Adult attractiveness and oviposition preference of Bemisia tabaci biotype B in soybean genotypes with different trichome density

Bemisia tabaci consists of a complex of morphologically indistinct biotypes, varying with respect to their host ranges and ability to transmit plant viruses. Biotype “B” has increased in importance at every growing season in soybean crops in Brazil. The objective was to evaluate B. tabaci biotype B infestations in 24 soybean genotypes, including cultivars of expression for planting and the main sources of insect resistance. The study was performed in a greenhouse with evaluations for adult attractiveness and oviposition preference (free-choice test); these parameters were correlated with trichome density. Three evaluations were carried out, and counts were obtained for number of adults, eggs, and trichomes on the abaxial surface of the leaves. The experimental design consisted of randomized blocks (192 plots). In all three evaluations, “Coodetec 215” was the most attractive to adults; the least attractive cultivars were “IAC 18” (first); PI 274453, “IAC 18,” and D 75-10169 (second); and “IAC 24” (third). As to oviposition preference, “Coodetec 215” showed the highest mean in all evaluations; the lowest means corresponded to “IAC 18” (1st); PI 274453 (2nd); and PI 274453 and L1-1-01 (3rd). No significant correlation was observed between trichome density and oviposition preference and adult attractiveness. Considering all parameters and focusing on commercial germplasm, “IAC 24,” as well as “BRS Barreiras,” “IAC 18,” “IAC 17,” and “IAC 19” can be indicated for planting in regions and/or seasons where B. tabaci biotype B is a problem for soybean production or even in properties where other crops affected by this whitefly are grown simultaneously with soybean or after this legume is grown.