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Field and laboratory experiments were conducted to determine resistance of cotton Gossypium hirsutum L. cultivars differing in leaf morphology (shape and pubescence) to the B biotype of sweetpotato whitefly Bemisia tabaci (Gennadius) and impacts on its parasitoids. Five cotton cultivars were evaluated in a field-plot experiment at Hastings, Florida. The pubescent cultivars, DP DES 119 and Stoneville 453, were significantly hairier than moderately hairy okra-leaf cultivar, Gumbo 500, and smooth-leaved cultivars NU COTN 33B and DP 51. There were significant differences among cultivars in eggs laid on the second and fifth node leaves. DP DES 119 and Stoneville 453 had greater numbers of whitefly eggs than did the glabrous cultivars. The okra-leaf cultivar, Gumbo 500, had greater numbers of eggs than the 2 glabrous varieties. There were significant differences among cultivars in numbers of first and second instars (young instars), third instars, unparasitized fourth instars and red-eyed nymphs on fif... |
