Life history traits of three cryptic species Asia I, Asia II-1 and Asia II-7 of Bemisia tabaci (Hemiptera: Aleyrodidae) reconfirm their genetic identities

The Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a pest of agricultural and horticultural crops. It is a species complex consisting of 34 cryptic species. For the distinction of these cryptic species molecular data is extensively used, but corroboration of these with life history traits has been inadequate. In the present study life history traits of 3 cryptic species Asia I, Asia II-1 and Asia II-7 were compared to verify whether biology data of these coincide with molecular data and genetic identities. The results revealed that developmental periods of Asia I, Asia II-1 and Asia II-7 groups ranged from 23.65 to 25.75 days and these were longer in Asia I than Asia II. Survivorships were nearly equal in all these varying from 68.23 to 69.12% with the variations being statistically insignificant. However, the durations of the preoviposition period, egg stage, fourth instar and longevity were observed to be significantly varying (P ≤ 0.001). Multivariate analysis of the life history parameters through principal component analysis (PCA) revealed that the first 4 principal components (PCs) account for 49.5% of total variation. Separate clusters were observed for the Asia I, Asia II-1 and Asia II-7 with slight overlapping. Overall 70% of the classifications got correctly attributed through canonical discriminant analysis (CDA) and the clustering confirmed the groups revealed by principal component analysis (PCA). These clusterings were reconfirmed in the genetic identity of the 3 cryptic species Asia I, Asia II-1 and Asia II-7 determined through molecular characterization. Thus this study adds to the knowledge on the life history traits of the B. tabaci and its cryptic species complex in India.