A Palearctic spider, Linyphia triangularis (Clerck 1757), has been accidentally introduced to the U.S.A. and populations successfully established in Maine. The date, origin, and focal point(s) of introduction are unknown, but suspected to be recent, European, and maritime. Extensive historical collections, records of maritime commerce, and recent chronological collections support this hypothesis. Results of cursory surveys in 1999 and 2000 indicate that L. triangularis is now widely distributed in Maine with specimens taken in 15 of 16 counties. The potential impact(s) of L. triangularis on the native araneofauna are unknown, but possibly detrimental. In Europe, this species exhibits aggressive behaviors (e.g., web “take-overs”) toward conspecifics and congenerics.

Male Schizocosa ocreata (Hentz) wolf spiders (Araneae, Lycosidae) have tufts of elongated, dark bristles on the patella and tibia of the forelegs, which are involved in visual signaling. Previous research has suggested that these tufts are used by females as a criterion in mate choice, raising the question of whether they might serve as indicators of male condition. We tested the hypothesis that tufts are condition-dependent indicator traits with a laboratory rearing study subjecting spiders to lifelong feeding regimens representing successful (high food) and unsuccessful (low food) foraging history, after which males were measured upon reaching adulthood. Mortality varied significantly with experimental treatment, and had a disproportionate impact on some egg sacs assigned to the low food treatment. Age at sexual maturity and several body size measures varied significantly with feeding history. Well-fed spiders survived better, matured earlier, were significantly larger, and were in relatively better condition (measured as a residual body condition index) than deprived spiders. Additionally, well-fed spiders had significantly larger relative tuft size (scaled for body size). These data suggest that male body size, condition and a conspicuous male signaling trait vary with feeding history, and thus have the potential to serve as “honest indicators” of male quality in mate choice.

A new species of Phrynus, P. exsul, from the Indonesian island of Flores, represents the first member of the family found outside of the New World.

In males of several Uruguayan lycosid species of the genera Lycosa, Schizocosa, Aglaoctenus and Allocosa, we used Scanning Electron Microscopy to investigate the existence and the morphology of pedipalpal stridulatory-like structures. These kinds of structures only appeared in species belonging to the subfamily Lycosinae, and representatives of the Allocosinae and Sosippinae subfamilies lacked them altogether. Unlike European Lycosa species, all surveyed Uruguayan species of the genus Lycosa presented the character to some extent, but interspecific differences occurred in the relative size and development of the structure. Lycosa thorelli, L. carbonelli and Lycosa sp. showed a very well developed pedipalpal structure, which was smaller in Lycosa poliostoma. Schizocosa malitiosa also exhibited an only partially developed structure. A possible role of these pedipalpal stridulatory-like structures in lycosid systematics is discussed.

RESUMEN. Mediante Microscopía Electrónica de Barrido, hemos analizado la existencia y la morfología de las estructuras pedipalpales de tipo estridulador en los machos de varias especies uruguayas de la familia Lycosidae (géneros Lycosa, Schizocosa, Aglaoctenus y Allocosa). Este tipo de estructuras sólo está presente en especies pertenecientes a la subfamilia Lycosinae, mientras que las especies representativas de las subfamilias Allocosinae y Sosippinae carecen por completo de ellas. A diferencia de las especies europeas de Lycosa, todas las especies uruguayas del género analizadas presentan la estructura, aunque existen diferencias interespecíficas en su tamaño y desarrollo relativos. Lycosa thorelli, L. carbonelli y L. sp. presentan una estructura pedipalpal muy bien desarrollada, mientras que su tamaño es menor en Lycosa poliostoma. Schizocosa malitiosa también posee una estructura sólo parcialmente desarrollada. Discutimos una posible aplicación de estas estructuras en la sistemática de la familia Lycosidae.

The homing behavior of Lycosa tarentula (Linnaeus 1758) (Araneae, Lycosidae) adult females was studied. They were tested under two conditions, diffused light (200 lux) and darkness, after having been placed in an open field. In both conditions the spiders did not orient towards the burrow position; instead, under diffused light, each spider turned at a constant angle with a value close to135°; this is the turn that the spider should have made in its terrarium to return to the burrow. In darkness, most of the spiders (71.4%) turned at random. In both conditions, the trajectory was roughly straight, finishing with a sudden directional change. The speed was higher under diffused light than under darkness. These results support the hypothesis that L. tarentula uses path integration in laboratory conditions and that it needs visual input to obtain a direction estimation in homing.

A new fossil Linyphiidae: Linyphiinae is described from 125–135 Ma old (Upper Neocomian–basal Lower Aptian) Cretaceous amber from the Kdeirji/Hammana outcrop, Lebanon. This is the oldest known linyphiid as well as the oldest described amber spider. The first major radiation of the linyphiid subfamilies occurred in the early Cretaceous, if not before, and the presence of Linyphiidae in this period predicts the presence of Pimoidae then too. Current evidence, which suggests the higher araneoids did not radiate and diversify until after the end-Cretaceous mass extinction event may be an artefact of sample size.

