1 School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington, 6140, NZ
2 Entecol Ltd. PO Box 142, Nelson 7040, New Zealand
By investigating the temporal variation in toxic bait preference in Argentine and Darwin’s ants, we can provide better control options because we can identify with more accuracy when ants will be foraging for one food type over another. Improving our understanding is also fundamental as we can improve future bait formulations, bait application and timing, and increase levels of bait uptake. I studied the food preferences, toxic bait preferences, and the toxicity of the baits for Argentine ants (Linepithema humile) and Darwin's ant (Doleromyrma darwiniana). Food preferences varied between species and within species considerably throughout the year, although Darwin's ant consistently favoured foods higher in carbohydrates. Despite differences in carbohydrate and protein preferences the preference for individual toxic baits showed little temporal variation. Bait preference, however, did not correlate to toxicity. The success of a toxic bait is its ability to kill an entire ant colony. Xstinguish and Extermanant baits produced the highest mortality rate. Other commercially available toxic baits had little effect on workers or queens. The efficacy of even highly toxic baits was influenced by the degree of hunger with the ants. I discuss the implications of these results for the control of invasive ants.