Potential for biopesticide use of essential oils against the bean beetle, Callosobruchus maculatus

Abstract

The bean beetle, Callosobruchus maculatus, is an invasive pest species to subtropical and tropical areas that economically depend on stored grains. These beetles are known to cause extensive damage to the stored grains, leaving them unsuitable for production. Currently, synthetic insecticides are the main mode of preventing and treating infestations. Due to well- known issues surrounding insecticides, alternative methods are being examined. We examined the potential for Cinnamon and Clove essential oils at 1% and 2% concentrations to be used as a biopesticide against these beetles. Petri dishes of mung beans were treated with each concentration before beetles were placed into dishes and allowed to reproduce for 48 hours at 30-35 degrees C. Adult mortality, oviposition, and emergence after 5 weeks were recorded. Significant differences (p<0.05) were found between control and oil treatments in all 3 parameters. Clove 2% treatment was most significant in increasing mortality and decreasing other factors compared to no treatment. Therefore, there is potential for essential oils to be effective in acting as a biopesticide against Callosobruchus maculatus. Future studies are needed to assess health risks of essential oils to humans and non-pest species, as well as most effective concentration of treatments.