INFLUENCE OF FOLIAR PUBESCENCE ON ABUNDANCE AND PARASITISM OF BEMISIA-ARGENTIFOLII (HOMOPTERA, ALEYRODIDAE) ON SOYBEAN AND PEANUT

Field experiments were established in 1993 and 1994 to investigate pop ulation levels and parasitism of silverleaf whitefly, Bemisia argentif olii Bellows & Perring, on 3 near-isolines of soybean, Glycine mar L., that varied in hairiness, and on 1 cultivar of peanut, Arachis hypoga ea L. The original intent was to determine whether soybean could be us ed as a trap crop to reduce whitefly infestation in peanut. In 1993, w e found that whiteflies preferred soybean to the extent that they laid few eggs on peanut in the trap crop experiment. Substantially greater populations of immature whiteflies occurred in pubescent and hirsute soybean than in either glabrous soybean or peanut. In 1994, only pubes cent soybean supported substantially greater number of whiteflies than glabrous soybean, however, all soybean genotypes supported more white flies than peanut. In 1993, whiteflies were less often parasitized on hirsute soybean than on peanut or on the other soybean genotypes. In 1 994, however, parasitism differed significantly among the 4 plant type s on only 2 dates. In both years, parasitoid species were distributed differently on the 4 plant types. Encarsia nigricephala Dozier and Enc arsia transvena Timberlake more commonly parasitized whitefly on peanu t and on glabrous soybean than on the hairy soybean genotypes. Convers ely, Encarsia pergandiella Howard and Eretmocerus nr. californicus How ard more often parasitized whitefly on the hairy soybean genotypes.