Estudo taxonômico do complexo rastrata, gênero Gnamptogenys (Roger), 1863 (Hymenoptera: Formicidae: Ectatomminae) no Brasil

Abstract

The rastrata complex is one of the largest group of species in Gnamptogenys in the Neotropical Region, with eight species known, that these six exists recorded in Brazil: (G. lanei Kempf, 1960, G. mecotyle Brown, 1958, G. menozzii (Borgmeier, 1928), G. rastrata (Mayr, 1866), G. triangularis (Mayr, 1887),). It are an specific predator of millipede. The last revision has unrepresentative diagnoses and discrepancies between the key and the descriptions. This study considered the characters of external morphology and morphometrics of the rastrata complex, redefined the complex and the species it includes. Were examined 530 specimens from the following collections: Centro de Pesquisa do Cacau (CPDC), Instituto Nacional de Pesquisa na Amazônia (INPA), Museu Paraense Emílio Goeldi (MPEG), Museu Nacional Quinta da Boa Vista (QBUM), Museus de Zoologia Da Universidade de São Paulo (MZUSP), Universidade Federal de Uberlândia (UFU) e da Universidade Federal de Viçosa (UFV), from 16 states in Brazil. The specimens studied were identified using the literature and by comparison with the type material, whenever possible. New species were described and known species were redescribed. Part of the specimens were measured using micrometric lens attached to a stereomicroscope. R software were used for the realization of an Analysis of Variance (ANOVA), to determine differences between the averages of the measures of the species, and the Test. T paired, to determine which species are separated by average values found for. Based on the geographic coordinates obtained from the labels of the specimens was made occurrence maps using Quantum GIS program. The number of known species in Brazil was increased from six to seven (G. lanei Kempf, 1960, G. mecotyle Brown, 1958, G. menozzii (Borgmeier, 1928), G. rastrata (Mayr, 1866), G. triangularis (Mayr, 1887), G. sp. n. 1 e G. sp. n. 2), with the recognition of two new species. The distribution of the species were updated and expanded in more than 70% of the Brazilian states. An identification key was developed, followed by illustrations and information on the biology of the genus and the complex were compiled. Tests showed great intraspecific variation in size. The species that were more separated were G. sp. n. 1 e G. sp. n. 2. The measured that most separated species were the scape length and the less separated were the mandibular length. The species that have had more size variations were G. menozzii and with less variation was G. sp. n. 1, except for measures of mandibular length and length of Weber. For the mandibular length the highest variation was G. menozzii, and the smallest was G. mecotyle, for the Weber`s length the largest variation was G triangularis and lower G. sp. n.1. Nine characters shall define the complex rastrata that was previously diagnosed by three characters. The number of known species in Brazil was increased from six to seven. The direction of the sculptures of the mesossoma, petiole and the shape of the petiole are considered important for the separation of complex`s species. The most species examined were collected in hot and humid regions, mainly in the Amazon and Atlantic biomes. The morphometry wasn t a good tool to separate all the species in the complex. The biggest variation intraspecific in size make the averages of the measures were much closer, preventing the separation of the species.