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Environmental microbes have the potential to be involved in nearly all behavioural processes. For example, mating systems where males use intromittent organs to transfer sperm to females represent a means by which environmental microbes collected by males can breach entry into females' body cavities during mating. However, the degree to which the acquisition of environmental microbes onto important sex structures alters courtship behaviours remains unknown. Here, we collected bacteria from the copulatory organs of Agelenopsis pennsylvanica funnel‐weaving spiders in situ to test whether exposure to bacteria on copulatory organs can alter hosts' courtship behaviour, reproductive success and survival. We used a standardized assay to repeatedly measure each spider's aggressiveness, a behavioural component of both male courtship and female sexual receptivity. Then, we experimentally altered the bacteria present on male and female spiders' copulatory organs with an application of either (a) a mixture of bacteria collected from conspecifics to increase bacterial presence, (b) an antibiotic to reduce bacterial presence or (c) a procedural control. Each spider was paired with a size‐matched spider of the opposite sex whose copulatory organs were unaltered, and we measured the latency until the onset and the duration of courtship. Spiders were then isolated, and we measured each individual's time until death and female fecundity over the next 40 days. We found that female exposure to bacteria had multiple effects on mating dynamics. Males took over four times longer to begin courting females that had been exposed to bacteria compared to unexposed and antibiotic‐treated females. Only when courting these bacteria‐exposed females, males began courtship sooner when females were more aggressive. Lastly, females whose mate had been exposed to bacteria experienced reduced survival. These data suggest that bacteria present on animals' copulatory organs can alter courtship behaviours, female survivorship, and may potentially play a role in mating dynamics. [ABSTRACT FROM AUTHOR]

Trait consistency over time is one of the cornerstones of animal personality. Behavioral syndromes are the result of correlations between behaviors. While repeatability in behavior is not a requirement for behavioral syndromes, the two concepts studied together provide a more comprehensive understanding of how behavior can change over ontogeny. The roles of ontogenetic processes in the emergence of personality and behavioral syndromes have received much individual attention. However, the characterization of both individual trait consistency and behavioral syndromes across both sexes, as in our study, has been relatively rare. Ontogeny refers to changes that occur from conception to maturation, and juveniles might be expected to undergo different selection pressures than sexually mature individuals and also will experience profound changes in hormones, morphology, and environment during this period. In this study, we test for behavioral trait consistency and behavioral syndromes across six time points during ontogenetic development in the desert funnel-web spider ( Agelenopsis lisa). Our results indicate behavioral traits generally lack consistency (repeatability) within life stages and across ontogeny. However, penultimate males and mature females do exhibit noticeable mean-level changes, with greater aggressive responses toward prey, shorter latencies to explore their environment and in the exhibition of risk-averse responses to predatory cues. These traits also show high repeatability. Some trait correlations do exist as well. In particular, a strong correlation between aggressiveness toward prey and exploration factors is observed in mature males. However, because correlations among these factors are unstable across ontogeny and vary in strength over time, we conclude that behavioral syndromes do not exist in this species. Nevertheless, our results indicate that increased consistency, increasing average trait values, and varying correlations between traits may coincide with developmentally important changes associated with sexual maturation, albeit at different time points in males and females. This period of the life cycle merits systematic examination across taxa. [ABSTRACT FROM AUTHOR]

Precopulatory sexual cannibalism is an extreme form of sexual conflict that can entail significant costs to the cannibalized individual and a variety of costs and benefits to the cannibal itself. Characterizing these costs and benefits is fundamental to our understanding of how this behavior evolves. Using the spider Agelenopsis pennsylvanica, we tested the reproductive consequences of precopulatory sexual cannibalism by staging cannibalization events and comparing the performance of experimental cannibals against natural cannibals (i.e., those that cannibalized on their own) and non-cannibals. We found two performance benefits associated with precopulatory sexual cannibalism: first, experimental cannibals were more likely to produce egg cases than non-cannibals, and second, egg cases from experimental cannibals and natural cannibals were significantly more likely to hatch than those produced by non-cannibals. We then tested whether males were more likely to approach the webs of experimental cannibals vs. non-cannibalistic control females. Our data demonstrate that sexual cannibalism increases female attractiveness to males. Although this result seems counterintuitive, in fact, rates of precopulatory sexual cannibalism were much lower in females that had already cannibalized their first male: 38% of sexually naïve females engaged in precopulatory sexual cannibalism, whereas only 5% of females engaged in cannibalism a second time. Thus, males that approach cannibals receive two benefits: they are less likely to be cannibalized precopula, and they have the possibility of mating with females that have a higher probability of producing viable egg cases. Taken together, our data suggest that precopulatory sexual cannibalism affords females numerous benefits and may have a hand in shaping male mate choice decisions. [ABSTRACT FROM AUTHOR]

