Populations of a species may show variation in mating systems, especially when the species is widely distributed. Aglaoctenus lagotis is a funnel-web wolf spider distributed in South America and with a ‘central Argentina form’ (CA) and a ‘southern Uruguay form’ (SU). Both forms differ in sexual behaviour, population density and copulatory season. This study evaluates the potential level of polyandry of both forms, sequentially exposing females to different males of their form under laboratory conditions. The number of copulations each female accepted and the characteristics of these sexual encounters were registered. CA females accepted more re-copulations than SU females and seemed to maintain more sexual attractiveness after the first copulation. In neither form was female re-copulation influenced by body characteristics, duration of the first copulation, ejaculation frequency or copulatory body shaking of females. Additionally, the PCA showed that both forms could be separated by their copulation behaviours. The higher level of polyandry in the CA form compared to the SU form suggested in our results adds another difference between these forms, currently under study to determine whether they are different species. This study is the first on mating systems in funnel-web wolf spiders, adding knowledge to the discussion about the evolution of sexual strategies in this group.

Several arachnid species use chemicals to detect sexual partners. In harvestmen, there are evidences that chemicals may play a role in intraspecific communication. Using the behavior of Discocyrtus prospicuus (Holmberg 1876), whose males expose the penis to females before they engage in mating posture, we tested if males detect females by contact chemoreception (chemicals left on the substrate) and if males detect females by olfaction. First, we exposed males to three experimental groups, where males had to choose between two substrates: female chemicals/blank control; male chemicals/blank control; female/male chemicals. Then, we gave males access to volatiles of males, females, and control simultaneously. We predicted that males would expose the penis when approaching volatiles and chemicals deposited on the substrate by females. We also tested if males spent more time close to the source of female volatiles and on the substrate with female chemicals and if males tapped the substrate with female chemicals for more time than the others. Finally, we put males and females together to observe if males would expose the penis upon touching the female’s cuticle. Most of our predictions were not supported, though males did tap for more time when exposed to female cues instead of male cues and exposed the penis in 70% of the observations when interacting with the female but only after touching her. Our data does not support olfaction as a way to detect females and corroborate the idea that contact chemicals, either on the substrate or on female’s cuticle, play an important role in the detection and recognition of the opposite sex. This is the first evidence in harvestmen that males may react differently to female/male chemicals.

Sexes' roles in post-copulatory processes have important effects on individual fitness and are promising to study in species showing complex mating behaviours. In the spider Schizocosa malitiosa, males perform two different copulatory patterns, pattern 1 includes 80% of total pedipalp insertions and pattern 2 includes 20%. Both patterns produce similar number of offspring, but pattern 1 induces higher female reluctance to remating than pattern 2. We hypothesised that the complex copulatory patterns are linked to post-copulatory sexual selection, affecting males' sperm transfer and the resulting sperm storage by females. First, we examined amounts of sperm in males and live females from uninterrupted (pattern 1+2) and interrupted matings (pattern 1, pattern 2). Second, in order to disentangle male and female actions, we induced males to mate with dead females and examined amounts of sperm. Males transfer in total 71% of the sperm available in their pedipalps, being higher but not significant in pattern 1 than in pattern 2. Females drastically reduced the amount of sperm stored in their spermathecae and such control is stronger in pattern 1 compared to pattern 2 matings. We propose that cryptic female control is a main factor driving males to strengthen sperm transfer. Active female reduction in ejaculate most probably diminished her reluctance to remate.

We describe for the first time the sexual behavior of Pavocosa gallopavo (Mello-Leitao, 1941) (Lycosidae), analyzing encounters between 25 pairs of virgin adult individuals. Both courtship and copulation were brief, averaging 3.66 min and 1.74 min respectively. Males showed a very conspicuous and vigorous courtship, with Leg Shaking and Palpal Drumming as the most noticeable displays. Females were also active during courtship, performing Leg Waving as well as showing some level of aggression by displaying Cheliceral Opening and Pushes against males. The males mounted the females in the typical position of wolf spiders, and females initially performed intense body shakes (Bucking). The copulatory pattern consisted of alternating single insertions of both palps, with a unique hematodochal expansion by insertion. Females cannibalized males three times, two of them before copulation and the third after copulation. Copulation was brief with respect to other wolf spiders, and females were unusually active during copulation. The species would be suitable for further studies of multimodal communication and the sexual inhibition of female aggression.

