In VitroEfficacy of Four Insecticides Against Eggs of Tunga penetrans (Siphonaptera)

Abstract

Systematic assessments of control measures against the jigger flea Tunga penetrans are scarce, and there are no published data available on the efficacy of environmental insecticides against immature stages. We tested four environmental contact insecticides used by Brazilian authorities for disease control (deltamethrin, bifenthrin, dichlorvos and etofenprox) against T. penetrans eggs. Eggs were reared in vitro. Hatch rates were observed under standardized conditions and compared to a control group (40 eggs in each group). No larvae hatched after treatment with the organophosphate dichlorvos (100% efficacy). The efficacies of the other products tested varied between 17% and 57%. The data show that the organophosphate dichlorvos had a good in vitro efficacy. The use of dichlorvos can be directed to typical spots where early stages of T. penetrans are expected, considering its toxicity. Disease control should also consist of prevention measures concerning housing and environmental conditions, veterinary and human health measures.