Female Pardosa milvina (Hentz 1844) wolf spiders advertise sexual receptivity toward males via silk draglines, and male P. milvina exhibit conspicuous courtship behavior when encountering silk from females. Previous studies suggest that female P. milvina may benefit by limiting silk advertisements and excreta deposition when encountering silk from the predator, H. helluo, and male P. milvina may exhibit corresponding reductions in courtship when encountering silk from conspecific females previously exposed to H. helluo silk. We tested these predictions by comparing the amount of silk and excreta deposited by unmated female P. milvina exposed or not exposed to predator cues (silk and excreta) from H. helluo. We also measured and compared male P. milvina courtship latency and intensity in the presence of silk from females previously exposed or not exposed to predator silk from H. helluo. Contrary to predictions, we found a significant increase in excreta, dragline, and attachment disk deposition after females were exposed to H. helluo cues. Male P. milvina courtship latency did not vary among treatments despite increases in female silk deposition, but males significantly decreased courtship intensity when exposed to silk from females under predation risk. Vertical climbing to escape the predator cues may cause an increase in female silk deposition.

Ocular arrangement and visual acuity were examined in Lycosa leuckartii Thorell 1870 (Araneae: Lycosidae), using histological techniques. Major structural and functional features of the visual system, including external and internal ocular organizations, resolution, sensitivity, focal lengths and the field of view, were characterized for each eye. Lycosa leuckartii had a large developmental investment in a specialized visual system with high visual acuity. The field of view extended 360° and displayed the potential for good depth perception. Anterior eyes showed average focal lengths (AL eyes 230.88 µm, AM eyes 276.84 µm), while the posterior eyes far exceeded them (PL eyes 499.26 µm, PM eyes 675.35 µm). Resolution of the anterior eyes was comparable to records in the literature for other lycosids (inter-receptor angle AL eyes 2.45°, AM eyes 1.85°), while the resolution of the posterior eyes was higher (PL eyes 0.78°, PM eyes 0.67°). Sensitivity of the lens (f-numbers) was highest in the secondary eyes and was close to some of the highest reported for Araneae (f-numbers PM eyes 0.58), but when receptor diameters were included in estimates, S-numbers were similar or lower than closely related species (PL eyes 17.5 µm², PM eyes 17.6 µm²). There is a clear distinction in organization and function between the posterior and anterior eyes of L. leuckartii. The posterior eyes suit long- range predator and prey detection, while the anterior eyes are best for distance judgment and prey capture.

This paper discusses the possible functional significance of the locations of the spigots of different types of silk gland on the different spinnerets of spiders. Deductions are based on recognition that some types of line are initiated by being attached to the dragline, that there is an anterior-posterior asymmetry in how such lines can be initiated, and that spigot location also affects the possibility of attaching lines to the substrate. Possible explanations are given for several morphological details, including the anterior location of the dragline, piriform and cribellum spigots, planar arrays of piriform and cribellum spigots, and posterior location of aciniform spigots. I argue that piriform gland products are not used to attach egg sac lines to each other, that sticky wrapping lines are initiated in theridiids and pholcids by attaching them to draglines and that lines from both aciniform and cylindriform glands are laid along with liquid that renders them sticky. The possible role of phylogenetic inertia in determining spigot locations is discussed. Further work is needed to determine whether termination of lines and accessibility of spigots for cleaning also influence their positions.

Reports of Palpigradi from South American caves are rare, and no troglobiotic species have yet been described. This apparent deficiency, however, reflects merely a lack of reporting. Ten years of biospeleological surveys of 603 caves in 16 of the 26 Brazilian states, in bedrocks including limestone, quartzite, iron ore, granite, and gneiss, have led to the capture of 494 palpigrades, and specimens with troglomorphic characteristics have been found in Minas Gerais, Bahia, and Espirito Santo. Palpigrades have been found to be relatively more common in iron ore caves, and troglomorphic species apparently occupy cave habitats different from those occupied by edaphomorphic species. The description of the first troglobite species from South America is presented here. Eukoenenia maquinensis, new species, collected in the Maquiné Cave Minas Gerais, Brazil, has six blades in the lateral organs, seven pairs of setae on the propeltidium, six setae on the basitarsus IV (a single proximal sternal seta) and a singular chaetotaxy of opisthosomal sternites.

