Woolly aphids and gall-making aphids

Overview

Eriosomatinae is the subfamily of woolly aphids and gall-making aphids. There are 310 valid species in 48 genera worldwide, at least 34 species in North America north of Mexico, and at least 23 species in Minnesota.

Eriosomatinae are plant parasitic aphids. They are found on the stems, leaves, and flowers of various plants. Some are vectors of plant diseases. Most cause just minor damage, but some are serious agricultural pests.

Many Eriosomatinae have a complex life cycle involving multiple generations per year. Many have life cycles involving cyclical parthenogenesis, undergoing several generations that reproduce without mating before producing a sexually reproducing generation.

After mating, the female lays just a single egg. Many alternate hosts each season, producing a winged generation that migrates to a second plant species. Most produce abnormal plant growths (galls) on the primary host plant. This is the feature that gives the subfamily the second of its two common names.

Description

Eriosomatinae are soft-bodied, usually somewhat pear-shaped, and ⅛″ to 5⁄16″ (4 to 8 mm) in length. Most produce large amounts of a filamentous substance that appears woolly or waxy and covers all or nearly all of the body, both in the nymphal and adult stages. This is the feature that gives the subfamily the first of its two common names. However, this feature is not unique to this family. Nymphs feed in close aggregations, forming a large woolly mass for protection.

Some Eriosomatinae have a pair of very small finger-like processes (cornicles) near the end of the abdomen. Others have no cornicles. When wings are present they are membranous and are not covered with a whitish powder. The media vein (M) on the forewing is not branched. The hindwing is much smaller than the forewing. The last part of the leg (tarsus), corresponding to the foot, has two segments.

Distribution

Sources

24, 27, 30, 82.

Eriosomatinae Kirkaldy, 1905 in Bánki, O., Roskov, Y., Döring, M., Ower, G., Hernández Robles, D. R., Plata Corredor, C. A., Stjernegaard Jeppesen, T., Örn, A., Pape, T., Hobern, D., Garnett, S., Little, H., DeWalt, R. E., Miller, J., Orrell, T., Aalbu, R., Abbott, J., Abreu, C., Acero P, A., et al. (2026). Catalogue of Life (2026-07-17 XR). Catalogue of Life Foundation, Amsterdam, Netherlands. https://doi.org/10.48580/dgykv