Spiders in caves: the CAWEB project

World experts of different disciplines, from molecular biology to macroecology, recognize the value of cave ecosystems as ideal ecological and evolutionary laboratories. Among other subterranean taxa, spiders stand out as intriguing model organisms for their ecological role of top-predators, their unique adaptations to the hypogean medium and their sensitivity to anthropogenic disturbance. Here, we provide a general overview of the spider families recorded in hypogean habitats in Europe–20 families including nearly 500 species, most of them with restricted distributions. We also review the different adaptations of hypogean spiders to subterranean life and summarize the information gathered so far about their origin, population structure, ecology and conservation status. Taxonomic knowledge on subterranean spiders in Europe appears to be well, but not exhaustively documented. The origin of the European assemblages is mostly explained by past climate dynamics, although other factors are likely to be involved. Most of the macroecological issues related to spiders in European caves are based on qualitative assessments or have been quantified only at a sub-regional scale. In order to shed light on cave spiders’ biogeography and the macroecological patterns driving the diversity of European subterranean spiders we created the CAWEB network, a spontaneous collaboration between subterranean arachnologists from 30 different European countries. We here present the team and provide some preliminary results, which highlight Southern Europe as an important hot-spot for the European subterranean spider diversity

Farmland biodiversity and agricultural management on 237 farms in 13 European and two African regions

Farmland is a major land cover type in Europe and Africa and provides habitat for numerous species. The severe decline in farmland biodiversity of the last decades has been attributed to changes in farming practices, and organic and low-input farming are assumed to mitigate detrimental effects of agricultural intensification on biodiversity. Since the farm enterprise is the primary unit of agricultural decision making, management-related effects at the field scale need to be assessed at the farm level. Therefore, in this study, data were collected on habitat characteristics, vascular plant, earthworm, spider, and bee communities and on the corresponding agricultural management in 237 farms in 13 European and two African regions. In 15 environmental and agricultural homogeneous regions, 6–20 farms with the same farm type (e.g., arable crops, grassland, or specific permanent crops) were selected. If available, an equal number of organic and non-organic farms were randomly selected. Alternatively, farms were sampled along a gradient of management intensity. For all selected farms, the entire farmed area was mapped, which resulted in total in the mapping of 11 338 units attributed to 194 standardized habitat types, provided together with additional descriptors. On each farm, one site per available habitat type was randomly selected for species diversity investigations. Species were sampled on 2115 sites and identified to the species level by expert taxonomists. Species lists and abundance estimates are provided for each site and sampling date (one date for plants and earthworms, three dates for spiders and bees). In addition, farmers provided information about their management practices in face-to-face interviews following a standardized questionnaire. Farm management indicators for each farm are available (e.g., nitrogen input, pesticide applications, or energy input). Analyses revealed a positive effect of unproductive areas and a negative effect of intensive management on biodiversity. Communities of the four taxonomic groups strongly differed in their response to habitat characteristics, agricultural management, and regional circumstances. The data has potential for further insights into interactions of farmland biodiversity and agricultural management at site, farm, and regional scale

Découverte en France de Theridion uhligi Martin, 1 974 (Araneae, Theridndae)

Discovery in France of Theridion uhligi Martin, 1974 (Araneae, Theridiidae). - A new species for France, Theridion uhligi , was found very frequently in the Midi-Pyrenees area. The author reminds the criteria for the determination of the species and provides high quality photographs of the genitalia and habitus. The ecology of the species is discussed and a distribution map of the species is provided for France.Une espèce nouvelle pour la France, Theridion uhligi Martin, 1974, a été récoltée très fréquemment dans la région Midi-Pyrénées. L'auteur rappelle les critères de détermination de l'espèce avec des photos de haute qualité des organes génitaux et de l'habitus. L'écologie de l'espèce est abordée et une carte de répartition de l'espèce est fournie pour la France.Déjean Sylvain. Découverte en France de Theridion uhligi Martin, 1 974 (Araneae, Theridndae). In: Bulletin mensuel de la Société linnéenne de Lyon, 81ᵉ année, n°9-10, Novembre-décembre 2012. pp. 265-269

