Iteomyia capreae

The midge forms two different galls which can be found, either on the leaf bade or on a side-vein of a leaf.

• in the leaf blade the gall is a hard, domed pouch above, and below it is conical, with a red-rimmed opening. The opening is hairless and initially greenish, later becoming yellow, brown, purple or red. It contains a single larva which is white at first and later orange or red.
• the side-vein is a 2–3 mm long, hard swelling, containing the larva.[2][3]

When mature the larvae drop from the gall, overwintering in the soil and pupating in the spring.[4]

The galls are found on sallows or their hybrids and include, almond willow (S. triandra), common osier (S. viminalis), crack willow (S. fragilis), dark-leaved willow (S. myrsinifolia), eared willow (S. aurita), European violet willow (S. daphnoides), goat willow (S. caprea), grey willow (S. cinerea) and S. appendiculata.[3]

The insect has been recorded in Asia, and Europe, from Ireland and Portugal in the west, through to Siberia, China and Japan in the east.[5]

• Bioimages
• Media related to Iteomyia capreae at Wikimedia Commons