Virulence of Five Isolates of Indigenous Beauveria Bassiana Against Eggs and Nymphs of Bemisia Tabaci Gennadius (Hemiptera: Aleyrodidae)

Abstract

This research aims to study the virulence of five isolates of Beauveria bassiana to eggs and nymphs of Bemisia tabaci on tomato. In the experiment eggs and second instar nymphs of B. Tabaci were used. Five isolates of the fungus, i.e., WS, TD312, PD114, PA221, PB211, were tested. Conidial concentration of B. bassiana used were 108 conidia/ml. Experimental parameters included mortality of eggs and nymph and percentage of adult emergence. The results showed that all B. bassiana isolates tested were able to kill B. tabaci eggs but with very low mortality (2-19%). Mortality of second instar B. tabaci nymphs was dependent on the fungal isolates. Isolate WS had the highest virulence, which caused 70% mortality of 2nd instar nymphs, with a LT50 of 4.87 days. Nymphs of B. tabaci were highly susceptible to B. bassiana infection compared with eggs. B. bassiana applicated to nymphs of B. tabaci can decrease the percentage of adult emergence.