Excito-Repellency of Citrus hystrix DC Leaf and Peel Essential Oils Against Aedes aegypti and Anopheles minimus (Diptera: Culicidae), Vectors of Human Pathogens

The essential oils of kaffir lime (Citrus hystrix DC.) at four different concentrations (0.5, 1.0, 2.5, and 5.0% v/v) were studied for their repellency, excitation, and knockdown properties against laboratory strains of Aedes aegypti (L.) and Anopheles minimus Theobald using an excito-repellency test system. Both contact and noncontact escape responses to leaf- and peel-derived kaffir lime oils were observed. Comparing unadjusted escape responses for An. minimus, leaf oil had strong combined irritant and repellent activity responses at 1–5% concentrations (90.0–96.4% escape) and the strongest spatial repellent activity at 1% and 2% (85.9% and 87.2% escape, respectively). The peel oil exhibited good excitation with repellency at concentrations of 2.5% (89.8% escape) and 5% (96.28% escape), while concentrations 1–5% showed more moderate repellent activity against An. minimus. For Ae. aegypti, 2.5% leaf oil produced the greatest response for both contact (56.1% escape) and noncontact (63.3% escape) trials, while 2.5% produced the strongest response among all concentrations of peel oil, with 46.5% escape. However, after adjusting the contact trial escape (a measure of combined excitation and repellency), the estimated escape due to contact alone was a much weaker response than spatial repellency for both species. Knockdown responses above 50% were only observed in Ae. aegypti exposed to 5% leaf oil. Kaffir lime oils were more active against An. minimus than Ae. ...
Source: Journal of Medical Entomology - Category: Biology Authors: Tags: Vector Control, Pest Management, Resistance, Repellents Source Type: research