Colonies of Linepithema humile in natural areas within the city of Buenos Aires

SOLA, F.; JOSENS, R

Conferencia; 7th International Conference on Urban Pests; 2011

We followed the distribution of Linepithema humile colonies over three years in a natural area of the University of Buenos Aires Campus, within the city of Buenos Aires. We determined the extent of multi-nest colonies by means of aggression tests. Colonies involved several nests up to four to five hundred meters apart, adding to areas of around 5,000 m2, though smaller ones were found. These dimensions coincided with literature for Argentine ant colony sizes within native ranges. Nests were found under rocks, in earth and in trees, dead logs, but also within buildings, grass medians, in and under flower pots, and even in cracks in roads. Colonies distribution, as defined by aggression behaviour was approximately maintained over the years, though individual nests could move, arise or disappear, while conserving similar areas for each colony. We shall discuss the role of the urban barriers as effective limits in colonies’ distribution.