STEATODA GROSSA

Spiders have eight legs and are air-breathing arthropods, with chelicerae that inject venom. According to facts, they are ranked seventh in the diversity of total species. Except for Antarctica, spiders are found in every continent over the World. In this post, we will discuss Steatoda grossa or False Black Widow spiders in detail.

False Black Widow spider is from the family of Theridiidae. It has around 120 acknowledged species also including many cosmopolitan species. False Black widow spiders are from the genus of Steatoda, Cosmopolitan usually found among human populations.

Theridiidae family is also known as cobweb spiders, tangle-web spiders, and comb-footed spiders. False Black Widow is also among the family of Theridiidae and due to less sight construct tangle-web.

Steatoda grossa or False Black Widow
Source: www.upload.wikimedia.org

Its common name is Cupboard spider, spider species build their webs in sheltered, undisputed place, in dark and garages. This spider has small white spots just like small splashes of paint.

They have egg-shaped small cephalothorax and a larger abdomen, color can be brown or reddish plum to satiny black.

Nomenclature

TypeDetails
NameSteatoda
Scientific NameSTEATODA GROSSA
SynonymCupboard spider

Vernacular Names

Here below some Vernacular names for Steatoda spider given:

  • English: Steatoda
  • Chinese: Steatoda
  • French: Steatoda
  • German: Steatoda
  • Italian: Steatoda
  • Japanese: ステーダダ
  • Urdu: سٹوناڈو

History of Steatoda

History of Spider on earth is more than 380 million years old and now having 35,000 species. Steatoda is also among the species of spiders. Further details of Steatoda are discussed below:

Origin of Cupboard spider

Cupboard spider has a number of species named as L. mactans which are black widow spider. Other species like L. hasselti a redback spider, L. indistinctus which is button spider. L. tredecimguttatus which is European black widow spider, and Steatoda species false widow spiders also come under Steatoda species.

False Widow is Steatoda Nobilis spider and is the most dangerous of the 12 species of biting spider in Britain. Among 6 false widow group spiders, nobilis are local spiders. They have black and shiny cream marks on their abdomen, in some eyes and skull.

Generally, people easily confused false widow which is the genus of Steatoda, with the Black widow of the Latrodectus genus. Black Widows are more harmful False Black Widow Spiders and their bite is extremely painful.

Fossil Records of Steatoda

Cupboard spider (False Widow) first sighted in 1879 in Torquay and it’s species spread across southern England. Now due to global warming, these False widows or Steatoda spiders spread further towards the north.

Distinctive Features of Steatoda

Let’s discuss some characteristics of False Widow Spiders. False Black Widow Spiders is from the genus of Steatoda and have a similar shape to Widow spiders.

Steatoda feature
Source: www.spiderbytes.org

Females False Black Widow spiders are more than males as they measure up to 15 millimeters while males measure up to 10 millimeters. They also have bulbous and round abdomens or stomach. Male and females color pattern is similar but compared with females, body Male is thinner and more elongate.

Morphology

It is from the family of Theridiidae and also known as false widows. It is generally flatter than other widows also Steatoda have shorter legs than other Widows.

Among the family of Theridiidae, Latrodectus mactans (black widow spider) is the largest spider. They are shiny coal black in color. There is a red hourglass mark under the female’s abdomen which is also called venter.

Black Widow spiders also have one or two red spots over the spinnerets and along the middle of her back. On the other-side Male’s legs are larger than females and their joints are orange-brown in the middle and black on the ends.

Males abdomen have four pairs of red and white stripes, young spiderlings are brown, orange and white in color and with age or with each molt they acquired black color.

Black Widow spider or Latrodectus mactans have average mass 1 gram, Average length of 3-10 mm. Female Sexual Dimorphism is larger than Males. 

Habitat

They usually found in gardens, the bark of trees under rocks, in walls, underwoods, and fences. As they have poor eyesight so compared with other web-weaving spiders they construct a cobweb of an irregular tangle of sticky silken fibers.

False Black Widow warns themselves from larger animals danger by depending on vibrations reaching through their webs.

Steatoda grossa habitat
Source: www.dogalhayat.org

As they are not aggressive spider and injuries to humans are due to defensive bites delivered by them. Due to global warming, they are increasing in the United Kingdom.

The habitat of the Latrodectus mactans is a terrestrial environment and usually construct their webs in dark sheltered spots.

Their webs can also be found near dustbins, in spaces under chips of woods and in the deserted animal holes. Temperate, Tropical and Terrestrial regions considered to be Habitat regions for these spiders.

Life Span of Steatoda

Male spiders have less lifespan than females Steatoda Grossa or False Black Widow. The lifespan of Males Steatoda is 1-1.5 years while females can live up to 6 years.

Behavior Of Steatoda

Steatoda is not of aggressive behavior but if they feel any threat they immediately attack in their defense. Their bite not usually felt but with short time burning starts with increasing pain.

Even within 20 minutes effected parts swell and develop a wound. After some hours two small puncture will appear in the area of swelling.

Taxonomy

There are almost 120 recognized species of Steatoda Grossa.

Types of Steatoda Grossa

Types of these arthropods are listed below :

  1. Steatoda bipunctata: Steatoda bipunctata is also known as the ‘rabbit hutch spider’ and is usually a very common spider of sheds and outbuildings. Bipunctata body exceeds 7mm in length for females and for males it is 5mm. These species are also dark and shiny with a pattern, and comprising a whitish line around the front. They also sometimes have a white stripe down the center. There are dots on their abdomen and cannot easily visible with the naked eye.
  2. Steatoda grossa: Steatoda grossa has a body length of around 10mm for females and males are generally smaller. These species are common in the south-east and due to global warming, they are now spreading towards the north.    
  3. Steatoda paykulliana: Steatoda paykulliana many time misidentified with Black Widow, Lactrodectus hasselti, and Lactrodectus mactans or a Redback spider. These species also occurs in imported grapes and other fruits. Paykulliana venum is quite mild but its bite effect is painful.
  4. Steatoda nobilis: Steatoda nobilis is also the largest of the false widows having a body length of 14mm for females and 10mm for males. These species first founded in the United Kingdom at Torquay in 1879. It is also now spreading due to global warming towards Lincolnshire and North Wales.

Steatoda Fun Facts

There are some fun facts about the Steatoda:

FUNFACTS Steatoda grossa

References

  1. www.britishspiders.org.uk
  2. www.dailymail.co.uk
  3. www.animalcorner.co.uk
  4. www.express.co.uk
  5. www.eol.org

Azka Hassan

A software engineering graduate from UET Taxila, I started my carrier as an SQA engineer in the year 2013 and have worked as a Quality Assurance Engineer and Content Creator at various organizations. Currently working as a Content Manager at Tapedaily. Writing research-based content related to Plants, Animals, and various kingdoms are my key interest.

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