Primary Screening of Plant Essential Oils as Insecticides, Fumigants, and Repellents Against the Health Pest Paederus fuscipes (Coleoptera: Staphylinidae).

The contact and fumigant toxicity as well as repellent activity of 10 plant essential oils were evaluated against Paederus fuscipes Curtis adults. Essential oils were identified through gas chromatography-mass spectrometry analysis. Results showed that wintergreen oil exhibited optimal contact and fumigant toxicity but had no significant repellent activity against P. fuscipes. The LC50 values of fumigant toxicity of wintergreen oil were 2.680 and 1.591 µL/L air after 1 and 8 h of exposure, respectively. The LC50 values of contact toxicity of wintergreen oil were 0.086 and 0.060 µL/adult after 1 and 8 h of exposure, respectively. Cinnamon oil exhibited the highest repellent activity. In particular, 0.1 µL/cm2 cinnamon oil showed 100% repellency against P. fuscipes even for 6 h. Moreover, 0.01 and 0.005 µL/cm2 cinnamon oil conferred 80% repellency against P. fuscipes for 8 and 4 h, respectively. Overall, wintergreen oil is the best candidate insecticide and fumigant, and cinnamon oil is optimal as a repellent. The low-dose, rapid action of wintergreen oil and the low-dose, persistent repellency of cinnamon oil are important factors that suggest their use as insecticides, fumigants, and repellents against P. fuscipes.