The effectiveness of botanicals and fungus isolates from fish pound on the population reduction of Bemisia tabaci

Abstract

Whitefly (Bemisia tabaci) is a key pest in majority of the crops due to higher species evenness, over lapping generations, activity throughout the year, and transmission of different plant diseases. It is the time to work for effective alternative for conventional insecticides to achieve sustainability. In this study, the pathogenicity of two entomopathogenic fungi (Beauveria bassiana and Metarhizium anisopliae) isolates from fish pound and toxic potential of two botanicals (extract of Allium sativum, and Azadirachta indica) was evaluated against Bemisia tabaci. The individuals of Bemisia tabaci were exposed to three concentrations (0.4 ppm, 0.5 ppm and 0.6ppm) with one control treatment of fungi, and three concentrations (5%, 10% and 15%) with one control treatment of plant extracts.  The Mean mortality was recorded after different time intervals (24, 48, 72 and 120 hours).  The highest mortality (71%) was observed at highest concentration of Metarhizium anisopliae after 120 hours against nymph of Bemisia tabaci, whereas lowest (47%) towards A. indica. Metarhizium anisopliae was also significantly affective against adults of Bemisia tabaci with highest mortality percent (57%) and A. indica was observed least affective with lowest mortality percentage (37%). The reduced mortality was observed towards botanicals because the prolonged time to express their toxic potential and fast degradation; on the other hand enhance activity of the fungi was observed due to their fast growth on soft bodied insects. In conclusion, the fungus (Metarhizium anisopliae) could precisely be used in integrated pest control strategy for the control of Bemisia tabaci.