Biology:Scytodes

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Scytodes is a genus of spitting spiders that occur all around the world, with the most widely distributed species being Scytodes thoracica, originally having a palearctic distribution but has since been introduced to North America, Argentina, India, Australia, Asia and New Zealand.[1]

Individuals of the genus are generally characterized by their predominant pale yellow coloration and black markings on their cephalothorax compounded with long, thin hairless legs with black bands.[2]

As other spitting spiders, they do not build a traditional web to catch prey, but instead spit a fluid on their prey that congeals on contact into a venomous and sticky mass.

Taxonomy

The first species of the genus was first described by Pierre André Latreille as Aranea thoraica in 1802 through "Histoire naturelle, générale et particulière des crustacés et des insectes" until the genus was later reclassified by Jean Victor Audouin as Scytodes in 1826.

Appearance

The genus exhibits sexual dimorphism, males range in size from 3.5 to 4 mm while females are slightly larger ranging from 4 to 4.5 mm.[3] Spitting spiders have pale yellow bodies with black spots on their wide cephalothorax, and legs that are characterized by black bands.[4] Scytodes have 3 paired eyes for a total of 6 eyes.[4] Scytodes legs are long, slender,[4] and have small claws attached to the chelicerae.[3]

Habitat

Scytodes are mainly nocturnal[3] and typically do not live in webs with the exception of some tropical species,[4] such as Scytodes longpipes[5]. The web, however, is not used for catching prey.[5] Instead, Scytodes live in under rocks, in crevices and can even be found living in human infrastructures.[4]

Niche

Similar to other arachnids, Scytodes occupy a vital role as secondary consumers (although some species, such as S. thoracica have been known to exhibit behaviour of tertiary consumers as they have been known to hunt other spiders) and work to control the populations of prey items in their habitats.[4][6]

Distribution

Spiders in the genus Scytodes follow a near global distribution, being present on almost every continent excluding the Arctic and Antarctic, with the majority of species within Europe and the Mediterranean around the 45th parallel, a sizable presence in Asia, Oceania and North America and extremely limited presence in Africa and South America

Behavior

Reproduction

Scytodes species are typically solitary until mating or hunting due to their aggressive nature. Males are cautious when trying to find a mate. Females carry their eggs until they hatch, typically under their body or in their chelicerae. This is the most vulnerable stage in life, the egg-carrying period. Upon hatching, the juvenile spiders remain in their mother's web. They cooperatively capture and feed on prey caught in the web. Upon reaching sexual maturity, the young spiders leave the web, move a short distance away and exhibit solitary behavior.[7]

Sociality and Parental care

Scytodes are known to perform a wide range of social organization, with some species being solitary, subsocial, communal-territorial, or social.[8][9][10] Many of the subsocial and colonial species are known to give extended parental care, such as S.[fusca,socialis, longipes, intricata, indet(a)(b)]

Females will sparsely wrap their eggs in a sac, and hold it in its chelicerae until they hatch,[8][9] sometimes dropping the egg sac to capture prey, after which they return and feed beside the eggs, picking them up again once finished.[8] This behaviour protects the eggs from desiccation, mould, parasites, and predation.[8]

Some species are subsocial and after hatching, the spiderlings will often cohabitate with their mother until a certain instar is reached, but some may stay longer or leave earlier. During this period the spiderling and adult will hunt prey, but not spit at or prey on each other. The mothers will sometimes take captured prey to the spiderlings. S. indet(a) and S. indet(b) will often share the meal with their spiderlings, but S.fusca will not, eating separate meals away from the spiderlings.[8][9][10] Cohabitating spiderlings will work together to capture large prey, but will hunt small prey individually. Conflict between spiderlings occurs in some species at early instars, but cannibalistic behaviour only arises in later instars of those species.[10]

S. socialis is known to be a social species, and individuals will continue cohabitation into adulthood, forming colonies, in which individuals show no aggression to each-other and share prey[11]

Hunting

File:Scytodes thoracica fg05.jpg
Scytodes thoracica in front of prey

Scytodes primarily detect prey by vibration and smell.[12] Scytodes will spit at prey until it is subdued. Once the prey is subdued, Scytodes wrap the prey in silk, and feed.[8] When prey flees, Scytodes will sometimes pursue the prey, and spit web once it gets close.[8] Prey often gets glued to substrate by the spit, and the Scytodes will cut it loose from the substrate to wrap it.[8] Sometimes when prey struggles during wrapping, or immediately after spitting web, the spider will quickly lunge and stab the prey with its fangs, retracting them immediately. Many Scytodes are known to be araneophagic, with some preferring to prey on other spiders.[8][13][10]

Hunting dangerous prey such as other spiders is thought to lead to behavioural flexibility, which can be observed in Scytodes, which will adjust their hunting methods based on prey size.[8]

S. pallida (and/or possibly S. indet(a)) shares an interesting relationship with the jumping spider Portia labiata, in which both are each other's primary prey.[8][13] These spiders do not die post-mating; males live 1.5–2 years and females live 2 to 4 years.