A new species of Ricinulei of the genus Cryptocellus Westwood 1874 is described from the Madeira-Purus Interfluve, Amazonas, Brazil. It shares a set of apomorphies with Cryptocellus peckorum Platnick & Shadab 1977 and Cryptocellus tarsilae Pinto-da-Rocha & Bonaldo 2007, with which it forms an assemblage of related species herein named the peckorum group. A second group of species, the Cryptocellus adisi group, is formed by the following species: Cryptocellus adisi Platnick 1988, Cryptocellus florezi Platnick & García 2008, and Cryptocellus lisbethae González-Sponga 1998.

Phoneutria is one of the most medically important spider genera; however, its ecology is poorly known. In Amazonian upland rainforests, there are two sympatric species of the genus Phoneutria, P. reidyi (F.O. Pickard-Cambridge 1897) and P. fera Perty 1833. For 15 months we collected data on the spatial distribution, use of habitat (activity on the ground or vegetation) and temporal changes in body size structure in a forest reserve near Manaus city in three distinct habitats: dense forest, located on the plateaus on yellow latossol; swamp forest, located in the valleys; and heath forest or “campinarana,” on dry white sand soil in the Reserva Florestal Ducke. A total of 239 P. reidyi and 239 P. fera were captured in nocturnal searches during their period of activity. There were significant differences between the two species: 1) P. reidyi existed in higher abundance in the swamp forest than in the dense forest areas and was almost absent in the heath forest, while P. fera existed in similar abundance in the three habitats. 2) During their development, members of both species used the vegetation as an area of activity, but the subadults and adults of P. reidyi were less often found on the ground than the subadults and adults of P. fera. 3) P. reidyi more frequently used small or acaulescent palms as a substrate, and its abundance was directly related to the abundance of these palms, independent of the habitat, while P. fera did not show such relationship. 4) There was a strong temporal variation in the body size structure of the P. reidyi population indicating seasonal reproduction, but there was no evidence of seasonal reproduction by P. fera. We suggest that the differences in the use of habitat and in the seasonality of reproduction are related to the avoidance of intraguild predation between these species.

The hypothesis that fluorescence in scorpions functions in the detection of ultraviolet light was tested. We reduced the fluorescence of scorpions by prolonged exposure to ultraviolet light on a 16:8 h light:dark cycle and compared their activity levels and light environment choices to unmodified scorpions in simple arenas that were half in shadow and half exposed to light. Three different lighting conditions were tested: infrared (IR) light only, IR ultraviolet light and IR white light. Treatments were illuminated by infrared light for videotaping. Activity level was measured by the number of transitions from the exposed to shadowed regions, and choice was measured by the percentage of time spent in the shadowed portion of the arena. Under IR ultraviolet light, fluorescent scorpions reduced their activity levels and the variance in habitat choice increased, compared with reduced-fluorescence scorpions. There were no differences between fluorescent and non-fluorescent scorpions in the IR only condition or in the IR white light condition. This is interpreted as evidence that fluorescence aids in the detection of and response to ultraviolet light, and possible implications of this result in natural habitats are discussed. This is the first experimental demonstration of a possible function for scorpion fluorescence.

A first step toward understanding why sociality has evolved in a particular taxonomic group is to establish comparison points by studying the organization of different social systems. We examined the social organization and spatial distribution of individuals in colonies of the undescribed colonial spider Leucauge sp. (Araneae: Tetragnathidae). The social organization of this species was typical of a colonial species, with spiders maintaining individual territories (orb webs) within a scaffolding of shared support lines maintained by the group. Furthermore, we observed a size-dependent vertical stratification of spiders within colonies, with large spiders occupying the highest positions, followed by medium, extra-small and small individuals, a spacing pattern that was consistent across colonies of all sizes. Spiders captured and consumed prey individually and displayed territorial behaviors involving web defense. This study provides a new example of a colonial spider species that shows a distinctive within-group spatial distribution. We discuss possible reasons underlying this species' spatial arrangement in the context of social evolution.

Of all the wolf spiders (Araneae: Lycosidae), the genus Schizocosa Chamberlin 1904 is probably the most widely studied, and has become an established model in studies of behavior, sexual selection, and speciation. Much of the work to date involves the complex, often multimodal courtship behaviors and secondary sexual traits used by males to elicit receptivity from potential mates. Schizocosa bilineata (Emerton 1885) is one of those species where males possess decorative tufts of bristles on the forelegs that likely play a role in sexual selection, but little is known of male courtship behavior or its role in mate choice. In the present study, we provide the first description of visual and seismic behaviors performed by males in response to female silk and chemical cues, and examine male-female behavioral interactions in live mating trials. Males clearly recognized and responded to female chemical cues by displaying several species-specific visual signaling behaviors accompanied by seismic signals from stridulation. As these behaviors rarely occurred in the absence of female cues, we suggest they function primarily in a courtship context. In live mating trials, females typically responded to male courtship with visual receptivity behaviors, which were seen prior to mounting and copulation. While both visual and seismic signals of males are clearly implicated in courtship and mate choice, future work will be necessary to fully understand the interaction between modalities in this species. The description of behavior provided here should help resolve the relationship between male ornamentation and courtship behavior in the genus Schizocosa.

