The western flower thrips feeds on the flowers and foliage by inserting its modified left mandible into the tissue, and sucking the fluids from cells. Oviposition and feeding scars reduce the aesthetic quality and marketability of ornamental plants. When thrips feed on developing tissues, affected cells are unable to expand, and mature leaves and petals are distorted. When thrips feed on expanded tissue, effected cells become filled with air, which imparts a silvery appearance. This thrips also is an important vector of tomato spotted wilt virus and impatiens necrotic spot virus.
Females lay eggs in tender plant tissue.
The eggs hatch in 2 to 14 days, depending on temperature. First instar larvae begin feeding on egg eclosion. Second-instar larvae also feed on plant tissue, usually in flowers. These larvae are found in the protection of perianth of the flower or within developing terminal foliage. Late in the second instar they stop feeding and move down the plant to pupate.