Disparate Xylébore

The disparate xylébore is a xylophagous Insecte about the Coléoptères, which drills galleries in the Bois of the branches or the trunk several species of fruit trees and forest gasolines.

Scientific name: Xyleborus dispar (F.), family of the Scolytidae (synonymous: Anisandrus dispar ).

Description

The adult insect is from small size, 1,8 to 2 mm for the male and 3 to 3,5 mm for the female. The body is of form hemicylindrical. The élytres are of color dark, brilliances and decorated longitudinal scratches.

Biology

After the coupling, as from April-May, the females dig in the branches of the trees of the characteristic networks of galleries, including/understanding a gallery of penetration perpendicular to the surface of the branch, a gallery out of ring forming a complete circle, and vertical in dead end, short galleries, in the axis of the branches, which are used as galleries of laying. The laying takes place approximately two weeks after the beginning of the attack. Each female deposits approximately 50 eggs, which hatch after a few days of incubation.

The larvae complete their growth in approximately five weeks then nymphosent themselves. They do not dig galleries but were nourissent of Champignon S xylophagous whose spores were brought by the females.

After the nymphose, which lasts approximately two weeks, the adults pass, motionless in the galleries, the remainder of the summer then the autumn and the winter, before essaimer next spring.

The complete biological cycle is thus spread out over a year.

This species attacks many trees (polyphagous species), but especially the fruit-bearing (Pommier, Poirier, Abricotier, Prunier, Pêcher…), but also various leafy gasolines: Oak, the Beech, the maple, the Chestnut, the Plane tree, the To drown, etc

The fruit trees are most sensitive, including subjects in good state. The attack of the disparate xylébore often results by a brutal drying of the old trees, but also in the death of young subjects. The young trees, very vigorous, resist well.

Means of fight

the use of insecticides does not give much result since the insect and its larvae are often with the shelter in wood. Moreover the period of flight, relatively long, the effectiveness of such treatments limits largely.
Destruction of the attacked branches.
Manure balanced of the orchard to activate the growth of the trees and to increase their capacity of resistance.
Installation of red traps limed (in pilot wheels) with an alcohol bottle in lower part (alcohol serves as gravitational). Only the alcohol etylic pure or cut to half with water gives good performances.

See too

List of the ravageurs of the crop plants

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