A clinico-epidemiological study of bites by spiders of the genus Phoneutria

From January, 1984 to December, 1996, 422 patients (ages 9 m-99 y, median 29 y) were admitted after being bitten by spiders which were brought and identified as Phoneutria spp. Most of the bites occurred at March and April months (29.2%), in the houses (54.5%), during the day (76.5%), and in the limbs (feet 40.9%, hands 34.3%). Upon hospital admission, most patients presented only local complaints, mainly pain (92.1%) and edema (33.1%) and were classified as presenting mild (89.8%), moderate (8.5%) and severe (0.5%) envenomation. Few patients (1.2%) did not present signs of envenomation. Severe accidents were only confirmed in two children (9 m, 3 y). Both developed acute pulmonary edema, and the older died 9 h after the accident. Patients more than 70 year-old had a significantly greater (p<0.05) frequency of moderate envenomations compared to the 10-70-year-old individuals. Proceedings to relief local pain were frequently performed (local anesthesia alone 32.0%, local anesthesia plus analgesics 20.6% and oral analgesics alone 25.1%). Only 2.3% of the patients (two cases classified as severe and eight as moderate, eight of them in children) were treated with i.v. antiarachnid antivenom. No antivenom early reaction was observed. In conclusion, accidents involving the genus Phoneutria are common in the region of Campinas, with the highest risk groups being children under 10 years of age and adults over 70 years of age. Cases of serious envenomation are rare (0.5%).

A structured inventory of spiders (Arachnida, Araneae) in natural and artificial forest gaps at Porto Urucu, Western Brazilian Amazonia

A preliminary survey of the spider fauna in natural and artificial forest gap formations at “Porto Urucu”, a petroleum/natural gas production facility in the Urucu river basin, Coari, Amazonas, Brazil is presented. Sampling was conducted both occasionally and using a protocol composed of a suite of techniques: beating trays (32 samples), nocturnal manual samplings (48), sweeping nets (16), Winkler extractors (24), and pitfall traps (120). A total of 4201 spiders, belonging to 43 families and 393 morphospecies, were collected during the dry season, in July, 2003. Excluding the occasional samples, the observed richness was 357 species. In a performance test of seven species richness estimators, the Incidence Based Coverage Estimator (ICE) was the best fit estimator, with 639 estimated species. To evaluate differences in species richness associated with natural and artificial gaps, samples from between the center of the gaps up to 300 meters inside the adjacent forest matrix were compared through the inspection of the confidence intervals of individual-based rarefaction curves for each treatment. The observed species richness was significantly higher in natural gaps combined with adjacent forest than in the artificial gaps combined with adjacent forest. Moreover, a community similarity analysis between the fauna collected under both treatments demonstrated that there were considerable differences in species composition. The significantly higher abundance of Lycosidae in artificial gap forest is explained by the presence of herbaceous vegetation in the gaps themselves. Ctenidae was significantly more abundant in the natural gap forest, probable due to the increase of shelter availability provided by the fallen trees in the gaps themselves. Both families are identified as potential indicators of environmental change related to the establishment or recovery of artificial gaps in the study area.

Palpimanid spiders from Guyana: new species of the genera Fernandezina and Otiothops (Araneae, Palpimanidae, Otiothopinae)

Two new species of the spider family Palpimanidae from Guyana are described: Fernandezina takutu, the first species of this genus known from this country andOtiothops giralunas, that seems to be the sister species of O. goloboffi Grismado, 1996 from northwestern Argentina.

Envia garciai, a new genus and species of mygalomorph spiders (Araneae, Microstigmatidae) from Brazilian Amazonia

The genus Envia, comprising only the new species Envia garciai, is proposed. These small mygalomorph spiders were abundantly collected in soil cores and litter samples in primary rain forests near Manaus, Amazonas, Brazil.

First record on Loxosceles laeta (Nicolet, 1849) (Araneae, Sicariidae) in the West Zone of São Paulo City, São Paulo, Brazil, and considerations regarding its geographic distribution

Loxosceles laeta spiders were captured in the West zone of São Paulo City, this being the first record of the specie in this area. Since loxoscelism is an important public health problem in the South region of Brazil, it is necessary to investigate the presence of this spider in São Paulo City.

Venomous and poisonous arthropods: identification, clinical manifestations of envenomation, and treatments used in human injuries

Abstract This review presents the main species of venomous and poisonous arthropods, with commentary on the clinical manifestations provoked by the toxins and therapeutic measures used to treat human envenomations. The groups of arthopods discussed include the class Arachnida (spiders and scorpions, which are responsible for many injuries reported worldwide, including Brazil); the subphylum Myriapoda, with the classes Chilopoda and Diplopoda (centipedes and millipedes); and the subphylum Hexapoda, with the class Insecta and the orders Coleoptera (beetles), Hemiptera (stink bugs, giant water bugs, and cicadas), Hymenoptera (ants, wasps, and bees), and Lepidoptera (butterflies and moths).

Rejanellus, a new genus of Thomisidae (Araneae, Stephanopinae)

A new genus, Rejanellus, type species Onocolus venustus Bryant, 1940, is established for four species of spiders of the subfamily Stephanopinae from Cuba and Haiti. The presence of dorsal tubercles on the male carapace is a possible synapomorphy for the genus. The four known species by now Onocolus venustus Bryant, 1948, O. pallescens Bryant, 1940, O. granulata [sic] Bryant, 1940 and Epicadus mutchleri Petrunkevitch, 1930 are transferred to the new genus. All species are redescribed and illustrated.