Tegeneria racovitzai Simon, 1 907 (Araneae, Agelenidae). Synthèse sur une espèce nouvelle pour la faune de France

Tegenaria racovitzai Simon, 1907 (Araneae, Agelenidae). Synthesis on a species new for French fauna. -This article contains information available to date on Tegenaria racovitzai : the history of its description, bibliography, sometimes old and different criteria for determining relevant. It also offers new drawings of the male palp and specifies the current distribution of this species new for France.Cet article regroupe les informations existant à ce jour sur Tegenaria racovitzai : l'historique de sa description, la bibliographie parfois ancienne et les différents critères de détermination pertinents. Il propose aussi des nouveaux dessins du palpe du mâle et précise la répartition actuelle de cette espèce nouvelle pour la France.Déjean Sylvain. Tegeneria racovitzai Simon, 1 907 (Araneae, Agelenidae). Synthèse sur une espèce nouvelle pour la faune de France. In: Bulletin mensuel de la Société linnéenne de Lyon, 82ᵉ année, n°1-2, Janvier-février 2013. pp. 27-31

Contribution de la mission La Planète Revisitée à la connaissance des araignées : 33 espèces nouvelles pour la Corse, dont deux nouvelles pour la faune de France (Arachnida, Araneae)

International audienceAs part of Our Planet Reviewed in Corsica 2019-2021 project, 364 spider taxa were inventoried. This mission made it possible to update the list of species recorded on the island: 33 species of spiders are added to the Corsican araneofauna, which goes from 687 to 721 taxa; two species are also new to the fauna of France, Orchestina longipes Dalmas, 1922 (Oonopidae) and Pseudeuophrys perdifumo van Helsdingen, 2015 (Salticidae). A comparison of sampling techniques is proposed, and for some new taxa comments on ecology or taxonomy are added. Finally, the main groups of species by type of habitat studied and a zoom on the “heritage” species are presented, in view of the recently published National Red List.Dans le cadre du projet La Planète Revisitée en Corse 2019-2021, 364 taxons d’araignées ont été inventoriés. Cette mission a permis de mettre à jour la liste des espèces répertoriées sur l’île. En effet, 33 espèces d’araignées sont ajoutées à l’aranéofaune corse, qui passe ainsi de 687 à 721 taxons. Deux espèces sont aussi nouvelles pour la faune de France, Orchestina longipes Dalmas, 1922 (Oonopidae) et Pseudeuophrys perdifumo van Helsdingen, 2015 (Salticidae). Une comparaison des techniques d’échantillonnage est proposée, et pour certains nouveaux taxons des commentaires sur l’écologie ou la taxonomie sont ajoutés. Enfin, nous présentons les principaux cortèges d’espèces par type d’habitat étudié et un zoom sur les espèces “patrimoniales”, au vu de la Liste rouge nationale parue récemment

Monitoring of the last stronghold of native pool frogs (Pelophylax lessonae) in Western Europe, with implications for their conservation

The original diversity of Pelophylax water frogs has been compromised by multiple biological invasions all over Western Europe. For the European pool frog (P. lessonae), the Joux Valley—a 30 km highland depression in northwestern Switzerland—stands as the last stronghold spared by exotic lineages. In order to manage P. lessonae in the valley, we combined traditional field surveys with environmental DNA metabarcoding and mapped the regional distribution of amphibian species. Both approaches concurred that P. lessonae persists at a single isolated site (Pontet). Continuous monitoring of this population throughout the spring and summer 2019 informed on their wintering quarters (most likely the forest litter immediately surrounding the breeding pond), as well as the timing of migration (end of April), breeding (June), and larval development (June–August). In parallel, we experimented the first use of drone technology for amphibian surveillance: 30 adults were individually counted during an aerial survey at the peak of the breeding season, confirming the small size of the population. Finally, we compared some biotic and abiotic properties among water bodies throughout the valley and flagged a few sites that were ecologically similar to Pontet. In a landscape dominated by pastoral activities where Pelophylax dispersal is virtually impossible, these could be candidates for future translocation efforts. Our study illustrates the application of next-generation monitoring techniques for the urgent management of threatened species and stresses the need for reevaluating the conservation status of P. lessonae in Western Europe, where it appears to subsist in low numbers at one last locality

