Field evaluation of an insecticide formulated with active ingredients acting on larval and adult stages of Lutzomyia Longipalpis.

LAURA W. JUAN, IGNACIO T. GOULD, ALEJANDRO LUCIA, OSCAR D. SALOMÓN, JUAN MOLINA, RAUL A. ALZOGARAY AND EDUARDO N. ZERBA

Iguazú - Misiones

Simposio; 8th International Symposium on Phlebotomine Sandfly (ISOPS 2014).; 2014

Organizado por INMET-REDYLA

In Argentina, the American tegumentaryleishmaniasis (ATL) is endemic, with wild enzootic cycles, while visceralleishmaniasis (VL) is urban. VL is more severe because it can affect internal organswith high fatality. Since 2006, this disease is an emerging phenomenon ofpublic health importance. The most practical way of prevention is to controlthe insect vector, phlebotomines sand flies from genus Lutzomyia, byapplication of residual insecticides, and dogs treatment with veterinaryformulations. Recently, insecticide treated nets were introduced withcontroversial results. The application of insecticides in phlebotomines citiesfoci could be an important vector control tactic to reduce urban transmission. With the objective to develop anew control alternative, we evaluated a formulation containing the pyrethroidinsecticide permethrin (10%) and the insect growth regulator pyriproxyfen (2%).According studies performed at our laboratory, permethrin is effective on adultL. longipalpis. Pyriproxyfen is an larvicide that disrupts metamorphosis ofimmature stages of sand fly, preventing it from reaching the adult stage. Thetrial was carried out inthe city of Puerto Iguazú, Misiones, Argentina inMarch-April, 2014. Three dwellings with presence of L. longipalpis, all of themwith poultry houses, were selected. Before applying the formulation, populationlevel of sand fly were monitored for two days with CDC type traps. Theformulation was emulsified in water and applied in two dwellings (TP and Chan).The third house (Ct) was untreated (control). The application was performedduring sunset using a hand pulverizer. Application covered the interior ofhouses and surroundings to a distance of three meters. One week before theapplication the average of number of adults sand flies catched by the trapswere 13 and 22 in the houses TP and Chan, respectively. Just before thetreatment the flies catched during two days were 21 and 11, respectively. Onemonth after the treatment, no flies were catched in TP and just one in Chan. Inthe control house, more than 50 sandflies were catched in all cases. This succesfullresult could be attributed to the complementary effects of the insecticidesapplied: permethrin against adults insects and pyriproxyfen against larvaepresent in soil.