The codling moth is a parasitic insect, called cydia pomonella; its parasitic action is expressed above all 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 tortricidi, 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 themselves a tunnel up to the center of the fruit, where they remain to feed on the pulp; generally they spend their lives near the seeds, which are also devoured or ruined. The fruits affected by the larvae of this insect often fall before maturing, or rot rapidly when collected. They would still be inedible, given the presence of the tiny little worm inside them.
These insects perform about three reproduction cycles during a season of fruit ripening. The mature larvae spend the cold months inside a dense cocoon, in which they can also bear frost; the cocoons are produced under shelter, under the scales of the bark, among the dry leaves, in all kinds of crevices. As soon as the climate becomes mild, the larvae pupate and from them the adults come out, around April or May. The mature females lay the eggs individually, on the leaves located near the flowers or the small fruits. 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 having ruined 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.
These insects cause serious damage to the orchard, as the affected fruits fall or rot; a single female can produce up to 60-80 eggs, so it is easy to understand how a large population of butterflies of this species can destroy an entire crop of apples or pears. The fight takes place as soon as you notice the presence of adults, in early spring. To keep the presence of carpocapse controlled, pheromone traps are used: if adults are collected, the necessary treatments are used to eradicate the larvae. We use products that kill eggs, immediately after flowering, and after a couple of months. For total safety, treatments are also practiced that kill the larvae, to be practiced more often, since the plants have finished their flowering, until the end of summer. Important it is to practice also the late treatments, to avoid that the surviving larvae svernino, waiting for the following year.
The products for the fight
Fundamental for the fight against the codling are the pheromone traps: as soon as at least two adults are found in the traps a week, it is necessary to carry out a treatment against the carpocapsa eggs. In the family orchard, in general, there is a tendency to avoid the use of chemical products, in this case it is quite useful, to contain the population of butterflies, to apply bands to the trunks of the trees: in autumn the larvae will find a valid shelter on these bands in cardboard, and towards the end of autumn they can simply be removed and destroyed. In recent years the method of sexual confusion has also produced some results: the release into the environment of large quantities of sexual pheromone causes the difficulty for males to find fertile females, with the consequent impossibility to practice mating. For the chemical fight are also available products suitable for organic farming, because they are harmless to other insects. Against the codling a fungus is also used, in autumn, which kills the hidden larvae waiting for spring.