The stridulatory setae of Acanthoscurria suina (Araneae, Theraphosidae) and their possible role in sexual communication: an experimental approach

Specialized setae placed on proximal segments of appendages in tarantulas have been related to sound production (stridulation), used in defense or sexual communication. The surface structure of called stridulatory setae of Acanthoscurria suina Pocock, 1903 was studied by SEM. Three morphological types of setae were recognized and at least two of them could be involved in stridulation. Their role in sexual communication was tested by experimental removal. Our results showed no differences in the sexual success between the setaeless and control individuals. Consequently, a defensive function for stridulatory setae seems to be more likely than a sexual function.

Species richness and community structure of arboreal spider assemblages in fragments of three vegetational types at Banhado Grande wet plain, Gravataí River, Rio Grande do Sul, Brazil

The taxonomic composition, observed and estimated species richness, and patterns of community structure of arboreal spider assemblages in eleven sites surrounding the "Banhado Grande" wet plain in the state of Rio Grande do Sul, Brazil, are presented. These sites represent three different vegetational types: hillside (four sites), riparian (five sites) and flooded forests (two sites). The spiders were captured by beating on foliage and "aerial litter". A sample was defined as the result of beating on twenty bushes, tree branches or "aerial litter" clusters, which roughly corresponds to one-hour search effort per sample. Fifty five samples (five per site) were obtained, resulting in an observed richness of 212 species present as adult or identifiable juveniles. The total richness for all samples was estimated to be between 250 (Bootstrap) to 354 species (Jackknife 2). Confidence intervals of both sample and individual-based rarefaction curves for each vegetation type clearly indicated that flooded forest is the poorest vegetation type with respect to spider species richness, with hillside and riparian forests having a similar number of species. The percentage complementarity between the eleven sites indicated that all sites contain a distinct set of species, irrespective of their vegetation types. Nevertheless, the spider assemblages in riparian and hillside forests are more similar with respect to each other than when compared to flooded forest. Both cluster and nonmetric multidimensional scaling analyses showed no strong correspondence between the spider arboreal fauna and the three vegetation types. Moreover, a Mantel test revealed no significant association between species composition and geographic distance among sites.

Three new species of Mesabolivar (Aranea, Pholcidae) from leaf litter in urban environments in the city of São Paulo, São Paulo, Brazil

In this study we describe three new litter inhabiting species of Mesabolivar González-Sponga, 1998 from nine urban forest remnants in the metropolitan region of the city of São Paulo, Brazil: M. forceps, M. mairyara and M. cavicelatus. In three of these remnants, we conduced a three year sampling using pitfall traps. Mesabolivar forceps sp. nov. was the most abundant pholcid (n=273 adults), always present in the samples, but with highest numbers in spring and summer. Mesabolivar mairyara sp. nov. was the second most abundant species (n=32), but the majority of individuals were collected in March 2001. Only three individuals of M. cavicelatus sp. nov. were collected.

Description and ecological notes on Isoctenus malabaris sp. nov. (Araneae, Ctenidae) from southern Brazil

A new species, Isoctenus malabaris, is described from southern Brazil. This spider was abundantly collected with pitfall traps at Araucaria Forests (Mixed Ombrophilous Forest) domain. The activity of this species was studied in three distinct habitats (primary and secondary forests and silvicultures) during 20 months. A bimodal seasonal activity pattern, of males, was observed. Abundance differences of this species between habitats were not significant.

On the Neotropical genus Cybaeodamus (Araneae, Zodariidae, Storeninae)

Four new species of the spider genus Cybaeodamus Mello-Leitão, 1938 are described and illustrated: C. meridionalis sp. nov. from Brazil and Argentina, C. taim sp. nov. from Brazil, Argentina and Uruguay, C. brescoviti sp. nov. and C. tocantins sp. nov. from setentrional region of Brazil. For the species Cybaeodamus enigmaticus (Mello-Leitão, 1939), C. lycosoides (Nicolet, 1849) and C. ornatus Mello-Leitão, 1938, new illustrations based on the examination of the types are presented. The species Cybaeodamus nigrovittatus Mello-Leitão, 1941 which the holotype is an immature specimen, C. pallidus (Mello-Leitão, 1943) which the type was not located, C. rastellifer (Mello-Leitão, 1940) and C. scottae Mello-Leitão, 1941, both described upon juvenile specimens, all from Argentina, are considered as species inquirendae.

Natural history of the lizard Enyalius iheringii (Squamata, Leiosauridae) in southern Brazilian Atlantic forest

Studies on the natural history of the lizard Enyalius iheringii Boulenger, 1885, as well as other tropical lizards, are rare. In this study, some aspects of the natural history of this endemic species from the Atlantic forest are reported in areas of Vale do Itajaí, state of Santa Catarina, Brazil. Twenty individuals were found, of which 18 were collected. Most of them were found over the vegetation (n=17) and on the ground (n=3). The main defensive strategy displayed was camouflage (n=16). Jumping (n=1), jumping and running (n=1) and running (n=2) were also observed in some individuals. When handled, lizards exhibited mouth wide open, hissing, and occasionally biting, as well as color change in males. Regarding its diet, the numerically most important prey was beetles (Coleoptera), followed by Lepidoptera larvae. Beetles, lepidopteran larvae and spiders were the most frequent food items. Males and females did not differ in size. Three sexually mature females (100-113 mm SVL) were found in December and January.

Neodrassex, a new genus of the Leptodrassex group (Araneae, Gnaphosidae) from South America

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.

Description of the male of Mangora brokopondo (Araneae, Araneidae), with notes on Mangora species from Brazilian Oriental Amazon

The male of Mangora brokopondo Levi, 2007 is described and illustrated for the first time. Variation in the color pattern of the females is documented. Mangora woytkowskii Levi, 2007 is considered a junior synonym of M. hirtipes (Taczanowski, 1878). New records of M. alinahui Levi, 2007 and M. pia Chamberlin & Ivie, 1936 are presented.