Resistant-varieties-available
Guides
Monarthropalpus flavus
boxwood leafminer
A small gnat-like gall midge (Diptera: Cecidomyiidae) native to Europe that is a significant pest of boxwood (Buxus spp.) in ornamental landscapes. Adults are delicate orange flies resembling mosquitoes. Females use a drill-like ovipositor to insert eggs into the undersides of young leaves. Larvae feed gregariously within leaf tissue, inducing rudimentary blister galls through hypertrophy and hyperplasia of spongy parenchyma. The species represents an evolutionary intermediate between leafminers and true gall inducers. First detected in the United States in 1910, it now causes serious damage to boxwood across the eastern U.S.