A new species, Santinezia noctiscansor, most similar to members of the S. festae group, is described from central Panama; this species is the only member of the genus that occurs in Central America. Our examinations of adults and nymphs collected from Coclé and Panamá Provinces revealed that males are sexually mature as penultimate nymphs. The subadult strongly resembles the adult with respect to coloration, scutal outline, armature of femora III–IV, and penis morphology, but differs in having fewer tarsomeres on each leg, a smaller body size (scutal length and width), and a much smaller tubercle on the ventral surface of coxa IV. Natural history observations are provided for specimens collected from the field site in Coclé Province.

In this paper we present a detailed study of the natural history of Gluvia dorsalis (Latreille 1817), a representative of the family Daesiidae, the only solifuge species known to occur in southwestern Europe. We studied its distribution, habitat preference, circadian activity, seasonal occurrence, burrowing, predatory and post-mating behavior, prey, fecundity, ontogenesis, and sexual dimorphism. Gluvia dorsalis occurs in lowlands across the entire Iberian Peninsula, preferring grassland or similar open-ground habitats with little summer rain. According to pitfall trap data, the species was active on the surface from May until the beginning of November. It is a nocturnal epigean predator, feeding principally on ants and spiders. However, under laboratory conditions, specimens captured and consumed a variety of arthropods. G. dorsalis seems to hide in underground burrows only when molting, overwintering, or laying eggs. Reproduction occurred in early summer, and females usually produced a single egg clutch containing, on average, 84 eggs, and died soon after. Our results indicate that the G. dorsalis is a biennial species. There was sexual dimorphism in several morphological structures that might be used for sex matching in juvenile instars.

Three species of the genus Sarax are recognized in the Papuan region. Among them, two species, Sarax newbritainensis, new species, from New Britain, and S. monodenticulatus, new species, from Waigeo Island are described. Sarax newbritainensis resembles S. willeyi in having the same number of denticles on the pedipalpal tarsus, but they distinctly differ from each other in body size, form of carapace, length of legs and number and arrangement of the trichobothria of tibia of leg IV. Sarax monodenticulatus is distinguished from the other two Papuan species by possessing a single denticle on the pedipalpal tarsus. The taxonomic status and the natural history of the species are discussed.

Web designs of young spiders are often less derived than those of older conspecific individuals. This study tested whether this “ontogeny repeats phylogeny” pattern occurs in two species of Latrodectus and two species of the closely related genus Steatoda. This pattern was assumed to occur in a recent study of a third Latrodectus species, L. geometricus, which attempted to deduce a probable evolutionary derivation of gum-foot webs of theridiids on the basis of ontogenetic changes. We found the same basic ontogeny repeats phylogeny ontogenetic pattern in all four species, suggesting that the previous suppositions were justified. As expected, the webs of the young instars of the two Latrodectus species were more similar than those of the adults, and were more similar to those of young than to those of adults of L. geometricus. One apparently derived trait of L. mirabilis, attaching prey remains as camouflage for the spider in the central portion of the web, did not change during ontogeny, and was present in even the webs of first-instar spiderlings. Field observations of L. mirabilis suggest that the ontogenetic change from light to darker abdominal color patterns that occurs in many Latrodectus species may result from changes in selection for camouflage associated with ontogenetic changes in web designs and the spiders' resting sites. The webs of Steatoda also fit the ontogenetic pattern: at least some ontogenetic changes in both species involved younger spiders having less derived traits than those of adults. The webs of young Steatoda spiders were more derived in some respects than those of the early instars of Latrodectus.

We describe a new species of Tarabulida Roewer 1933 from Kenya. This genus was previously known from only two species (Tarabulida ephippiata Roewer 1933 and Tarabulida fumigata Roewer 1933) from Libya, which were described from specimens reported as females. Tarabulida mugambii new species is based on specimens collected in northwestern Kenya, representing the first complete description of a male Tarabulida and the first record for the genus from Kenya. We also discuss problems associated with characterizing Tarabulida and its placement within the Daesiidae. A lectotype is designated for the type species of Tarabulida, T. ephippiata Roewer 1933.

