A VILLAGE-SCALE TRIAL WITH INSECTICIDES CARBARYL AND FOLITHION IN SOUTHERN NIGERIA

Abstract

The insecticides carbaryl and Folithion were tested on a village scale in the vicinity of Lagos, Nigeria, by the WHO Insecticide Testing Unit in 1963. Whereas carbaryl reduced the density of anophelines and culicines for 2 months, Folithion greatly reduced their density for six months or more. The mortality among mosquitos leaving treated dwellings and caught in window-traps in the carbaryl-treated village was fairly high for only one month after treatment, but in the Folithion-treated village it was high for seven months. Bio-assay results showed that Folithion was effective on mud for two-and-a-half months, on wood for seven months, and on thatch for six months. Carbaryl was not effective on mud; on wood it was effective for nine months or more, and on thatch for six to nine months. Anopheles hargreavesi was found to be more exophilic than Anopheles gambiae or culicines.