Première note : Espèces absentes de France ou mises en nomen dubium

Les statuts respectifs de dix-neuf espèces citées dans la faune de France sont exposés et discutés. Les seize espèces suivantes sont à supprimer de la faune de France : Ariadna insidiatrix Audouin, 1826, Attulus dzieduszyckii (L. Koch, 1870), Cybaeodes marinae Di Franco, 1989, Erigone welchi Jackson, 1911, Gnaphosa modestior Kulczyński, 1897, Gnaphosa rhenana Müller & Schenkel, 1895, Hypsocephalus pusillus (Menge, 1869), Lycosoides flovomaculata Lucas, 1846, Panamomops tauricornis (Simon, 1881), Porrhomma cambridgei Merrett, 1994, Tegenaria ramblae Barrientos, 1978, Tegenaria tyrrhenica Dalmas, 1922, Theridion wiehlei Schenkel, 1938, Walckenaeria clavicornis (Emerton, 1882), Walckenaeria plumata (Millidge, 1979) et Zelotes devotus Grimm, 1982. Enfin, nous proposons de placer Salticus truncatus Simon, 1937 et Walckenaeria dulciacensis (Denis, 1950) en nomen dubium.The respective status of nineteen species cited in the fauna of France are presented and discussed. The following sixteen species are to be removed from the fauna of France: Ariadna insidiatrix Audouin, 1826, Attulus dzieduszyckii (L. Koch, 1870), Cybaeodes marinae Di Franco, 1989, Erigone welchi Jackson, 1911, Gnaphosa modestior Kulczyński, 1897, Gnaphosa rhenana Müller & Schenkel, 1895, Hypsocephalus pusillus (Menge, 1869), Lycosoides flovomaculata Lucas, Panamomops tauricornis (Simon, 1881), Porrhomma cambridgei Merrett, 1994, Tegenaria ramblae Barrientos, 1978, Tegenaria tyrrhenica Dalmas, 1922, Theridion wiehlei Schenkel, 1938, Walckenaeria clavicornis (Emerton, 1882), Walckenaeria plumata (Millidge, 1979), Zelotes devotus Grimm, 1982. Finally, we propose to consider Salticus truncatus Simon, 1937 and Walckenaeria dulciacensis (Denis, 1950) as nomen dubium

Early detection and spatial monitoring of an emerging biological invasion by population genetics and environmental DNA metabarcoding

Rapid management responses against invasive species soon after their establishment are the most efficient way to limit their biological and economic impacts. Early detection and reliable monitoring is however challenging when cryptic taxa are involved. Here we show how environmental DNA (eDNA) metabarcoding of water samples efficiently unveiled an emerging invasion of Italian crested newts (Triturus carnifex), one of the most successful amphibian invaders in Europe. We compared and validated an eDNA survey by multilocus population genetics of wild‐caught individuals. Both approaches consistently mapped a localized T. carnifex invasion in northwestern Switzerland, most likely following imports from the Italian Po Plain. We found evidence of gene flow with the indigenous and endangered Triturus cristatus in nearby populations, suggesting a potential expansion. Yet the currently small invasive range should be efficiently contained by future eradication programs. This textbook case emphasizes the implementation of eDNA metabarcoding to screen aquatic communities for exotic species, from which targeted studies can be designed on emerging biological invasions