Genetically diverse harvester ant colonies are more efficient in nest maintenance and foraging
Maya Saar, Maya Saar , Inon Scharf
The School of Zoology, Tel - Aviv University; The School of Zoology, Tel - Aviv University ; The School of Zoology, Tel - Aviv University
There is accumulating evidence that genetic diversity improves the behavioral performance and consequently the fitness of groups of social animals. We examined the behavioral performance of colonies of two congeneric harvester ant species (Messor arenarius and a newly-described Messor sp.) in fitness-related behaviors pertaining to foraging success, nest maintenance and aggression. We linked these behaviors to the general colonial genetic diversity, while genotyping workers of the two species. We found contrasting effects of genetic diversity on colony performance and aggression between the two species. In M. arenarius, genetic diversity predicted foraging success and nest maintenance but not overall aggression level, while in M. sp., genetic diversity predicted overall aggression level, but neither foraging success nor nest maintenance. The two species exhibited similar specific aggression levels with highest aggression against heterospecifics, lower against non-nestmate conspecifics, and lowest against nestmates. However, M. sp. workers interacted much longer with heterospecifics than did M. arenarius. We suggest that the different foraging strategies, individual vs. group foraging, and possibly the different mating systems, have contributed to the differences in behavior between the two species.