Comparison of life history parameters of two different genetic clusters of Bemisia tabaci MED (Hemiptera: Aleyrodidae) through single and cross mating.

Bemisia tabaci Mediterranean (Gennadius) (Hemiptera: Aleyrodidae) is an economically important insect pest worldwide. Previously, we have reported that most B. tabaci Mediterranean (MED) populations occurring in greenhouse tomatoes in Korea have been displaced from well-differentiated two genetic clusters (C1 and C2) to one (C2) during one-year period. To elucidate factors responsible for this phenomenon, we compared life history parameters of these two different genetic clusters through single and cross mating experiments on two different host plants, cucumber and tobacco, at 26°C. Intrinsic rate of increase (r), finite rate of increase (λ), and net reproductive rate (Ro) were significantly higher in the dominating cluster (C2) (0.247, 1.280, and 192.402, respectively on cucumber; 0.226, 1.253, and 133.792, respectively on tobacco) than in the other cluster (C1) (0.149, 1.161, and 50.539, respectively on cucumber; 0.145, 1.156, and 53.332, respectively on tobacco). Overall performances of cross mating groups, C2fC1m (C2 female × C1 male) and C1fC2m (C1 female × C2 male), were in-between those of C2 and C1, with C2fC1m performing better than C1fC2m. Thus, maternal inheritance appeared to be significantly associated with their life history parameters, with partial involvement of paternal inheritance. Our results demonstrated that the rapid displacement of genetic clusters of B. tabaci MED populations was clearly associated with differences in their life history parameters.