Versatile predatory tactics might favor success during intra-guild predation. In the case of spiders, the preditory spitting spiders (Scytodidae) invade webs and feed on certain weaver spiders. Based on preliminary observations of Scytodes globula, we tested if this spider species as predator could feed on the sympatric hacklemesh weaver Metaltella simoni (Amphinectidae) as host, or if the host spider could prevent the attack. We exposed adult females of M. simoni on 2-week-old webs to adult female spitting spiders. The spitting spider preyed on the host spider in 28 % of the 72 trials in which the two spider species interacted. Leaving the retreat, approaching the predator, and touching the invader apparently made the host spider vulnerable to predation in 55 % of those interactions; therefore, those were considered risky behaviors. To the contrary, the host spider had a success rate of 67 % of surviving predation by performing defensive behaviors (moving hind legs, performing defensive displays). In four trials, the invader performed a defensive spit to deter the attack of the host spider, which points to the versatility of this trait. We found no effect of body size ratio of the spiders on the outcome of the interactions. The host spider left the retreat after the spitting spider entered its web, suggesting that the spitting spider could be performing aggressive mimicry, but notion is supported by only indirect evidence and needs further exploration. In summary, behavioral interplay mediated the outcome of the interactions between the two coexisting predators assessed in our study.

The presence of pheromones has been reported for several spider species but their persistence in field conditions has scarcely been studied. We test the activity and persistence of female sex cues outdoor in the tarantula Eupalaestrus weijenberghi (Thorell, 1894), using male courtship as an indicator of cue attraction. We studied female silk fields in two conditions: protected and exposed and in both we found a long persistence of sex signals, up to 55 and 46 days, respectively. We discuss the nature and adaptive significance of these cues.

Constructing webs for survival is rare in wolf spiders. However, some species, postulated as basal in the family, live in funnel-webs. Aglaoctenus lagotis (Holmberg 1876), a South American lycosid, lives permanently in webs. It is virtually unknown how web construction occurs for this species and the few other lycosid weavers. Also, costs associated with construction have not been studied, although funnels are suggested to be particularly costly webs. This study describes the funnel-web construction behavior of A. lagotis (Lycosidae: Sosippinae) and measures its costs in subadult and adult individuals. We recorded web construction, effects of sealing spinnerets in weaving activity, and immune costs of weaving (measuring melanization of an implant) in individuals allowed to weave and prevented from weaving. Construction consisted of three alternating behaviors: deposition of thick threads with a radial orientation and prolonged attachments (mainly involving the anterior spinnerets); deposition of swaths of fine threads without consistent orientation and with short attachments (mainly involving the posterior spinnerets); and motionlessness. No sticky threads are present in the web. The thick threads have a supporting function and the fine threads have a filling function. Subadults and males allowed to weave reduced their immune response compared with those prevented from weaving; no such relationship was observed for females. Males presented the weakest immune response, followed by subadults and females. The web construction process showed greater similarity with agelenid spiders than with the only other lycosid studied, Sosippus janus Brady 1972, and appears to be a costly activity, especially for males.

Aglaoctenus lagotis (Lycosidae: Sosippinae) is a spider that, in contrast to the predominant wandering habit of the family, constructs funnel webs. The species is widely distributed throughout the Neotropics and is credited with high levels of intraspecific variation. Here, we evaluate whether reproductive isolating barriers operate between some populations of A. lagotis. We used heterotypic encounters between individuals from two distant localities: southern Uruguay (SU) and Central Argentina (CA). Additionally, we used spiders from an intermediate locality, western Uruguay (WU), where both forms of the species overlap (SU.WU was used to describe individuals from WU reminiscent of those from SU; and CA.WU was used to describe individuals from WU reminiscent of those from CA). No copulations occurred between SU and CA individuals, whereas a single and atypical copulation occurred between SU.WU and CA.WU individuals. Attacks (only by females on males) were rare. In tests of choice based on silk cues, SU males did not prefer homotypic cues but almost did not court CA females, whereas CA males preferred homotypic cues but usually courted heterotypic females. These findings, with a previously reported temporal asynchrony between populations, suggest the occurrence of reproductive isolation between both spider forms and a speciation process favoured by the wide distribution and plasticity of the species. © 2015 The Linnean Society of London, Biological Journal of the Linnean Society, 2015, 114, 646–658.

Diurnal and nocturnal activity patterns shown by different species will strongly determine the characteristics of signals as well as the sensory channels used during sexual interactions. Despite this, few studies have experimentally tested the effects of lighting and time of day on courtship characteristics in arthropods. Previous studies have shown that the wolf spider Schizocosa malitiosa can be active during the day or at night. We tested whether the period of the day affects the sexual behavior of S. malitiosa, by pairing males and females under diurnal or nocturnal conditions. We carried out mating trials in diurnal and nocturnal conditions in arenas containing female refuges. In diurnal conditions, male leg shaking behavior occurred at higher rates and consisted of greater leg raising angles relatively to nocturnal conditions. We did not find differences in mounts and mount latency between both experimental groups. In nocturnal conditions, female attacks and emergence from refuges were higher. Also, although mount occurrence did not differ between the two treatments, mounts inside the refuge were more frequent in diurnal conditions. Results suggest behavioral flexibility in male courtship and female receptivity responses relative to the time of the day.

