Horizon 1 1 17 ACL : Articles dans des revues avec comité de lecture répertoriées par l'AERES Medical and Veterinary Entomology 288-293 Aedes aegypti DEET IR3535 KBR 3023 irritancy knock down effect mortality repellent 2006 fdi:010037660 ENG Medical and Veterinary Entomology 0269-283X CC:0002411555-0004 3 10.1111/j.1365-2915.2006.00630.x https://www.documentation.ird.fr/hor/fdi:010037660 https://www.documentation.ird.fr/intranet/publi/2006/11/010037660.pdf 20 Horizon (IRD) The knock-down, mortality and 'irritancy' effects of three synthetic repellents (DEET, IR3535 and KBR 3023) on Aedes aegypti (L) (Diptera: Culicidae) were evaluated in the laboratory in the absence of animal bait. Filter paper tests were carried out to assess the knock-down effect (KDt(50) and KDt(95)) and mortality (LC50 and LC95) induced by each repellent. 'Irritancy' tests were carried out to compare the flight response (time to first take-off, or FT) to increasing concentrations of repellents (2-7%) and at five distances from the treated surface (0-40 mm). DEET had an insecticidal effect (KDt(50) = 9.7 min at 7%; CL50 = 1165 mg/m(2)), whereas IR3535 and KBR 3023 did not. Relative to an untreated control, IR3535 was an irritant (relative irritancy or RI > 1) at doses of 5% and 7% (RI = 17.7 and 9.9, respectively), whereas DEET was an irritant at lower concentrations (RI = 12.3 at 2% DEET). KBR 3023 was the weakest irritant over the same range of concentrations (RImax = 3.6 at 6%). DEET was more of an irritant (RI20 = 9.4) than IR3535 (RI20 = 2.9) over a range of distances (0-20 mm), and KBR 3023 was not an irritant unless mosquitoes made contact with the treated surface. All three repellents had a significant effect on mosquitoes, but DEET exhibited a more complex mode of action than the others due to its insecticidal properties. The repellents do not behave as a single class of compounds with a common mode of action, but most probably affect different physiological systems in insects. The physiological and molecular mechanisms of repellents, especially DEET, should be investigated to ensure a better use of these molecules for skin applications and/or for treating, materials against mosquitoes. 052