Efficacy of Origanum vulgare essential oil and carvacrol against the housefly, Musca domestica L. (Diptera: Muscidae).

The toxicity of Origanum vulgare essential oil to the housefly Musca domestica L. was evaluated. The major constituents of the O. vulgare essential oil by gas chromatographic mass spectrometry (GC-MS) analysis were carvacrol (58.13%), p-cymene (17.85%), thymol (8.15%), γ-terpinene (4.96%), and linalool (3.69%). Toxicity of O. vulgare essential oil against larvae and pupae was evaluated using fumigation and contact assays. The contact toxicity (LC ₅₀ ) of O. vulgare essential oil and carvacrol for larvae was 0.23 and 0.03 μL/cm ² , respectively. The fumigation toxicity (LC ₅₀ ) of O. vulgare essential oil and carvacrol for larvae was 9.52 and 2.78 μL/L, respectively. Pupal toxicity was evaluated by percentage inhibition rate (PIR). PIR of O. vulgare essential oil at 0.25 μL/cm ² was 90.9% for the contact assay and 100% at 20 μL/L for the fumigation assay. PIR of carvacrol was 29.5% (0.025 μL/cm ² ) and 81.8% (1.25 μL/L) for the contact toxicity and fumigation assay, respectively. O. vulgare essential oil and carvacrol have significant toxicity to the housefly and are potential insecticides for housefly control.