Insecticide activity of <i>Baccharis dracunculifolia</i> essential oil against <i>Cochliomyia macellaria</i> (Diptera: Calliphoridae)

The ethnobotanical uses of Brazilian plants for different injuries and diseases conjoined with local rich biodiversity represent an important resource for research and development. This study aimed to characterise BDEO and its <i>in vitro</i> activity on the third instar larvae (L3) of <i>Cochliomyia macellaria.</i> Groups of 20 L3 were placed on filter paper impregnated with increasing concentrations of 5–30% (v/v), equivalent to 0.79–4.77 μL/cm², solubilised in ethanol or acetone. The major constituents of BDEO were <i>β</i>-pinene (9.94%), D-limonene (9.59%), <i>β</i>-nerolidol (7.93%), caryophyllene (7.69%), spathulenol (6.69), <i>α</i>-muurolene (6.74%) and <i>α</i>-pinene (5.31%). Lethal concentrations of 50% for BDEO on <i>C. macellaria</i> (LC₅₀) after 24 and 48 h of exposure were 2.63 and 2.47 μL/cm² for ethanol and 9.58 and 8.11 μL/cm² for acetone, respectively. Furthermore, larvae cuticle abnormalities and adult deformity were observed. Our data confirm the effectiveness of BDEO as an ecofriendly product against blowflies.