Frankliniella occidentalis (Pergande, 1895)
Last updated: October 31th, 2006
Western flower thrips, alfalfa thrips.
Tiny, slender insect with narrow fringed wings. Males, 1.2–1.3 mm long, are pale yellow, with a narrow abdomen rounded at the end. Females, 1.6-1.7 mm long, are yellow to brown, with a more rounded abdomen ending in a point. Nymphs (larvae) are yellowish-white. Adults and larvae suck plant fluids from flowers and leaves, and also eat pollen and nectar on a wide range of plants (244 species from 62 families at least). It is an outdoor pest as well as a glasshouse pest.