Effects of ethanolic bouhinia extraction on fourth instar nymph of Schistocerca gregaria (Forskal) (Orthoptera: Acrididae).

摘要

Effect of the Bouhinia purpurea ethanolic extract on the desert locust Schistocerca gregaria (Forskal) (Orthoptera: Acrididae) 4th nymphal instar was evaluated under laboratory conditions. The studied parameters when the topical application was applied were: percentages of nymphal mortality, inhibition of the next nymphal instar and adult formation. Effects on the reproductive system of the survived males and females were observed. The tested concentrations were 50, 100, 500, 1000, 5000 and 7500 ppm. by using ethyl alcohol as a solvent. The nymphal mortality percentages were ranged from 6.66 to 40%. The inhibition of nymphs and adult formation was concentration dependent. Drastic malformation was observed in the treated nymphs and adults resulted from the treated nymphs either externally or in the reproductive system of the survived males and females. Also, food consumption, food deterrent effects and chitin deposition of body wall were estimated by using no choice feeding method. The results of the chitin deposition of the body wall indicated that the treated nymphs were less than the check. Studies of some nutritional indices showed that food consumption and growth rate decreased with the increase of the tested concentrations. By calculating the feeding deterrent effect of the Bohinia extract, it was proved to be moderate deterrent for the desert locust.