Occurrence of a new cryptic species of Bemisia tabaci (Hemiptera: Aleyrodidae): an updated record of cryptic diversity in India

Bemisia tabaci (Hemiptera: Aleyrodidae) is a polyphagous, phloem-feeding insect infesting more than 600 plant species worldwide. It is considered as a complex of morphologically indistinguishable cryptic species that differ in biological, physiological, and genetic traits. To date, 45 such cryptic species of B. tabaci have been identified worldwide with up to 4% genetic divergence of mitochondrial cytochrome oxidase subunit I (mtCOI) sequences, and nine of these cryptic species have been reported in India. However, north-eastern India on the verge of two biodiversity hotspots, Eastern Himalaya, and Indo-Burma, remained unexplored until now. The present study included a large number of populations from diverse ecological niches of north-eastern India and updated the cryptic diversity of B. tabaci. B. tabaci Asia II 5, Asia I, and Asia II 1 were widespread in north-eastern India. In Bayesian phylogenetic inference and genetic divergence study, an isolate of B. tabaci branched separately within China clade, closest to China 3, and was proposed as a new cryptic species, B. tabaci China 7. Based on the available sequence data, we reported occurrence of nine established and one new cryptic species of B. tabaci in India. B. tabaci Asia II 1 and Asia 1 were predominant in northern and central India, whereas Asia I and Asia II 7 were in western India. Predominant occurrence of B. tabaci Asia 1, Asia II 5, and Asia II 8 were recorded in southern India. The present study proposed to update the global diversity of B. tabaci to 46 cryptic species under 11 genetic groups. The genetic divergence between the cryptic species and genetic groups of B. tabaci ranged from 4.1–23.4 and 11.7–21.2%, respectively. The findings will help to understand the epidemics of B. tabaci and formulate effective management strategies against B. tabaci and B. tabaci-transmitted viruses.