The effect of termite soldier number on Pachycondyla chinensis predation

Pachycondyla chinensis is an atypical invasive ant in North America. Differing markedly from other invasive ants, P. chinensis does not exhibit a mass recruiting strategy and preys preferentially on termites. It has been shown that termites are important as a food source for native woodland ants like Aphaenogaster. Termites are also an important factor in the decomposition of dead trees, contributing significantly to the cycle of carbon within a forest. We predicted that termite colonies with the largest proportion of soldiers would best defend against P. chinensis attack. In laboratory experiments P. chinensis invaded termite nests with a small portion (~12%) of its work force. In colonies with low soldier proportions this invasion lead to a significant increase in termite mortality. However, colonies with higher soldier ratios retarded P. chinensis invasion. It is evident that P. chinensis interaction with termites is detrimental to native termites, impacting other ants that may rely on termites as food, and forest decomposition rates. Further studies focusing on the termite-ant interaction are required to better understand the future of this system. Measuring worker-soldier ratios in P. chinensis-infested vs. un-infested habitats may reveal how termites cope with this invasive ant.