Impact of Essential Oils on Biological Traits of Trichogramma chilonis Ishii

Abstract

Trichogramma chilonis Ishii (Hymenoptera: Trichogrammatidae) reared on factious host rice moth Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae) is an egg parasitoid on lepidopteran pests. The essential oils, viz., ajowan Trachyspermum ammi, betel Piper betle, and sweet basil Ocimum basilicum and neem oil were assessed for their toxicity and biological traits like parasitism and emergence on T. chilonis. Among the EOs tested, T. ammi caused highest toxicity to T. chilonis (LC50 0.316 ppm) followed by P. betle (LC50 0.567 ppm). At sublethal dose, they had an impact on parasitism and adult emergence of T. chilonis. Whilst O. basilicum and neem oil were relatively safe at sublethal doses to T. chilonis. This study highlights the need to maintain a waiting period before the release of T. chilonis in EOs treated substrates.