DefinePK

Abstract

Toxicity of aqueous, methanolic and acetonic extracts of three plants Rhazya stricta Decaisne, Azadirachta indica A. Juss and Heliotropium bacciferum Forssk. to the khapra beetle, Trogoderma granarium Everts larvae was investigated. All extracts showed remarkable toxicities. The acetonic extract from R. stricta has shown a relatively more pronounced toxic effect, having an acute 2-day and chronic 6-day LC50 s of 391 and 214 ppm compared to 467 and 251 and 576 and 317 ppm, for A. indica and H. bacciferum, respectively. The toxic effect was found to be dose and exposure-time dependent. The toxic effect observed for acetone extract was about 1.4 fold that observed for either aqueous or methanol extracts. These materials could have promising practical application in protection of stored grains against attack by T. granarium.