Nurse Dornfinger

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Nurse Dornfinger
Nurse's thornfinger (Cheiracanthium punctorium), female

Nurse's thornfinger ( Cheiracanthium punctorium ), female

Systematics
Order : Spiders (Araneae)
Subordination : Real spiders (Araneomorphae)
Partial order : Entelegynae
Family : Thorn Finger Spiders (Cheiracanthiidae)
Genre : Thorn finger ( Cheiracanthium )
Type : Nurse Dornfinger
Scientific name
Cheiracanthium punctorium
( Villers , 1789)

The nurse's thorn finger ( Cheiracanthium punctorium ), in German often simply referred to as thorn finger , is a species from the genus Dornfinger in the family of the thorn finger spiders (Eutichuridae). This Palearctic species , which needs warmth, is a predominantly Mediterranean fauna element in Europe and in Central Europeto be found only occasionally. Nurse thorn fingers are nocturnal like other species of the genus and spend the day in quiet webs in herbaceous vegetation. For the egg cocoon and the young spiders that hatch from it, the females build conspicuous webs up to the size of a hen's egg in midsummer.

Besides the water spider ( Argyroneta aquatica ), the wet nurse's thorn finger is the only Central European spider whose bite can have medically relevant consequences for humans.

features

male
Detail view of a female

The wet nurse's thorn finger is the largest European species of the genus Cheiracanthium . The spider reaches a body length of up to 1.5 centimeters, with the females becoming slightly larger than the males. The prosoma (front body) is solid red-orange. From the front, the nurse's thorn finger shows a striking warning look. The very strongly developed chelicerae (jaw claws) are also colored red-orange in the upper part, and black in the lower part as well as the subsequent poisonous claws. The legs are relatively long in relation to the body and brownish-yellow in color, only the tips of the tarsi are dark gray to black.

The opisthosoma (back of the body) is yellowish to olive green. Females show a clear, diffuse, light-colored tip spot on the opisthosoma until they lay their eggs. After the egg has been laid, this tip spot is barely noticeable and the opisthosoma therefore appears monochrome.

In the male, the opisthosoma shows a broad, green-gray central band dorsally , and in the males the chelicerae are greatly elongated and slightly curved outwards.

Possible confusion

A total of 25 species of the genus Cheiracanthium occur in Europe . The wet nurse's thorn finger differs macroscopically from all other species occurring in Europe by the combination of size, pronounced black-red warning look on the front of the prosoma and a monochrome greenish-yellow opisthosoma . Further reliable identification features can be determined by microscopic examination of the genitals .

distribution

The range of the species includes the warm temperate to subtropical zones from eastern Central Europe and the Mediterranean area eastwards to Central Asia . More precise information on the distribution is not available for most of this area. The northwestern distribution limit scale deposits in Europe went in the late 1990s by Germany about on a line Rathenow - Frankfurt am Main ; the species is already absent in Lower Saxony and further west and north in the Netherlands , Great Britain , Norway and Finland . It is possible that it still occurs in the Baltic Sea region north of the distribution limit described above. The only Swedish evidence comes from the 1940s and 2004 from the Baltic island of Öland . To the south there are individual finds from Denmark , Schleswig-Holstein and to the east a find from Usedom in Mecklenburg-Western Pomerania . The occurrence on Usedom was confirmed in summer 2010. Further evidence was provided in 2012 in the Devin peninsula nature reserve near Stralsund .

Nurse thorn finger females on the underside of their brood web

The species is also only sparsely distributed in Germany southeast of the above-mentioned distribution limit. Today two widely separated areas in the south-west and in the north-east are populated over a large area, otherwise the species is absent here or has only been identified with isolated finds. Such individual finds are from Bavaria , Thuringia , Saxony and Brandenburg (Havelland).

Area expansion in Central Europe

Whether and to what extent the species has spread in Central Europe in the last few decades is only rudimentarily clear, as intensive faunistic processing of the spiders in many regions of Europe only began around the early 1990s. More or less extensive information on the distribution of the species is only available from Germany.

