The current biodiversity crisis makes the quantification of the diversity and the description of organism distribution particularly pressing. Biological inventories are among the most effective ways to improve the knowledge about local biota, but they can be very time and money‐consuming. The determination of adequate sampling effort and the selection of cost‐effective collecting methods are critical issues. In this article, a spider diversity inventory in an Atlantic semi‐deciduous forest fragment in Brazil was used to compare the efficiency of three collecting methods in two different seasons in order to propose an optimised sampling protocol. The worthiness of increasing sampling effort in the target area and similar tropical ecosystems was estimated and evaluated in terms of its cost‐effectiveness. For a better sampling of the spider community, it is suggested that a proportion of 55, 29 and 16% of total sampling hours should be dedicated to nocturnal hand collecting (NHC), pitfall traps and beating trays, respectively, in the rainy season. If only one method can be applied, the most efficient in terms of species per sampling is the NHC. A completeness of 70% of the estimated spider species richness (as predicted by the Chao1 estimator) was observed in the complete inventory and increasing sampling effort in the studied area may be highly ineffective when the costs involved are considered. Other studies in similar tropical rainforest areas also presented completeness around 70%, which might be a threshold from which the sampling effort necessary to raise the observed species richness substantially starts to be ineffective.

This manuscript describes the general biochemical properties and immunological characteristics of Peruvian spider Loxosceles laeta venom (PLlv), which is responsible for the largest number of accidents involving venomous animals in Peru. In this work, we observed that the venom of this spider is more lethal to mice when compared with L. laeta venom from Brazil (BLlv). The LD₅₀ of PLlv was 1.213 mg/kg when the venom was intradermally injected. The venom displayed sphingomyelinase activity and produced dermonecrotic, hemorrhagic and edema effects in rabbits. 2-D SDS-PAGE separation of the soluble venoms resulted in a protein profile ranging from 20 to 205 kDa. Anti-PLlv and anti-BLlv sera produced in rabbits and assayed by ELISA showed that rabbit antibodies cross-reacted with PLlv and BLlv and also with other Brazilian Loxosceles venoms. Western blotting analysis showed that bands corresponding to 25-35 kDa are the proteins best recognized in every Loxosceles spp venoms analyzed. The immunized rabbits displayed protective effect after challenge with PLlv and BLlv. In vitro assays with horse anti-loxoscelic antivenoms produced in Brazil and Peru demonstrated that these commercial antivenoms were efficient to inhibit the sphingomyelinase activity of PLlv and BLlv.

A new species of Nesticus is described based on specimens collected during a structured inventory of the Reserva Particular do Patrimônio Natural Mata Samuel de Paula, state of Minas Gerais, Brazil. Nesticus ivone sp. nov. can be recognized by the paracymbium of the male palpus with three not hooked processes, and by the presence of a central vulval plate in the female epigynum. Additionally, a new record is presented for Nesticus taim Ott & Lise, 2002, extending the known distribution range of this species northwards

The genus Runcinioides is revised, including the redescription of R. argenteus Mello-Leitão, 1929 and R. litteratus (Piza, 1933). The male of R. litteratus is described and illustrated for the first time and Misumenops paranensis (Mello-Leitão, 1932) is here considered a junior synonym of R. argenteus. The known geographic distribution of both species is expanded with the inclusion of new occurrence data. Runcinioides pustulatus Mello-Leitão, 1929 and Runcinioides souzai Soares, 1942 are not related to the other species of the genus, and provisionally considered as incertae sedis.

Three new species of the spider genus Philoponella Mello-Leitão, 1917 are described: Philoponella opelli n. sp. from Brazil and Ecuador, and Philoponella fluviidulcifis n. sp. , and Philoponella duopunctata n. sp. from Brazil. New records for Philoponella vittata (Keyserling, 1881), P. republicana (Simon, 1891), P. fasciata (Mello-Leitão, 1917) and P. divisa Opell, 1979 are provided for Brazil and Ecuador.