Efficacy of Some Medicinal Plant Essential Oils, Extracts and Powders Combined with Diatomaceous Earth on Cowpea Weevil, Callosobruchus maculatus F. (Coleoptera: Bruchidae)

Background Cowpea weevil, Callosobruchus maculatus F. (Coleoptera Bruchidae) is an important storage pest around the world. Material and Methods In this research, we were examined the synergistic interaction between Satureja hortensis L. , Trachyspermum ammi I. Sprague, Ziziphora tenuior L. , Cuminum cyminum L. and Foeniculum vulgare Mill. essential oils, ethanolic extracts and powders alone and with Diatomaceous earth (DE) against C. maculatus adults under laboratory condition. Principle results Results showed that DE had high toxicity to the pest (LC50= 0.15 g/kg). Probit analysis showed that the most effective essential oil, extract and powder were T. ammi, Z. tenuior and C. cyminum which exhibited LC50 values equivalent to 0.64 (L/L air), 578.5 (L/kg of grain) and 0.45 (g/kg of grain), respectively. Essential oils, ethanolic extracts and powders of mentioned plants synergized the performance of DE sample. Hence, combination of these plants with DE could have potential for use in integrated stored product pest-management programs. The results of this research revealed the high repellency of savory essential oil for controlling the pest. But other EOs showed weak repellency. The results demonstrated the average repellency of mentioned extracts.