Jump to content

Dysdera

From Wikipedia, the free encyclopedia

Dysdera
Temporal range: Palaeogene–present
Dysdera erythrina
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Chelicerata
Class: Arachnida
Order: Araneae
Infraorder: Araneomorphae
Family: Dysderidae
Genus: Dysdera
Latreille, 1804[1]
Type species
D. erythrina
(Walckenaer, 1802)
Species

297, see text

Dysdera is a genus of woodlouse hunting spiders that was first described by Pierre André Latreille in 1804.[2] They originated from Central Asia to Central Europe.

The family has gained many common names from their individual species, including the "European garden spider", the "slater-eating spider", the "sow-bug killer", the "woodlouse hunter", and the "woodlouse spider".[3]

A bite from one of these spiders can be painful due to their large fangs and wide jaw. It may leave an itchy, swollen, or red bump, but the venom from one of their bites is not harmful to humans.[3]

Description

[edit]
The eye arrangement of spiders in the genus Dysdera

Adults have a reddish-brown body and legs, and can grow up to 2 centimetres (0.79 in) long. Females are generally larger growing from 1.1 to 1.5 centimetres (0.43 to 0.59 in), while males are about 0.9 to 1 centimetre (0.35 to 0.39 in).[4] Their six eyes are close together in an oval shape, and they have eight reddish legs, the second pair facing backward.[3]

Dysdera live in natural shelters, which they wrap by totally white silk. The inhabitants of hot and humid forest will take any potential shelter on or close to the ground. The shelters are used to hide from predators as well as for keeping the spider warm. During the day, they are commonly found taking shelter under objects like gravel with organic material covering it, in forests beneath bark or leaf litter, and occasionally in suburban gardens.[5]

Diet

[edit]

Dysdera are one of the few known arthropods to hunt and prey on woodlice, one of their main food sources. These spiders have wide jaws and large fangs to help to overcome the solid armor-like shells of woodlice. It makes them powerful predators for their size, allowing them to dominate or kill competitors, such as centipedes or other spiders. D. crocata is the only species from the Dysdera family known to prey on other spiders.[6]

They can also excrete certain enzymes that neutralize the chemical defenses of potential prey, allowing them to subsist on other common ground-dwelling invertebrates, including silverfish, earwigs, millipedes, and small burying beetles.

Mating

[edit]

Mating is mainly done during the month of April. The female is the main caregiver for the young. After mating, the male has minimal to no role in the child rearing process.[6] Before laying the eggs, females will make a silk pouch to protect and give them shelter. She can lay up to seventy eggs at once,[4] and will stay in the silk pouch with the eggs, protecting them and waiting for them to hatch.

Distribution

[edit]

The D. crocata, D. ninnii, D. dubrovninnii, D. hungarica, and D. longirostris are the five species still found in Central Europe after the last glacial period.[6] They are also abundantly found in North African countries like Morocco and Egypt, but also in Ethiopia, the Iberian Peninsula, and Australia. In the United States, Dysdera crocata is found from New England down to Georgia, and all the way across the country in California. At least two species inhabit South America: D. solers in Colombia- possibly a relict species from the post-miocene era- and D. magna in Brazil, Uruguay, and the central area of Chile.

Canary Islands

[edit]

Dysdera inhabits all of the Macaronesian archipelagos, but the most drastic variety is in the Canary Islands, a 22 million year old volcanic archipelago nearly 100 kilometres (62 mi) off the northwestern coast of Africa. These islands house over forty endemic species of Dysdera, thirty-six of which likely descended from a single ancestor, and six of which are associated with the oldest eastern island.[7] On Lanzarote and Fuerteventura, the spider populations are limited to the highest elevation.

The most likely reason that these spiders are so abundant on the Canary Islands is due to the abundance of species on the nearby Iberian Peninsula and North Africas. Groups like Dysdera crocata and Dysdera erythrina, found on two neighboring lands, are found more often than D. lata and Dysdera longirostris, found also in North Africa and Iberia.[7] Over time, these spiders either made their way to the islands or diversified when adapting to the different environments found in the islands.

In total, two to four colonization events are assumed. This probably happened by rafting, or even more likely by transport on floating islands, for Dysdera is not known to use ballooning. Dydera lancerotensis is the only species where an independent origin from continental ancestors is unquestionable; it was originally described as a subspecies of Dysdera crocata. While some of the remaining Macaronesian archipelagos have been colonized from the Canaries, the Azores have been independently colonized from the continent.

The radiation of Dysdera is surpassed on the Canary Islands only by the snail genus Napaeus, the millipede genus Dolichoiulus, and the beetle genera Attalus and Laparocerus.

Species

[edit]

As of January 2023 it contains 297 species.[1]

A study published in 2021 used an integrative approach combining morphological and molecular evidence to describe 8 species new to science as well as re-describing and synonymising some existing species.[8]

References

[edit]
  1. ^ a b Gloor, Daniel; Nentwig, Wolfgang; Blick, Theo; Kropf, Christian (2019). "Gen. Dysdera Latreille, 1804". World Spider Catalog Version 20.0. Natural History Museum Bern. doi:10.24436/2. Retrieved 2019-06-02.
  2. ^ Latreille, P. A. (1804). "Tableau methodique des Insectes". Nouveau Dictionnaire d'Histoire Naturelle, Paris. 24: 129–295.
  3. ^ a b c Borges, Paulo; et al. (2013). "Invasibility and species richness of island endemic arthropods: A general model of endemic vs. exotic species". Journal of Biogeography. 33 (1): 169–187. doi:10.1111/j.1365-2699.2005.01324.x. hdl:10400.3/1402. S2CID 53986568.
  4. ^ a b Jacobs, Steve (2002), Woodlouse Hunter Spider (Department of Entomology), Department of Entomology (Penn State University)
  5. ^ Cooke, J. A. L. (1965). "A Contribution to the Biology of the British Spiders belonging to the Genus Dysdera". Oikos. 16 (1/2): 20–25. doi:10.2307/3564861. ISSN 0030-1299.
  6. ^ a b c Milan, Řezáč; Jiří, Král; Stano, Pekár (2007). "The Spider Genus Dysdera (Araneae, Dysderidae) In Central Europe: Revision And Natural History". Journal of Arachnology. 35 (3): 432–462. doi:10.1636/h06-38.1. S2CID 86196958.
  7. ^ a b Macías-Hernández, Nuria; Oromí, Pedro; Arnedo, Miquel A. (2008-06-28). "Patterns of Diversification on Old Volcanic Islands as Revealed by the Woodlouse-Hunter Spider Genus Dysdera (Araneae, Dysderidae) in the Eastern Canary Islands". Biological Journal of the Linnean Society. 94 (3): 589–615. doi:10.1111/j.1095-8312.2008.01007.x.
  8. ^ Crespo, Luís C.; Silva, Isamberto; Enguídanos, Alba; Cardoso, Pedro; Arnedo, Miquel A. (2021). "Integrative taxonomic revision of the woodlouse-hunter spider genus Dysdera (Araneae: Dysderidae) in the Madeira archipelago with notes on its conservation status". Zoological Journal of the Linnean Society. 192 (2): 356–415. doi:10.1093/zoolinnean/zlaa089.
  9. ^ "Genus Dysdera". BugGuide. Retrieved 2019-06-02.

Further reading

[edit]
[edit]