VP36 Plant extracts as alternative botanical insecticides for control the grasshopper Heteracris littoralis (Orthoptera: Acrididae) with reference to histological changes on the reproductive system
In the present study , alchoholic85% extract of five different medicinal plants that possess insecticidal activity against other insects pests, namely , Euphorbia pulchrrima and Euphorbia cotimfabia ( Euphorbiacae ) Dodonea viscose (Sapindaceae ), Schinus trbinlitolia ( Anacardiaceae ) and Eucalyptus rostata (Myrtaceae ) , were tested for toxic effects against the grasshopper Heteracris littoralis 1St nymphal instars . The toxic activity according the LC50 values could be arranged in the order that E. pulchrrima = E.cotinfabia > D.viscosa > Eucalyptus rostata > Chinus trbinlitolia , The effect of LC50 values of the most effective extracts ( E. pulchrrima , E.cotinfabia and D.viscosa ) were tested on some biological aspects of H. littoralis treated 1St nymphal instars . Results cleared that there was statistical variable numbers of reduction in preoviposition ,Oviposition and postoviposiyion periods for the adult offspring resulting from the treated nymphs . Highly reduction in the deposited eggs, adults longevity and egg hatchability. Also normal development was exhibited . However water ethanolic extract of the tested plants had a toxic effect and retarding the development of H.littoralis . Histological changes on the reproductive system of both male and female adults resulting from the treated nymphs that detected by light microscopy has been discussed .