The occurrences reaching north to about Frankfurt am Main in the climatically favored Upper Rhine Plain and from the Rhine-Main area were already known from the beginning to the middle of the 20th century, in the rest of Germany the species was missing. In Saarland Ammen-Dornfinger were detected in 1983 Targeted searches from 1990 onwards resulted in an almost area-wide settlement of the lowlands. Another find was made in autumn 2013 in Münster, Westphalia, at a military training area in the Handorf district .

The first reliable evidence of the species in northeast Germany was made in 1961 near Treuenbrietzen in the west of Brandenburg . After that, however, Ammen-Dornfinger was not detected again until the beginning of the 1980s in Saxony-Anhalt . A targeted search in the area of ​​today's districts of Dahme-Spreewald and Teltow-Fläming also produced a number of finds there in 1989. Numerous other finds until 1998 resulted in a fairly closed distribution area from the northwestern Niederlausitz in the central south of Brandenburg via the Fläming to the west of Saxony-Anhalt and north to Rathenow and Potsdam . Isolated individual occurrences were found south of this area from the Dübener Heide in Saxony, further west from the Huy north of the Harz Mountains and near Haldensleben . It is unclear whether the species was really missing in the area outlined here before 1980. With “greater certainty”, however, the settlement here has increased considerably since 1990. It remains unclear whether this is due to the extensive spread of fallow land after 1990 or a change in the climate.

Berlin, which is to the northeast of the Brandenburg distribution area described above, was definitely not populated until 1991. Today the wet nurse's thorn finger occurs there, but in 2002 it was classified as very rare.

Occurrences of the species were also described in Austria as early as the 19th century. Here the species has been found today in the federal states of Lower Austria , Vienna, Burgenland , Styria , Tyrol and Carinthia , the extensive distribution is not precisely known.

As early as 1910 de Lessert reported Cheiracanthium punctorium for Switzerland for the predominantly western and southern cantons of Basel-Landschaft , Geneva , Ticino , Vaud and Valais .

habitat

The spiders inhabit extensively used open biotopes with tall grass and tall perennials, in Central Europe mainly forest clearings, fallow fields and meadows, particularly often fringing biotopes such as roadsides, railway embankments or ditch edges. The species is usually found in dry locations, but occasionally also in wet meadows. Ammen-Dornfinger show, at least regionally, a clear preference for stocks of land riding grass . The species can occur frequently in suitable places; In Saxony-Anhalt, for example, 34 breeding spines were found on a sandy path bordered by land riding grass over a distance of 150 meters.

Way of life

Like all species of the genus, nurse thorn fingers do not build safety nets. They search for food at night, nothing is known about this night hunt. Information on the range of prey is also not yet available.

The day is spent in spherical, resting webs that are laid out low in herbaceous vegetation in flowers, inflorescences or fruit stands and similar places. They usually have one or two openings, but are closed during the moult. These dormant webs are greatest at sexual maturity (in Central Europe mostly in July). During marking attempts on the Upper Rhine, these webs were only used for a maximum of five days. The species is annual, sexually mature males and females can be found from June to September and from July to November, respectively.

Reproduction

Compared to most other Central European spiders, the reproductive biology of the nurse's thorn finger has been relatively well studied.

Brood web of a nurse thorn finger female between fern leaves. The fern leaves are drawn together around the very firm inner cover.

Sexually mature males spin their own web of rest directly onto the web of rest of subadult females, in Central Europe this usually happens in July. After the female's last moult, the male breaks through the partition and copulates with the female. As with all species of the genus, the partners turn towards the ventral side, rotated 180 ° against each other, so the ventral side of the male is in front of the front body of the female. The male then alternately introduces his pedipalps into the sexual opening ( epigyne ) of the female. Such a mating position is found outside the genus Cheiracanthium only in a few other spiders such as Argyroneta . Shortly after copulation, the males die.

