Wasmannia auropunctata (Hymenoptera: Formicidae): ¿Unicolonial o multicolonial? in the valley Cauca river

Abstract

With the aim of identifying little fire ant Wasmannia auropunctata’s social structure in drastically disturbed environments, we modeled the spatial distribution of this species in two patches of dry forest with contrasting levels of disturbance, at southand and north of the Cauca river valley, a region for which W. auropunctata is considered native with a multicolonial social structure. For the analysis, we took into account both, population density and nests/m2, in biotopes: edge, interior forest and pasture. The modeling was framed in the field of geostatistics, were, by the estimation of semivariograms’ models and parameters, the spatial continuity of variables we were interested in was defined. They were used to interpolate and construct the maps for those regions not sampled all of this through kriging. it was found that the spatial distribution model was well described by spherical and exponential semivariograms, which explained the pattern of spatial autocorrelation. interpolation maps of workers per bait and nests/m2 allowed  usto show that the little fire ant has an unicolonial social structure in the patch of san Julian’s forest, at south of the valley. That was associated with a greater degree of disturbances, which may justify their low intraspecific aggression in its native range. in contrast, in the Alejandria’s forest patch situated at north of the department and which exhibited a lower disturbance, it introduced a social structure multicolonial and high intraspecific aggression.