Caloptilia roscipennella

Walnut leaf miner

Description

Caloptilia roscipennella is a moth from the Gracillariidae family, widespread across Central and Southern Europe. It mainly infests Juglans regia (common walnut), where larvae mine the leaves. The larvae start feeding in the leaf and creates narrow corridor-like mine, which then expands into a small tentiform mine, typically near the leaf margin. As they mature, the larvae leave the mine and roll the leaflet into a tube, continuing to feed inside. Pupation occurs under a silk membrane within a conical roll at the edge of the leaf. This species is active from August to May, with adults hibernating over winter.

Symptom

Infestation symptoms include narrow snake-like mine + tentiform mines near the leaf margin and rolled leaflets. Unlike related species, C. roscipennella creates a conical roll at the leaflet edge for pupation.

Tree Species: Walnut

Part of a plant- attacked: Leaf / Needle

Pest significance: Less harmful

Pest Category: Insects

Invasive Species: No

Present in EU: Yes