Nest and foraging characteristics of Acromyrmex landolti Balzani (Hymenoptera: Formicidae) in northeast Brazil

Abstract

The objective of this study was to survey leaf-cutting ants in the Campus of the Federal University of Sergipe in Sergipe State, Brazil, and to analyze characteristics of nests and foraging dynamics of the most frequent species. Six transects with 20 meters wide by 50 meters long were cast every 150 meters where leaf-cutting ants were collected . Eighty-three ant nests were found in the six transects. In 88% Acromyrmex landolti balzani (Hymenoptera: Formicidae) was the only species of this genus found, with the other 12% composed of Atta spp. Seven nests of A. landolti balzani were evaluated after its identification and observed during the photophase (07:00 A.M. to 06 P.M.) for periods of 20 min at intervals of 50 minutes during five days. The depths of nests ranged from 12cm to 140cm in the rainy and dry seasons, respectively, and their vaulted chambers have an elliptical shape. The foraging behavior of this species increases, gradually, from 10:00 A.M. to 02:00 P.M. and reached a peak, which is related to the sensitivity of the ant workers to microclimatic gradients, time and space. These gradients affect the nesting and foraging behavior of this insect.