Elm sack gall aphid Tetraneura ulmi

Features

It is a species of aphid in the family Aphididae. There are about 30 species in the Tetraneura genus.

Species	Insect
Living space	Deciduous forest
Size

Description

At least seven of them host alternate between leaf galls on elm (Ulmaceae) and roots of grasses (Poaceae). The remainder are only described from either elm or the roots of grasses. They usually have a sexual stage in the life cycle. The fundatrices induce stalked, pouch-like red, yellow or green galls on the upper sides of leaves. Tetraneura are not attended by ants. The winged forms of the elm-grass root aphid (known in America as the elm sack gall aphid) emerge from elm galls (Ulmus spp.) in June-July to colonize roots of grasses (Poaceae). Populations without sexual forms occur commonly on secondary hosts. In September winged forms make a return migration to elm where they produce larvae which feed on the bark, and mature to apterous males and females. Fertilized females only lay one egg each. Tetraneura ulmi is found in Europe, across Asia to eastern Siberia, and has been introduced to North America.