Reduced infection by neogregarine protozoan Farinocystis sp. following improved collection methods of the West Indian sweet potato weevil Euscepes postfasciatus (Coleoptera: Curculionidae) from the larval rearing cage

Abstract

Prevention or reduction of infection by the neogregarine parasite Farinocystis sp. is indispensable for effective mass-production of the West Indian sweet potato weevil Euscepes postfasciatus (Fairmaire). The established method of weevil collection, coercively drawing weevils from the larval rearing cage, was suspected to increase the risk of breaking infected individuals, which causes horizontal transmission of the parasite to uninfected individuals. Here, we developed a novel collection method in which the weevils were permitted to spontaneously leave the larval rearing cage. The significant decrease in infection rate and the significant increase in the fecundity of weevils collected by the novel method suggested that this method may improve the mass-production of weevils.