Tricca lutetiana (Simon 1876) (Lycosidae) lives hidden underground and, thus, is not well known. Our objective was to document more fully basic information on reproduction, particularly copulation, in this species. We obtained and observed in the laboratory 86 individuals from the wild between 2006 and 2008. Vibratory and tactile communication is an important medium during sexual communication. We described unique movements of the mating male's legs during copulation, for the first time in the family Lycosidae. Adult females live for two years and, in their underground burrows, they produce one cocoon per season. They carry the cocoon, mostly using legs IV, and look after it for one month until the offspring leave. Maternal care for spiderlings lasts one week following the spiderlings' emergence.

The female of Orsolobus pucara Forster & Platnick 1985 is described and its genitalia examined using the scanning electron microscope (SEM). A small phylogenetic matrix with female genital and sexual behavior characters was made with the aim to study the evolution of these characters in the superfamily Dysderoidea. This is the first time that the female genitalia of a species of the family Orsolobidae have been studied in detail with SEM. The anterior portion of the female genitalia is a sclerotized structure with gland ducts and sites for muscle attachments. The posterior portion has a membranous receptaculum and a sclerotized plate that serves as attachment for muscles. We discuss the probable function of genital characters in a phylogenetic context. The anterior sclerotized elements of the female genitalia of some Dysderidae, Orsolobidae and Oonopidae species and the anterior receptaculum in the Segestriidae seem to be homologous structures because of the presence of gland ducts and sperm. However, both of these characteristics are lost in some species of these families, the anterior portion of the female genitalia being transformed into a highly modified structure serving mainly as attachment for muscles implicated in sexual behavior mechanisms.

Based on a firsthand parsing of the original literature, a Zoological Record-style tabulation of all nomenclatural acts regarding species of the order Opiliones is presented for the interval between 1758 and 1804. A total of 52 species was described as new, 14 of which are not Opiliones or remain unrecognizable (nomina dubia), six species have been synonymized (one revalidated), in all resulting in 33 valid species of Opiliones. Four genera were established, although no more than three were used simultaneously. The family Phalangita (Phalangiens) was described and coincides with the modern use of the order Opiliones. Of the current four recognized suborders of Opiliones, three (Cyphophthalmi, Eupnoi and Dyspnoi) were recorded. Laniatores remained unknown. A checklist is given for the order Opiliones up to 1804.

The native Nearctic species of the family Sparassidae are revised. Eight synonymies are proposed, reducing the number of species to five: Olios schistus Chamberlin 1919, O. scepticus Chamberlin 1924 and O. positivus Chamberlin 1924 with O. peninsulanus Banks 1898; O. albinus Fox 1937 and O. foxi Roewer 1951 with O. naturalisticus Chamberlin 1924. Olios concolor Keyserling 1884 and O. pragmaticus Chamberlin 1924 are removed from the synonymy of O. fasciculatus Simon 1880 and synonymized with O. giganteus Keyserling 1884. All species currently included in the genus Olios Walckenaer 1837 are redescribed and illustrated, and new distribution records are presented. Comparisons between these species and the type species of the genus Olios, Olios argelasius (Walckenaer 1805), shows that none of them are congeneric and that true Olios does not occur in the Nearctic region. Nevertheless, the correct placement of these species in new genera will only be possible after a more thorough revision of the Nearctic and Neotropical fauna, especially that of Mexico and Central America.

The wolf spider Pardosa sierra was described and illustrated by Banks in 1898 based on specimens from the Sierra de la Laguna, Baja California Sur. Later, two morphologically similar species, P. atromedia Banks 1904 from Claremont, California, and P. sura Chamberlin & Ivie 1941, also from California, were described. However, the latter two species were subsequently synonymized with P. sierra, due to similarities in male genitalia. In this study we test the species limits within this group. We suggest that the details of the epigynum are different enough among the genitalic morphs studied to consider them different species as originally designated. We conducted a morphological and genetic-distance analysis of a fragment of the cytochrome c oxidase subunit I gene sequences of some species of lapidicina group, as well as some sequences of Pardosa astrigera L. Koch 1878 from the GenBank database. Genetic analysis revealed greater genetic distances (GD) among haplotypes of P. sierra, P. atromedia, and P. sura (GD  =  0.053–0.069) than with other species of the lapidicina group. Moreover, P. sierra was closest to P. sura (GD  =  0.053), P. sura was closest to P. vadosa Barnes 1959 (GD  =  0.040), and P. atromedia was closest to P. steva Barnes 1959 (GD  =  0.052). Overall, morphological and genetic differences, and disjoint distributions, suggest that the synonymy of P. sierra, P. atromedia, and P. sura was in error, and that these “morphs” do indeed represent different species.

