Genetic diversity and geographic distribution of the Bemisia tabaci species complex in Bangladesh.

Bemisia tabaci (Gennadius) is a species complex consisting of at least 40 cryptic species. Although the genetic diversity of B. tabaci has been studied in various regions, little is known about distribution in Bangladesh, which is covered by the Bengal delta, the largest delta on Earth. We conducted an extensive survey throughout the country and determined the nucleotide sequence of mitochondrial cytochrome c oxidase subunit 1 (COI) from 110 individuals. We then examined phylogenetic relationships. The results identified four cryptic species that expressed distinct interspecific variation but low intraspecific variation. Asia I was the most abundant, both Asia II 1 and Asia II 5 were moderately abundant, and Asia II 10 was found only in the central region. COI sequences of each cryptic species were distinctive and differentiated into many haplotypes. Our study provides important information to better understand the genetic diversity and geographic distribution of cryptic species in Bangladesh and nearby countries.