The female practices intensive brood care. Shortly before the oviposition, which usually takes place in August, the female builds what is known as the brood web. This conspicuous web is the size of a pigeon or a hen's egg, usually completely closed and very stable. It is usually laid out exposed upwards between blades of grass or stems of herbaceous plants. For this purpose, either several leaves or up to 30 blades of grass are tightly interwoven. The very tightly woven inner web is often provided with a further cover made of loosely woven threads. The egg cocoon is attached to the inside of the brood web. Ten cocoons on the Upper Rhine contained between 173 and 292 eggs, six cocoons in Saxony-Anhalt contained a minimum of 80 and a maximum of 164 eggs.

The young spiders hatch three to five weeks after they have laid their eggs, around September to early October. They remain in the web for at least three weeks until after the first moult. The female spends almost uninterrupted periods in the brood spider from laying her eggs until the young spiders migrate and guards them. If it is disturbed, it rushes forward with the chelicerae wide open and tries to bite.

Usually in October, occasionally not until November, the females tear open the web with their chelicerae to release the young spiders. The opisthosoma of the females, which had been heavily shriveled up until then, indicates that they no longer hunt after oviposition. The females stay in the web and die there in late autumn, brood webs with dead females can still be present in December and January. The young spiders overwinter near the ground in small webs on withered leaves.

Nurse thorn finger female with an egg cocoon in an open brood web

Meaning of the name

The German name "Dornfinger" is a literal translation of the generic name Cheiracanthium given by Carl Ludwig Koch in 1839 (Greek ἡ χείρ hē cheir = "the hand"; ἡ ἄχανθα hē áchantha = "the thorn"). The name does not refer to the jaw claws, but to a thorn-like extension on the cymbium called the reshaped tarsus of the male pedipalps , i.e. to part of the male sexual organs . The epithet punctoria (now punctorium ) assigned by Villers in 1789 - at that time still to the linguistically feminine genus Aranea - is a derivative of the Latin noun punctum (= "stitch, point"), which is derived from the verb pungĕre , and can be combined with " able (or "used") to stab "translate. The German name "Ammen-Dornfinger" also refers to the intensive guarding of the brood web by the female, which is also characteristic of other species of the genus Cheiracanthium .

Systematics

Systematic processing of the at least 209 described species of the genus Cheiracanthium has not yet been carried out, so no information is available on the closer relationship between the species. So far, no subspecies have been described.

Danger

While Cheiracanthium punctorium was not listed as endangered for Germany in 1984, the Nurse Dornfinger is now on the Red List in category 3 (“endangered”). In the individual federal states, however, the risk is assessed very differently. In the countries with the main occurrences (Brandenburg, Saxony-Anhalt, Baden-Württemberg) the species is considered to be harmless. In Baden-Württemberg the species was still designated as “critically endangered” in 1986 (Category 2), but classified as harmless in the new Red List from 2003 due to numerous records. Similarly, it was still listed in Category 3 in Saxony-Anhalt in 1993.

In the countries with individual occurrences, the species was either classified as “rare” without endangerment (Berlin), endangered without a more precise classification (Schleswig-Holstein), not assigned to a hazard category (Thuringia), assigned to the warning list (Saxony) or as “severe endangered ”(Category 2) as in Bavaria, where it was not yet classified in 1992.

There is no current red list for Austria as a whole. In the federal state of Carinthia, Cheiracanthium punctorium was classified as "endangered" (category 3).

Toxic effect on humans

The wet nurse's thorn finger is one of the few spider species in Central Europe that can inflict relevant poisoning on humans. Both males and females can penetrate human skin with their venomous bite . In almost all other native spider species, the poisonous claws are too short and / or fragile (an exception is the water spider ).

With stretched out and spread chelicerae threatening wet nurse thorn finger female after opening of the resting web. The poison emerges at the tips of the spread chelicerae.

