Feeding on the petals causes pale spots and necrotic patches so that infested blossoms age prematurely. Feeding on young foliage by this pest results in distorted growth as the leaf tissue expands. Damaged leaves may be puckered and twisted. Feeding on expanded tissue forms pale spots as the thrips slash the surface of the leaf and suck out the contents of the cells beneath. The western flower thrips is now the most damaging insect pest of greenhouse floral crops in the United Stated.
Females insert eggs into succulent host plant tissue.
Soon, tiny first stage larvae hatch that molt into second stage larvae. These soon molt into a prepupal stage that sometimes drops to the soil. Prepupae do not feed although they can crawl about. In a few days, the prepupae molt into the pupal stage and within a few more days, new adults emerge from the pupal stage. At 86 degrees F, development takes 13 days, and the adults live about 28 days and lay an average of 44 eggs.