Foraging Activity of Native Ants on Trees in Forest Fragments Colonized by the Invasive AntLasius neglectus

摘要

Our aim was to investigate the foraging activity of native ants on tree trunks in accordance with their location in forest fragments and the presence or absence of the invasive antLasius neglectus. Trees were categorized as isolated, edge, or core trees according to their location in forest fragments. In invaded fragments,Lasius neglectushad the highest spatial-temporal tree visitation. Isolated trees were visited more and for a longer time by this invasive ant. Invaded fragments had low native ant activity on trees compared to fragments withoutL. neglectus. The few encountered native ant species showed a lower frequency of visitation and for less time in comparison with their spatial-temporal visitation in control fragments.Crematogaster scutellarisandTemnothorax lichtensteinivisited all tree categories in both fragments (invaded or control) butLasius grandisstayed for longer on isolated trees from control fragments. We conclude that in fragments invaded byLasius neglectus, the richness of native ant foraging on trees was negatively affected. Isolated trees close to roads could act as dispersal stepping stones forLasius neglectus.