Solenopsis (Labauchena) daguerrei (Santschi) is a parasitic ant of fire ants in South America. This parasite produces no worker caste, and is totally reliant on its host colony for its care. Having no worker caste, only reproductive males and females represent this species. S. daguerrei will attach, or yolk, themselves to queens of the black and red imported fire ants, Solenopsis richteri and S. invicta, respectively, and divert resources from the host queen(s). In addition, the host colony also feeds and maintains the brood of S. daguerrei. Thus, S. daguerrei is a potential stress factor of fire ant colonies.

Field studies and observations of the impact of S. daguerrei on the fire ant, S. richteri, are being conducted in sites located in Argentina by ARS scientists at the USDA-ARS South American Biological Control Laboratory in Hurlingham, Argentina . Average percent parasitism from pastures located at 21 sites was 5.1%. Mound densities were 33% less in sites with S. daguerrei and the number of fire ant queens was 47 % less in parasitized colonies.