Webs

Some species of Scytodes are known to build webs. Webs of many Scytodes consist of a sheet of web connected to a small tubular shelter, in which the spider tends to reside.[8][9]

Spitting

Pattern of Scytodes glue that is spit on prey and how glue pins prey to ground

The spitting from which its common name derives is used as a method of trapping prey or escaping predators.[14] Scytodes glue is made in a large gland in the cephalothorax[15] where venom is synthesized in the front of the gland and the glue is produced in the back of gland.[4][15] Sticky glue is expelled from their fangs from a small opening in their chelicerae[5][14] and can be shot up to 4 -10 body lengths from the spider.[4] Scytodes spit their glue in a zigzag pattern to trap their prey to a substrate.[15] Though, for many years it was thought that the glue contained venom that diffused into the prey,[5] researchers now believe that the glue does not contain any toxic properties.[4][15] Once the whole prey is trapped to the ground, the spider then bites the prey with a venomous bite to kill it.[4][15][16]

Diet

Scytodes primarily feed on soft bodied insects such as moths, other spiders, mosquitoes, silverfish [4] and crickets.[17] Scytodes typically hunt their prey, however scavenging behaviour has been observed to happen rarely.[17] When scavenging occurs a spider will not spit on the prey as the glue is energetically expensive to produce.[17]

Fossil Record

One of the oldest fossils of an extinct species of Scytodes is Scytodes weitschati (Wunderlich 1993)[18] found in Baltic amber dating to the Eocene 43 million years ago.[18] Its morphology is similar to that of Scytodes seen today.[18]

Species

As of September 2025, this genus includes 228 species and one subspecies.[19]

Species with articles on Wikipedia:

  • Scytodes arenacea Purcell, 1904 – Namibia, South Africa
  • Scytodes armata Brescovit & Rheims, 2001 – Costa Rica
  • Scytodes broomi Pocock, 1902 – Namibia, South Africa
  • Scytodes caffra Purcell, 1904 – DR Congo, South Africa, Eswatini
  • Scytodes cedri Purcell, 1904 – South Africa
  • Scytodes clavata Benoit, 1965 – DR Congo, South Africa
  • Scytodes constellata Lawrence, 1938 – South Africa
  • Scytodes drakensbergensis Lawrence, 1947 – South Africa
  • Scytodes elizabethae Purcell, 1904 – South Africa
  • Scytodes flagellata Purcell, 1904 – South Africa
  • Scytodes fusca Walckenaer, 1837 – North to South America. Introduced to St. Helena, Europe, Africa, Seychelles, India, Myanmar, Indonesia, China, Japan, Hawaii
  • Scytodes globula Nicolet, 1849 – Bolivia, Brazil, Uruguay, Chile, Argentina
  • Scytodes gooldi Purcell, 1904 – South Africa
  • Scytodes karrooica Purcell, 1904 – South Africa
  • Scytodes kumonga Zamani & Marusik, 2020 – Oman, Iran
  • Scytodes lanceolata Purcell, 1904 – South Africa
  • Scytodes lawrencei Lessert, 1939 – DR Congo, South Africa
  • Scytodes leipoldti Purcell, 1904 – South Africa
  • Scytodes longipes Lucas, 1844 – Central and South America. Introduced to Guinea, DR Congo, Indonesia (New Guinea), Japan, Australia (Queensland), Pacific Is. Hawaii
  • Scytodes lycosella Purcell, 1904 – South Africa
  • Scytodes lyriformis Purcell, 1904 – South Africa
  • Scytodes maritima Lawrence, 1938 – South Africa
  • Scytodes marshalli Pocock, 1902 – South Africa
  • Scytodes montana Purcell, 1904 – South Africa
  • Scytodes pallida Doleschall, 1859 – India, China, Philippines, Indonesia (Moluccas, New Guinea)
  • Scytodes quinqua Lawrence, 1927 – Namibia, South Africa
  • Scytodes rubra Lawrence, 1937 – South Africa
  • Scytodes schultzei Purcell, 1908 – South Africa
  • Scytodes silvatica Purcell, 1904 – South Africa
  • Scytodes subulata Purcell, 1904 – South Africa
  • Scytodes symmetrica Lawrence, 1938 – South Africa
  • Scytodes testudo Purcell, 1904 – South Africa
  • Scytodes thoracica (Latreille, 1802) – Europe, North Africa, Turkey, Iran, temperate Asia to China, Korea, Japan. Introduced to North America, Argentina, South Africa, India, Australia, New Zealand (type species)
  • Scytodes triangulifera Purcell, 1904 – South Africa
  • Scytodes trifoliata Lawrence, 1938 – South Africa
  • Scytodes univittata Simon, 1882 – Turkmenistan, Kyrgyzstan, India. Introduced to Hawaii, Mexico, Cuba, Venezuela, Brazil, Paraguay, Chile, Ascension Island, Cape Verde, Canary Islands, Morocco, Spain, Italy, Cyprus, Egypt, Iraq, Iran
  • Scytodes venusta (Thorell, 1890) – Sri Lanka to Indonesia (Java)

