Effi ciency of foraging behavior in the ant genus Messor (Hymenoptera: Formicidae: Myrmicinae) in response to food distribution

Harvester ants are known to be species that collect seeds of plants and store them in underground chambers. Workers forage solitarily or in groups, and the intensity of their foraging depends, among other things, on the rate of food intake. To evaluate the efficiency of foraging in response to food distribution, we studied the foraging rate on different distributions of seeds in three species of the genus Messor, M. barbarus (Linnaeus, 1767), M. marocanus Santschi, 1927 and M. sanctus Emery, 1921. Foraging rates were higher on more clumped seed distributions in all studied colonies. The number of foragers did not influence the foraging behavior of these colonies in response to seed distribution. Monitoring the foraging rate over time revealed that it remains stable for all three species, except for the initial and final stages of bait consumption. Additionally, M. marocanus collected seeds from several sources simultaneously, whereas the other two species collected seeds from one resource at a time.