The bite itself and the subsequent clinical symptoms are described very differently in the literature, as apparently often poisoning without sufficient certainty was ascribed to the wet nurse's thorn finger. Secured nurse's thorn finger bites are occasionally barely noticed, but mostly felt as painful as a wasp or bee sting . A burning pain almost always occurs at the bite site after a few minutes. This pain then spreads to the entire bitten limb within minutes or a few hours. When biting the fingers, there is almost always pain and tenderness in the lymph nodes of the armpits. More severe courses with chills, dizziness, vomiting, mild fever or circulatory failure are rare . After 24 to 30 hours, the symptoms usually have completely subsided. There have been no reports of permanent damage or even death. Bites in children and more sensitive adults should be monitored by a doctor, but only treated symptomatically.

The statement that can often be found in the literature that bites of the nurse's thorn finger also cause small-area necrosis is apparently incorrect across the board. A critical evaluation of all published Cheiracanthium poisonings showed in only one case a bean-sized necrosis at the bite site which was definitely caused by a wet nurse's thorn finger. Neither in Europe nor in America or Australia could further necrosis from nurse thorn finger bites or bites from other species of the genus Cheiracanthium be detected.

There is no reliable information on the frequency of bites. Even with numerous published reports on poisoning, it is often unclear whether the patients were actually bitten by wet nurse's thorn fingers, as the animal responsible was mostly not available for identification or in some cases was not seen at all. Vetter et al. could only prove 12 confirmed cases of poisoning by Cheiracanthium punctorium for the whole of Europe until 2006 .

For unintentional contact with the species in rural areas, wet nurse thorn finger males come into question, as they get into houses at night looking for females. Two of the 12 confirmed bites above were from sleeping people. There is also a possibility of biting when mowing by hand if the animals are disturbed in the resting webs.

After moving into the brood web in August, the females can only be provoked to bite by destroying the brood web, as they are now almost exclusively in it. Of the 12 people mentioned above, one was bitten by a female when the brood web was opened; Sacher and Wolf describe further cases of this type.

Web links

Commons : Ammen-Dornfinger ( Cheiracanthium punctorium )  - Album with pictures, videos and audio files

Nurse Dornfinger in the World Spider Catalog

literature

  • Heiko Bellmann : Cosmos Atlas Arachnids of Europe . 3. Edition. Kosmos, Stuttgart 2006, ISBN 978-3-440-10746-1 .
  • A. Wolf: Cheiracanthium punctorium - portrait of a notorious spider . In: Natur und Museum , No. 118, 1988, pp. 310-317.
  • Kurt Rudnick, Dirk Karoske: Remarkable spiders discovered in Mecklenburg-Western Pomerania . In: Nature conservation work in Mecklenburg-Western Pomerania . Vol. 56, issue 2/2013, ISSN  0232-2307 , pp. 3-8.

