Insecticidal activities of enriched sulfur-containing compounds essential oils from Afrostyrax lepidophyllus and Scorodophloeus zenkeri seeds against two stored grain pests: Acanthoscelides obtectus and Callosobruchus maculatus

This work consisted of evaluating the insecticidal activities of essential oils of the seeds of two Cameroonian aromatic plants namely Afrostyrax lepidophyllus Milbdr.(Huaceae) and Scorodophloeus zenkeri Harms.(Fabaceae).These seeds are generally used to flavour the meals in Cameroon and their essential oils are mainly constituted by sulfurcontaining compounds (96.1% for S. zenkeri and 91% for A. lepidophyllus) and with the same major constituent, 2,4,5,7-tetrathiaoctane (52.9% in A. lepidophyllus and 51.5% in S. zenkeri).Thus, these oils were evaluated for their insecticidal activities against Acanthoscelides obtectus Say, (Coleoptera: Chrysomelidae) and Callosobruchus maculatus Fabricius, (Coleoptera: Chrysomelidae) main stored grain pests of common bean and cowpea seeds respectively.It has been established that the repellent and toxic effects of the oils vary according to the plant and the insect species.Moreover, production of progeny was completely suppressed on treated common beans and cowpea.Finally, these mixtures of organosulfur compounds from plant origin considerably reduce the weight losses of cowpea and common bean grains, without detrimental effect on their germination.These oils could therefore be used as alternative to some hazardous pesticides currently use for protection of stored grains against insect pests.