Barrier spraying to control the malaria vector Anopheles albimanus: laboratory and field evaluation in the Dominican Republic

Abstract

<jats:p><jats:bold>Abstract. </jats:bold> To develop a new strategy for control of exophilic/exophagic malaria vectors which rest on peridomestic foliage, <jats:italic>Anopheles albimanus</jats:italic> was used for laboratory bioassays of mosquito adulticides applied to various vegetation types. Of the three classes of insecticide tested, the pyrethroid (permethrin at 112 g/ha) showed greater foliar persistence than either the carbamate (bendiocarb at 340g/ha) or the organophosphorus compound (malathion at 277g/ha).</jats:p><jats:p>Field evaluation of barrier spraying against <jats:italic>An.albimanus</jats:italic> was evaluated in rural villages of southwest Dominican Republic during 1989. The pyrethroid deltamethrin was sprayed aerially for ultra‐low volume application at treatment rates of 17‐19ga.i./ha in a radius of 500m around two villages. <jats:italic>An.albimanus</jats:italic> were monitored by light‐traps and human bait collections at both treated villages, compared with two similar untreated villages, up to 9 nights post‐treatment. Densities of female <jats:italic>An.albimanus</jats:italic> were significantly reduced in the sprayed villages for at least 8 or 9 nights. Further evaluation of barrier spraying is recommended to determine optimal pyrethroid formulations and applications rates, their impact on non‐target fauna and efficacy against malaria transmission.</jats:p>