Promotion of nucleopolyhedrovirus infection in larvae of the silkworm, Bombyx mori (Lepidoptera: Bombycidae) by an antibiotic, nikkomycin Z

Abstract

Nikkomycin Z, an antibiotic, promoted infection of Bombyx mori nucleopolyhedrovirus (BmNPV) in 4th-stadium B. mori larvae, when the chemical was incorporated into the larval diet. The median lethal dose (LD₅₀) of BmNPV was decreased as the concentration of nikkomycin Z was increased. LD₅₀ of BmNPV in larvae that received 10 ppm nikkomycin Z was 0.7–1.1 polyhedra/larva. The peritrophic membrane was not observed in the gut of larvae that had received 10 ppm nikkomycin Z. Although the growth of larvae that had received 10 ppm nikkomycin Z was delayed, they molted to the next stadium.