Field evaluation of a new insect growth regulator, pyriproxyfen, against Anopheles farauti, the main vector of malaria in the Solomon Islands

Abstract

A field study to control A. farauti with pyriproxyfen (S-31183) was carried out in northern Guadalcanal, Solomon Islands, in September 1987-February 1988. An emulsifiable concentrate of 1% pyriproxyfen was applied to 2 'breeding' sites: one with fresh water and another with brackish water. Pyriproxyfen at a dosage of 0.1 p.p.m. inhibited emergence of A. farauti completely, at both test sites, for at least 5 weeks after treatment and the efficacy (more than 70% inhibition) lasted for ca. 2 months. The body colour of the larvae and pupae in the test sites whitened noticeably after the application of the compound. ADDITIONAL ABSTRACT: An emulsion of pyriproxyfen (S-31183, 4-phenoxyphenyl (RS)-2-(2-pyridyloxy)propyl ether) was applied by knapsack sprayer to a fresh water pond and a brackish water lagoon on the north coast of Guadalcanal, at a dosage of 0.1 p.p.m. active ingredient. At both sites, the emergence of Anopheles farauti adults was inhibited totally for at least 32 days and more than 50% for 110 days after treatment. Larvae and pupae at both test sites were much paler than those at 2 control sites, for about 8 weeks after treatment.