Field experiments were established in 1993 and 1994 to investigate population levels and parasitism of silverleaf whitefly,Bemisia argentifoliiBellows&Perring, on 3 nearisolines of soybean,Glycine maxL., that varied in hairiness, and on 1 cultivar of peanut,Arachis hypogaeaL. The original intent was to determine whether soybean could be used as a trap crop to reduce whitefly infestation in peanut. In 1993, we 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 pubescent soybean supported substantially greater number of whiteflies than glabrous soybean, however, all soybean genotypes supported more whiteflies than peanut. In 1993, whiteflies were less often parasitized on hirsute soybean than on peanut or on the other soybean genotypes. In 1994, however, parasitism differed significantly among the 4 plant types on only 2 dates. In both years, parasitoid species were distributed differently on the 4 plant types.Encarsia nigricephalaDozier andEncarsia transvenaTimberlake more commonly parasitized whitefly on peanut and on glabrous soybean than on the hairy soybean genotypes. Conversely,Encarsia pergandiellaHoward andEretmocerusnr.californicusHoward more often parasitized whitefly on the hairy soybean genotypes.