A pest of the western U.S., where it is found on several species of native oaks as well as tanoak, coffee berry, and chinquapin. Heavy infestations can nearly cover the lower surfaces of the leaves, leading to heavy production of honeydew. Typical whitefly life cycle of eggs laid over the surface of the leaf hatching to the mobile first instar nymph. As this moves to the second instar the legs are lost and the insect becomes sessile, feeding in one place through the next nymph stages and the pupa.
Initiating control as soon as a few whiteflies are noticed will increase the chances of success. Contact insecticides often provide very little control due to the repellency of the wax on the insect and the occurrence of resistance to may insecticides. A systemic product that can penetrate the plant’s tissues may be most effective. Horticultural oils also will help by coating the insects and smothering them. Reapplications at 5 to 7 day intervals may be needed, and any sprays should be directed at the lower surface of the leaf and applied thoroughly.