Ant diversity in chaco phytogeographical region, ?Los Llanos? area, La Rioja province, Argentina.

BAUDINO, FLORENCIA; BUFFA, MARÍA LILIANA; VISINTIN, ANDRÉS MARIO

Fortaleza

Simposio; XXI Simposio Internacional de Mirmecología; 2013

Universidad Estatal de Ceará

Ants are eusocial insects with a high abundance and present in wide variety of habitats, performing multiple functions in the ecosystems and responding quickly to environmental changes. In La Rioja province, Argentina, records of previous studies on these insects have been carried out in Talampaya National Park as well as in cultivated environments, where Formicidae was the most abundant group. Other studies of this family in the rest of the phytogeographical regions of the province are scarce. The objective of the present work was to study ants diversity in three different environments in Los Llanos region (30º37?50??S, 66º16?3??W), General Belgrano department, south-east La Rioja province. According to vegetation characteristics, three sites were selected as follows: 1. Salinas, 2. Transition Monte-Salinas, 3. Monte. Site 1 presents scarce vegetation development and poor leaf coverage; site 3 is mainly dominated by a tree layer (3-6 m height) and shrub layer (0.5-3 m height), while site 2 has intermediate characteristics between site 1 and site 3, being the tree layer replaced by cacti (Stetsonia coryne) and the shrub layer the dominant. In each of the sites four transects were delimited, 50 meters apart from each other, where 4 pitfall traps were set up at a distance of 5 meters. Totally, 48 traps were used remaining active for a period of 7 days during spring season. The Species diversity & richness program was used to calculate the different diversity indexes. A total of 35 species were collected, distributed in 15 genera and 6 subfamilies: Myrmicinae (6:12)*, Dolichoderinae (3:7), Formicinae (2:7), Ecitoninae (2:2), Ponerinae (1:2) y Pseudomyrmicinae (1:1) *(Nº genera:Nº species). The genera with higher richness were Camponotus (S=6), Pheidole (S=5) and Dorymyrmex (S=4). Out of 15 registered genera, 66.6% were found in Salinas, 73.3 in Transition and 93.3% in Monte. Categories of dominance were determined, being Forelius and Pogonomyrmex eudominants (Do>10%), while Pseudomyrmex and Ectatomma were rare (Do