The Cerro de Montevideo is a symbolic reference of Uruguay that currently presents an artificialised landscape with environmental deterioration. We used combined techniques including documentary analysis, cartography, remote sensing, biogeographical relict biota, digital recreation and estimated valuation of visual fragility to characterise its pre-Hispanic ecological landscape: a grassy matrix with large patches and corridors of grasslands and woody vegetation, with an estimated intermediate-level visual fragility. The physiognomic changes would have initiated since ca. 1520, much earlier than was formerly proposed (1851), due to supply of firewood from native forests to vessels and livestock introduction by Europeans. Landscape artificialisation by urbanisation and industrialisation was intensified since 1870. Environmental degradation has increased since 1930. For the first time, cryptozoic arachnofauna, visual fragility and digital satellite photographic recreations were included in an historical landscape study. In addition, Dorstenia brasiliensis was found to be the first known identified plant for the Uruguayan flora.

A new genus and species of a mygalomorph nemesiid spider collected in a hill of Northern Uruguay and in Araucaria forest at Southern Brazil is diagnosed, described and illustrated. A remarkable characteristic of the new genus is its dense body pubescence, unusual in most Nemesiidae. Also genital and somatic characters led to differentiate it from related genera. The habitat is characterized by a tubular burrow followed by an aerial tubular portion made with silk and vegetation. The sexual behaviour is briefly described from a copula between the types, observed in the laboratory. LSID: zoobank.org: pub: D5A6D7EA-19DD-4427-E6A41162EE4E.

Male choice has been associated with situations in which there is variation in the quality and reproductive status of females within a population. However, few studies have looked at the ability of males to discriminate between females of different reproductive status when the intensity of the sex pheromone produced by these females is known. Here we investigated the ability of male wolf spiders, Schizocosa malitiosa, to discriminate between silk-born sex pheromones produced by females of different age and mating status using a T-maze system. In particular, we analysed male sexual response between young virgin (YV) and old recently mated (ORM) females, two different reproductive groups that produce similar intensities of sex pheromone. We found that males chose and displayed more courtship behaviour in the silk thread from old virgin females (OV). However, males did not show any preference between silk thread of YV versus ORM females, and there were no differences in courtship behaviours. According to our results, male decision will be constrained by the sex pheromones produced by YV and ORM females. YV females are receptive to mates and do not have any sperm stored, while ORM females are partially reluctant to re-mate and male would share paternity. In other species, females change the composition, or stop the production of the sex pheromone providing information on their reproductive status. However, in this species it seems that females are not emitting clear information about their mating status, which will in turn affect the reproductive decisions of the male.

Males from gift-giving species attempt to obtain food to offer to females. Therefore, food access may affect both their body condition and their reproductive success. In some species, males reduce the costs associated with giving gifts by reusing gifts, or by offering inedible items. Males from the spider Paratrechalea ornata (Trechaleidae) offer fresh prey or ‘genuine gifts’ to females, but also offer prey leftovers or ‘worthless gifts’. We examined gift weight and content, and their relation to male condition in the field. We also investigated how gift content, male condition and female reproductive status (virgin/mated) affect male mating success. In the field, most gifts were worthless; genuine gifts were heavier than worthless ones; and gift weights (both genuine and worthless gifts combined) were positively correlated with male condition. In the laboratory, males in good condition had higher mating success than males in poor condition. Males offering gifts (genuine or worthless) to virgin females enjoyed similar mating success and duration; neither differed significantly when compared to males without gift. In contrast, mated females behaved differently. Males without gifts were consistently rejected by mated females, while those that offered worthless gifts achieved matings. The interplay between male condition, prey access, female mating history and female preferences for gifts can favour the evolution of worthless gifts under certain conditions. Females do not penalize males with non-nutritive items by not mating or by reducing mating duration, but penalties may be potentially exerted via postcopulatory process.

Comparisons of phenological patterns among populations within a species are uncommon in arachnids. Aglaoctenus lagotis is a wolf spider that lives in funnel-webs across South America. The aim of this study was to describe the phenological patterns of two distant populations of A. lagotis (central Argentina, CA, and southern Uruguay, SU). Individuals of each population were sighted along transects, every month for two years. The CA and SU populations differed in their phenological patterns (Wald chi(2) = 966.94, df = 66; p < 0.001). The CA population showed a spring-summer unified reproductive season and immature individuals overwintered. SU showed the sexual period during autumn, the maternal period during spring-summer and the females, mostly mated, overwintered. These strong differences imply temporal isolation in mating possibilities between both populations. The differences encountered could be due to phenotypic plasticity or have a phylogenetic basis. Interpopulation studies of other features of A. lagotis would show whether they also vary, suggesting speciation.

