Estudo da comunidades de formigas associadas a palmeiras da ilha do Combu e Estação Científica Ferreira Penna, em Caxiuanã

Abstract

The Arecaceae family has a wide distribution, and can be found in the woods and understory of primary and secondary forests on terra firme and floodplain areas. About twenty genera are known for the Amazon region, and some species have intrinsic interaction with insects (Rocha 1997). The accumulation of material in the bracts favors the nesting and survival of several groups of fauna, such as ants. Although no palm species present structures to house ants, we investigated the palm species that serve as support for ant nests and the relationships that exist between these plant species and ant communities. This work aimed to study the patterns of association and interactions between the palm ant communities on Combu Island, Acará/PA and the Scientific Station Ferreira Penna (ECFPn) in Caxíuanã, Melgaço/PA. At each site six points were sampled with a radius of 15m. At each point the ant nests of five plants were collected. For data analysis the Shannon diversity test (H) and species richness were used. A total of 34,946 individuals were collected, 13,548 of them belonging to 28 species of ants on the island of Combu in 07 species of palm trees. At ECFPn, 21,398 individuals belonging to 38 ant species were collected from 11 palm species. In all, 53 ant species were collected from 14 palm species. On Combu Island, the açaí palm (Euterpe oleracea Mart.) had the highest ant species richness (22 spp; 56%). In ECFPn, the highest species richness (14 spp; 45%) was found in the inajá palm (Attalea maripa Mart.). The species dominance curve was less pronounced in ECFPn, where the estimated richness was Z=73 and showed higher diversity (H=1.145) of ants compared to Ilha do Combu (H=0.829). The largest ant colonies were collected in the ECFPn, with Solenopsis (Diphorhoptrum) presenting 2,987 individuals in the bacaba palm (Oenocarpus distichus Mart.) and Dolichoderus septenspinosus a total of 2,873 individuals in the bacabinha palm (Bactris tomentosa Mart.). The two arboreal genera Camponotus and Crematogaster (Wheeler 1910; Luederwalt 1926; Kempf 1959) occurred in 09 and 06 palm species, respectively, and showed higher abundance at both sites. The diversity and abundance of palm ants was higher in the ECFPn in Caxiuanã than on the island of Combu.