The Use of Fumidil-B to Reduce Microsporidian Disease in Colonies of the Boll Weevil

When Fumidil-B® was fed to larval and adult boll weevils, Anthonomus grandis Boheman (Coleoptera: Curculionidae), to reduce the percent of weevils infected by a microsporidian (designated as 1069), a dose of 0.25% in the adult diet resulted in an average of 2% infected weevils (determined by presence of spores) at 2 weeks postemergence compared with 21% infection of similar weevils fed diet without Fumidil-B. Longevity was not affected by this dose, but fecundity and egg hatch were reduced to 32 and 76% of the control, respectively. Weevils from a diseased colony fed larval and then adult diets containing 0.15 and 0.0025% Fumidil-B, respectively, were 12% diseased compared with 86% of weevils reared and maintained on untreated diets.