Monday, December 10, 2007
D0082

Reduced aggressive behavior of fire ants (Solenopsis invicta) in Puerto Rico

Vilmarie Figueroa-Nieves, vilmaystephanie@hotmail.com and Bert Rivera-Marchand, brivera@bc.inter.edu. Inter American University of Puerto Rico, Natural Science and Mathematics, 500 John Will Harris Rd, Bayamon, PR

Solenopsis invicta, known as fire ants, arrived to Puerto Rico in the 1970`s. This ant considered an invasive species, impacts biodiversity, economy and human health. One of its negative characteristics is aggressive behavior. The objective of our study was to evaluate the aggressive behavior of this ant on the island. As with Africanized bees on the island, we expected reduced aggressive behavior in these ants. We first classified the nests of origin of each sample as monogyne or polygyne using a PCR based assay. Then we evaluated intraspecific aggressiveness by observing the interactions of ants from different nests placed in an arena. Observed interactions between ants from the same nest were considered a negative control while interactions between S. invicta and S. geminata were considered positive controls. Assays with all possible combinations of monogyne and polygyne samples were considered experimental groups. There was no significant difference between the negative control and experimental groups. There were, however significantly high levels of aggressive behavior between the positive control and experimental groups. The results of the experiments suggest that the intraspecific aggressive behavior of the studied fire ants is low. These results are similar to studies of invasive Argentine ants in California which were also found to be relatively unaggressive. This study supports the hypothesis that island species tend to be less aggressive than continental ones and extends our knowledge in conservation as well as evolution on islands.


Species 1: Hymenoptera Formicidae Solenopsis invicta (fire ant, red imported fire ant)