Understanding the interactions among the crop plants, a virus, insect vector whiteflies and their endosymbionts

Interactions among the four biotic agents - the host plants, a virus, insect vector whiteflies and their bacterial endosymbionts was investigated in this study. The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is an important crop pest that is infected by several endosymbiotic bacteria that can play varying roles on their hosts. Both whiteflies and endosymbionts are affected by the host plants they feed on, which in turn affect the fourth agent – the viruses, which are transmitted by the whiteflies. We investigated these interactions on five different host plants – eggplant, tomato, beans, okra and cotton - using a single whitefly species Asia 1 infected with three different bacteria Portiera, Wolbachia and Arsenophonus. B. tabaci Asia 1 transmits the Tomato leaf curl Bangalore virus (ToLCBV) effectively, which was the virus used in the study. We found host plants having a significant impact on whitefly growth and development. Eggplant was most favourable, while okra and tomato were least preferred. The endosymbiont Wolbachia was significantly affected by feeding of B. tabaci on different host plants while Portiera and Arsenophonus were unaffected. When whiteflies fed on ToLCBV-infected tomato plants, the concentration of Arsenophonus increased significantly while other endosymbionts remain unchanged. Understanding these interactions will help in managing both whiteflies and viral diseases