A proposal for disentangling Pheidole? ant species into different functional groups

AVALOS, ANDREA; HANISCH, PRISCILA; PARIS, CAROLINA; SÁNCHEZ RESTREPO, ANDRÉS FERNANDO; GUASTAVINO, J M

Congreso; X Congreso Argentino de Entomología; 2018

The classification of ant communities in functional groups allows analyzing patterns ofcommunity composition and its response to disturbance. Pheidole? ant species are all included, apriori, in the functional group of ?Generalized Myrmicinae? i.e cosmopolitan sub-dominant ants,occurring in most habitats with rapid recruitment to, and successful defense of, clumped foodresources. However, several species of Pheidole have different ecological roles and may differ intheir response to natural and anthropic disturbances. Previous studies showed that morphologicaltraits (MT) of ants are strongly related to their ecological role. Our aim was to explore dissimilaritiesbetween morphological traits of Pheidole species. We sampled ants along five transects of 100m, atOsununu Natural Reserve, Misiones; an area preserving 168ha of Paranaense rain forest. Every 10m,we placed a pitfall trap for 48hs and sifted 1m2 of litter to extract ants with mini-Winkler over 48hs.Opportunist hand collecting sampling was performed. We measured MT of workers related to thequantity of resources consumed and habitat complexity (body size), feeding behavior (head widthand head, mandible and eye length), foraging speed (hind tibia and femur length) and sensory ability(scape length). Cluster analysis (Ward method) was performed to produce a functional dendrogramfor major and minor castes separately. We collected 688 individuals but only those species withworkers of both castes were analyzed (S= 6, n= 58). Pheidole oxyops workers clustered separatelyand showed the highest values of MT for both castes. This is in accordance with its scavenger andpredatory feeding behavior, high speed locomotion and preference for nesting and foraging in lesscomplex habitats (open areas and edges of forest). Majors of P. cornicula (unknown ecology) clusteredwith P. oxyops indicating similar ecological role. Pheidole rugatula, P. rudigenis, P. transversostriata andP. radowszkoskii grouped in two clusters due intermediate or low values of MT. Our results show thatPheidole species could belong to different groups according to its MT and suggest that the ecologicalrole of species could be inferred by ecological knowledge of other species from the same group.