Records of pholcid spiders from Micronesia and Polynesia are presented, along with records from Indonesia and parts of Melanesia. Nineteen species representing eleven genera are included. An illustrated key for Pacific pholcids is provided. Two species and one genus are not yet known from Micronesia or Polynesia, but are included in the key because they may occur there. Seven species are widespread synanthropic or anthropophilic species, two species are widespread native species, and nine species are endemics of one or several neighboring islands. Distribution maps include only specimens we have seen, not literature records.

The nine species of Sassacus Peckham & Peckham 1895 known from Canada, the United States, and Mexico are described. The genus as defined here includes: Sassacus papenhoei Peckham & Peckham 1895, Sassacus paiutus (Gertsch 1934), Sassacus samalayucae Richman (new species), Sassacus cyaneus (Hentz 1846), Sassacus alboguttatus (F.O. Pickard–Cambridge 1901), Sassacus vitis (Cockerell 1894), Sassacus aztecus Richman (new species), Sassacus barbipes Peckham & Peckham 1888, and Sassacus lirios Richman (new species). Agassa Simon 1901 is synonymized with Sassacus. “Typical” (beetle-like) and more “normal” (spider-like) Sassacus range from Southern British Columbia south into Central America. The Sassacus arcuatus group, which is much more extensive in South America, possibly belongs to its own genus and is not treated beyond one species described here from Mexico.

The Hemerotrecha banksi group is revised and the status of the genus Hemerotrecha is examined. The female of H. truncata Muma 1951 is described for the first time, and five new species are named: H. hanfordana, H. kaboomi, H. prenticei. H. pseudotruncata, and H. vetteri.

Trochosa sepulchralis (Montgomery 1902) is recognized as the senior synonym of Trochosa acompa (Chamberlin 1924) based upon careful examination of critical morphological characteristics. In addition, Trochosa abdita (Gertsch 1934), once considered a junior synonym of T. acompa, is now recognized as a valid species. Trochosa sepulchralais and T. abdita are fully illustrated and described, and essential information regarding species identification, morphological dimensions, and geographic distribution is included.

The spider genus Enna is revised and the five previously known species [E. estebanensis (Simon 1898) (Venezuela), E. jullieni (Simon 1898) (Panama, Colombia), E. minor Petrunkevitch 1925 (Panama, Colombia), E. nesiotes Chamberlin 1925 (Panama) and E. velox O. Pickard-Cambridge 1897 (type species) (Mexico)] are redescribed. Dossenus redundans Platnick, 1993 is transferred to Enna and is redescribed and illustrated. Descriptions of 18 new species include the following: E. baeza (Ecuador), E. bartica (Guyana), E. braslandia. (Brazil), E. bonaldoi (Brazil) E. caliensis (Colombia), E. chickeringi (Honduras), E. colonche (Ecuador), E. eberhardi (Costa Rica, Panama), E. hara (Peru), E. huanuco (Peru), E. huarinilla (Bolivia), E. igarape (Brazil), E. kuyuwiniensis (Guyana), E. maya (Honduras, Panama), E. paraensis (Brazil), E. pecki (Costa Rica), E. riotopo (Ecuador) and E. rothi (Ecuador). The type of E. approximata (O. Pickard-Cambridge), collected in Bugaba, Panama, is based on a juvenile and is considered as a nomen dubium. Similarities in the geographical distributions of species of Enna with the distributions of species in the genera Trechalea and Hesydrus are noted.

The genus Dyrines, is revised for the first time since Simon provided the name in 1903 to replace the preoccupied Drances. A female lectotype is designated for the type species, Dyrines striatipes (Simon 1898), which is redescribed and illustrated. The holotype of D. taeniatus Mello-Leitão 1943 is a tiny spiderling and is considered a nomen dubium. Dyrines lineatipes Petrunkevitch 1925 is regarded as a junior synonym of D. striatipes. Dyrines rubriosignatus Mello-Leitão 1943 is transferred to the genus Thaumasia, resulting in Thaumasia rubrosignata (Mello-Leitão 1943b), new combination. Two new species are described and illustrated: D. huanuco from Huanuco, Peru, and D. ducke from Reserva Florestal Adolfo Ducke near Manaus, Brazil.