Using the road tarantula Eupalaestrus weijenberghi (Thorell 1894), we tested the importance of the third pair of legs in male courtship behavior. Our results showed that the third pair of legs is essential for males to elicit female sexual receptivity. Males with their second pair of legs immobilized elicited receptive responses from females, but males with the third legs immobilized did not. The potential role of the third pair of legs in the generation and/or transmission of seismic signals via the substrate is discussed.

Strong reproductive barriers are expected between similar species that co-occur in time and space. We experimentally analysed sexual interactions between the theraphosids Acanthoscurria suina and Eupalaestrus weijenberghi which met those conditions. Unexpectedly, males courted on heterospecific female cues. Furthermore, A. suina females seemed to be more receptive to heterospecific males than conspecific ones in early courtship. Although precopulatory confusion occurred, no interspecific copulations were observed, which indicate that reproductive barriers operate.

Predators such as spiders are particularly vulnerable to habitat fragmentation and are considered good bio-indicators of nature conservation or habitat degradation. As occurs all around the globe, the Uruguayan coastal sand dunes have been drastically diminished and fragmented, and seriously affected by human modifications such as urbanization, tourism, and introduction of exotic species. The objectives of the present study were to identify the indicator species of two adjacent areas of the sandy coastline of Uruguay (Marindia, Canelones) and, specifically, to confirm whether Allocosa brasiliensis can be considered a biological indicator of the open dunes with scarce psammophile vegetation in this locality. We used the IndVal method which quantifies the indicator value of each species. Allocosa brasiliensis had the highest indicator value for open dunes fixed with psammophilic native vegetation, reflecting its greatest specificity and fidelity to this environment.

When two similar species co-occur in time and space, strong mechanisms isolating them from each other are expected. Acanthoscurria suina Pocock, 1903 and Eupalaestrus weijenberghi (Thorell, 1894) are two sympatric and synchronic tarantulas that inhabit burrows in Uruguay's meadows. Here we test how and when reproductive isolation operates between these species. We exposed females of each species simultaneously to two males: either one male of each species, or two males of the same species. Males courted females of both species. Contrary to expectations, however, females of A. suina responded more effusively to heterospecific than to conspecific males, whereas females of E. weijenberghi only responded to conspecific males. Clasping (prelude of mating) was only recorded for couples of the same species. Females of A. suina at first seem to prefer the stronger body vibrations performed by heterospecific courting males than by males of their own species.

Males frequently show conspicuous decorations for attracting selective females. In Schizocosa malitiosa, a large Neotropical wolf spider, males have long forelegs with ventral, large, dark setae. Raised forelegs are shaken and exposed to the females during courtship. We experimentally tested if male long and dark leg setae are traits driven by female choice in this spider by exposing females to males with painted black forelegs, males with painted white forelegs and males without treatment, maintaining a white background. Females did not show preference for any male group, suggesting they select males by other characteristics. The experimental technique did not significantly affect male courtship and could be useful to modify sexually selected male traits on other spiders with good vision.

Generally, sexual repertoire within a species is conserved, but frequencies of occurrence of sexual behavioral acts often vary, and wide geographic distributions may favor these variations. Aglaoctenus lagotis is distributed along South America and belongs to Sosippinae, a subfamily of wolf spiders that builds funnel webs. Previous reports, based on different populations, suggested variations in sexual behavior and life cycle. Our objective was to describe and compare the sexual behavior of two populations of A. lagotis: ‘Southern Uruguay’ (SU) and ‘Central Argentina’ (CA). We carried out intrapopulation trials, in the laboratory, with 15 female–male pair matings. The most representative courtship acts in SU were web-stretching, striding-forward and forelegs-elevating, whereas in CA they were alternate-waving, web-stretching and leg-tapping. Juddering, forelegs-elevating and striding-forward were exclusive for SU, while alternate-waving and simultaneous-waving were exclusive for CA. We also found differences in copulatory characteristics such as frequencies of insertions and ejaculations. We documented body-shaking during copulation for the first time. Some sexual acts were exclusive of each population, while the shared ones differed in pattern and frequencies of occurrence. In addition to variations in sexual periods, these differences may favor divergence processes or an exceptional high level of flexibility in the sexual behavior of A. lagotis.