REPELLENT ACTIVITIES OF SOME INDIGENOUS MEDICINAL PLANTS AGAINST THE STORED GRAIN PESTS TRIBOLIUM CASTANEUM (HBST.) (COLEOPTERA: TENEBRIONIDAE)

The petroleum (Pet.E), methanol (MeOH) and chloroform (CHCl₃) extracts of Rauvolfia canescens (whole plant), Desmodium heterocarpon (whole plant) and Vitex negundo (leaf CHCl₃ MeOH and root Pet. E.) have been thoroughly screened through residual film assay against T. castaneum adults and the repellent activity tests were also carried out on the same to find biological activities. The residual film assay offered promising results with remarkable activity against the adult beetles of T. castaneum. A perusal of the data achieved in this experiment clearly showed the presence of insecticidal properties in Rauvolfia canescens (whole plant), Desmodium heterocarpon (whole plant) and Vitex negundo extracts as well as traces of repellent potential. For repellency D. heterocarpon (whole plant /Pet. Ether) extract and V. negundo (leaf /Pet. Ether) extract were weakly active (P <0.05) and R. canescens (whole plant /Pet. Ether) extract and V. negundo (root /Pet. Ether) extract were mildly active (P<0.01); while the rest showed no repellent activity against the adults beetles of T. castaneum. Comprehensive phyto-chemical analyses of the test plants for its repellent as well as the physiological studies of the active ingredients are very much to be solicited for their effective use in the future pest control and pharmaceutical endeavors.