Sticky threads improve an orb web's ability to retain the insects that strike it, allowing a spider more time to subdue these insects before they can escape from the web. The adhesive capture threads found in most orb webs feature small droplets of aqueous material. Inside each droplet, glycoprotein granules coalesce to impart thread stickiness. An independent contrast analysis of threads produced by the adults of five species (Leucauge venusta, Argiope trifasciata, Micrathena gracilis, Cyclosa conica, Araneus marmoreus) and ontogenetic studies of the threads of two of these species show that the volume of material in a thread's droplets is directly related to its stickiness. Models based on these analyses predict thread stickiness to within an average of 11% of the mean measured values using measurements of droplet diameter and distribution that are easily made with a compound microscope. This approach will facilitate the inclusion of thread stickiness in studies that examine the properties and performance of spider orb-webs.

We studied the phenology and the daily activity patterns of Pardosa milvina Hentz 1844 and Hogna helluo (Walckenaer 1837) in replicated soybean fields in southwest Ohio over three years (1994–1996) using pitfall traps. For the phenology study we established an array of five pitfall traps in 12 replicate 0.42 ha fields. These traps were either set for two days at two-week intervals (1994), or for three days at three-week intervals (1995 & 1996), over the field season from May–October on a total of 20 trap dates. We found that P. milvina was more common overall, and found evidence for one population peak per year. Numbers of H. helluo tended to be lowest in the earlier censuses, and we found evidence for one peak of male activity per year. The immature male and female, and adult female H. helluo were larger (based on carapace width) than the immature male and female, and adult female P. milvina on most trapping dates. For the circadian activity periodicity study we used two different drift-fence trap designs, both with dry-cup pitfall traps set for two or three days and checked at 12 h intervals. For three sampling periods in 1994 we found H. helluo to be more frequently trapped at night, and for two sampling periods P. milvina was more frequently trapped during the daylight hours.

The two male morphs of the dimorphic jumping spider, Maevia inclemens, differ dramatically in morphology and courtship behavior. The purpose of this study was to examine and compare the mating success of the two male types. Mating success was measured by the number and duration of copulation events, the latency of visual orientation by the female to a courting male, signals of female receptivity, risk of predation by the female, and the number of offspring produced by each morph. The morphs did not differ significantly with respect to copulation success, mating events, mating duration, signals of receptivity or the number of offspring produced. However, males did differ with respect to latency of visual orientation as a function of distance from the female. Near to the female, the gray males attracted female attention in significantly less time than tufted males. Conversely, at far distances from the female, the tufted males attracted female attention in less courtship time. This study suggests that males attain equal levels of mating success and that the two male morphs may have evolved alternative reproductive strategies for courtship at different distances from the female.

The monotypic Brazilian genus Sickius Soares & Camargo 1948 is revalidated, rediagnosed, and tentatively transferred to the Ischnocolinae. The formerly unknown female of S. longibulbi Soares & Camargo 1948 is found to lack spermathecae. This unusual genital feature, not found in any other mygalomorph spider species, is described and discussed.

This paper contains keys to the 65 genera of araneid spiders known from the Americas. These genera hold approximately fifteen hundred species found in the Americas. The key to females uses mostly artificial characters; the key to males uses diagnostic characters. There are four new synonyms and two new placements.

The new species Leptoneta changlini, L. huisunica, L. nigrabdomina and L. taiwanensis are described and illustrated from Taiwan, and the natural history of L. changlini and L. huisunica is described. These species are only known from male specimens.

We describe the reproductive biology of seven theraphosid species from Uruguay. Species under study include the Ischnocolinae Oligoxystre argentinense and the Theraphosinae Acanthoscurria suina, Eupalaestrus weijenberghi, Grammostola iheringi, G. mollicoma, Homoeomma uruguayense and Plesiopelma longisternale. Sexual activity periods were estimated from the occurrence of walking adult males. Sperm induction was described from laboratory studies. Courtship and mating were also described from both field and laboratory observations. Oviposition and egg sac care were studied in the field and laboratory. Two complete cycles including female molting and copulation, egg sac construction and emergence of juveniles were reported for the first time in E. weijenberghi and O. argentinense. The life span of adults was studied and the whole life span was estimated up to 30 years in female G. mollicoma, which seems to be a record for spiders. A comprehensive review of literature on theraphosid reproductive biology was undertaken. In the discussion, we consider the lengthy and costly sperm induction, the widespread display by body vibrations of courting males, multiple mating strategies of both sexes and the absence of sexual cannibalism.

