of: Dow AgroSciences
A Summer Fruit Tortrix Moth resting on a leaf (Photo from: www.bugwood.org Credit to: Pest and Disease Image Library Austraia)