Estudo taxonômico dos entomobryoidea (Arthropoda: Collembola) em áreas prioritárias para conservação da Caatinga

Abstract

Collembola are small arthropods widely distributed all over terrestrial ecosystems, with a body size ranging between 0.12 and 17 mm, and about of 9,000 described species in the world. Entomobryoidea is the largest Collembola superfamily, encompassing Microfalculidae, Entomobryidae and Paronellidae, with only the last two recorded from Brazil, where the Collembola taxonomic richness is subestimated, with about of 401 recorded species. Caatinga is among the less sampled Brazilian domains, although it comprises a huge diversity of environments and microhabitats, forming a mosaic of different types of deciduous vegetation with high endemism rates. In Collembola, morphology is the primordial source of taxonomic characters and the study of the dorsal chaetotaxy is almost universally used as a preponderant character. In this study, four priority areas for the Caatinga biodiversity conservation were sampled, all of them with very few information about Collembola: Serra da Capivara, Serra das Confusões and Sete Cidades National Parks, and Picos municipality, all these areas in the Piauí State. At the end of this study it was possible to delineate an initial profile of the Entomobryoidea fauna in the sampled areas, providing an inventory of species occurring in these areas and their distribution. Eight new species were described: Capbrya sp. n., Cyphoderus equidenticulati Nunes and Bellini, Lepidosira neotropicalis Nunes and Bellini, Nothobrya sertaneja Nunes and Bellini, Pseudosinella triocellata Nunes and Bellini, Seira sp. nov.1, Seira sp. nov.2 and Trogolaphysa piracurucaensis Nunes and Bellini. Identification keys were provided for the Brazilian species of Cyphoderus, Pseudosinella and Trogolaphysa, for the Neotropical genera of Entomobryinae, for the known species of Nothobryinae, and for the Entomobryoidea species from the four sampled areas. Records of Entomobryoidea from the studied areas went from 4 to 22 species, 9 genera, 6 subfamilies and 2 families. After an extensive bibliographic revision, we proposed a new diagnosis for Lepidosira, described the complete dorsal chaetotaxy of a species of this genus for the first time, and proposed a hypothesis of phylogenetic positioning based on two nuclear (18SrRNA and 28SrRNA) and one mitochondrial (COI) markers, corroborating the transfer of the Lepidosira-group from Seirinae to Entomobryinae for the first time. We also elucidate key characters for the Nothobryinae systematics and proposed its division in two tribes (Capbryini and Nothobryini), and their inclusion in the subfamily Orchesellinae, invalidating Nothobryinae as an independent subfamily.