COMPATIBILITY OF TWO FALL ARMYWORM PATHOGENS WITH THE PREDACEOUS BEETLE, CALOSOMA SAYI (COLEOPTERA: CARABIDAE)

Abstract

Adult carabid beetles (Calosoma sayi DeJean) were allowed to feed on fall armyworm larvae [Spodoptera frugiperda (J. E. Smith)] infected with either a nuclear polyhedrosis virus or a microsporidian protozoan (Vairimorpha sp.). Subsequent longevity of the beetles was monitored and fecal material was bioassayed to determine pathogen infectivity. Beetles fed infected larvae lived at least as long as beetles fed noninfected larvae. Both pathogens were highly infective when voided in beetle feces within 24 hours of ingestion. Concentration of pathogens and infectivity declined in subsequent fecal samples, with some infectivity detected in feces voided 13 – 15 days after consumption of infected larvae.