ARACHNOLOGISCHE GESELLSCHAFT

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Spider of the Year 2024

The Comb-footed Cellar Spider Nesticus cellulanus  (Clerck, 1757)

The comb-footed cellar spider, Nesticus cellulanus (Clerck, 1757), belongs to the family Nesticidae. This spider family comprises 291 species worldwide, of which 58 are known in Europe (including Turkey and the Caucasus). In the genus Nesticus (true cave spiders) there is only this single species in Central Europe.

The comb-footed cellar spider is widespread and common throughout Europe and into Turkey. In Central Europe the species is mainly restricted to planar-colline altitudes (up to 800 m above sea level), but there is also evidence for it reaching almost 1000 m above sea level. Nesticus cellulanus lives mainly in caves and mine tunnels. In almost all Red Lists, the species is not considered endangered, but can be on the "near threatened" list as in Carinthia in Austria for example.

Text: Christoph Hörweg 

Female on a stone
Photo: Klaus Bogon

Description

The body length of Nesticus cellulanus is 3.5–6 mm in females, while males are slightly smaller at 3–5 mm. The front half of the body is yellowish in colour and has a blackish marking. The sternum is light yellow with black spots. The abdomen is greyish-yellowish-whitish with blackish spots, and the legs are yellowish with black annulations.

Lifestyle

As its name suggests, the comb-footed cellar spider is mostly found in caves, mine tunnels, grottoes and old cellar vaults. It is therefore dependent on locations with a cool and humid microclimate. These places must also be protected from frost and not have large temperature fluctuations. For this reason, the species can occasionally be found in open habitats in the crevice system of scree slopes, in dark, damp crevices in the earth, under moss cushions, in hollow trees or in well shafts.

Nesticus cellulanus usually builds a wide-meshed sheet web in the hollows of cave walls, from which capture threads run downwards. The lower part of each capture thread is covered with a very regularly arranged row of glue droplets. Once a prey animal has become entangled in the sticky droplets, the spider throws further trapping threads over it, kills the prey with several venomous bites and then pulls it up into the sheet web. Typical prey are animals walking on the ground or on the walls, such as mosquitoes or other insects.

Mating behavior also has some peculiarities: mating is preceded by courtship, with the male plucking on a thread of the female's web. And after a brief copulation lasting only a few minutes, in which both partners hang backwards in the net, the female helps the male to insert the pedipalp.

The spherical reddish-yellow egg cocoon, in which the female lays the eggs, is carried by the female on her spinnerets until the young spiders hatch, and only later attached to the web.

Maturity and the reproductive period extends continuously throughout the year, such that all growth stages can be encountered at the same time, albeit with an accumulation of adults during the summer months.

Similar species

The comb-footed cellar spider can be confused with the much rarer pale cave spider (Kryptonesticus eremita), which is somewhat brighter in color. The dark central stripe on the forebody of the comb-footed cellar spider runs from front to back and becomes narrow from the middle or is no longer present at all in the pale cave spider. A reliable distinction can only be made by examining the genitalia or through DNA barcoding.

 

Text: Christoph Hörweg

Pale Cave Spider Nesticus eremita
Nesticus eremita (Photo: H. Höfer)

The election followed an inquiry by the Association of German Cave and Karst Researchers, which has been selecting a Cave Animal of the Year since 2009. Its members had the idea – similar to 2012, when the cave spider Meta menardi was selected – to combine the cave animal and the spider of the year. This proposal was endorsed by the "Spider Jury" (84 arachnologists from 27 European countries). This is also to be understood as a clear sign that there is still great need for action, especially in the study of underground ecosystems and the species occurring in them, and that the good cooperation between cave researchers (speleologists) and spider researchers (arachnologists) should be further expanded.

The selection of the Spider of the Year is not only intended to put a "less popular" group of animals in a good light and to draw attention to endangered habitats – in this case caves as special habitats worthy of protection – but at the same time the scientists hope to obtain data on its current distribution. With this in mind: keep your eyes open the next time you visit a cave and help to document this species with your discovery and/or photo.

The Spider of the Year is coordinated by the Natural History Museum Vienna, in cooperation with the Arachnologischen Gesellschaft (AraGes) and the European Society of Arachnology (ESA).

