Dasineura thomasiana

Gall midge Dasineura thomasiana

Description

Dasineura thomasiana is a gall midge species that induces galls on linden trees (Tilia spp.), including Tilia cordata, T. platyphyllos, T. tomentosa, and hybrids like T. x europaea. This monophagous insect is widely distributed across Europe, particularly in urban parks and avenues where lindens are commonly planted.

The larvae feed on young terminal leaves, causing them to roll and distort, with the veins thickening noticeably. Initially white, the larvae turn orange-red as they mature. Dasineura thomasiana typically has two generations per year, with pupation occurring in the soil. Although the intensity of infestations is generally not high, repeated attacks can diminish the aesthetic value of linden trees and reduce their photosynthetic efficiency. However, the overall impact on the health of well-maintained trees is usually minor.

Symptom

On affected linden trees, young terminal leaves are rolled and distorted with thickened veins. Inside the galls are orange-red larvae, and the galls give leaves a deformed appearance.

Tree Species: Lime

Part of a plant- attacked: Leaf / Needle

Pest significance: Less harmful

Pest Category: Insects

Invasive Species: No

Present in EU: Yes