Dr Peter Yeeles1, Angela Strain1, Carl Shuetrim1, Lucy Karger2, Professor Lori Lach1

1James Cook University, Australia, 2Wet Tropics Management Authority, Cairns, Australia

Biography:

Dr Peter Yeeles has over 20 years of experience working in science, with the past 12 years in ecology and entomology. Peter is broadly interested in the ecology and natural history of insects, with his work to date falling within with two main themes; the use of functional traits to understand insect community ecology, and ant invasions, including the optimization of eradication program methods, and the consequences of ant invasion and any subsequent invasive species management. At present, Peter is primarily working on a project providing science-backed support to the Wet Tropics Management Authority’s yellow crazy ant eradication efforts.

Abstract:

Many studies document the consequences of invasive species. Less understood is the trajectory of ecological community recovery once eradication of an invader has been achieved. We assessed the responses of native rainforest ant communities in the Australian Wet Tropics to yellow crazy ant (YCA) invasion, and baits to eradicate YCA, by sampling ground-dwelling ant communities at 21 sites of three types: sites invaded by YCA and treated using aerial bait application, buffer sites that were treated but uninvaded, and control sites that were untreated and uninvaded. Over seven years of sampling, we collected 122,914 ants of 169 morphospecies. Ant species richness in invaded and buffer sites was initially lower than in control sites but increased to become similar to control sites four years after treatment cessation. We observed no effect of site type on ant abundance. However, multivariate analysis revealed that community composition remained significantly different four years following bait application (LRT=218.3, p=0.01), indicating that the species of ants recolonising after invasion and baiting were different to those in control sites. At the 12 sites at which we continued monitoring, convergence of community composition required seven years. Our results demonstrate the importance of assessing species composition, not just diversity, when evaluating recovery of ant communities after removal of invasive ants using broadscale insecticide application. Careful evaluation of community recovery provides valuable information for planning insecticidal baiting of invasive species in sensitive habitats such as the Wet Tropics.