INSECTICIDE PROPERTIES OF THE ESSENTIAL OILS FROM HAPLOPAPPUS FOLIOSUS AND BAHIA AMBROSOIDES AGAINST THE HOUSE FLY, MUSCA DOMESTICA L

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). Accordingto 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.