Whiteflies begin life as minute, virtually invisible eggs arranged in a semicircle on the underside of the leaves. These hatch into the crawler stage of the insect. Once the active crawlers settle down to feed they molt and become nymphs. Nymphs are stationary, light green, flat oval and with a fringe of short, white, waxy filaments radiating from the border of the body. Pupae develop from the nymphs and are similar in appearance, but have a few waxy filaments on their back.
Adults emerge from the pupae, and in about four days begin laying eggs.
All stages of development may occur at the same time on the plant. When an infested plant is shaken or disturbed, the adults will flutter from the plant but quickly resettle. The entire life cycle takes about a month. Whiteflies cannot overwinter outdoors at our latitude, but can continue from year to year in greenhouses, and in the far south. Whitefly problems in gardens in Kentucky usually begin from infested transplants.