The spider genus Syntrechalea is redefined and revised with a total of seven species recognized. The previously described species S. tenuis F.O. Pickard-Cambridge 1902 and S. reimoseri Caporiacco 1947 are redefined. Syntrechalea porschi Reimoser 1939 is a new junior synonym of S. tenuis. Trechalea syntrechaleoides Mello-Leitão 1941 is transferred to the genus Syntrechalea. The males of S. tenuis and S. syntrechaleoides are described for the first time. A lectotype is designated for Syntrechalea reimoseri (Caporiacco 1947). Three new species, S. adis, S. caporiacco, and S. brasilia, are described from both males and females. The new species S. caballero is described from only the female, and S. napoensis is described from only the male. The arboreal nature of the genus is emphasized and discussed.

Males of the araneid genus Cyrtophora Simon 1864 are comparatively rare in collections, possibly because they are much smaller and less conspicuous than their female counterparts and are expected to have a much shorter lifespan. Field work on Christmas Island (Indian Ocean) revealed a male of Cyrtophora unicolor (Doleschall 1857) copulating with a female. Both male and female are described here. The known distribution of C. unicolor is updated to include southern parts of China, Taiwan and Japan in the North, the Philippines and Papua New Guinea to the south-east, Indonesia and Christmas Island to the South, and Thailand, Myanmar, and Sri Lanka to the East. Cyrtophora acrobalia (Thorell 1895), described from a juvenile from Myanmar, is considered a nomen dubium.

Although the temperatures at which the brown recluse spider (Loxosceles reclusa) is active have been described, no work has been done on lethal thermal limits that may influence the distribution of this medically important species. We tested the cold tolerance of L. reclusa at temperatures ranging from 3° C to −14° C. First, we tested spiders over brief 4-h exposures to a test temperature. Second, we tested spider tolerance to long-term, 30-da exposures to constant, low temperatures to simulate overwintering conditions. We also recorded temperatures beneath the plant litter layer and compared these to ambient surface air temperatures to estimate the effect of litter insulation. We then used the regression of ambient temperature to litter temperature to predict isotherms of litter retreats in Illinois during January, the month of lowest mean winter temperatures. Using the cold temperature lethal limits we found in the lab, we predicted a theoretical distribution of L. reclusa based solely on temperature that approximately matches its currently known distribution in Illinois.

I examined prey choice of the brown recluse spider (Loxosceles reclusa Gertsch & Mulaik 1940) with reference to unusual scavenging behavior originally reported by Sandidge (2003). Because scavenging is an unexpected behavior in normally predatory spiders, I hypothesized that special circumstances must converge for the brown recluse to prefer dead prey over live prey. I offered crickets (Acheta domesticus) to brown recluses in several choice experiments. I varied predator satiation (spiders not fed for two or four weeks), prey size (small or large), and prey quality (live, fresh dead, dead 1–2 days, 1 week or 1 month). Overall, recluses preferred live prey over dead, but their choice was influenced by all three variables. Recluses were more likely to scavenge when presented with large live prey paired with dead prey of equal size than when presented with small live and dead prey. Spiders that had fed recently were more likely to scavenge. Finally, recluses preferred dead prey that were freshly killed or less than 24 hours old to items dead for longer periods. My results suggest that scavenging is an opportunistic behavior in recluses that requires specific circumstances that may rarely occur in nature.

A new species, Cryptocellus florezi, is described from a cave in Caquetá Department, Colombia, and may be most closely related to the Venezuelan species C. lisbethae González-Sponga 1998. The first known female of C. peckorum Platnick & Shadab 1977 is described, and new records of C. narino Platnick & Paz 1979 extend the known distribution of that species into Boyacá and Tolima Departments.