References

  1. ↑ "araneae - Scytodes thoracica" (in en). https://araneae.nmbe.ch/data/1224/Scytodes_thoracica. 
  2. ↑ Brand, Jacqueline. "Scytodes thoracica" (in en). https://animaldiversity.org/accounts/Scytodes_thoracica/. 
  3. ↑ 3.0 3.1 3.2 Belosludtsev, E. A.; Gasilin, V. V. (March 2018). "Cosmopolitan Distribution of the Spitting Spider Scytodes thoracica Latreille, 1802 (Aranei, Scytodidae) and Its New Findings in the Northern Parts of the Range" (in en). Contemporary Problems of Ecology 11 (2): 123–136. doi:10.1134/S1995425518020038. ISSN 1995-4255. Bibcode: 2018CPrEc..11..123B. http://link.springer.com/10.1134/S1995425518020038. 
  4. ↑ 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 4.10 Nentwig, Wolfgang; Ansorg, Jutta; Cushing, Paula E.; Kranz-Baltensperger, Yvonne; Kropf, Christian (2024) (in en). House Spiders - Worldwide. Cham: Springer Nature Switzerland. doi:10.1007/978-3-031-70448-2. ISBN 978-3-031-70447-5. https://link.springer.com/10.1007/978-3-031-70448-2. 
  5. ↑ 5.0 5.1 5.2 5.3 Nentwig, Wolfgang (January 1985). "Feeding ecology of the tropical spitting spider Scytodes longipes (Araneae, Scytodidae)" (in en). Oecologia 65 (2): 284–288. doi:10.1007/BF00379231. ISSN 0029-8549. PMID 28310679. Bibcode: 1985Oecol..65..284N. http://link.springer.com/10.1007/BF00379231. 
  6. ↑ "Spitting spiders - nature's strangest hunters" (in en). 2017-11-20. https://imb.uq.edu.au/article/2017/11/spitting-spiders-natures-strangest-hunters#:~:text=Spitting%20spiders%20belong%20to%20the,under%20rocks%20during%20the%20day.. 
  7. ↑ Li, Daiqin; Jackson, Robert R.; Barrion, Alberto T. (March 1999). "Parental and predatory behaviour of Scytodes sp., an araneophagic spitting spider (Araneae: Scytodidae) from the Philippines". Journal of Zoology 247 (3): 293–310. doi:10.1111/j.1469-7998.1999.tb00993.x. 
  8. ↑ 8.00 8.01 8.02 8.03 8.04 8.05 8.06 8.07 8.08 8.09 8.10 8.11 Li, Daiqin; Jackson, Robert R.; Barrion, Alberto T. (March 1999). "Parental and predatory behaviour of Scytodes sp., an araneophagic spitting spider (Araneae: Scytodidae) from the Philippines". Journal of Zoology 247 (3): 293–310. doi:10.1017/S0952836999003027. http://doi.wiley.com/10.1017/S0952836999003027. 
  9. ↑ 9.0 9.1 9.2 9.3 Bowden, Karen; Jackson, Robert R. (July 1988). "Social organisation of Scytodes fusca , a communal web-building spitting spider (Araneae, Scytodidae) from Queensland" (in en). New Zealand Journal of Zoology 15 (3): 365–368. doi:10.1080/03014223.1988.10422961. ISSN 0301-4223. https://www.tandfonline.com/doi/full/10.1080/03014223.1988.10422961. 
  10. ↑ 10.0 10.1 10.2 10.3 Yap, L.-M. Y. L.; Li, D. (2009-04-20). "Social behaviour of spitting spiders (Araneae: Scytodidae) from Singapore". Journal of Zoology 278 (1): 74–81. doi:10.1111/j.1469-7998.2009.00555.x. ISSN 0952-8369. http://scholarbank.nus.edu.sg/handle/10635/101686. 