Although there is much interest in behavioral syndromes, very little is known about how syndromes are generated in wild populations. Here, we assess the roles of correlated selection and divergent rearing environments in generating a syndrome between foraging aggressiveness and boldness in the spider Agelenopsis pennsylvanica. We first tested for and confirmed the presence of a behavioral syndrome between boldness and foraging aggressiveness in wild penultimate A. pennsylvanica ( r = 0.24). Then, to assess the effects of rearing environment on the boldness-aggressiveness syndrome, we compared the behavioral tendencies of field- vs. laboratory-reared spiders over the course of their development. The presence of the boldness-aggressiveness syndrome differed based on spiders' developmental stage and rearing environment: field-reared juveniles did not exhibit a syndrome between boldness and foraging aggressiveness, but field-reared penultimates did. In contrast, laboratory-reared spiders never exhibited a behavioral syndrome, regardless of their developmental stage. Thus, the boldness-aggressiveness syndrome in A. pennsylvanica manifests only when individuals are reared in the field. Selection data from a mark-recapture study failed to indicate any signature of correlated selection, despite our finding that at least one element of the syndrome (foraging aggressiveness) can respond to selection (Heritability h2 = 0.27, from mid-parent breeding study). Thus, contemporary correlated selection does not appear to be a major driver of the boldness-aggressiveness syndrome of A. pennsylvanica. Taken together, our data are consistent with the hypothesis that the boldness-aggressiveness syndrome exhibited by wild A. pennsylvanica develops as a result of environmentally induced phenotypic plasticity, and not correlated selection. [ABSTRACT FROM AUTHOR]

Although the study of ecological interactions often takes into account functional variation between species, intraspecific variation is commonly ignored. Here, we investigate the importance of an intraspecific polymorphism in shaping interspecific interactions in a habitat-building species. Colonies of the social spider Anelosimus studiosus provide habitat for dozens of arthropod species, and colony members exhibit markedly polymorphic behavioral temperaments (BT): "aggressive" or "docile." We manipulated the phenotypic compositions of colonies (100% aggressive, 50% aggressive and 50% docile, 100% docile) and measured the nature and magnitude of interactions between A. studiosus and two heterospecific web associates, Larinioides cornutus and Agelenopsis emertoni. We found that BT composition significantly affected the outcome of interspecific interactions, changing the relationship between A. studiosus and its web associates from an ammensalism (where A. studiosus experiences reduced fecundity and survival) to a commensalism or mutualism. Our study successfully illustrates the potential of BTs to impact whole community dynamics, and conversely, for community structure to influence the maintenance of BTs. [ABSTRACT FROM AUTHOR]

1. Many animals are adapted for a ‘feast or famine’ existence, and will opportunistically engage in gluttonous foraging bouts. However, how gluttonous feeding influences individual performance (e.g. running speed) and the fitness consequence of modified performance are not frequently considered. 2. Using laboratory track trials I establish baseline locomotor performances (burst speed) for four spider species: two active foragers ( Hogna helluo and Schizocosa ocreata (family: Lycosidae)), and two sit-and-wait foragers ( Agelenopsis emertoni and Barronopsis texana (family: Agelenidae)). I then fed each species ad libitum, assessed what influence this meal had on individuals’ burst speed relative to baseline performance, and performed a field census to assess selection on running speed for all four species. 3. Sit-and-wait foragers fed significantly more than active foragers and slowed significantly after feeding; however, neither active forager was slowed by their meal. 4. My field census detected no selection on speed for sit-and-wait foragers, and positive directional selection on speed for both active foragers. 5. The negative association between the amount of food consumed and selection on burst speed suggests that selection pressures to maintain locomotor performance may set an upper limit to how much an animal can, or will, eat during a foraging bout. [ABSTRACT FROM AUTHOR]