Individual evidence

  1. ↑ a b c Natural History Museum of the Burgergemeinde Bern: World Spider Catalog Version 17.5 - Cheiracanthium . Retrieved November 9, 2016.
  2. ↑ Heiko Bellmann: Cosmos Atlas Arachnids of Europe . 3rd edition Kosmos, Stuttgart 2006, ISBN 978-3-440-10746-1 .
  3. ↑ a b Nentwig W, Blick T, Gloor D, Hänggi A, Kropf C: Spinnen Europa. www.araneae.unibe.ch. Version 11.2016.
  4. ↑ Arachnida - Overview map of Europe (and Turkey) Map of the European distribution of the Nurse Dornfinger on www.spiderling.de. The arages maps only indicate the countries for which evidence is available, so they are by no means to be interpreted as distribution maps in the narrower sense.
  5. ↑ LJ Jonsson: The giftiga större taggspindeln Cheiracanthium punctorium (Araneae, Miturgidae) återfunnen i Sverige. In: Entomologisk Tidskrift 126; 2005, pp. 161–224 (exact number of pages not given) Abstract online ( Memento from May 11, 2009 in the Internet Archive ) (Swedish; German translation on the discussion page of the article)
  6. ↑ Albert Tullgren: Egentliga Spindlar. Araneae - Fam. 5-7. Clubionidae, Zoridae och Gnaphosidae . Svensk Spindelfauna, 3, 1946, pp. 1–141, here p. 39.
  7. ↑ a b Atlas of the arachnids of Europe , evidence of the wet nurse thorn finger in Germany
  8. ↑ K. Rudnick & D. Karoske: Remarkable spiders discovered in Mecklenburg-Western Pomerania . In: Nature conservation work in Mecklenburg-Western Pomerania . Vol. 56, issue 2/2013, pp. 3–8.
  9. ↑ W. Bösenberg, Die Spinnen Deutschlands, Zoologica, 14, (H. 35), E. Nägele, Stuttgart 1901-1903 (1903), 1902, I-VI & pp. 1-465, plate AB, plate I -XLIII, here p. 283f, sub "Chiracanthium nutrix Walck.", Animals from the Bertkau estate.
  10. ↑ Peter Sacher: New evidence of the thorn finger spider Cheiracanthium punctorium (Arachnida: Clubionidae) . Hercynia NF, 27, 1990, pp. 326-334, here p. 326.
  11. ↑ M.schichtel : Cheiracanthium (Chiracanthium) punctorium (VILL.) In the southern Saarland. - Faun.-flor. Need. Saarl. 15, 1983, pp. 201-202
  12. ↑ Surprising find at the Handorf military training area
  13. ↑ G. Olberg: A German poison spider . Cosmos 60; 1964: pp. 201-205
  14. ↑ a b c d e P. Sacher: New records of the thorn finger spider Cheiracanthium punctorium (Arachnida: Clubionidae). Hercynia NF 27, 1990, pp. 326-334
  15. ↑ J. Sauer: The wet nurse thorn finger (Cheiracanthium punctorium (Villers)) in the north-western Lower Lusatia. Biological Studies Luckau 19, 1990, pp. 98-100
  16. ↑ a b c A. Herrmann, P. Sacher & D. Braasch: The spread of the nurse's thorn finger (Cheiracanthium punctorium Villers, 1789) in eastern Germany (Araneae, Clubionidae). Entomological News and Reports 43, 1999, pp. 53-57.
  17. ^ R. Platen, M. Moritz & B. v. Broen: List of spider and harvestman species (Arach .: Araneida, Opilionida) in the Berlin area and their evaluation for nature conservation purposes (Red List). In: A. Auhagen, R. Platen & H. Sukopp (eds.): Red list of endangered plants and animals in Berlin. Focus on Berlin (West). Landscape development and environmental research. Series of publications from the Department of Landscape Development at TU Berlin, special issue S6, 1991, pp. 169–205
  18. ↑ a b R. Platen & B. von Broen: list of total species and red list of weavers and harvestmen (Arachnida: Araneae, Opiliones). In: State Commissioner for Nature Conservation and Landscape Management and Senate Department for Urban Development Berlin (Ed.): Red lists of endangered plants and animals of Berlin. Berlin 2005, ISBN 3-00-016815-X
  19. ^ A b c d e Lower Austrian State Museum: Dornfinger - a spider becomes a media star . Brochure, 2007 ( full text as PDF )
