Insecticidal Activity of Essential Oil against the Stable Fly (Diptera: Muscidae) and the Horse Fly (Diptera: Tabanidae).

The stable fly, (Diptera: Muscidae), and the horse fly, (Diptera: Tabanidae), are important ectoparasites of livestock in Thailand. These species affect animal health and cause economic losses. This study investigated the insecticidal activity of essential oil against and through contact and fumigant toxicity tests and evaluated the effects of the essential oil on these flies through histopathological and scanning electron microscopic (SEM) studies. The results of the contact toxicity test indicated that the median lethal dose against and was 12.05 and 131.41 µg/fly, and the 90% lethal dose was 45.53 and 200.62 µg/fly, respectively. The results of the fumigant toxicity test showed that the median lethal concentration against and was 1.34 and 7.12 mg/L air, and the 90% lethal concentration was 4.39 and 30.37 mg/L air, respectively. Histopathology revealed neuronal degeneration in the brain of and interstitial neuronal edema of the brain and ovarian necrosis in No external morphological changes were observed via SEM. Given its insecticidal properties against and , essential oil could be developed into a natural insecticide to control these fly species.