Silverleaf whiteflies, Bemisia argentifolii Bellows and Perring, feed on a wide variety of plants and are capable of causing significant economic damage. Host selection may be determined by a wide variety of factors. Adult whiteflies may feed on one leaf and then move to another, however, their feeding and oviposition choices may well determine the success of egg hatch and nymph survival. Current theory suggests that whiteflies feed (Fig. 1) and oviposit on the abaxial surface of leaves due to the closer proximity of phloem tissue. This is believed to be particularly important for nymphs which are stationary during much of their development and have shorter stylets than adults. We examined whitefly stylet penetration into cotton and hibiscus leaves using both light and scanning electron microscopic techniques.

Adult silverleaf whitefly stylets were found to range from 100 urn to more than 300 um in length.