Four new species belonging to the mexicanus group of the genus Vaejovis C.L. Koch 1836 from Oaxaca, Mexico are described. The number of species of this group for the state is raised to seven. The males of V. franckei and V. setosus are described for the first time. A key to Oaxacan species of the mexicanus group is provided.

A new species of harvestman from the endemic North American genus Hadrobunus Banks, 1900 is described. The species, H. fusiformis, differs substantially from known USA species in both somatic and genital morphology, but the male resembles that of H. knighti from northern Mexico in having a long, narrow penis and posteriorly tapered opisthosoma.

Intersexual differences in juvenile behavior in invertebrates are poorly understood despite the recognition that they may be widespread. We present a study designed to explore sex differences in behavior in early instar long-bodied cellar spiders Pholcus phalangioides (Fuesslin 1775). Our findings reveal that sex differences in activity and feeding are present early in P. phalangioides, which may have important implications for studies of behavior that involve juveniles. Further investigation of the factors that underlie the early emergence of sex differences in behavior is needed.

The chemical composition of the scent gland secretion of Pachylus paessleri Roewer 1913, a pachyline harvestman, was analysed by gas chromatography–mass spectrometry. The secretion is a six-component mixture of benzoquinones, with 2,3-dimethyl-1,4-benzoquinone and 2,3,5-trimethyl-1,4-benzoquinone being the main components (together amounting for ¾ of the secretion). Minor components are 2,5-dimethyl-1,4-benzoquinone (about 12%), 2-ethyl-3-methyl-1,4-benzoquinone (about 8%), 2,5-dimethyl-3-ethyl-1,4-benzoquinone (5%), and 2-ethyl-5-methyl-1,4-benzoquinone (about 1%). No sex-dependent differences could be detected. While dimethyl- and trimethyl-benzoquinones are widespread in scent gland secretions of Gonyleptoidea, 2,5-dimethyl-3-ethyl-1,4-benzoquinone and 2-ethyl-5-methyl-1,4-benzoquinone are reported for the first time in Opiliones. The phylogenetic implications of these compounds are briefly discussed in the scope of the present knowledge of Laniatores.

A new Trachyzelotes spider species, Trachyzelotes minutus n. sp. is described. The new species likely belongs to the “barbatus group”, based on the rounded embolus base and terminal apophysis, as well as the anterolaterally expanded copulatory ducts. Trachyzelotes minutus may be a sister species of T. fuscipes, given the similarities of the embolus and terminal apophysis.

Two spider species of the subfamily Coelotinae from Japan, Coelotes decolor Nishikawa 1973 and Hypocoelotes tumidivulva (Nishikawa 1980), are revised. We focus particularly on the female vulva structures, which are illustrated and described for the first time. Both species have unique genitalic structures compared with other coelotines. The female Coelotes decolor is similar to C. akakinaensis Shimojana 2000 and C. iheyaensis Shimojana 2000 in having long spermathecal stalks, but no species have been found to be similar to Hypocoelotes tumidivulva.

Although venom glands were described for the Mesothelae many years ago (Bristowe & Millot 1933), a more recent monograph (Haupt 2003) denied the existence of such glands in the Mesothelae. Our morphological studies of nine different species of Liphistius demonstrated the presence of venom gland openings on the cheliceral fangs in all of these species. Also, we observed a small venom gland in the anterior portion of the cheliceral basal segment. The possibility that venom glands may be lacking in adult males is discussed. The presence of venom glands in the Mesothelae indicates that this is a plesiomorphic character of all Araneae.

Adult male Liphistius have dense hair pads on the ventral side of their tarsi. At first glance they appear like the adhesive scopulae, which are well known from mygalomorph spiders. However, a fine structural analysis of these scopulate hairs shows that they lack the brush-like structure with tiny “endfeet” that is typical for such adhesive hairs. Instead, the smooth hair shaft exhibits a small pore ventrally, about 8–10 µm from the blunt tip. A thin cuticular canal extends from that pore through the middle of the hair shaft and terminates about 30 µm above the hair base. Transmission electron microscopy reveals that this central canal contains about 16 delicate dendrites. The morphology of these scopulate hairs thus corresponds closely to contact chemoreceptors known from other spiders. Since these scopulate hairs occur only in adult males, they are likely involved in the perception of female pheromones.