  11. ↑ Zamani, Alireza (2014-05-31). "The spitting spider genusScytodes(Araneae: Scytodidae) in Iran". Arachnologische Mitteilungen 47: 41–44. doi:10.5431/aramit4706. ISSN 1018-4171. 
  12. ↑ Koh, Teck Hui; Seah, Wee Khee; Yap, Laura-Marie Y. L.; Li, Daiqin (April 2009). "Pheromone-based female mate choice and its effect on reproductive investment in a spitting spider" (in en). Behavioral Ecology and Sociobiology 63 (6): 923–930. doi:10.1007/s00265-009-0735-4. ISSN 0340-5443. Bibcode: 2009BEcoS..63..923K. http://link.springer.com/10.1007/s00265-009-0735-4. 
  13. ↑ 13.0 13.1 Jackson, Robert R.; Li, Daiqin; Fijn, Natasha; Barrion, Alberto (1998-05-01). "Predator–Prey Interactions Between Aggressive-Mimic Jumping Spiders (Salticidae) and Araneophagic Spitting Spiders (Scytodidae) from the Philippines" (in en). Journal of Insect Behavior 11 (3): 319–342. doi:10.1023/A:1020946529246. ISSN 1572-8889. Bibcode: 1998JIBeh..11..319J. https://link.springer.com/article/10.1023/A:1020946529246. 
  14. ↑ 14.0 14.1 Gilbert, Cole; Rayor, Linda S. (1985). "Predatory Behavior of Spitting Spiders (Araneae: scytodidae) and the Evolution of Prey Wrapping". The Journal of Arachnology 13 (2): 231–241. ISSN 0161-8202. 
  15. ↑ 15.0 15.1 15.2 15.3 15.4 Zobel-Thropp, Pamela A.; Correa, Sandra M.; Garb, Jessica E.; Binford, Greta J. (2014-02-07). "Spit and Venom from Scytodes Spiders: A Diverse and Distinct Cocktail" (in en). Journal of Proteome Research 13 (2): 817–835. doi:10.1021/pr400875s. ISSN 1535-3893. PMID 24303891. 
  16. ↑ Ariki, Nathanial K.; Muñoz, Lisa E.; Armitage, Elizabeth L.; Goodstein, Francesca R.; George, Kathryn G.; Smith, Vanessa L.; Vetter, Irina; Herzig, Volker et al. (2016-05-26). Silman, Israel. ed. "Characterization of Three Venom Peptides from the Spitting Spider Scytodes thoracica" (in en). PLOS ONE 11 (5). doi:10.1371/journal.pone.0156291. ISSN 1932-6203. PMID 27227898. Bibcode: 2016PLoSO..1156291A. 
  17. ↑ 17.0 17.1 17.2 Vetter, Richard S. (November 2013). "Scavenging behavior in spitting spiders, Scytodes (Araneae: Scytodidae)" (in en). Journal of Arachnology 41 (3): 392–394. doi:10.1636/J13-38.1. ISSN 0161-8202. http://www.bioone.org/doi/abs/10.1636/J13-38.1. 
  18. ↑ 18.0 18.1 18.2 Luo, Yu-Fa; Li, Shu-Qiang (2024-01-18). "Indian monsoon drove the dispersal of the thoracica group of Scytodes spitting spiders" (in en). Zoological Research 45 (1): 152–159. doi:10.24272/j.issn.2095-8137.2023.364. ISSN 2095-8137. PMID 38247177. 
  19. ↑ "Genus Scytodes". World Spider Catalog. doi:10.24436/2. https://wsc.nmbe.ch/genus/3070. 

Wikidata ☰ Q2248809 entry



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