The gall midge is the only known dipteran herbivorous insect on oak trees (with the exception of occasional opportunistic pollen feeders). The quercus gall midge is very host specific, it develops on the turkey oak (Quercus cerris). In Romania, there are 4 species of gall midges associated with Quercus spp., and recently the species Janetia cerris has been found in the urban green landscape of Timisoara. The damage caused by this species manifests itself in the appearance of conical galls on the upper side of the leaves, up to 3 mm high and light green in colour. The larvae develop inside these galls. Our investigations were carried out during 2022 – 2023 in 4 observation points in parks and green urban spaces in the city of Timișoara. During our investigation we used the same collecting method at each sample points. We noted in the protocol the geographical characteristics of biotopes and the local abundance of species. The survey indicates a high infestation level with gall midges in all 4 observation points that exceeds 70% of all analyzed samples. The attack can be recognized by the galls that appear on the upper side of the leaf, which have a sharp appearance, are about 2 mm long and lack pubescence; while on the lower side of the leaf, the gall is prominent, up to 5 mm in diameter, with long, yellow-brown hairs. Photos with larvae, galls on leaves, identification keys and brief description for this species are presented in this paper.

gall midges, Diptera, Cecidomyiidae, green landscapes, western Romania

agronomy

Presentation: poster