The development and survival of sand fly Phlebotomus papatasi Scopoli (Diptera: Psychodidae) larvae fed feces of Syrian hamsters, Mesocricetus auratus, that had been fed a diet containing novaluron were evaluated. In total, six larval diets were used in sand fly larval bioassays. Four groups of larvae were fed feces of hamsters that had been maintained on a diet containing either 0, 9.88, 98.8, or 988 ppm novaluron. Two additional groups were fed a larval diet composed of equal parts composted rabbit feces and rabbit chow containing either 0 or 988 ppm novaluron. No pupation, hence no adult emergence, occurred when larvae were fed feces of hamsters that were fed diets containing novaluron. The mortality of sand flies fed feces of treated hamsters occurred during larval molts. The results of this study suggest that a control strategy using rodent baits containing novaluron to control phlebotomine sand flies and zoonotic cutaneous leishmaniasis may be possible.

Ivermectin was evaluated as a potential rodent feed-through for the control of immature stages of Phlebotomus papatasi. The survival of sand fly larvae fed feces of Syrian hamsters (Mesocricetus auratus) that had been fed a diet containing 0, 2, 6, 10, 20, 60, or 100 ppm ivermectin was measured. Sand fly larvae fed the feces of ivermectin-treated hamsters had significantly reduced survival, with 100% mortality of larvae fed feces of hamsters fed a diet containing 20, 60, and 100 ppm ivermectin. The results of this study suggest that a control strategy using rodent baits containing ivermectin to control phlebotomine sand flies may be possible. Because rodent reservoirs and sand fly vectors of Leishmania major live in close association in many parts of the Middle East, the control of transmission of the agent of zoonotic cutaneous leishmaniasis also may be possible.

In laboratory studies, insecticides (diflubenzuron, novaluron, methoprene and, pyriproxyfen) that have been incorporated into rodent diets were effective as feed-throughs against sand fly larvae. Novaluron also was effective against sand fly larvae at low concentrations and under simulated field conditions. Ivermectin has been shown to be effective as a systemic insecticide, killing 100% of blood-feeding sand flies for up to seven d after rodents were treated. The fluorescent tracer technique (FTT) is the use of certain fluorescent dyes (rhodamine B or uranine O) as feed-through transtadial biomarkers for phlebotomine sand flies, systemic biomarkers for blood-feeding sand flies, and permanent markers for nectar-feeding sand flies. The results of these laboratory studies provide proof of concept for the FTT and indicate that the FTT could be used to delineate specific foci with rodent/sand fly associations that would be susceptible to control by using feed-through or systemic insecticides, or foci where insecticide-treated sugar baits could be used against sand flies. Journal of Vector Ecology 36 (Supplement 1): S132-S137. 2011.

The sand fly Phlebotomus papatasi Scopoli is the vector of Leishmania major (Yakimoff & Schokhor), which is maintained in populations of burrowing rodents. The purpose of this study was to conduct a laboratory study to determine the efficacy of oral treatment of rodents with fipronil for control of sand flies that feed on rodent feces as larvae or on rodent blood as adults. We determined through larval bioassays that fipronil was eliminated in feces of orally-treated hamsters at a level that was significantly toxic to sand fly larvae for 21 d after the hamsters had been withdrawn from a fipronil-treated diet. Through bloodfeeding bioassays, we also found that fipronil was present in the peripheral blood of hamsters at a concentration that was significantly toxic to bloodfeeding adult female sand flies for 49 d after the hamsters had been withdrawn from their treated diet. The results of this study suggest that fipronil acts as well as or better than feed-through or systemic insecticides that previously have been measured against sand flies, and is particularly promising because this single compound acts against both larvae and bloodfeeding adults. An area-wide approach using rodent baits containing a fipronil could suppress vector populations that originate in the vicinity of rodent reservoirs, and could be used to eliminate the most epidemiologically important part of the vector population: female sand flies that take bloodmeals on rodent reservoirs.

Abstract. The juvenile hormone analogues methoprene and pyriproxyfen were evaluated as rodent feed-through insecticides for control of immature stages of the sandfly Phlebotomus papatasi Scopoli (Diptera: Psychodidae). The development and survival of P. papatasi second-instar larvae fed faeces from Syrian hamsters, Mesocricetus auratus, that had been fed a diet containing methoprene (0, 9.788, 97.88 or 978.8 p.p.m.) or pyriproxyfen (0, 9.82, 98.2 or 982 p.p.m.) were evaluated. The faeces of methoprene-treated hamsters greatly reduced the percentage of larvae that pupated at all concentrations tested and prevented adult emergence at all but the lowest concentration (9.788 p.p.m.). Pyriproxyfen prevented both pupation and adult emergence at all concentrations tested. The results of this study suggest that a control strategy using rodent baits containing juvenile hormone analogues to control phlebotomine sandflies that live in rodent burrows and feed on rodent faeces may be possible. As rodent reservoirs and vectors of Leishmania major live in close association in many parts of the Middle East, control of the transmission of the agent of zoonotic cutaneous leishmaniasis may also be possible.