Stereonychus fraxini

Slimy ash weevil

Description

2.5-3 mm. Adults oval-shaped, thorax and elytra brown-blackish color coated by minute white-yellow and light brown scales. Larvae pale green or yellow color with black head, covered by clear slime. The adults hibernate into the litter and start flying to the crowns in April. They initially feed on buds and leaf-stalks, later on leaves. The young larvae start feeding by skeletonizing the leaves, then open large holes on them by chewing and finally pupate in small brown-goldish cocoons. The new adults can either hibernate or start a second generation, after an intense feeding period in June-July. 1-3 generations per year depending on local climate conditions. Delay of sprouting and defoliation may recur over several years, causing a serious tree weakening. Mixed broadleaved forests, mainly riparian woods in lowlands.

Symptom

The young larvae start feeding by skeletonizing the leaves, then open large holes on them by chewing and finally pupate in small brown-goldish cocoons. The images are gray-brown, the ocher is ocher white with a black head.

Tree Species: Ash

Part of a plant- attacked: Leaf / Needle

Pest significance: Harmful

Pest Category: Insects

Invasive Species: No

Present in EU: Yes