Species Gossyparia spuria - European Elm Scale

Up to 10 mm.

Mature females are up to 10 mm, oval, reddish-brown with a white, waxy fringe. Blood-like, red liquid results when scales are crushed

Overwinter as second instar nymphs in bark cracks and crevices. Females mature in late May, mate and begin laying eggs. Crawlers begin appearing in late June and egg hatch may extend through the end of July. Crawlers feed on leaves throughout the summer, then migrate to branches before leaves drop in the fall. There is one generation per year.

Sap-sucking can cause stunted, chlorotic foliage, premature leaf drop and branch dieback. Associated black sooty mold growth from honeydew secretions on tops of branches gives trees an overall black appearance. Honeydew secretions are also a common nuisance to cars parked under infested elms.

Introduced from Europe.