Repellent activity of natural origin substances as a strategy of protection and integrated management for Aedes aegypti (Diptera: Culicidae).

ALVAREZ COSTA, AGUSTÍN; GONZALEZ, PAULA V; HARBURGUER, LAURA V; RODRIGUEZ, MORENA; MASUH, HÉCTOR M

Valparaiso

Congreso; 5th Congress of the Latin American Association of Chemical Ecology (ALAEQ); 2018

ALAEQ

Aedes aegypti (L.) is the main vector of some arboviral diseases. One of the first lines of defense that is possible to constitute between mosquitoes and humans is the use of repellents. N,N-diethyl-3-methylbenzamide is a synthetic insect repellent used worldwide to protect people from bites of blood-sucking arthropods. δ-dodecalactone is an aliphatic lactone widely found in vegetable tissues, who has shown to have repellent effect on lice resistant to permethrin. The aim of this study was to evaluate the repellent effect in Ae. aegyptifemales of δ-dodecalactone alone and in combination with DEET (in a nonrepellent concentration) through different behavioral bioassays. In vitro bioassays were carried out in a petri dish (diam.: 9 cm), with a filter paper divided into a treated zone (different concentrations of δ-dodecalactone from 0, 01 to 200 mg/ml in combination with 0,005mg/ml of DEET) and a control zone (acetone). The individual behavior of the females was registered for 10 min and then analyzed with the Ethovision XT video tracking software, which allowed the automated tracking and quantification of the behavior. The repellency index was determined (RI) = [(Tt-Tr)/Tt)] where, Tt is the total time in both areas and Tr is the time in treated zone. Secondly, in vivo bioassays were conducted on pigeons with a section of skin impregnated with the effective concentrations of δ-dodecalactona (100 mg/ml) and DEET in alcohol, including a positive (DEET 7%) and negative (alcohol) control. The percentage of feed inhibition was calculated as follows FI [%] = [(1−T/C) ×100] where C is the number of females eaten in the control and T the number of females eaten in the treated. The results showed an effective repellent effect of the δ-dodecalactone and an increased effect in combination with DEET. These studies can contribute to the production of repellents using natural compounds as the main active ingredient.