A review of the pseudoscorpion family Ideoroncidae in North and South America has revealed seven genera and 43 species. The genus Albiorix occurs in xeric environments in western USA and in Mexico, with two outlying species in Chile and Argentina. It includes 18 species, including five new species from Mexico (A. meraculus, A. minor, A. oaxaca, A. puebla and A. rosario), and three from USA (A. gertschi, A. sarahae and A. vigintus). Albiorix bolivari is treated as a junior synonym of A. retrodentatus. The genus Ideoroncus has nine species and is endemic to southern Brazil and Paraguay. Pseudalbiorix has four species and occurs in Central America and western Cuba. Typhloroncus has six species from Mexico and U.S. Virgin Islands, including the new species T. planodentatus from Mexico. Xorilbia has three species and occurs in the Amazonian rainforest ecosystems of northern Brazil and southern Venezuela. Two new genera are described: Mahnertius Harvey & Muchmore for the new species M. stipodentatus (type species) and M. hadrodentatus, both from Colombia; and Muchmoreus Harvey for the new species M. ignotus (type species) from Mexico. Several keys are provided, including one to separate the New World genera, and others to distinguish the species of each genus (apart from the monotypic Muchmoreus). The post-embryonic development of New World ideoroncids is reviewed, particularly the trichobothrial patterns of nymphs and adults.

The harvestman genus Philora Goodnight & Goodnight 1954 and the type species P. tuxtlae are redescribed, and Philora quetzalzin new species is described. The genus is newly assigned to the family Stygnopsidae Sørensen 1932 based on external morphology and male genitalia, which are described herein for the first time. The genus is compared with the morphologically similar genera Paramitraceras Pickard-Cambridge 1905, Sbordonia Šilhavý 1977, and Troglostygnopsis Šilhavý 1974 sensu stricto. Philora is unique within the family in having a scutum completum. The presence of a scutum completum in Philora and others laniatoreans is discussed. The male genitalia of the genera Paramitraceras, Philora, Troglostygnopsis and presumably the genus Sbordonia, are very similar and share a morphological pattern described here as the Paramitraceras-pattern.

Melanopa zhui, a new species from Hunan Province, China, is described. M. grandis Roewer 1910 and M. wangi Zhu & Song 1999 are redescribed. The morphological characters and male genitalia of the three species are illustrated.

Spiniform macrosetae have been useful as a taxonomic trait in the genus Diplocentrus, such as the telotarsal spiniform macrosetae formula widely used to separate species. Basitarsal spiniform macrosetae have been studied in the family Scorpionidae but not in its sister family (Diplocentridae). In this study, we analyzed the variation in the position and number of spiniform macrosetae on the basitarsus of one species of the genus Diplocentrus. We found minimal ontogenetic, intersexual and geographical variation within the species. We also compare the pattern found in Diplocentrus tehuacanus Hoffmann 1931 to those of two morphologically similar species, and found that the basitarsal macrosetal pattern is also a good, reliable taxonomic character at the interspecific level.

We examined a group of seven morphologically similar species of the genus Pardosa to determine the reliability of morphological identification characters independently of additional specimen data, such as habitat and geography. Of the seven, four shared diagnostic character states with other species. These four species have areas of both sympatric and allopatric distribution. Specimens collected from allopatric areas, thus expected to contain only one species, were identified using only the morphology of the specimens, keeping the locality data hidden, and the reliability of the identifications was assessed. Identifications of the allopatric specimens resulted in a 32% success rate, indicating that the sole use of morphological characters did not work well for identification in this group. Reliance on geographical data to direct an identification would likely result in identification errors in areas of sympatry. As a result we conclude Pardosa tristis (Thorell 1877), P. prosaica Chamberlin and Ivie 1947 and P. dromaea (Thorell 1877), are new synonyms of Pardosa groenlandica (Thorell 1872).

New records of the extinct arachnid order Trigonotarbida are described from Upper Pennsylvanian (Moscovian: Bolsovian [ = Westphalian C]) spoil heaps associated with the Týnec mine near the village of Týnec in West Bohemia, Czech Republic. Three specimens are recorded, two of which are incomplete opisthosomas assigned to Trigonotarbida incertae sedis. A third fossil is more complete and is described here as Tynecotarbus tichaveki gen. et sp. nov. Its familial position is uncertain, but the presence of a weakly lobed carapace and finely tuberculate body ornament suggests affinities with the ‘eophrynid assemblage’ sensu Dunlop & Brauckmann (2006) and particularly the family Lissomartidae from Mazon Creek, USA. In order to be comprehensive in our study, we include a complete list of Czech trigonotarbids.

