Description and Sexual Behavior of Two New Species of Mygalomorph Spiders (Araneae: Theraphosidae, Pycnothelidae), and First Record of (Pycnothelidae) of Corrientes, Argentina.

Paraje Tres Cerros is a low altitude hilly natural area surrounded by cattle fields and characterized by three isolated rocky formations of about 150-180 m a.s.l.

First record of Tmesiphantes Simon, 1892 (Araneae, Theraphosidae) in Peru: a new species and its phylogenetic placement.

The tarantula genus Tmesiphantes Simon, 1892 includes 20 valid species distributed in Argentina and Brazil. These spiders are distinguished from other Theraphosinae genera by the presence of an incrassate femur III, more evident in males, urticating hair types III and IV on the abdominal dorsum, few cuspules on the labium (0 to 30), maxillae with a maximum of 200 cuspules and sternum rounded. From recent examination of material from Peru, we discovered specimens that share all the morphological characters of Tmesiphantes, but did not fit with any known species.

Four new species of Goloboffia (Mygalomorphae: Migidae) from Chile.

The spider family Migidae Simon, 1889 is represented in Chile by three genera: Calathotarsus Simon, 1903, Mallecomigas Goloboff Platnick, 1987 and Goloboffia Griswold Ledford, 2001. In the present study, four new species of Goloboffia from Chile are described, increasing the known diversity and geographic distribution of the genus. Goloboffia megadeth sp.

The role of silk in courtship and communication in mygalomorph spiders: Do males regulate their courtship in response to female mating status?

In spiders, pheromones are known to be responsible for attracting the opposite sex, eliciting male searching and courtship behaviors, as well as for synchronizing potential mates in space and time. Most spiders are cannibalistic and aggressive. Thus, early recognition of a female as a possible mate is essential for males, who may suffer high energetic or reproductive costs to the extreme of losing all fitness opportunities.

Species conservation profile of the rare and endemic trapdoor spider (Araneae, Migidae) from Central Argentina.

Background: Schiapelli & Gerschman 1975 is the only species of Migidae in Argentina. It is a rare and endemic spider only found in relict grassland of mountain systems in the province of Buenos Aires. This species is a habitat specialist spider occupying specific areas with certain microclimatic conditions on hilly and rocky grassland areas at about 500-1500 meters above sea level.

Linking Vegetation Structure and Spider Diversity in Riparian and Adjacent Habitats in Two Rivers of Central Argentina: An Analysis at Two Conceptual Levels.

The link between vegetation structure and spider diversity has been well explored in the literature. However, few studies have compared spider diversity and its response to vegetation at two conceptual levels: assemblage (species diversity) and ensemble (guild diversity). Because of this, we studied spider diversity in riparian and adjacent habitats of a river system from the Chacoan subregion in central Argentina and evaluated their linkage with vegetation structure at these two levels.

Chaco ansilta new species from Mendoza province, Western Argentina (Araneae: Nemesiidae).

A new species of Chaco Tullgren, 1905 is described and illustrated from the Andean foothills of Mendoza province, western Argentina. This is the tenth species of the genus and the first record of Chaco in Mendoza. An updated key is presented for all Chaco species.

Cladistic reanalysis and historical biogeography of the genus Thorell, 1894 (Araneae: Mygalomorphae: Nemesiidae) with description of two new species from western Argentina.

Background: The genus includes ten species, one from Argentina, eight from Chile, and one from Brazil. Two new species from western Argentina are described, and some data on natural history are presented. A cladistic reanalysis with the newly described species is carried out, and a reconstruction of ancestral areas and primary Brooks Parsimony Analysis are performed.

On the ecology of the cursorial spider Odo bruchi (Araneae: Zoridae) in a grassland natural reserve from central Argentina.

The "Ernesto Tornquist" Provincial Park (ETPP) is located inside the Ventania system (Argentina) and was created to protect one of the last relicts of pampean grasslands. Even though many studies have looked at the vertebrate faunal diversity, biology, and conservation in this Park, few studies have been dedicated to arthropods. Among these, spiders have been used as ecological indicators to evaluate nature conservation status, nevertheless, basic information on their distribution and ecology is necessary for their use as indicator taxa in this region.

Mygalomorph spider community of a natural reserve in a hilly system in central Argentina.

The diversity, abundance, spatial distribution, and phenology of the mygalomorph spider community in the "Ernesto Tornquist" Strict Nature Reserve were analyzed in this study. Located in southwestern Buenos Aires, Argentina, the Reserve is representative of the Ventania system, which is a sigmoidal mountain belt 180 km in length. This exceptional hilly ecosystem is home for many endemic species and rich native fauna and flora.

Intraspecific non-sexual interactions of Grammostola schulzei (Araneae: Theraphosidae) under laboratory conditions.

Intraspecific interactions of araneomorph spiders have received considerable attention, but there are few detailed studies on intraspecific interactions of mygalomorph spiders. Moreover, a thorough understanding of theraphosid biology and ecology is necessary from a conservation standpoint because natural populations may be threatened by habitat disturbances and captures for pet commerce. We described the behavior of conspecific individuals of Grammostola schulzei during non-sexual interactions, under laboratory conditions.