Problem: Whitefly (Avocado)
This insect is a common pest of avocado. The four-winged adult lays eggs on the undersides of leaves. The larvae are the size of a pinhead, flat, oval, immobile, and semitransparent. In about a month, they change to the winged adult form. The larvae are more damaging because they suck more sap from the plants than do the adults. They cannot digest all the sugar in the sap, and they excrete the excess in a sticky material called honeydew, which coats the leaves and may drop from the plant onto surfaces below.
Remove heavily infested leaves. Vacuum plants to pick up adults. Apply an insecticide labeled for edibles, or houseplants if grown indoors, following label instructions. Treat plants at night when insects are not flying. Continue treatment if the problem continues.