The effect of aqueous leaf extract of Andrographis paniculata on cowpea seed treated against cowpea weevil (Callosobruchus maculatus) was investigated. One hundred and fifty (150) adult cowpea weevils with three hundred cowpea seeds were used and divided into five treatment groups (0 (control); 0.125; 0.250; 0.375 and 0.500 w/v) with three replicates. The phytochemical analysis revealed that it contains some active ingredients such as terpenoid, flavonoid, glycosides and sugar moiety. All the extracts at different concentration showed antefeedant and repellant effects since all the treated groups gave 100 % mortality at 96 h post treatment. The extract inhibits egg laying and development, prevents seed damage and was statistically different (p>0.05) compared with the control. Survival of adult cowpea weevil was least on highest dosage (50%) of extract treated seeds. The inhibitory potential of the extract shows it was dose- dependent. It is well obvious from our results that plant extract can control cowpea stored pest. Result of this investigation showed that A. paniculata possessinsecticidal activity againstC. maculatus.In conclusion, results obtained from this study confirmed that the aqueous extracts of test plants species has great potential for use as a plant-based biopesticide for effective in controlling cowpea weevil population in stored seeds.The aqueous extracts ofA. paniculata couldserve as alternatives to synthetic insecticides for use by resourcepoor farmers who store small quantities of the seeds for their consumption, sales and planting