Loxosceles spiders are of concern outside of the arachnological world because their bites can cause occasional necrotic skin lesions and/or systemic complications; these manifestations are known as loxoscelism. Once these spiders became well associated as medical entities, much notoriety was attained through the publication of medical case histories as well as tales of horrific wounds in the general literature. Although most Loxosceles spider bites are unremarkable, require only general supportive care, and often result in excellent outcome, they are an occasional source of severe dermonecrotic injury with long healing times and significant scarring. In rare cases of systemic loxoscelism, serious intravascular, nephrological and/or multi-organ damage can occur, sometimes resulting in death. However, also of concern is that loxoscelism is diagnosed by medical personnel or presumed by the general public in highly improbable scenarios preventing or delaying proper remedy, which can lead to deleterious outcome. Herein, Loxosceles spider biology and medical aspects are reviewed. In particular, an extensive discussion of the distribution of the brown recluse spider, L. reclusa Gertsch & Mulaik 1940, is presented along with life history characteristics, which relate to the medical aspects of the genus. Also presented are manifestations and epidemiology of loxoscelism, misdiagnoses of bites by the medical community, alternative diagnoses confused with recluse spider bites and a discussion of the psychological basis for the proliferation of the myth of loxoscelism by both the general public and the medical community. North and South American species are reviewed because this is where the genus predominates and is the region where the most pertinent research has originated.

Males of Drymusa spelunca Bonaldo, Rheims & Brescovit 2006 and D. colligata Bonaldo, Rheims & Brescovit 2006 are described based on additional material collected in their type localities: the FLONA Carajás, Carajás and Juruti, both in the state of Pará, Brazil.

The genus Mecynometa contains one species, M. globosa O. Pickard-Cambridge 1889 that has three new synonyms. However, species belonging to two distinct genera, Alcimosphenus and Opas, had been included. Opas includes six known species. Two other Mecynometa species based on males, are synonyms of each other and appear to be the otherwise missing male of the common West Indian Alcimosphenus licinus Simon 1895. Male palpi of species of the three genera are illustrated for the first time. Three species of Leucauge are synonymized.

The male of the species, Trechalea trinidadensis Carico 1993, is described for the first time. The distributional range for this species is extended from Trinidad to Brazil.

A single male from Oaxaca, Mexico is described as the new species, Tinus oaxaca, based on distinct features of the palpus including the shape of the retrolateral apophysis, the position of components of the palpal bulb, and the color pattern of the dorsum. Notes on the current taxonomic status of the genus Tinus are included.

Templar incongruens new genus and species (Monoscutidae) is described and assigned to the subfamily Monoscutinae (Opiliones). It is distinguished from other Monoscutinae by different ornamentation, relatively shorter legs, and enlarged chelicerae in the male. A redescription of Monoscutum titirangiense Forster 1948 is also given.

Fourteen adult specimens of Berlandina nubivaga (Simon 1878) (two females and twelve males) were collected in Aosta Valley (NW Italy) by pitfall traps mostly placed in alpine pastures at about 2000 m elevation. The male is described and the palpal morphology is illustrated; a new drawing of the female internal genitalia is also given. The critical analysis of previous records suggests the distribution of B. nubivaga may be restricted to the Alps.

Two nominal species of harvestmen from eastern North America, Leiobunum verrucosum and L. nigripes, are generally distinguished by color patterns. However, laboratory-reared individuals and sequential sampling in the field clearly show that adult individuals change from the “verrucosum” pattern to the “nigripes” pattern during normal maturation. Specimens of the two nominal species were obtained from the original H. C. Wood and C. M. Weed collections and found to be effectively identical in all diagnostic details. Leiobunum nigripes is a junior synonym of L. verrucosum.

Spider field collections often consist of a high percentage of immature specimens that are not identifiable to species; in many studies these juveniles are discarded and not used in analyses. To evaluate if this practice affects the results of a community study, we sampled foliage-dwelling spiders in two habitats, reared the collected immature spiders until maturity, and identified them to species. We tested if measurements of species richness, evenness, and assemblage composition changed with the exclusion of data from immature specimens by analyzing two datasets: one including mature spiders only, the other including both mature and immature spiders (complete dataset). Nine of the total 49 spider species were collected only as juveniles, but only one of these nine species, Philodromus praelustris Keyserling 1880, was common (≥ 10% of collection). The distribution of individuals among species was more even in the complete dataset than the mature-only dataset, which could either indicate differences in composition or reflect sampling effort. However, species richness estimates were similar regardless of dataset, and there were only small changes in species composition of the samples between datasets, suggesting that there were not important compositional differences between the samples in each dataset. The inclusion of immature spiders in the data in this study yielded the same results that would occur with increased sampling effort.

Juvenile Araneus expletus often place a visually conspicuous, disc-like white silk stabilimentum on one side of the retreat where the spider rests during the day away from its orb. Placement of the stabilimentum at this site rules out a prey attraction function and argues instead that it may function to defend the spider from visually orienting enemies.

