Toxicological Effects of five Insecticides on Cabbage Aphid, Brevicoryne brassicae (L.) (Homoptera: Aphididae) and its Parasitoid Aphelinus sp. (Hymenoptera:Aphelinidae)

Abstract

Cabbage aphid, Brevicoryne brassicae (L.) is an important agricultural insect pest that attacks many vegetable crops all over the world. Herein, the study was conducted to evaluate the efficacy of five insecticides, acetameprid 20% SP (neonicotinoid), abamactin 1.8% EC (avermectin), indoxicarb 15% EC (oxadiazine), chlorpyrifos methyl 50%EC (organophosphate) and lambda cyhalothrin 5% EC (pyrethroid) against cabbage aphids Brevicoryne brassicae (L.) and its parasitoid Aphelinus sp. under laboratory conditions. Mortality percentages for both cabbage aphid and parasitoid were determined after 24, 48 and 72h after treatment. Result revealed that acetamiprid was the greatest toxic insecticide against cabbage aphid followed by abamectin and indoxacarb after 24 and 48-h of treatment. Otherwise, lambda cyhalothrin followed by chlorpyrifos methyl was the lowest toxicity on cabbage aphid after 24 and 48-h from treatment. In contrast, toxicological results for parasitoid suggested that acetamiprid had less toxicity followed by abamectin and indoxacarb after 24 and 48-h of treatment. whereas, lambda cyhalothrin followed by chlorpyrifos methyl demonstrated great toxicity on the parasitoid after 24 and 48-h of treatment. In addition, safety factor for each treatment was determined, and results revealed that greater safety factor was recorded for acetamiprid, abamectin and indoxacarb than chlorpyrifos methyl and lambda cyhalothrin. Thus, these results suggest that acetamiprid can be included in the Integrated Pest Management (IPM) Program against cabbage aphid with safe side and minimum harmful effect on its parasitoid.