The aim of this study was to provide descriptive and quantitative data regarding behaviors involved in courtship and in sperm transfer of the whip spider Phrynus gervaisii (Pocock 1894) in order to complete the previous description for this same species given by P. Weygoldt. The specimens were captured in anthills of Paraponera clavata, on Barro Colorado Island, Panama. Ten courtship and five sperm transfer sequences were recorded. Four out of five mating sequences with sperm transfer ocurred between adults with similar body size and in the other case the female was smaller than the male. Sexual interactions did not occur between very small adults. Two male behavior patterns that have not been reported were observed during the initial stage of courtship: “pedipalp rubbing” and “female operculum rubbing”. Contrary to Weygoldt's description, in this study the female never performed “shaking” movements with her antenniform legs. It was observed that the two distal horn-like extensions of the spermatophore facilitate the female´s movements during the sperm transfer. The distal part of the spermatophore stalk provides a suspension area when the female rests on those horns. It was verified that the female can move the claw-like sclerites of the gonopods in all directions. The male executed copulatory courtship and successfully transferred sperm in five analyzed sequences. The female did not pick up the sperm packages when copulatory courtship was not performed. Males that lacked one antenniform leg were able to mate, however they had to perform vibrations more intensely with their non-injured leg for a longer duration. The data are compared with those previously obtained in other whip spiders. Some functional characteristics of the spermatophore and female genitalia of P. gervaisii are also discussed.

RESUMEN. El objetivo de este trabajo es aportar datos descriptivos y cuantitativos sobre patrones de comportamiento que ocurren durante el cortejo y transferencia espermática del amblipígido Phrynus gervaisii (Pocock 1894) con la finalidad de completar la descripción previa de P. Weygoldt para esta misma especie. Los especímenes fueron capturados en hormigeros de Paraponera clavata, en la Isla de Barro Colorado, Panamá. Se registraron 10 secuencias de cortejo y cinco de transferencia espermática. Cuatro de las cinco secuencias de apareamiento con transferencia espermática completa ocurrieron entre adultos de tamaño corporal similar mientras que en el otro caso la hembra fue más pequeña que el macho. No se produjeron interacciones sexuales entre adultos muy pequeños. Durante la etapa inicial del cortejo fueron observados dos patrones de comportamiento masculinos que no habían sido citados con anterioridad: “roces de pedipalpos” y “roces al opérculo genital femenino”. Al contrario de la descripción de Weygoldt, en el presente estudio la hembra nunca realizó movimientos de “latigueo” con sus patas anteniformes. Se observó que las dos expansiones distales con forma de cuerno del espermatóforo facilitan los movimientos de la hembra durante la transferencia espermática. La parte distal del tallo del espermatóforo ofrece un área de suspensión cuando la hembra se apoya sobre estos cuernos. Se verificó que la hembra puede mover los escleritos en form de uña de sus gonópodos hacia todas las direcciones. El macho efectuó cortejo copulatorio en cinco secuencias analizadas, en ellas la transferencia espermática fue existosa. Por el contrario, la hembra no recogió los paquetes espermáticos cuando no existió cortejo copulatorio. Los machos que carecían de una pata anteniforme también fueron capaces de aparear. Sin embargo, ellos tuvieron que realizar más intensamente las vibraciones con sus patas no dañadas, y sobre todo dura

Wolf spiders, Pardosa lapidicina Emerton 1885, occupy cobble beaches along the tide line about Narragansett Bay, Rhode Island, USA, and move back and forth on the beaches with the tides. I compared the orientation and movement in the low intertidal of three groups with normal access to the entire intertidal zone and a group from the high intertidal prevented from using the low intertidal by a barrier of dense salt-marsh cordgrass Spartina alterniflora. They included a group captured in the high intertidal (High), one captured in the low intertidal (Low), one from the low intertidal but not captured (Observed), and one captured behind cordgrass (Cordgrass). The High group moved farther and more unidirectionally than the others, and the Cordgrass group exhibited the most variable orientation of the manipulated spiders. All groups exhibited a roughly southwesterly orientation from the release site. The Low and Observed groups moved shorter distances than the others, and High individuals appeared more strongly inclined to leave the low intertidal than individuals initially positioned there (Low, Observed). Thus, experience likely played a role in the orientation and movement of the spiders.

The present paper describes Deinopis liukuensis new species, from the Gaoligong Mountains, Yunnan Province, China. This is the first mature deinopid described from China.

The feeding behavior of the cave pseudoscorpion Maxchernes iporangae Mahnert & Andrade 1998 was studied in the laboratory. We also investigated aspects such as preference and frequency. Nymphs are more active in prey capture. Cannibalism is uncommon. The frequency of feeding of adults was about once a month, with an increased rate for females during the reproductive period.

The ant hunting behavior of Zodarion rubidum (Araneae, Zodariidae) is described from specimens collected in Colorado, USA. Like other members of this genus, Z. rubidum constructs igloo-shaped stone retreats under rocks and feeds on ants. Details of the prey capture behavior are provided including initial and subsequent reactions of ants to the bites of Z. rubidum and data on the time it takes for ants to become completely paralyzed as a result of the bites.