Department of Entomology Texas A and M University, College Station, TX 77843-2475, USA.
Interference competition and aggressive behavior have been known to play important roles in the organization of ant colonies. Our earlier studies on the behavioral response of founding Solenopsis invicta colonies to Monomorium minimum incursion has given us an insight into the aggressive behavior of these two species. When the frequency of certain behaviors exhibited during confrontation by both species were plotted, one of the behaviors, gasterflagging (raising the abdomen and spraying venom) was observed to be the predominant offensive and defensive behavior used by both S. invicta and M. minimum. Ant’s venom produced by its poison gland is known to be a mixture of enzymes, toxic proteins and biogenic amines. There are a few reports that ant venom repel other species of ants, and have insecticidal activity. Although the venom chemistry of both S. invicta and M. minimum are similar, the behavioral modifications induced by the venom in each of the species was different. Thus, in this study our goal was to study the venom of M. minimum in detail. Further, the persistence of this venom on various substrates and their impact on S. invicta behavior are examined. The results showed that when a crude extract of the M. minimum was applied on a glass surface, S. invicta avoided walking on that surface or covered the surface with debris. The extract activity was observed to be persistent for three days, and a glass surface seems to hold the extract better than filter paper or polyethylene. Similarly, other aspects of relevance are underway.