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The araneofauna of the Neotropical region can be considered undersurveyed and lacking standardized inventories that can be used as a base for biodiversity studies. Spiders are recognized as important components of forest ecosystems and appear to be good organisms for studies concerning biodiversity standards. A survey was carried out in the Parque Estadual do Turvo, Rio Grande do Sul, Brazil to determine the richness and composition of the spider fauna. The Park is a protection area that includes the only remainder of the Floresta do Alto Uruguai in Brazil. Four expeditions were conducted over the period of two years, in Spring and Autumn (2003-2005). The main sampling technique was the beating tray, sampling the vegetation along the trails inside the park. Additionally, pitfall-traps, Winckler extractors, nocturnal manual collecting and random samplings were used. Shannon-Wiener (H') diversity indices and rarefaction curves were calculated for the beating tray samplings. A total of 8724 spiders belonging to 37 families were collected. Of these, 34% (2946) were adults, distributed in 31 families, 157 genera and 447 morphospecies. The richest families were Salticidae (23%) followed by Araneidae (18%), Theridiidae (16%) and Thomisidae (9%). In the beating tray samples 29 families were recorded. The most abundant families (including young individuals) were Salticidae (23%), Araneidae (18%), Thomisidae (14%), Theridiidae (12%) and Anyphaenidae (12%). Nineteen species presented a percentage higher than 1% of the total of collected adult individuals. The most abundant being Thwaitesia affinis O. P.-Cambridge, 1881 (Theridiidae), Tariona sp.1 (Salticidae) and Misumenops argenteus (Mello-Leitão, 1929) (Thomisidae). The Spring periods revealed more adult individuals and species and the Shannon-Wiener (H') diversity was considered higher in the periods of Autumn. The rarefaction curves did not reach asymptote, suggesting the existence of non-sampled species. The spider richness registered in this survey is the greatest observed for Rio Grande do Sul, and the second greatest for Brazil. These information show the importance of this ecosystem for biodiversity conservation in Brazil.Keywords: spiders, inventory, Neotropical, biodiversity. A região Neotropical é considerada pouco amostrada com relação à sua araneofauna, carecendo de inventários padronizados que possam servir de base para estudos de biodiversidade. As aranhas são consideradas como importantes componentes dos ecossistemas florestais e aparentam ser organismos ideais para estudos de padrões de biodiversidade. Neste estudo foi efetuado um levantamento da riqueza e composição da fauna de aranhas do Parque Estadual do Turvo, Rio Grande do Sul, Brasil, local que protege o único remanescente representativo da Floresta do Alto Uruguai no Brasil. Foram realizadas quatro expedições semestrais, durante dois anos, no outono e na primavera (2003)(2004)(2005). Como principal técnica de coleta foi empregado o guarda-chuva entomológico, com o qual amostou-se a vegetação arbór...

, 17 samples were taken, distributed in three periods: before seeding, during the development of the rice plants and after the harvest. Samples were done in the morning using sweeping nets (35 cm diameter), 50 sweeps in each of four randomly chosen transects. A total of 918 spiders were sampled, distributed in 14 families, mostly Araneidae, Anyphaenidae, Oxyopidae and Tetragnathidae. Among the adults, 38 morphospecies were found, the most abundant were Alpaida veniliae (Keyserling, 1865), Tetragnatha nitens (Audouin, 1826), Ashtabula sp.1 and Tetragnatha aff. jaculator, the four together comprising more than 45% of the adult specimens. Of the species richness estimators used, Chao 1 was closer to the observed richness; 87,4% of the potentially present species were effectively sampled. Both abundance and species richness showed an increasing trend, accompanying rice development (and thus increasing habitat complexity), with a stern decrease after harvesting. A constant colonization of the habitat is thus postulated, also given the high number of young spiders found at all times. There were no significant correlations between climatic factors (temperature and rainfall) and neither abundance nor species richness, except a positive one between rainfall and richness. Among the functional groups, ambushing hunters dominated, followed by orb-web builders. An analysis of similarity (ANOSIM) found significant differences among the fauna of the three evaluated periods. Thus, system disturbance, in the form of rice sowing and harvesting, brutally altering environmental structure, leads to strong spider diversity changes both in terms of species richness and species composition. The results suggest biodiversity studies in agroecosystems can help us understand not only applied but also basic problems.

