author(s)
Dongmo Tonleu Ingrid, Seino Richard Akwanjoh and Manjeli Yacouba

abstract
Ageratum conyzoides is an annual plant used to cure many diseases worldwide and also to control some insect pest. During the present study, effects of infused and macerated aqueous extracts of this plant had been investigated on the testes of the pest grasshopper Zonocerus variegatus (Orthoptera: Pyrgomorphidae). Different concentrations (0, 10, 30 and 100 µg/ml) were prepared and administrated through injection to the grasshoppers. Pycnosis, formation of spaces and vacuoles, detachment of the epithelium from the testicular tissue and necrosis were observed after 72h of treatment. Spermatogonia, spermatocytes and spermatids became pycnotic and gradually degenerate with increased concentration. Necrosis were observed after treatment with the two aqueous extracts at 100 µg/ml. These overall results indicated that infused and macerated aqueous extracts of A. conyzoides could induce modification of the normal histology of Z. variegatus and could therefore be exploited in the formulation of biopesticides to fight against this grasshopper.