  20. ^ Richard Maurer & Ambros Hänggi: Catalog of the Swiss Spiders , Documenta Faunistica Helvetiae, 12, CSCF, Neuchatel [? 1990]; incompletely paginated, ISBN 2-88414-001-8 , here serial number 663, with reference to R. de Lessert: Araignées . In: Catalog des Invertebrés de la Suisse , 3, Mus. Hist. Nat. Genève, 639 pp.
  21. ↑ a b c d A. Wolf: Cheiracanthium punctorium - Portrait of a notorious spider. Natur und Museum 118, 1988, pp. 310-317
  22. ↑ Ulrich Gerhardt & Alfred Kästner: 8th order of the Arachnida: Araneae = real spiders = web spiders . In: Willy Kükenthal (original) & Thilo Krumbach (ed.): Handbuch der Zoologie - Eine Naturgeschichte der Stämme des Tierreiches , 3, (half 2), (part 1: Chelicerata), DeGruyter, Berlin 1941, p. (2 ) 394- (2) 656, (3) 194-215, (3) 221- (3) 315, here p. (2) 549
  23. ↑ Norman I. Platnick 2007, The World Spider Catalog , Version 8.0, American Museum of Natural History, with reference to C. de Villers: Caroli Linnaei entomologia, faunae Suecicae descriptionibus aucta , Lugduni, 4, pp. 86–130, here p 128
  24. ↑ Fritz Clemens Werner: Word elements of Latin-Greek technical terms in the biological sciences . Suhrkamp, ​​1st edition 1972, ISBN 3-518-36564-9 , here p. 339.
  25. ↑ Fritz Clemens Werner: Word elements of Latin-Greek technical terms in the biological sciences . Suhrkamp, ​​1st edition 1972, ISBN 3-518-36564-9 , here p. 53f sub "~ orium"
  26. ^ Karl Hermann Harms (cow .: Rainer Blanke, Ute Grimm, Ralf Platen & Jörg Wunderlich): Red list of spiders (Araneae) . In: Josef Blab, Eugeniusz Nowak, Werner Trautmann & Herbert Sukopp: Red List of Endangered Animals and Plants in the Federal Republic of Germany . 4th edition. Kilda, Greven 1984, pp. 122-125.
  27. ^ Karl Hermann Harms: Red List of Spiders in Baden-Württemberg - Improved and expanded version (as of February 1, 1985) . Worksheets on nature conservation, 5, 1986, pp. 65–68, here p. 66.
  28. ↑ D. nutritive & KH Harms, in collaboration with J. Kiechle, H. Rausch, W. & J. Schwaller Spelda: Red lists and check lists of spiders in Baden-Wuerttemberg, as of 2003. State Institute for Environmental Protection Baden-Wuerttemberg, 2003 ( Online )
  29. ↑ Peter Sacher: Red list of the weaving spiders of the state of Saxony-Anhalt . Reports of the State Office for Environmental Protection Saxony-Anhalt, 9, 1993, pp. 9–12, here p. 10.
  30. ^ Theo Blick & Manfred Scheidler: Red List of Endangered Spiders (Araneae) Bavaria . Bayer publication series. State Office for Environmental Protection, 111, Munich 1992, pp. 56–66, here p. 59.
  31. ↑ Christian Komposch & Karl-Heinz Steinberger: Red List of Carinthian Spiders (Arachnida: Araneae) . In: WE Holzinger, P. Mildner, T. Rottenburg & C. Wieser (eds.): Red lists of endangered animals in Carinthia. Naturschutz in Kärnten, 15, 1999, p. 567–618, here p. 591 ( full text as PDF ( Memento from September 27, 2007 in the Internet Archive ))
  32. ↑ RS Vetter, GK Isbister, SP Bush & LJ Boutin: Verified bites by yellow sac spiders (genus Cheiracanthium) in the United States and Australia: where is the necrosis? American Journal of Tropical Medicine and Hygiene 74, 2006, pp. 1043-1048
  33. ↑ P. Sacher: New evidence of the thorn finger spider Cheiracanthium punctorium (Arachnida: Clubionidae). Hercynia NF 27, 1990, pp. 326-334
  34. ↑ RS Vetter, GK Isbister, SP Bush & LJ Boutin: Verified bites by yellow sac spiders (genus Cheiracanthium) in the United States and Australia: where is the necrosis? In: American Journal of Tropical Medicine and Hygiene , 74, 2006, pp. 1043-1048, PMID 16760517 .
  35. ↑ Richard S. Vetter, Geoffrey K. Isbister, Sean P. Bush & Lisa J. Boutin: Verified bites by Yellow Sac Spiders (genus Cheiracanthium) in the United States and Australia: where is the necrosis? In: American Journal of Tropical Medicine and Hygiene , 74, 2006, pp. 1043-1048, here p. 1046.
This version was added to the list of articles worth reading on November 7, 2007 .