Coloration of the egg sacs of spiders varies widely to the human eye, both across and within taxonomic groups. These differences in coloration are expected with differences in the biology and ecology of different species. Here we measure the spectral properties of the egg sacs of 15 species in six families. Ultraviolet chroma, red chroma, and particularly overall brightness vary widely across and within taxonomic groups. We discuss the spectral properties of the silk of the egg sacs in the context of the physical characteristics of the silk, the reflective properties of the background, the environmental illumination, and the natural history and behavior of the spider species. In most cases, the spectral characteristics of the egg sacs seem to reduce their conspicuousness against the background and in those cases in which the coloration does not reduce the contrast in relation to the background, the low environmental light available may help to camouflage the egg sacs.

This study used radioimmunoassay (RIA) to explore the relationship between levels of hemolymph ecdysteroids and female reproductive behavior in Schizocosa wolf spiders. Specifically, we investigated the relationship between circulating ecdysteroid concentrations in females and 1) likelihood to copulate, or female receptivity [Experiment I—Schizocosa avida (Walckenaer 1837)], 2) time post copulation (Experiment 2— Schizocosa rovneri Uetz & Dondale 1979) and 3) exposure to conspecific male courtship (Experiment 3— Schizocosa uetzi Stratton 1997). In Experiment 1, we expected higher levels of circulating ecdysteroids in receptive versus unreceptive females, based upon prior research demonstrating an increase in receptivity following injections of 20-hydroexyedysone (e.g., Tegenaria atrica C.L. Koch 1843). In contrast, we found no relationship between female receptivity and ecdysteroid levels. Our second experiment compared ecdysteroid levels in mated versus virgin females at three time points following mating trials (24 h, 7 d and 14 d). We predicted low and constant ecdysteroid levels, independent of both mating status and time post mating trial—our results support this prediction. Our third experiment explored the relationship between exposure to conspecific courtship and ecdysteroid levels; again, we found no relationship. Thus, circulating ecdysteroid concentrations were not associated with any aspect of reproductive biology we explored. However, we found a negative trend between female age post maturation and circulating ecdysteroid concentration in the species for which we had the greatest age range, consistent with its role as a molting hormone.

Urbanization negatively affects biodiversity by increasing disturbance and habitat fragmentation. We compared three different urban habitats (vacant lots, gardens and forests) to examine differences in spider communities. We selected four sites of each habitat type and sampled spiders with pitfall traps. We collected a total of 547 individuals from 19 families. The most common families were Lycosidae, Corinnidae, Liocranidae, Cybaeidae, and Dictynidae. Spider activity-density overall and for males and females was higher in vacant lots than in forests, and female spiders had greater activity-density in gardens than in forests. Observed species richness did not differ with habitat type. Spider family composition differed significantly between urban habitat types, female morphospecies composition differed in forests and gardens and male morphospecies composition differed in forests and lots. The site characteristics differed significantly with habitat, and these habitat differences explained a large fraction (53.3% to 90.9%) of the variation in composition and richness. Yet, bare ground was the only factor that significantly correlated with declines in female richness. Thus, spider communities, aspects of specifically activity-density and composition, differ between habitats in urban green spaces with potentially important implications for conservation and trophic interactions within urban areas.

Wetland complexes in Mediterranean deltas play an important ecological role, as they harbor a diverse flora and fauna with numerous specialized species. Intensification and expansion of agricultural land use, as well as increasing withdrawal of water over the past decades, has led to considerable habitat loss in many places. Although studies from temperate Europe have already demonstrated the conservation needs of wetlands, analogous data for the Mediterranean region are very scarce. The present paper analyzes spider assemblages of the Aladjagiola wetland complex and provides ecological descriptions of diversity patterns and assemblage structures. We aim to provide the first ecological descriptions of several species and effective data sets to characterize the ecological status of the wetland habitats investigated. Spiders were collected by pitfall trapping from April to July 2008 in seven habitat types: pseudo-maquis, dry grassland (short growth), dry grassland (long growth), fringes, reed belts, humid grassland and fallow land. Diversity (alpha and functional) and evenness were both found to be lowest in humid habitat types. Community structure was analyzed by non-metric multidimensional scaling. Humid habitat types harbored a distinct species assemblage comprising many hygrophilic species that could clearly be separated from all other habitat types. By means of generalized linear models, habitat preferences of numerous xerophlic, hygrophilic and photophilic species could be assessed. Our study demonstrated that especially humid habitat types are worth protecting.

