Acute and Synergistic Effects of Some Monoterpenoid Essential Oil Compounds on the House Fly (Musca domesticaL.)

Acute toxicity and synergistic effects of six monoterpenoids on Musca domestica adults were found. Of the essential oils compounds tested for topical acute toxicity, the most potent were thymol and carvacrol, with LD50 values < 100 µg per adult. In comparison, for fumigant acute toxicity the most potent were γ-terpinene, p-cymene and cineole, with LD50 values < 100 µg per cm3. Twelve binary mixtures out of 15 tested couples showed synergistic effects in topical application. The most significant synergism was found with p-cymene in combination with 1,8-cineole, γ-terpinene or carvacrol. In the fumigant application, 8 binary mixtures showed a synergistic effect. The most profound synergistic effect was found in p-cymene with γ-terpinene or with 1,8-cineole and γ-terpinene in the mixture with 1,8-cineole.