Detrimental effects of feeding Pleistophora schubergi (Microsporida) to spruce budworm (Choristoneura fumiferana) naturally infected with Nosema fumiferanae

Abstract

Spores of the microsporidian Pleistophora schubergi Zwölfer were fed to spruce budworm, Choristoneura fumiferana (Clem.), naturally infected with Nosema fumiferanae (Thorn.). Larval mortality increased while female pupal weights, adult longevity, and fecundity were significantly reduced by feeding P. schubergi spores. High spore concentrations (5 × 108 spores) and inoculation as second-instar larvae produced the most detrimental effects.