Host correlated morphometric variations in the populations ofBemisia Tabaci(Gennadius) (Hemiptera: Aleyrodidae)

Morphometrics by way of univariate and multivariate statistical analyses undertaken on the four populations of Bemisia tabaci (Gennadius) from brinjal, cotton, okra and soybean from Delhi establish that these are morphologically distinct entities showing significant variations in the taxonomic characters currently in use for defining this species. Taking into account the diagnostic features of B. tabaci, and the conclusions obtained through univariate statistical analyses, 32 characters were chosen for morphometrics in case of puparia and 8 in case of adults. Both univariate and multivariate analyses concluded that these four populations vary morphologically and statistically to a significant extent in their taxonomic characters, and are thus phenotypically distinct populations. The adult and puparia morphometrics strongly confirm that populations from soybean are significantly distinct without much overlap with other three populations. Similar trend was observed in case of populations from okra and brinjal while populations from cotton alone were significantly overlapping with the other three populations. These analyses conclude that B. tabaci exhibits a wide range of host correlated, intraspecific and morphological variations. These also establish that characters from puparia are consistent and preferable for distinguishing these intraspecific populations.