A main goal of ecological and evolutionary biology is understanding and predicting interactions between populations and both abiotic and biotic environments, the spatial and temporal variation of these interactions, and the effects on population dynamics and performance. Trait-based approaches can help to model these interactions and generate a comprehensive understanding of ecosystem functioning. A central tool is the collation of databases that include species trait information. Such centralized databases have been set up for a number of organismal groups but is lacking for one of the most important groups of predators in terrestrial ecosystems – spiders. Here we promote the collation of an open spider traits database, integrated into the global Open Traits Network. We explore the current collation of spider data and cover the logistics of setting up a global database, including which traits to include, the source of data, how to input data, database governance, geographic cover, accessibility, quality control and how to make the database sustainable long-term. Finally, we explore the scope of research questions that could be investigated using a global spider traits database.

Triage in conservation biology necessitates the prioritization of species and ecosystems for conservation. Although highly diverse, ecologically important, and charismatic, spiders are rarely considered. With 2,253 known species, South Africa's spider diversity is among the highest in the world. A 22-year initiative culminating in a national assessment of all the South African species saw a 33% increase in described species and a 350% rise in specimen accessions of the national collection annually. Endemism is high, at 60% of all South African species. Levels of endemicity are particularly high in Fynbos, Succulent Karroo and Forests. Relative to its area, Forests have three times more endemics than any of the other biomes, followed by the Indian Ocean Coastal Belt. A total of 127 species (5.7%) are either rare or endangered. Threats to these species are largely linked to habitat destruction in the form of urbanization and agriculture. The bulk (62.8%) of taxa are of least concern, but many species are data deficient (27%). Predicted large-scale diversity patterns are confounded by the localised nature of distribution records. Best estimates of compositional turnover point to an east-west bias in our understanding and conservation of spiders in the country, a bias that is most acute in the north-western parts of the country because this region has seen less collecting and has fewer conservation estates. In general, rare and threatened species are mainly ground-dwelling taxa that are either relictual or have poor dispersal abilities. Complemented with long-term surveys that will provide insights into population dynamics of spiders, exploring the use of species traits in predicting extinction probability could provide additional criteria for conservation prioritization. Based on these assessments, targeted species-level interventions might provide a platform for more public awareness and institutional involvement.

Sphagnum farming is paludiculture aiming to produce Sphagnum biomass as a sustainable alternative to peat in horticultural growing media. Here we focus on the habitat value of artificial Sphagnum farming sites for peatland species. We report results from seven years of biodiversity monitoring (2011–2018) in a 14 ha Sphagnum farm in north western Germany, using spiders and harvestmen as indicator groups for succession of invertebrate communities. Species richness and abundance more than doubled in the first two years of Sphagnum growth, but remained rather constant since then. Peatland generalists rapidly colonized the site and constitute some 30%–40% of activity dominance since the second year. Stenotopic peatland spiders arrived later, but their abundance proportion increased significantly from 2014 to 2017. Nevertheless, the spider communities remain distinct from (semi-)natural reference sites. Highly characteristic species of pristine bogs are still lacking. We conclude that a novel community has assembled that bears only moderate resemblance to natural peatlands. Persisting high annual turnover rates in terms of species composition and dominance structure (both > 30%) corroborate high levels of ongoing dynamics and the significance of stochastic processes. The long-term trajectory of community succession in the Sphagnum farm remains vague.

In many spiders, limb autotomy (self-amputation) is a common anti-predator behavior. While many species are able to regenerate lost limbs without apparent fitness costs, there are demonstrable costs in others. Previous studies have shown males of the brush-legged wolf spider Schizocosa ocreata (Hentz, 1844) incur reduced mating success after autotomy and/or regeneration of their decorated forelimbs, which affects visual courtship displays. However, because courtship of male S. ocreata is multimodal and contains vibratory/seismic signals, communication in this channel might also be affected. We recorded female receptivity to isolated male vibratory/seismic courtship signals from: males with intact forelimbs (control), males with a regenerated forelimb, and males missing a forelimb. Females were more receptive to isolated vibratory/seismic signals of intact males over males missing a foreleg, but not males that regenerated a foreleg. Although initial size and body condition did not differ among treatments, regeneration of a limb had a significant negative impact on growth increment from penultimate instar to adult, suggesting a possible physiological cost of regeneration. To investigate the impact of autotomy and regeneration on vibratory/seismic signals, we used laser Doppler vibrometry (LDV). Analysis of overall signal amplitude across treatments revealed significantly reduced amplitude for males with regenerated limbs, despite these males having receptivity responses statistically similar to control males. Analyses of component elements of vibratory/seismic signals showed three (of four) had significantly reduced amplitude in males regenerating limbs. These results demonstrate a potential fitness impact of autotomy and regeneration on the vibratory/seismic component of male courtship signals.

This study assessed the effects of forest succession and microenvironmental variables on the abundance of ctenid spiders in a montane tropical forest in Costa Rica. We surveyed 20 plots (5 × 5 m) in both primary and secondary forest for a total of 40 samples measuring the following variables: leaf litter depth, canopy density, slope, number of trees above 3 m and average stem diameter of trees exceeding 3 m in height. A total of 150 adult and subadult specimens belonging to five species were observed. The most abundant species were Spinoctenus escalereteHazzi et al., 2018 which has not previously been recorded in Central America and Kiekie griswoldiPolotow & Brescovit, 2018. The larger species, K. griswoldi was significantly more abundant in primary than in secondary forest. Conversely, S. escalerete was more abundant in the secondary forest. A generalized linear model indicated that the most important variable influencing ctenids abundance was leaf litter depth. Whereas the abundance of K. griswoldi was positively related with leaf litter depth, the abundance of S. escalerete was negatively related to litter depth. Thus, forest succession and leaf litter are important factors that influence the abundance of floor ctenid community and may allow the coexistence of co-occurring species.

