Meeting Abstract
Ants include some of the most successful and widespread urban invaders. Rough harvester ants (Pogonomyrmex rugosus) are found throughout urban habitats in the Southwest, likely as a result of invasion from neighboring rural areas. Founder effects following urban invasion are expected to decrease genetic diversity within colonies and increase genetic similarity between colonies, and thus lower intraspecific aggression. We conducted 350 trials comparing inter-colony aggression within and between urban and rural settings. In trials conducted between neighboring colonies, urban colonies displayed lower aggression than rural colonies. In contrast, urban and rural colonies showed similar levels of aggression towards non-neighbors from the same setting and across the two settings. We assessed genetic diversity within colonies using three microsatellite loci. Preliminary results for three markers and six colonies per setting indicate that urban colonies exhibit lower genetic diversity than rural colonies. These results suggest lower genetic diversity within neighboring urban colonies has led to lower intraspecific aggression among neighboring colonies.
