Triangulate cobweb spider
Encyclopedia
The triangulate cobweb spider (scientific name: Steatoda triangulosa; also called the triangulate bud spider) is a common house spider in the genus Steatoda
. As the name indicates, it is well-known for the triangle
-shaped pattern on the dorsal side of its abdomen.
and spindly, yellowish legs. The round, bulbous abdomen is creamy in color, with parallel purply-brown zigzag lines running front to back. This distinctive pattern sets it apart from other theridiids in its area.
The triangulate cobweb spider is known to prey on many other types of arthropods, including ants (including fire ant
s), other spiders, pillbugs, and ticks. It preys on several other spiders believed to be harmful to humans, including the hobo spider
and the brown recluse.
The egg sac of the triangulated cobweb spider is made from loosely woven silk, and is about the same size as the spider itself. Each egg sac contains approximately 30 eggs.Cobweb spiders typically live on windows or in dirt areas, they eat for a margin of their day and spend hours developing their web, it does not break if it is woven well.If you have a cobweb spider on your window or somewhere you may notice that there are many dead insects below or in the web, which range from stinkbugs to other spiders, even wasps. it is small with a circular bottom and a patten on it. Their web is very strong, in fact if you see ones web and pull it you may find it difficult to break, because it weaves a very strong material.
S. triangulosa is a cosmopolitan species, and is found in many parts of the world, including all three coasts in North America
, in southern Russia
and New Zealand
, and in Europe
. The spider is believed to be native to Eurasia. This species is primarily a house spider, and builds webs in dark corners of buildings and other man-made structures.
Steatoda
The spider genus Steatoda, in the family Theridiidae, includes over 120 recognized species, distributed around the world ....
. As the name indicates, it is well-known for the triangle
Triangle
A triangle is one of the basic shapes of geometry: a polygon with three corners or vertices and three sides or edges which are line segments. A triangle with vertices A, B, and C is denoted ....
-shaped pattern on the dorsal side of its abdomen.
Description
The adult female triangulate cobweb spider is 1/8 to 1/4 inch long (3 mm to 6 mm), with a brownish-orange cephalothoraxCephalothorax
The cephalothorax is a tagma of various arthropods, comprising the head and the thorax fused together, as distinct from the abdomen behind. The word cephalothorax is derived from the Greek words for head and thorax...
and spindly, yellowish legs. The round, bulbous abdomen is creamy in color, with parallel purply-brown zigzag lines running front to back. This distinctive pattern sets it apart from other theridiids in its area.
The triangulate cobweb spider is known to prey on many other types of arthropods, including ants (including fire ant
Fire ant
Fire ants are a variety of stinging ants with over 285 species worldwide. They have several common names, including ginger ants, tropical fire ants and red ants.- Appearance :...
s), other spiders, pillbugs, and ticks. It preys on several other spiders believed to be harmful to humans, including the hobo spider
Hobo spider
The hobo spider is a member of the genus of spiders known colloquially as funnel web spiders, but not to be confused with the Australian funnel-web spider. It is one of a small number of spiders in North America whose bites are generally considered to be medically significant...
and the brown recluse.
The egg sac of the triangulated cobweb spider is made from loosely woven silk, and is about the same size as the spider itself. Each egg sac contains approximately 30 eggs.Cobweb spiders typically live on windows or in dirt areas, they eat for a margin of their day and spend hours developing their web, it does not break if it is woven well.If you have a cobweb spider on your window or somewhere you may notice that there are many dead insects below or in the web, which range from stinkbugs to other spiders, even wasps. it is small with a circular bottom and a patten on it. Their web is very strong, in fact if you see ones web and pull it you may find it difficult to break, because it weaves a very strong material.
Habitat and range
In common with other members of the Theridiidae family, S. triangulosa constructs a cobweb, i.e. an irregular tangle of sticky silken fibers. As with other web-weavers, these spiders have very poor eyesight and depend mostly on vibrations reaching them through their webs to orient themselves to prey or warn them of larger animals that could injure or kill them. They are not aggressive. Other, larger members of the Steatoda genus do have medically significant bites, but there are no recorded bites or envenomations by this spider.S. triangulosa is a cosmopolitan species, and is found in many parts of the world, including all three coasts in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, in southern Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
and New Zealand
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
, and in Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
. The spider is believed to be native to Eurasia. This species is primarily a house spider, and builds webs in dark corners of buildings and other man-made structures.
External links
- Triangulate Household Spider
- Steatoda triangulosa Images on BugGuide.net
- The World Spider Catalog
- University of Arkansas Arthropod Museum Notes: Triangulate cobweb spider
- http://www.puyallup.wsu.edu/plantclinic/resources/pdf/pls107steatodaspider.pdf
- Penn State University Dept. of Entomology: Commonly Encountered Pennsylvania Spiders
- Levi, H.W. 1957. The spider genera Crustulina and Steatoda in North America, Central America, and the West Indies (Araneae, Theridiidae). Bull. Mus. Comp. Zool. 117(3):367-424
- Descriptions of four Steatoda species found in New Zealand
- pictures
- Hobospider.com: Steatoda spiders as competitors/predators of the hobo spider