Exploration of various essential oils as fumigant to protect stored grains from insect damage

Abstract

A considerable research effort has been focused on developing effective insecticide from natural origin. The essential oils and its major chemical constituents have great potential to explore as new insecticide due to insect resistance against synthetic insecticide. In this study, the fumigant toxicity assay of selected essential oils was performed against adults of Callosobruchus maculates (Chickpea weevil/pulse beetle) and Tribolium castaneum (Red flour beetle). Results showed that the Mentha spicata var. viridis oil (MVO) was the most potent fumigant against both the pests namely C. maculates (100% average mortality at 1% oil concentration) and T. castaneum (100% average mortality at 4% oil concentration) among selected essential oils, while Cymbopogon citratus, Cymbopogon nardus and Eucalyptus hybrid exhibited 100% average mortality at 6% oil concentration against C. maculates only. Conclusively, MVO had been identified as active lead from the present study and will be further evaluated for its active phytoconstituent(s).

Deleterious Effects of Cymbopogon nardus (L.) Essential Oil on Life Cycle and Midgut of the Natural Predator Ceraeochrysa claveri (Navás, 1911) (Neuroptera: Chrysopidae)

“…Chemicals present at high concentrations in C. nardus EO, in particular geraniol and citronellol, have been reported as highly efficient inducers of repellency against the booklouse, Liposcelis bostrychophila, and the red flour beetle, Tribolium castaneum [33]. In fact, this EO has great agricultural interest due to reports on its fumigant, repellent, and insecticidal action, properties that have also been evaluated on insects such as Callosobruchus maculatus [34], Ulomoides dermestoides [21], Oryzaephilus surinamensis, and Sitophilus zeamais [19]. As presented, the literature and data shown here with C. claveri evidence that Cymbopogon nardus EO has little specificity on its biotargets, and it may act on both natural predators and insects considered to be pests.…”