PROTOZOAN AND FUNGAL DISEASES IN SOLENOPSIS-RICHTERI AND S-QUINQUECUSPIS (HYMENOPTERA, FORMICIDAE) IN BUENOS-AIRES PROVINCE, ARGENTINA

The diversity and abundance of protozoa and fungi infecting colonies o f the fire ants Solenopsis richteri Forel and S. quinquecuspis Forel w ere sun eyed in Buenos Aires province, Argentina. A total of 185 roads ide sites was selected, and 1,836 colonies were sampled and examined u nder phase-contrast microscopy. Pathogens were found at 32% of the sit es and in 10% of the colonies. The microsporidium Thelohania solenopsa e Knell, Allen & Hazard was the most common microorganism; it was pres ent at 25% of the sites and 8% of the colonies. In some sites within t he surveyed region, the percentage of infected colonies with T. soleno psae ranged from 40 to 80%. Other pathogens present were the microspor idium Vairimorpha invictae Jouvenaz & Ellis and the fungus Myrmecomyce s annellisae Jouvenaz & Kimbrough. A field site was selected for futur e ecological studies.