State Size Features
Larva 20 mm Brown head and salmon body.
Adult 20 mm (wingspan) A distinguishing feature is that it has a darker spot surrounded by a bright area towards the end of the wings.
They winter in the form of a larva, inside a silk cocoon on the ground or in the crevices of the bark of the trees. At the beginning of spring, or a little earlier, they reactivate their activity, feed on leaves and then introduce themselves into the fruits, if there are any, to feed themselves. After completing its larval development, which lasts about 30 days, they leave the fruit to pupate inside a silk cocoon. At the end of spring, the first adults appear in a very gradual manner. After reproducing, the female of carpocapsa makes the laying on leaves and fruits. The new generation of newborn larvae are directed to the fruit to feed on the bark and, later, to penetrate the fruit, this time more grown, from which they feed until they complete their larval development. Finally, they come out of the fruit and pupan on the wood of the tree. Depending on the temperature, another generation can be produced. The biological cycle is completed when the caterpillars direct their shelters to spend the winter.
Symptoms / Damage
Galerias inside fruits many times with direction to the seeds.
There are traces of dark red excrement in these galleries.
The fruits affected by the caterpillar of carpocapsa lose all their value, either because the bark is gnawed or because there are galleries in the interior.
The greater sensitivity to pesticides is presented by the egg phase and the first larval stages, when the caterpillars have just emerged from the egg. The critical moment for the crop is from fruit setting.
The first possible treatment is about eggs and it is applied when the adults start the flight. Spray with: diflubenzuron, flufenoxuron, tebufenocide, or other IGR. These insecticides are growth regulators, biorational substances and quite respectful with the environment. Thiacloprid may also be used. None of these products is convenient to use more than twice a year.
When they begin to increase the catches of adults a treatment is applied in order to destroy the caterpillars in their first phases, repeating the application to the two weeks.
Use pyrethroids (cypermethrin, alpha-cypermethrin, cyfluthrin, deltamethrin, acrinatrin, etofenprox, etc.) or a phosphorous (chlorpyrifos, methyl chlorpyrifos or fosmet).
All the active materials described are authorized in pome fruit trees (with the exception of the quince tree, where some of the described products can not be used).
In walnut the authorized active substances are: deltamethrin, tebufenocide or fosmet.
Try to alternate active subjects with different mode of action to avoid resistance. IGR-pyrethroid, pyrethroid-phosphorous, etc.
If you opt for natural substances use any of the following products:
Bacillus thuringiensis var. kurstaki. The treatment is more effective the younger the larva is.
Virus of the granulosis of the carpocapsa. It is pulverized when observing the first generation of carpocapsa.
These treatments are less effective than the previous ones described and should be repeated more frequently; once a week or every two weeks.
It is convenient to respect natural enemies, which has enough. Hymenoptera parasites, egg predators (Trichogramma spp.), Birds (such as blue tits and chickadees), bugs, earwigs, etc.
Therefore treat chemically when absolutely necessary and at the right time to obtain the best results.
- Cultural measures
It is essential to track adults through trapping with the specific pheromone in order to obtain the flight curve and determine the most appropriate time for chemical treatments.
A threshold of treatment could be the following: place 4 traps / Ha and treat if there are more than 3 adults / trap and week.
Reduce the number of next generation individuals by eliminating attacked fruits fallen to the ground and thus prevent the caterpillar from leaving the fruit and pupe.