Bemisia tabaci in Java, Indonesia: genetic diversity and the relationship with secondary endosymbiotic bacteria

Abstract

Bemisia tabaci is a complex of cryptic species of whitefly distributed worldwide; they are serious agricultural pests and vectors of plant viruses. Whiteflies are commonly infected by endosymbiotic bacteria, but the infection profiles among genetic groups of B. tabaci are highly complex. Here we analyzed the genetic variation of B. tabaci and endosymbiont infection patterns in Java, Indonesia. Specifically, adult B. tabaci were collected from four provinces and 43 partial cytochrome oxidase subunit I gene sequences were determined to identify the genotypes. Results showed that B. tabaci was grouped into three different cryptic species, Asia I, Asia II 5, and Asia II 7, at rates of 90.70%, 6.98%, and 2.32%, respectively. The dominant group, Asia I, was distributed throughout the island, whereas Asia II 5 and Asia II 7 were detected only in West Java. In these cryptic species, the infection rates of the secondary endosymbionts Arsenophonus, Cardinium, Hamiltonella, Rickettsia, and Wolbachia were 37.21%, 72.09%, 37.21%, 88.37%, and 90.70%, respectively. Arsenophonus and Cardinium were detected two subgroups (A1 and A2; C2 and C4), but Hamiltonella, Rickettsia, and Wolbachia were detected a one subgroup (H1, R1, and W1). The A1 and A2 subgroups were distributed in a mixed manner across the entire island; however, the C2 and C4 subgroups were distributed differentially in West Java and in Central and East Java, respectively. Multiple infections were common and their patterns were highly variable in each cryptic species. In particular, Hamiltonella was detected in Asia I and Asia II 5 but never coinfected with Arsenophonus in the same individual. Overall, this study shows that Asia I is the dominant genetic B. tabaci group on Java Island and that infection by endosymbionts occurs in a highly complex and sometimes geographically related manner.