Iteomyia major
Iteomyia major is a gall midge which forms galls on willows. It was first described by Jean-Jacques Kieffer in 1889.
Description of the gall
The gall is a coalesced group of 2–10 hard round galls, on the midrib or side vein and are equally prominent on either side of the leaf. Each gall has a single larva, initially white and later orange or red. There is a single generation each year and pupation takes place in the soil. Females prefer to lay their eggs on the ″broad-leaf willows″ and the galls are found on sallows, or their hybrids, which include bay willow, bitter willow, dark-leaved willow, eared willow, goat willow, gray willow, grey willow, purple willow, tea-leaved willow and woolly willow.
Similar species
Iteomyia capreae galls are small, hard, green pouches, up to 4 mm in diameter and, as they mature, have a reddish or purplish tinge. They are not as prominent on the lower leaf surface, having red-rimmed conical pores.
Distribution
Recorded from Great Britain and the Netherlands.