Ash plant bugs—Tropidosteptes spp.
Ash plant bugs are in the plant bug family Miridae. They occur throughout the United States on ash and
may occasionally feed on nearby plants if ash becomes heavily infested and defoliated. Depending on the
species, adults may be yellow, brown, or black and nymphs may be light brown or green with black spots.
Nymphs and adults suck plant juices from ash leaves, twigs, flowers, and seeds. Ash plant bug damage usually
consists of leaf stippling as well as varnishlike specks. Tiny, dark spots of excrement may be visible
on foliage. Extreme infestations can defoliate trees.
Ash plant bugs overwinter as eggs in twig bark. These hatch in February or March and the nymphs feed
until they mature in April or May. The adults feed until June or July when they lay eggs. Ash plant bugs
have one or two generations a year.
adults and green nymphs of the Pacific ash plant bug