Distribution ofBemisia tabaciGenetic Groups in India

Abstract

The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is a phloem-feeding, economically important pest of crops worldwide. In addition to direct damage, it also vectors a number of plant viruses belonging to the family Geminiviridae. Its populations differ biologically with respect to insecticide resistance, virus transmission and host range. Therefore, understanding genetic variation among populations is important for management. We sequenced 850 bp of the mitochondrial COI (mtCOI) gene from B. tabaci populations surveyed across India. BLAST analysis of the mtCOI sequences generated in this study with sequences from the mtCOI dataset showed the presence of one invasive group, MEAM1, and eight other groups of B. tabaci in India. mtCOI sequence analyses showed the presence of Asia I, Asia I-India, Asia II-1, Asia II-5, Asia II-7, Asia II-8, and Asia II-11 genetic groups. We also found China-3 in a field in Birbhum district, West Bengal, India, suggesting a role of anthropogenic activities in the distribution of B. tabaci. Interestingly, more than one genetic group was found coexisting in the same field.

Identification of mungbean lines with tolerance or resistance to yellow mosaic in fields in India where different begomovirus species and different Bemisia tabaci cryptic species predominate

“…As B. tabaci species differ significantly in their sensitivity to insecticides with the invasive species MEAM1 and MED having a high propensity for developing resistance against many pesticides (Horowitz et al 2007;Horowitz and Ishaaya 2014), a comprehensive knowledge of whitefly species abundance is essential for a rational use of insecticides to avoid ineffective protection measures that burden farmer's health and environment. In recent more extensive investigations of B. tabaci species distribution in India Ellango et al (2015) and Prasanna et al (2015) found the indigenous Asia II 1 genotype in high abundance confirming the finding of Asia II 1 in three consecutive years in the North in this study. In another study, Asia1 was found to be predominant in the North of India, butin the South a higher diversity of B. tabaci species was found (ChowdaReddy et al 2012;Ellango et al 2015), whereas in this study Asia II 8 was predominant in the south.…”

“…In recent more extensive investigations of B. tabaci species distribution in India Ellango et al (2015) and Prasanna et al (2015) found the indigenous Asia II 1 genotype in high abundance confirming the finding of Asia II 1 in three consecutive years in the North in this study. In another study, Asia1 was found to be predominant in the North of India, butin the South a higher diversity of B. tabaci species was found (ChowdaReddy et al 2012;Ellango et al 2015), whereas in this study Asia II 8 was predominant in the south. A first report of B. tabaci MEAM1 in India was from Banks et al (2001) who collected this invasive species from infected tomato in the Kolar district.…”

“…Therefore, there might have been a bias to the indigenous B. tabaci species. However, as no MEAM1 was found in both recent studies and Ellango et al (2015) found it only in a very restricted region the rapid invasion of MEAM1 in south India suggested by Rekha et al (2005) appears not to have occurred. To date there is no report of the invasive MED in India.…”

“…A first report of B. tabaci MEAM1 in India was from Banks et al (2001) who collected this invasive species from infected tomato in the Kolar district. Further reports of MEAM1 were primarily from the same region (Rekha et al 2005;Shankarappa et al 2007;Ellango et al 2015) with one find in Dabhoi in the West (Chowda-Reddy et al 2012). In all cases MEAM1 were collected from tomato plants suggesting this species may have a preference for solanaceous hosts compared to legumes, though MEAM1 usually is reported to have a very broad host range.…”

Insecticide resistance status in the whitefly, Bemisia tabaci genetic groups Asia-I, Asia-II-1 and Asia-II-7 on the Indian subcontinent

“…Extensive information is available on the insecticide resistance status of Mediterranean (MED) and the Middle East-Asia Minor 1 (MEAM 1) genetic groups, known in older literature as the Q and B biotypes, respectively1. Although Indian geographical regions display an enormous diversity of B. tabaci with the presence of nine out of the 36 genetic groups recorded so far5253, only limited literature is available on the insecticide resistance status of Indian contingent of B. tabaci species complex101227. The present investigation attempts to take a snapshot view of resistance development in field populations of B. tabaci (collected across agro-climatic zones) against OPs, synthetic pyrethroids and neonicotinoids concurrently used for controlling B. tabaci in India along with information on their genetic group status.…”