Biological activities of Zingiber officinale (Zingiberaceae) and Piper cubeba (Piperaceae) essential oils against pulse beetle, Callosobruchus chinensis (Coleoptera: Bruchidae).

Zingiber officinale (Zingiberaceae) and Piper cubeba (Piperaceae) was essential oils were investigated for repellent, insecticidal, antiovipositional, egg hatching, persistence of its insecticidal activities against pulse beetle, Callosobruchus chinensis (Coleoptera: Bruchidae). Essential oil vapours repelled bruchid adults significantly as oviposition was formd reduced in choice oviposition assay. Z. officinale and P. cubeba essential oils caused both fumigant and contact toxicity in C. chinensis adults. In fumigation toxicity assay, median lethal concentrations (LC50 ) were 0.34 and 0.27 µL cm- 3 for Z. officinale andP. cubeba essential oils, respectively, while in contact toxicity assay, LC50 were 0.90 and 0.66 µL cm- 2 for Z. officinale andP. cubeba essential oils, respectively. These two essential oils reduced oviposition in C. chinensis adults when treated with sublethal concentrations by fwnigation and contact method. Oviposition inhibition was more pronormced when adults come in contact than in vapours. Both essential oils significantly reduced egg hatching rate when fwnigated. Persistence in insecticidal efficiency of both essential oils decreased with time. P. cubeba showed less persistence than Z. officinale essential oil because no mortality was observed in C. chinensis adults after 36 h of treatment with?. cubeba and after 48 h of treatment of Z. officinale essential oil. Fwnigation with these essential oils has no effect on the germination of the covVpea seeds. Findings of the study suggest that Z. officinale and P. cubeba essential oils can be useful as promising agent in insect pest management programme.