Transmission of Beauveria bassiana within nests of Solenopsis invicta (Hymenoptera: Formicidae) in the laboratory

This study evaluated transmission of Beauveria bassiana (Bals.) Vuill. within populations of the red imported fire ant, Solenopsis invicta Buren. Treatments consisted of populations of B. bassiana-infected ants mixed with untreated ants in laboratory colonies. In the absence of soil, survival of untreated ants decreased with increasing percentage of infected ants in the populations. In the presence of soil, no significant differences were observed in the survival of the untreated ants. Differences in ant infection in experiments with and without soil were not caused by differences in infectivity of conidia produced on cadavers. The transmission of the disease within the colony is decreased by the presence of soil. Reliance on transmission of B. bassiana within the nest initiated by infection of a small proportion of the population may not be a viable strategy for control of fire ant colonies with B. bassiana