Evaluation of Essential Oil and its Three Main Active Ingredients of Chinese Chenopodium Ambrosioides (Family: Chenopodiaceae) Against Blattella Germanica

Background: The efficacy of essential oil of Chenopodium ambrosioides flowering aerial parts and its three mainactive ingredients was evaluated against Blattella germanica male adults.Methods: Composition of essential oil was determined by GC-MS. Topical application bioassay was used to evaluatecontact toxicity of essential oil and three main components. Fumigant toxicity of essential oil and its main components was measured using a sealed space method.Results: Twenty-two components were identified in the essential oil and the main components were (Z)-ascaridole(29.7%), isoascaridole (13.0%), ρ-cymene (12.7%) and piperitone (5.0%). The essential oil and (Z)-ascaridole,isoascaridole and -cymene possessed fumigant toxicity against male German cockroaches with LC50 values of 4.13,0.55, 2.07 and 6.92 mg/L air, respectively. Topical application bioassay showed that all the three compounds weretoxic to male German cockroaches and (Z)-ascaridole was the strongest with a LD50 value of 22.02 g/adult while the crude oil with a LD50 value of 67.46 g/adult.Conclusion: The essential oil from Chinese C. ambrosioides and its three main active ingredients may be explored as natural potential insecticides in the control of cockroaches.