Ricinus communis seed extracts in 4 different solvents (petroleum ether, chloroform, acetone and methanol) at LC50 and LC95 as surface treatment were tested to protect cowpea seeds against the cowpea weevil, Caliosobruchus maculatus F. Effect of extracts on the fer­tility of C.macuistus, hatchability of its eggs, progeny of emerging adults and immature stages were tested. Results indicated that R.communis ex­tracts reduced egg production of C.maculatus females, hatchability of eggs and adult emergence. Chloroform extract was the most effective at LC50 and LC₉₅ levels. Other extracts could be arranged according to their effect on egg laying as follows: methanol > acetone> petroleum ether. As for egg hatchability, chloroform extract was more effective than the other tested extracts. For all tested 4 extracts, rates of adult emergence were considerably reduced at LC₅0 level and dropped to zero at LC₉₅ level. All tested extracts affected percentages of adults emerged from treated seeds, 5, 10 and 15 day after infestation at both LC50 and LC95 levels.