1. Locomotor performance can influence individual fitness through several ecological contexts, such as prey capture and predator escape. One means of determining which contexts act as significant selective forces on running speed is to quantify individual speed in each context. The underlying hypothesis is that animals will exhibit their highest speeds in contexts most crucial to fitness. 2. We measured running speeds in three ecological contexts (prey capture, fleeing predators and territory defence) in lab-reared offspring of the funnel-web spider Agelenopsis aperta collected from two arid grassland and two riparian populations. Arid populations experience little predation pressure, are prey limited, and are highly territorial; riparian populations experience high predation, have high prey availability, and are less territorial in nature. 3. The offspring of arid individuals exhibited their highest burst speeds in territory defence, and ran more slowly in response to predator threats. The offspring of riparian populations, however, ran fastest when responding to predatory threats and displayed lower velocities in prey capture and territory defence. Thus, our findings support the hypothesis that A. aperta are selected to exhibit their highest speeds in contexts most important to their fitness. 4. Contextual use of running speed can differ among conspecific populations experiencing differing selective forces on locomotion. [ABSTRACT FROM AUTHOR]

The pandemic distribution of Wolbachia (alpha-proteobacteria) across arthropods is largely due to the ability of these maternally inherited endosymbionts to successfully shift hosts across species boundaries. Yet it remains unclear whether Wolbachia has preferential routes of transfer among species. Here, we examined populations of eight species of the North American funnel-web spider genus Agelenopsis to evaluate whether Wolbachia show evidence for host specificity and the relative contribution of horizontal vs. vertical transmission of strains within and among related host species. Wolbachia strains were characterized by multilocus sequence typing (MLST) and Wolbachia surface protein (WSP) sequences, and analysed in relation to host phylogeny, mitochondrial diversity and geographical range. Results indicate that at least three sets of divergent Wolbachia strains invaded the genus Agelenopsis. After each invasion, the Wolbachia strains preferentially shuffled across species of this host genus by horizontal transfer rather than cospeciation. Decoupling of Wolbachia and host mitochondrial haplotype (mitotypes) evolutionary histories within single species reveals an extensive contribution of horizontal transfer also in the rapid dispersal of Wolbachia among conspecific host populations. These findings provide some of the strongest evidence to support the association of related Wolbachia strains with related hosts by means of both vertical and horizontal strain transmission. Similar analyses across a broader range of invertebrate taxa are needed, using sensitive methods for strain typing such as MLST, to determine if this pattern of Wolbachia dispersal is peculiar to Agelenopsis (or spiders), or is in fact a general pattern in arthropods. [ABSTRACT FROM AUTHOR]

The influence of historical climatic vs. geological changes on species diversification patterns was investigated in a widely distributed North American desert spider,Agelenopsis aperta(Araneae: Agelenidae), with particular reference to Pleistocene glacial cycles and earlier patterns of mountain building. Levels of sequence divergence obtained from the mitochondrial gene, cytochrome oxidase I, dated to the Pleistocene, eliminating Rocky Mountain orogeny as a cause of diversification, as orogeny ended 4 million years ago. The results of phylogenetic and network analyses showed the presence of three geographically defined clades, which were consistent with the presence of at least three glacial refugia: (i) east of the Rocky Mountains; (ii) between the Rocky Mountains and Sierra Nevadas; and (iii) west of the Sierra Nevadas. In addition, populations within the Rocky Mountains exhibited significantly lower genetic diversity than populations east of the Rocky Mountains and the haplotypes found within the Rockies were a subset of eastern haplotypes. These patterns suggest that a post-Pleistocene range expansion occurred out of an eastern glacial refugium into the Rocky Mountains. Examination of phylogeographical studies of other North American desert taxa indicated that mountain building explained diversification patterns more effectively for some taxa but Pleistocene climate change was more important for others, includingA. aperta. [ABSTRACT FROM AUTHOR]