Jumping spiders (Salticidae) are known for their complex eyes and exceptional spatial vision, but less is known about the role of chemoreception in salticid behavior. Here we investigate whether olfactory pheromones (i.e., airborne chemical signals) from conspecific spiders and their draglines elicit the display behavior typically performed during vision-based courtship from the males of Cyrba algerina (Lucas 1846) and C. ocellata (Kroneberg 1875). We used conspecific and heterospecific spiders and their draglines as potential sources of chemical cues. We show that olfactory cues from conspecific females, but not conspecific males or heterospecific females, effectively elicit vision-based courtship from the males of both Cyrba species. These results demonstrate that C. algerina and C. ocellata males make display decisions on the basis of species- and sex-specific olfactory information. Moreover, even in the absence of a conspecific female spider, female draglines suffice as a source of olfactory pheromones, illustrating the difficulty of ruling out olfaction when testing for chemotactile pheromones.

Cryptic animals tend to spend most of their lives keeping still. The majority of predators, however, including those cryptically colored, are forced to move in order to find and approach their prey. For such predators visibility may be an important factor influencing predatory behavior. Therefore we can expect differences in the way they approach their prey on backgrounds with different camouflaging properties. To test this, we examined the behavior of Yllenus arenarius Menge 1868 (Araneae: Salticidae), a cryptically colored jumping spider, hunting leafhoppers on backgrounds matching and non-matching for the spiders. Juvenile and female Y. arenarius are cryptic on light sand, but males lose their cryptic coloration for this background after their final molt. We designed an experiment to determine if increased visibility of the spiders influenced their predatory behavior. We found that background color had a significant effect on jumping distance, approaching speed and predatory success. On the light background cryptic spiders attacked from closer distances, approached prey with faster speeds and had higher success than on the dark background. Differences in approaching speed between males before and after final molt suggest a combined effect of background color and ontogenetic change of body coloration on the predatory decisions of these male spiders.

We investigated the mating biology of the previously unstudied central European spider Leviellus thorelli (Ausserer 1871) by staging laboratory mating trials using males and females of varying mating histories. Our aim was to seek common themes in sexual behaviors of the sexually size-monomorphic “zygiellid” spiders with their putatively close relatives, araneids and nephilids, which are relatively well studied with respect to sexual biology. We found L. thorelli mating biology to more closely resemble that of sexually size-monomorphic araneids than that of dimorphic nephilids. Unlike in nephilids with sexually conflicted adaptations, we found no evidence for genital damage or plugging in Leviellus Wunderlich 2004, although we found rare cases of half-eunuchs. We suggest that the mating system of L. thorelli spiders is determined by short female sexual attractiveness, reduced receptivity after mating and/or intensive mate guarding.

Spitting spiders, Scytodes spp., rapidly expectorate a zig-zag of silk from cephalothoracic glands through openings at the base of their fangs, tacking down prey before feeding. Previously, scavenging of dead prey was considered rare among the Araneae but, in laboratory bioassays, it is exhibited across a wide spectrum of spiders including Scytodes Latreille 1804. When presented with dead spiders as prey, two species of araneophagic Scytodes spiders secured their meals without deploying the probably metabolically expensive cephalothoracic silk in 25 of 30 feeding episodes. Scytodes globula Nicolet 1849 scavenged without spitting in 16 of 30 trials (53%), whereas S. atlacoya Rheims et al. 2007 did so in 9 of 36 trials (25%). Therefore, spitting spiders show behavioral plasticity in securing prey, conserving resources when necessary.

We describe the mimetic relationship between the ant-like spider Myrmecotypus iguazu Rubio & Arbino 2009 (Araneae: Corinnidae) and the carpenter ant Camponotus sericeiventris Guérin (Hymenoptera: Formicidae), studied in a subtropical rainforest in Iguazú National Park, Argentina. The morphological adaptations, aspects of coloration, and behavior responsible for the ant-like appearance in M. iguazu (the mimic) provide strong evidence that its model is C. sericeiventris. Both field observations and field and laboratory experiments suggest that this spider is a Batesian mimic.