A manipulative experiment was done in corn fields and their adjacent forests using enclosures that restricted access to ground-dwelling spiders. Enclosures were either closed from the adjacent habitat but open to ballooning and ground-dwelling spiders (using holes cut in the side of enclosures) or were open plots (controls). This allowed us to test the role of ballooning compared to cursorial dispersal of ground-dwelling spiders within these habitats. A reciprocal substrate treatment was included in which leaf-litter was added to cornfields and removed from forests to test the interaction between mode of dispersal and habitat use. Ninety species were collected using visual surveys and with pitfall traps. More species were collected in cornfields, and more individuals were collected in litter-addition plots, but we uncovered no interaction between substrate treatment and enclosure type. However, enclosures that excluded cursorial spiders had fewer mature and immature spiders, suggesting that cursorial activity (at a small spatial scale) is an important mode of dispersal within both types of habitats.

Among the most enigmatic Cyphophthalmi are members of the genus Pettalus, a monophyletic group endemic to Sri Lanka. To date three species have been named, Pettalus cimiciformis (O. Pickard-Cambridge 1875), P. brevicauda Pocock 1897, and P. lampetides Sharma & Giribet 2006. However, the identity of the two XIX Century species remains confusing. Here the identity of the three original Pettalus specimens is revised based on their re-examination and comparison to the original descriptions, which do not match the redescriptions of these species published in the monograph of Hansen & Sørensen (1904).

Arctosa lutetiana (syn. Tricca lutetiana) (Simon 1876) (Lycosidae) is found in many European countries; however, the biology of the species is still unknown because it lives hidden under ground and is difficult to find. The objective of this study was to fill in basic information about the biology of this species. The specimens were obtained between 2005–2006. This species lives in primitive underground burrows that are not lined with silk. Herein we describe, for the first time, the burrows and the prey capture method of this species.

We report release of silk threads by males of Schizocosa malitiosa (Tullgren 1905) during copulation. The silk is deposited over the female's front legs and near her mouthparts. Possible functions for this behavior could be inhibiting female aggressiveness through chemicals deposited on the silk, inducing female catalepsy during copulation or repelling other males. We propose future studies manipulating male silk release to test these hypotheses.

Spiders of sexually dimorphic and nocturnal species, Poltys grayi Smith 2006 and P. laciniosus Keyserling 1886, were reared from egg sacs. Spiders were kept in small containers and were fed on a non-living food mix based on house-flies, pollen, egg, and moths. Despite setbacks while developing the method, 41% of P. grayi spiderlings matured (all males) and 24% of P. laciniosus matured (both males and females). Details of the food mix and conditions of rearing are presented. This method of rearing spiders may be useful for taxonomic purposes and for studies of variation, but is probably unsuitable for behavioral studies.

Despite a wealth of research on the benefits of mate choice, empirical evidence for the costs of courtship is scarce. Understanding the interplay between the costs and benefits of reproductive behaviors is critical to our understanding of sexual selection. I present a study designed to explore the potential reproductive benefits of male choosiness for large mates as well as the costs of courtship in the jumping spider Phidippus clarus (Keyserling 1885). My findings suggest that a positive relationship between female tibia length and the number of emerging spiderlings may underlie male choice for large females. However, this benefit may be mitigated by the longevity costs of courtship. Further investigation of the potential trade-offs between the benefits of male preferences for large females and the costs of courtship in this species is required.

The super-cooling point (SCP) of Pardosa groenlandica was found to be −10.54° C, which is lower than for species from warmer climates, in agreement with predictions. There was no significant difference found between sexes. There were also no significant differences between the seasons, although there was a slight trend towards lower SCP temperatures in the winter months. Dehydration lowered SCP in P. groenlandica, with a mean depression of over 3° C in desiccated individuals. Specimens of P. groenlandica were able to move at temperatures as low as −2.3° C. These data allow for comparisons with samples from other climatic regions, and reinforce predictions based on previous studies with a variety of arthropods, regarding the effects of hunger and desiccation on the SCP.

The name Madrepeira amazonica Levi 1995 is a synonym of Spintharidius rhomboidalis Simon 1893. Spintharidius is currently monospecific.