Effect of Some Aromatic Plant Extracts, Silica Nanoparticles and Imidacloprid on the Cotton Whitefly, Bemisia tabaci (Genn.) and its Associated Parasitoid, Eretmocerus mundus Mercet on Tomato

Abstract

This study was conducted at the Experimental Farm belonging to Sakha Agricultural Research Station, Kafr El-Sheikh, ARC, during 2016 and 2017 seasons to investigate the role of aqueous extracts of nine aromatic plants, silica nanoparticle, and the insecticide Imidacloprid (admire) on Bemisia tabaci (Genn.) infesting tomato plants . Results showed that the highest value of unhatched B. tabaci eggs was 84.40 and 84.60 %respectively on tomato plants treated with the highest concentration of geranium extract, which was significantly different from the other treatments. Silica nano particles killed90.99 and 91.00 %resp. of early nymphal stage , which was not significantly different from mortality caused by admire . Silica nano particles, spurge and geranium extracts prevented adult development and killed adults at levels that were not significantly different from admire . However, the extracts of four plants; geranium, peppermint, spurge and rosemary had high repellent effect against whitefly adults . The highest parasitism percentage (93.88 and 93.63% respectively) was recorded on tomato plants treated with the highest concentration of hot pepper extract, followed by 86.23 and 86.04%resp. on tomato plants sprayed with the highest concentration of sweet basil extract. While the lowest parasitism percentage (16.53 %in both the two seasons) was obtained on tomatoplants treated with imidacloprid.