Insecta, Lepidoptera, Tortricidae .
Description, Biology, Life Cycle, Damage, Common Names, Images
- Host plants: apricot, quince,walnut, pear, apple and sometimes peach and plum.
- Adult: medium longevity, 15 to 18 days. Active during the day at temperatures of >15°C.
- Fecundity: 30 to 50 eggs, on average.
- Eggs: time until hatching, 18 days at 15°C, and 6 at 25°C.
- Larva: developmental duration, 20 to 30 days.
- Pupa: developmental duration, 20 to 28 days.
- 1 or 2 generations per year in France, sometimes 3 in the south of France.
- The eggs hatch at the end of May.
- The caterpillar first undergoes a so-called "wandering stage" (2 to 5 days) (*) . After a couple of exploratory bites, it penetrates a fruit where a second fruit or a leaf is touching, or at the stalk or stalk-eye (*) . When development is completed, it leaves the fruit and weaves a cocoon in a sheltered spot. From then onwards, two developmental routes are possible: it will either pupate and give rise to a 2nd-generation of moth, or enter diapause. The caterpillars that become fully fed from August to October all enter diapause. They overwinter in cocoons hidden in cracks in the tree-trunk or in a natural shelter on the soil.
- Pupation in April.
- The adults emerge at the end of April, beginning of May. They mate and lay the eggs on leaves, twigs, or young fruits.
On pomaceous fruit, around the entrance hole made by the young larva, a gnawed area, followed by a spiral gallery leading down to the pips which the caterpillar also eats (*) . On walnuts, the caterpillar burrows through the husk to the kernel; when the latter hardens, it leaves by the hilum or remains in the husk. The bite marks on the damaged fruit makes them impossible to sell. Damaged fruit drops prematurely.
Late or seasonal varieties of pear are not very susceptible to the 1st generation because their epidermis is hard.
* Biological control trials: enemies: hymenopterous egg parasites (Trichogramma) or caterpillars (Ascogaster, various Ichneumonidae, and a Tachinidae fly).
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