ASSESSMENT OF THE EFFECTS OF THREE WEED EXTRACTS FOR THE PROTECTION OF CHICKPEA SEED AGAINST CALLOSOBRUCHUS CHINENSIS L. (COLEOPTERA: BRUCHIDAE)

Abstract

The study was conducted to evaluate the efficacy of three indigenous weed extracts namely chaglagacha (Ageratum conyzoides), bon morich (Croton bonplandianus) and bishkatali (Polygonum hydropiper) in acetone solvent for their direct toxicity and residual effects against the pulse beetle, Callosobruchus chinensis L. (Bruchidae: Coleoptera) in the laboratory conditions of the Department of Entomology, HSTU, during June to December 2017. The four concentrations (20, 15, 10 and 5 mg/ml) along with a control of the botanical plant extracts were applied. The results of the present study indicated that all the plant extracts had toxic and residual effects for controlling pulse beetle in storage but chaglagacha extract was more toxic to the insects. Mortality and residual effects were statistically different for plant extracts and doses with hour (24, 48 and 72) after treatments. Among the plant extracts, chaglagacha extract provided the highest mortality (56.00%) whereas bishkatali extract possessed the lowest (39.11%). The order of the toxicity of three plant extracts were found chaglagacha > bonmorich > bishkatali. Considering four doses, the highest toxicity (69.63%) was recorded at 20 mg/ml while the lowest toxicity (38.15%) at 5 mg/ml. The residual toxicity was evaluated considering oviposition, egg bearing seed, adult emergence, seed infestation and weight loss caused by the insect. The highest residual toxicity was found in chaglagacha while the lowest in bishkatali extract. So, chaglagacha extract may be used as effective against the invasion of pulse beetle in store