Identification of Fire-ants of the Solenopsis Saevissima Species-group Based on Mtdna Sequences and Morphological Characters

Abstract:
The fire-ants are widely distributed in Brazil, including urban areas, but few studies are found in this country. The Solenopsis saevissima species-group encompasses ecologically and economically important ants, and has the largest number of species of the genus Solenopsis. In Brazil, the main species considered pests are S. invicta e S. saevissima. Due to the high species diversity and the reduced number of diagnostic morphological characters, identifying them is very hard, and the advanced in molecular techniques have been solved some of this problems. Thus, this study aimed to identify the ants of the S. saevissima species-group, in the city of São Paulo, through observations on mitochondrial DNA and morphological characters. Sixty-four nests were evaluated. We identified the occurrence of four haplotypes. Two of them were more similar to S. saevissima and the others showed greater similarity to S. invicta. Morphological analysis did not distinguish the two species, through major worker investigation.