EVect of mono- and polygyne social forms on transmission and spread of a microsporidium in Wre ant populations

Thelohania solenopsae is a pathogen of the red imported Wre ant, Solenopsis invicta, which debilitates queens and eventually causes the demise of colonies. Reductions of infected Weld populations signify its potential usefulness as a biological control agent. Thelohania solenopsae can be transmitted by introducing infected brood into a colony. The social forms of the Wre ant, that is, monogyny (single queen per colony) or polygyny (multiple queens per colony), are associated with diVerent behaviors, such as territoriality, that aVect the degree of intercolony brood transfer. T. solenopsae was found exclusively in polygyne colonies in Florida. Non-synchronous infections of queens and transovarial transmission favor the persistence and probability of detecting infections in polygynous colonies. However, queens or alates with the monogyne genotype can be infected, and infections in monogyne Weld colonies have been reported from Louisiana and Argentina. Limited independent colony-founding capability and shorter dispersal of alate queens with the polygyne genotype relative to monogyne alates may facilitate the maintenance of infections in local polygynous populations. Demise of infected monogyne colonies can be twice as fast as in polygyne colonies and favors the pathogen’s persistence in polygyne Wre ant populations. The social form of the Wre ant reXects diVerent physiological and behavioral aspects of the queen and colony that will impact T. solenopsae spread and ultimate usefulness for biological control. Published by Elsevier Inc.