RESPONSE OF Orius laevigatus TO WEED EXTRACTS DURING THE PREDATION OF Thrips tabaci

The predatory response of Orius laevigatus on onion thrips, Thrips tabaci and their response to the extracts from Azadirachta indica, Parthenium hysterophorus and Datura alba were investigated during 2014 at The University of California Davis USA. Aqueous extracts of A. indica, P. hysterophorus and D. alba, caused general deterrent/antifeedant effects on onion thrips. The leaf discs treated with these botanicals extracts showed relatively less feeding damage of T. tabaci and better performance of O. laevigatus against T. tabaci mortality/consumption as compared to leaf discs treated with conserve® (Spinosad) a synthetic insecticide. The conserve® caused 100% mortality of both T. tabaci and O. laevigatus while all the three tested botanicals showed no effect on O. laevigatus in terms of its mortality. The O. laevigatus coupled with these botanicals can reduce the feeding damage of T. tabaci and the feeding reduction was measured as 83%, 80% and 75% for A. indica, P. hysterophorus and D. alba respectively as compared to the O. laevigatus placed on untreated leaf discs. These results indicated that O. laevigatus can effectively control and reduced the feeding damage of T. tabaci showing no or very little effect in response to A. indica, P. hysterophorus and D. alba.