The carpocapsa is a parasitic insect, called cydia pomonella; its parasitic action occurs mainly on apple and pear trees, but these insects can occasionally attack even cherry, medlar or other fruit plants. They are tiny butterflies, belonging to the group of tortricides, which lay their eggs at least two or three times a year, on the leaves of the trees, or directly on the ripening fruits. Once out of the egg, the larvae dig a tunnel up to the center of the fruit, where they feed on the pulp; generally they spend their life near the seeds, which are also devoured or ruined. Fruits affected by the larvae of this insect often fall before ripening, or rot quickly when harvested. However, they would be inedible, given the presence of the tiny worm inside them.
These insects perform around three breeding cycles during a fruit ripening season. The mature larvae spend the cold months inside a thick cocoon, inside which they can also bear the frost; the cocoons are produced sheltered, under the scales of the bark, among the dry leaves, in ravines of all kinds. As soon as the climate becomes mild, the larvae pupate and adults emerge from them, towards April or May. Mature females lay their eggs individually, on the leaves located near the flowers or fruit trees. The first generation larvae from the leaves pass to the fruits, and consume them from the inside, more or less towards the end of May. In July these larvae will be ready to produce the second generation of larvae, whose eggs will be laid directly on the peel of apples and pears. If the climate is particularly hot, the second generation larvae, after ruining the fruits, enter a sort of rest period, finding a place to winter; if the climate is favorable, the second generation larvae will give rise to a third generation, which will carry out its action in September.