Background: The efficacy of root and stem barks oil of Cleistopholis patens as a fumigant agent on Plodia interpunctella infesting maize grains as well as its toxic potential in wistar rats were investigated. Both plant oils were used for fumigant bioassay while only the root oil extract was used for all toxicological studies due to its higher toxicity on P. interpunctella when compared to stem oil extract. Both insects and wistar rats were exposed to different concentrations (0.0, 5%, 10%, 15%, 20% and 25%) of the extract. 36 wistar rats were divided into Group A-F and each group received different concentrations of the oil extract except for Group A that received only dimethyl sulphide saline and various toxicological tests were conducted.
Results: Result shows that both stem and root extracts significantly evoked (p<0.05) higher larva and adult mortality in treated grains when compared to both controls except at 5% of both oil extracts. Ten percent root oil extract achieved 50% mortality in Plodia interpunctella within 48 hrs and 25% achieved 100% mortality in larva and adult of Plodia interpunctella within 72 hrs when compared to the amount needed to achieve 50% and 100% mortality in stem oil extract within 48 hrs and 72 hrs. Irrespective of the concentration administered to the animal, there were no significant alteration (p>0.05) in the toxicological test using both liver and kidney biochemical parameters.
Conclusion: This study shows that root oil extract of C. patens is a very good fumigant poison to Plodia interpunctella with no toxic impact in wistar rats.