Although our basic knowledge regarding the natural history of amblypygids (commonly called whip spiders; Order: Amblypygi) is expanding, there is much about these mysterious animals that remains unknown and unexplored. In particular, we know relatively little about social interactions and potential communication displays within and across sexes, despite observed variation in species studied to date. To acquire basic knowledge about amblypygid communication, we quantified the behavior of juvenile and adult Paraphrynus laevifrons (Pocock, 1894) across social interaction types. Specifically, we staged the following adult interaction types – male-female, female-female, and male-male - as well as juvenile-juvenile interactions. Adults performed an array of behavior during social interactions. Some of the observed behaviors are similar to those reported in other species, while others we describe here de novo. Across adult social interaction types, we found no significant differences in social interaction duration nor escalation. Adult social interactions were more likely to escalate to pedipalp grappling the larger the size of the interacting pair. Juveniles rarely engaged in social interactions, and those that did occur were shorter than adult social interactions; juvenile social interactions never escalated beyond antenniform leg touching, a behavior associated with examining an individual's surroundings. We discuss the behavioral repertoire of social interactions in P. laevifrons in relation to what is known from other amblypygid species.

Pseudoscorpions are predators of arthropods and primarily inhabit soil litter and tree bark in forests, although some species have been collected from animal nests, suggesting close associations with mammals and birds. We made preliminary observations on the life cycle and life history traits of Megachernes ryugadensis Morikawa, 1954, phoretic on the wood mice Apodemus speciosus and A. argenteus, by sampling wild specimens in the field and rearing these specimens in a laboratory. The main phoretic host at the study site was A. speciosus; we observed an average of 1–1.7 pseudoscorpions on 5–36% of mice within the 2-year study period. The observed phoretic stages of M. ryugadensis were adults and tritonymphs; the phoretic ratio on A. speciosus was relatively stable for 2 years. The duration of full development from egg to adult in M. ryugadensis was unclear, probably due to unsuitable rearing conditions; however, individuals survived as adults for over one year. Typical maternal care was confirmed in pseudoscorpions and egg hatching was synchronized to within ca. 8 h. Further study, including close examination of mouse nests, is required to elucidate the symbiotic relationship between the pseudoscorpion and host rodents.

Observations on the entire life history of scorpion species are uncommon, and these studies primarily focus on postembryonic development. So far, little is known on how changes in temperature or humidity could affect communities of scorpions. Here, we present data on the embryonic and postembryonic development of Tityus forcipula (Gervais, 1843), a scorpion living in the Colombian Central Cordillera that was subjected to different climate regimes. For a comparative approach, one group was raised under lower conditions (23–24°C) and another group was raised under higher temperatures (25–27°C, meaning a 2–3°C increase). Our results clearly demonstrate that T. forcipule reared under laboratory conditions is not able to thrive under constant higher temperatures. A minority of the latter group (< 10%) reached adulthood, but never reproduced. Of the 43 specimens kept under lower temperatures (with a mild diapause), 21 females and 19 males reached maturity in the 5^th instar; only one female and two males required an extra molt to mature. Tityus forcipula specimens reached maturity after 463 days of postembryonic development. The average for embryonic development was 208 days, with an average of 12 neonates per litter. Twenty-four different morphometric measurements were taken from all specimens for each exuvium of the juveniles and the adult stage. The results indicated a relationship, albeit partly poorly developed, between the sexes, in several measured structures and the instars.

The open-holed trapdoor spider genus Aname L. Koch is widely distributed across mainland Australia and Tasmania, and currently includes 34 named species. Many species are poorly known, and their descriptions based on female type material only render their identification difficult, as the best taxonomic characters are usually found on the adult male pedipalp and first leg. To better understand the diversity of Aname in Western Australia, we present descriptions of 11 new species primarily distributed in arid ecosystems: A. baileyorum sp. nov., A. frostorum sp. nov., A. grothi sp. nov., A. lorica sp. nov., A. mcalpinei sp. nov., A. munyardae sp. nov., A. nitidimarina sp. nov., A. sinuata sp. nov., A. vernonorum sp. nov., A. watsoni sp. nov. and A. whitei sp. nov. All species are described from adult males but we were only able to confidently associate females of A. lorica, A. sinuata, A. watsoni and A. whitei. DNA sequence data were obtained for six species and were used to test morphological species hypotheses and where possible to match females and juveniles with males. Haplotype networks for A. lorica, A. sinuata and A. whitei, demonstrate that there is significant genetic structure within these species, corresponding to geographically isolated populations. We also provide the first sequence data for specimens of Aname mainaeRaven, 2000 collected from near the type locality in South Australia.

In the spider families Trechaleidae and Pisauridae, males offer nuptial gifts to females during courtship. Nutritive gifts contain recently caught prey wrapped in silk, while worthless gifts contain prey leftovers or plant parts. The presence of wrapped gifts is known in three out of 16 genera (Paratrechalea Carico, 2005, Trechalea Thorell, 1869 and Trechaleoides Carico, 2005) in Trechaleidae, suggesting that this sexual trait is of widespread occurrence in the family. Here, we report the presence of wrapped nuptial gifts in the genus Paradossenus F.O. Pickard-Cambridge, 1903. Males of P. longipes (Taczanowski, 1874) produce prey-gifts following the same sequence of behavioral units as described for other species of the family. More surprisingly, these males may also produce empty gifts consisting of a silken structure lacking contents. This is the first record of empty nuptial gifts in spiders. This novel male tactic may have evolved from worthless gifts as a further step in the evolution of deception in gift-giving spiders.