Text: Christoph Hörweg

Countries involved

Albania, Austria, Belgium, Bulgaria, Croatia, Czech Republic, Denmark, Finland, France, Germany, Great Britain, Hungary, Ireland, Italy, Liechtenstein, Luxembourg, Macedonia, The Netherlands, Norway, Poland, Portugal, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland

Supporting societies

Contact for Europe

Dr. Milan Řezáč
Biodiversity Lab, Crop Research Institute
Drnovská 507
161 06 Praha 6 – Ruzyně
Czech Republic
reza(a)cvurv.cz

Distribution in Europe

Wikis and photo galeries

  • Arachnologische Gesellschaft e.V. 2022 Atlas der Spinnentiere Europas (Arachnida: Araneae, Opiliones, Pseudoscorpiones, Amblypygi, Solifugae, Scorpiones, Schizomida) für Nesticus cellulanus – (link) (07.12.2023)
  • Arachnologische Gesellschaft e.V. 2023 Wiki des Spinnen-Forums – (link) (07.12.2023)
  • Bellmann H 2016 Der Kosmos Spinnenführer. Franckh-Kosmos Stuttgart. 429 pp.
  • Blick T, Bosmans R, Buchar J, Gajdoš P, Hänggi A, Helsdingen P van, Růžička V, Staręga W & Thaler K 2004 Checkliste der Spinnen Mitteleuropas. Checklist of the spiders of Central Europe. (Arachnida: Araneae). Version 1. Dezember 2004
  • Breitling R, Merches E, Muster C, Duske K, Grabolle A, Hohner M, Komposch C, Lemke M, Schäfer M & Blick T 2020 Liste der Populärnamen der Spinnen Deutschlands (Araneae) – Arachnologische Mitteilungen 59:38-60. doi: 10.30963/aramit5907
  • Bürgis H 1989 Bemerkenswerte Spinnenfunde vom Heidenberg bei Lautertal-Raidelbach (nordwestlicher Odenwald). 4. Die Höhlenspinne Nesticus cellulanus (Clerck 1757) (Araneae: Nesticidae) – Hessische Faunistische Briefe 9:56-63
  • CSCF (Centre Suisse de Cartographie de la Faune) 2019 Fauna der Schweiz – Spinnentiere oder Arachniden (Skorpione, Pseudoskorpione, Spinnen, Weberknechte, Milben) – (link) bzw. Verbreitungskarte für Nesticus cellulanus: (link) (07.12.2023)
  • Hänggi A, Stöckli E & Nentwig W 1995 Lebensräume mitteleuropäischer Spinnen. Charakterisierung der Lebensräume der häufigsten Spinnenarten Mitteleuropas und der mit diesen vergesellschafteten Arten – Miscellanea Faunistica Helvetiae 4: 1-459
  • Helsdingen PJ van 2022 Araneae. In: Fauna Europaea version 2017.06 – (link) (06.12.2022)
  • Jäger P 1998 Weitere Funde von Nesticus eremita (Araneae: Nesticidae) in Süddeutschland mit Angaben zur Taxonomie im Vergleich zu N. cellulanus. – Arachnologische Mitteilungen 15:13-20. doi: 10.5431/aramit1503
  • Kirchner W & Kullmann E 1972 Ökologische Untersuchungen an einer Freilandpopulation von Nesticus cellulanus im Siebengebirge unter besonderer Berücksichtigung der Kälteresistenz (Araneae, Nesticidae) – Dechenia 125(1/2):219-227
  • Komposch C 2023 Spinnen (Arachnida: Araneae) – In: Komposch C (Hrsg): Rote Liste gefährdeter Tiere Kärntens. – Verlag des Naturwissenschaftlichen Vereins für Kärnten, Klagenfurt am Wörthersee, pp. 481-568
  • Nentwig W, Ansorg J, Bolzern A, Frick H, Ganske A-S, Hänggi A, Kropf C & Stäubli A 2022 Spinnen – Alles, was man wissen muss. Springer Berlin. 265 pp.
  • Nentwig W, Blick T, Bosmans R, Gloor D, Hänggi A & Kropf C 2022 araneae – Spiders of Europe, version 12.2023 – (link) (07.12.2023). doi: 10.24436/1
  • Reichholf JH & Steinbach G 1997 Die grosse Enzyklopädie der Insekten, Spinnen und Krebstiere, Band 1. Bertelsmann Lexikon Verlag Gütersloh. 360 pp.
  • Rote Liste Zentrum 2023 Artensteckbrief Gefleckte Höhlenspinne in Rote-Liste-Zentrum.(link) (07.12.2023)
  • Verband der deutschen Höhlenund Karstforscher e.V. 2023 Gefleckte Höhlenspinne – Höhlentier des Jahres 2024 – (link) (07.12.2023)
  • World Spider Catalog 2023 World Spider Catalog, version 24.5. Natural History Museum Bern – (link) (07.12.2023)