Foraging by an organism varies over the season in response to environmental conditions. Predatory arthropods, such as spiders, are frequently in a food-limited state despite their polyphagous habits and may feed opportunistically to enhance rates of growth, survival and reproduction. We predicted that, to circumvent food limitation, spider foraging would be related to prey availability. We examined the extent to which body condition of spiders, a correlate of recent foraging, was related to prey availability and habitat type. Wolf spiders Pardosa milvina (Hentz 1844) were collected between May and October in two habitat types, corn and soybean fields. To assess changes in spider condition, we calculated and compared multiple body condition indices derived from morphometric measures of individual spiders. Prey abundance was monitored over the same period using a vacuum suction sampler. Body condition indices provided qualitatively equivalent results. Interestingly, juvenile males were in better condition than adult males, but the opposite was the case for juvenile versus adult females. Although the availability of potential prey generally increased over the growing season, changes in body condition fluctuated independently of prey, suggesting that Pardosa milvina have life history differences in foraging and demand for resources that may influence foraging decisions.

Pitfall traps are a common and inexpensive sampling method for epigeal spiders. They are most effective when the top edge of the trap is flush with the soil surface, which is not always possible if soil disturbance is prohibited, the soil layers are thin or the substrate is only exposed rock. Ramp traps are also inexpensive to construct and do not require soil disturbance, making them an appealing alternative to pitfall traps. We tested the efficacy of ramp traps for capturing wandering spiders at the Fort Pierre National Grassland in central South Dakota, USA. We set parallel transects of pitfall and ramp traps during three sampling periods from late May to early August 2010. Ramp traps captured twice as many individuals and, on average, 1.1 ± 0.34 SE more species than pitfall traps. Overall, ramp traps outperformed pitfall traps, and ramp traps are better for non-permanent sampling at point-specific locations.

Ballooning, a form of dispersal rarely seen in mygalomorph spiders, was observed in 13 individuals of an undetermined species of Actinopus under laboratory conditions. After ascending a stick, each spiderling initiated ballooning from either the horizontal lines between sticks or from the stick's edges. They became airborne by dropping and dangling from a dragline, which then gradually lifted and lengthened to 10–15 cm in the breeze, broke at its attachment point, and served as a ballooning thread. This method of ballooning has also been observed in araneomorphs and other species of mygalomorphs, and this is probably a more primitive and shorter distance form of ballooning than that typically practiced by higher araneomorphs, which produce airborne silk lines that are pulled from the spider by air currents and are used either as spanning lines or as balloon lines that allow the spider itself to become airborne.

Two new species in the genus Theridion Walckenaer 1805 (Araneae: Theridiidae) are described: T. logan, sp. nov., from Utah, USA, and T. pierre, sp. nov., from South Dakota, USA. Diagnoses, descriptions and habitat notes are provided for both sexes of these new species. Both species are from open, grassland-type habitats.

There are conflicting statements in the literature about the date and organ of publication for the endemic Galápagos scorpion Centruroides exsul (Scorpiones: Buthidae) by Wilhelm Meise. In contrast to what the current authoritative taxonomic references suggest, this species was not described in 1934 but rather in 1933. Before the article containing the description finally was included in Volume 74 of the Norwegian journal Nyt Magazin for Naturvidenskaberne in 1934, it was distributed as a preprint in the form of Volume 39 of the separately issued series Meddelelser fra det Zoologiske Museum, Oslo in 1933. The latter publication, in full agreement with Article 21.8 of the International Code of Zoological Nomenclature, has priority over the former and consequently has to be referred to when citing the original taxonomic reference. The present contribution furthermore reviews the distribution of this species and, due to loss and mislabeling, revises its type material.

A new name Honolophus bastawadei is proposed for Euphalangium martensi Das and Bastawade 2006 non Staręga 1986.

We report the recent collection and observation of large numbers of specimens of the troglobitic harvestman Speleosiro argasiformis Lawrence 1931 in the Wynberg Cave system, Table Mountain, South Africa. Specimens were collected and/or photographed in different caves of the system. Live observation showed specimens fleeing bat carcasses when disturbed.

A new species of the genus Protoschizomus Rowland 1975 is described with adult males and females. We collected Protoschizomus franckei new species from Cueva del Diablo in the state of Guerrero, Mexico. Currently, the genus Protoschizomus is composed of eight species including the new species described here, of which five have been found inside caves.