Response of the Wasp Cephalonomia tarsalis (Hymenoptera: Bethylidae) to Beauveria bassiana (Hyphomycetes: Moniliales) as Free Conidia or Infection in Its Host, the Sawtoothed Grain Beetle, Oryzaephilus surinamensis (Coleoptera: Silvanidae)

Cephalonomia tarsalis, an ectoparasitoid, and Beauveria bassiana, an entomopathogenic fungus, are potential biological control agents for the sawtoothed grain beetle, Oryzaephilus surinamensis. everal experiments were conducted to determine hether the two beneficial organisms are compatile. Wasps exhibited little avoidance behavior toard the fungus. Adult wasps oviposited on B. bassiana-infected larvae up to within 1 day of the host’s death and the appearance of red fungal pigment. Wasp larvae are susceptible to the fungus and die within 1 day of oviposition on host larvae with mycosis. A 3-h exposure of adult wasps to 100 mg of B. bassiana/kg of wheat resulted in 52.7% mortality. Nevertheless, the wasps entered into grain containing B. bassiana conidia as freely as they entered into onidia-free grain. The mean prevalence of B. bassina in 46 samples of pooled wheat representing 276 ocations was 7.5 colony-forming units/g of wheat. atural C. tarsalis exposure to B. bassiana in unreated stored wheat is likely to be below lethal uantities, and the introduction of the fungus in nsecticidal quantities would have a negative impact n C. tarsalis populations.