Insecticide properties of the essential oils from Haplopappus foliosus and Bahia ambrosoides against the house fly, Musca domestica L.

Abstract

The compositions of the essential oils (EO?s) obtained by hydro distillation from fresh leaves of Haplopappus foliosus and Bahia ambrosoides was analyzed by gas chromatography/mass spectroscopy (GC/MS). The insecticidal activity of each oil against the house fly Musca domestica was evaluated by placing flies in a glass jar with a screw cap that held a piece of EO-treated cotton yarn. The dose necessary to kill 50% of flies (LC50) in 1 h was determined at 26±1°C. The essential oil from Haplopappus foliosus was the most potent insecticide (LC50 = 4.43 mg/dm3), wile the EO from Bahia ambrosoides shows only moderated insecticide activity (LC50 = 19.27 mg/dm3). According to GC and GC/MS analysis, limonene (28,00%); epi-bicyclosesquiphellandrene (9,84%); bornyl acetate (7,74%); 4-terpineol (6,36%); p-cymene (6,00%); agarospirol (5,53%); α-muurolene (4,34%); δ-cadinene (3,98%) and caryophyllene (3,97%) were the principal components of Haplopappus foliosus EO and limonene (28,16%); α-pinene (11,12%); germacrene D (8,81%); sabinene (5,93%); α-thujene (3,48%); γ-curcumene (3,45%) y α-bergamotene (3,36%) were the principal components of Bahia ambrosoides EO. The EO from Haplopappus foliosus seem promising as a natural insecticide against houseflies and the difference with the activity of the EO of Bahia ambrosoides can be ascribed to the content of oxygenated monoterpenoids and sesquiterpenoids.