EFFECT OF THE MICROSPORIDIUM THELOHANIA-SOLENOPSAE (MICROSPORIDA, THELOHANIIDAE) ON THE LONGEVITY AND SURVIVAL OF SOLENOPSIS-RICHTERI (HYMENOPTERA, FORMICIDAE) IN THE LABORATORY

The longevity of colonies of the black imported fire ant, Solenopsis r ichteri Forel, and the survival of starved workers and sexual females was compared between healthy colonies and colonies infected with the m icrosporidium Thelohania solenopsae Knell, Alien, & Hazard. The coloni es were collected in the field and reared for approximately four mo. I ndividual workers and sexuals were held without food until death. The body weight of infected and healthy workers was compared. After 3 mo o f laboratory rearing, longevity of infected colonies was significantly shorter than that of healthy ones mortality of infected colonies was 92% and mortality of healthy colonies was 49%. At 27 degrees C, mortal ity rate of workers from infected colonies was higher than in healthy workers. Workers from infected colonies lived between 8.8 and 29.2% le ss than healthy workers. At 22 degrees C, no statistical significance was observed. At 21 degrees C, only the initial mortality of sexual fe males was higher in infected than in healthy individuals. The weight o f infected workers was very similar to that of healthy workers. T. sol enopsae should be considered for the biological control of the importe d fire ants in the United States.