ABSTRACT
Various workers have recognised four immature stages of Bemisia tabaci between the egg and emergence of the adult. The first three stages are generally referred to as larval instars and the fourth as the pupal stage. Since the metamorphosis undergone by the whitefly is incomplete, the term nymph seems to be more appropriate than larva. The chapter discusses the intraspecific variations in pupal morphology. Before going through the morphology of B. tabaci, it may be pointed out that the measurements given for different morphs are after A. Lopez-Avila to give an idea of the relative differences in size. The egg is subelliptical in shape, the basal portion being considerably broader than the tapering distal end. Host-correlated variation in the morphology of pupal cases of B. tabaci was demonstrated by L. A. Mound. A great degree of genetic plasticity in adult host selection behaviour and host suitability for nymphal development of B. tabaci, has resulted in apparent race formation.
