SUPERCOOLING STUDIES ON THE IMPORTED FIRE ANTS: SOLENOPSIS INVICTA AND SOLENOPSIS RICHTERI (HYMENOPTERA: FORMICIDAE) AND THEIR HYBRID

The discovery of hybrid fire ants, Solenopsis invicta × S. richteri, in northwest Georgia at a more northern latitude than S. invicta led to an investigation into the hybrid's ability to withstand cold temperatures. This study was undertaken to determine if the hybrid would supercool at a lower temperature than either parental species. Major workers, male alates, and female alates of the three ant types were collected, and supercooling points were determined. Of the three castes tested, only male alates of the hybrid and S. richteri had lower supercooling points than did S. invicta. The inhabitance of north Georgia by the hybrid fire ant and not S. invicta does not seem to be determined by supercooling.