The Effects of Space Dimension and Temperature on the Cross Mating of Three Cryptic Species of the Bemisia tabaci Complex in China

Abstract

The sweetpotato whitefly Bemisia tabaci (Homoptera: Aleyrodidae) is a destructive pest of agriculture and horticulture worldwide. Recent phylogenetic analysis using mitochondrial cytochrome oxidase 1 sequences indicates that this whitefly is a species complex including at least 24 morphologically indistinguishable but genetically distinct cryptic species. In this study, the inter-species crosses of Middle East-Asia Minor 1 (MEAM1), Mediterranean (MED) and Asia II 7 cryptic species, which were referred to as B, Q and Cv biotypes before, were conducted in two different devices, leaf cages (7 cm3) and cylinder cages (280 cm3), and at three temperatures of 22, 30 and 38°C. Results indicated that no female progeny were produced in the reciprocal cross between MEAM1×Asia II 7, between MED×Asia II 7 cryptic species neither in leaf cage nor in cylinder cages, while 0.81 and 1.37% of females in the offspring were recorded in the reciprocal cross between MEAM1×MED in leaf cage experiments. Approximately 0.95–0.98% female progeny were recorded in the reciprocal cross between MEAMl×MED at 30°C, 0.77% female progeny were recorded in the single cross direction between MEAMl♀× MED♂× at 22°C, and no female progeny were found in their reciprocal cross at 38°C in leaf cage. Our findings indicated that neither space dimension nor temperature have a significant effect on the hybridization of different B. tabaci cryptic species.