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ABSTRACT. List of spiders species (Arachnida, Araneae) of the state of Rio Grande do Sul, Brazil. A spiders species list including 808 species of 51 families occurring in the state of Rio Grande do Sul, Brazil, is presented. Type locality, municipalities of occurrence and taxonomic bibliography concerning these species are indicated. KEYWORDS.Inventory revision, type localities, municipalities records, Neotropical.RESUMO. É apresentada uma lista de 808 espécies de aranhas, incluídas em 51 famílias ocorrentes no Rio Grande do Sul, Brasil. São indicados localidade-tipo, municípios de ocorrência e a bibliografia taxonômica de cada espécie. PALAVRAS-CHAVES.Inventário, localidades-tipo, registros municipais, Neotropical.A ordem Araneae reúne atualmente 110 famílias distribuídas em 3821 gêneros e 42055 espécies, mostrando nas últimas décadas um aumento progressivo no conhecimento das espécies e sua distribuição mundial (PLATNICK, 2011). Na Europa do século XIX, era prática usual promover expedições com a finalidade de colecionar animais para os museus de história natural. Pesquisadores contavam com o auxílio de colaboradores ou de naturalistas viajantes para obtenção de espécimes. No Brasil inúmeras aranhas foram coligidas em localidades do Rio de Janeiro e Santa Catarina pelos naturalistas Emílio Goeldi e Fritz Plaumann, respectivamente.Para o Rio Grande do Sul, um número significativo de espécimes foi reunido por Hermann von Ihering, médico e naturalista, nascido na Alemanha. Residiu em Taquara do Mundo Novo de 1880-1883, região que incluía o atual município de Taquara além de municípios limítrofes, em Rio Grande (1884/1885) e posteriormente em São Lourenço do Sul, locais onde colecionou centenas de aranhas. As coletas desses períodos foram enviadas ao aracnólogo alemão Eugen von Keyserling, o qual publicou os resultados em uma expressiva obra, "Die Spinnen Amerikas" (KEYSERLING, 1880b;1884a;1886;1892;1893). Um dos volumes, "Die Spinnen Amerikas. Brasilianische Spinnen" (1891), é dedicado às aranhas brasileiras, com ênfase aos estados do Rio de Janeiro e Rio Grande do Sul. A maioria dessas aranhas está depositada em museus europeus da Inglaterra e da Polônia.Posteriormente, MELLO-LEITÃO (1931) assinalou para o Rio Grande do Sul a ocorrência de três novas espécies de Cacimbinhas, atual município de Pinheiro Machado.O primeiro catálogo de aranhas do estado do Rio Grande do Sul foi apresentado por MELLO-LEITÃO (1943), o qual relacionou 431 espécies, pertencentes a 173 gêneros e 31 famílias. Registrou as 219 espécies descritas por Keyserling em "Die Spinnen Amerikas" e relacionou mais 212 espécies, entre as quais 67 novas para a ciência. A maior parte dessas aranhas foi coletada pelo Padre Balduino Rambo, tendo sido depositadas no Museu Nacional do Rio de Janeiro. Ainda para o Rio Grande do Sul, BÜCHERL (1952) realizou um estudo sobre aranhas e teceu comentários sistemáticos, ecológicos, biológicos e ação da peçonha.A partir de 1970, intensificaram-se as pesquisas aracnológicas no Museu de Ciências Naturais (MCN), estab...

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ABSTRACT. The new genus Neodrassex is proposed to include two new species of Gnaphosidae from Brazil. Neodrassex aureus sp. nov. is described from Amazonas, Paraná and Rio Grande do Sul states, and N. iguatemi sp. nov. is described from Paraná state. Neodrassex gen. nov. is characterized by small size, pale coloration, large anterior median eyes surrounded by black pigmentation, absence of a dorsal abdominal scutum in males and by the cheliceral dentition with 2-3 teeth on the promargin and 2-4 on the retromargin. The new genus is tentatively placed at the Leptodrassex group.

A new genus of goblin spiders, Simlops, is proposed for 15 species found in Brazilian and Colombian Amazonia and southern Caribbean (Venezuela and Guyana). The new genus belongs to the Scaphiella complex, a group of Neotropical genera that share a sexually dimorphic condition in which the abdominal dorsal scutum is present in males but absent in females. Simlops is hypothesized to be a monophyletic group united by a unique conformation of the male endites, which present three apical portions, a prolateral, curved process, with laminar apices, a retrolateral process and a median, more dorsal, unsclerotized portion. The species Triaeris bodanus Chickering, 1968, is transferred to Simlops and the female of this species is described for the first time. The remaining 14 species are newly described: