Simarouba versicolor (Simaroubaceae) dispersal by the leaf-cutter ant Atta sexdens

Abstract

The importance of Simarouba versicolor St. Hil. fruit dispersal by the leaf-cutting ant Atta sexdens (L.) was studied in the Cerrado, Tocantins, Brazil. The trees and nests were located between a forest area and a Brachiaria decumbens Stapf pasture. Seeds were collected in October 2015 along foraging trails and on the anthill of an A. sexdens colony. Germination of three groups of seeds was tested: (1) seeds with the tegument removed by the ants; (2) seeds without tegument, cleaned manually, and (3) seeds with tegument. The germination rates for the three treatments were similar; however, it was verified that the seeds cleaned by ants germinated faster. In addition, it was verified that the ants dispersed the seeds by at least 20 meters in the study area. Simarouba versicolor is a plant studied for its insecticidal properties, and this is the first study to our knowledge reporting its dispersal by ants.