Steatoda grossa
Encyclopedia
Steatoda grossa, commonly known as the cupboard spider, the dark comb-footed spider, the brown house spider (in Australia), or the false black widow (though several other species are known by these names), is a common species of spider
in the genus Steatoda
. As one of this spider's common name indicates, the spider superficially resembles, and is frequently confused for, the black widow
and other venomous spiders in the genus Latrodectus. It is a cosmopolitan species found in many parts of the world, including North America
, Australasia
, and Europe
.
The S. grossa sheds up to six instars before reaching full growth. They can go several months without feeding, provided they have access to water.
A well fed female can lay 3 or more egg sacs each year, in which each egg sac typically contains between 40 - 100 eggs. The mother can often be observed watching her eggs for hours, even days at a time once the eggs start changing color and grow close to hatching. At normal household temp/humidity, and egg will usually hatch within a month of being laid. The spiderlings are independent from time of hatch.
Female S. grossa spiders can live up to six years; the typical lifespan for the male is 1-1.5 years. Males often die shortly after mating.
S. grossa is a cosmopolitan species, and is found in many parts of the world, including all three coasts in North America
, in Australia
and New Zealand
, and in Europe
.
A related species, commonly found in North America, is Steatoda borealis. This spider is similar to S. grossa in shape, but slightly smaller, and is generally found in colder climates. This spider can be identified by colored markings on the dorsal side of its abdomen, rather than on the ventral side.
lasting for several days. The Latrodectus antivenom has been shown to be effective at treating bites from Steatoda grossa, after it was mistakenly administered to a S. grossa bite victim who was erroneously believed to have bitten by the far more dangerous redback. These spiders are known for preying on true black widows, redback spiders, and hobo spider
s, in areas where the species share a common range.
in the Sam Raimi
-directed Spider-Man
film, released in 2002.
Spider
Spiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...
in the genus Steatoda
Steatoda
The spider genus Steatoda, in the family Theridiidae, includes over 120 recognized species, distributed around the world ....
. As one of this spider's common name indicates, the spider superficially resembles, and is frequently confused for, the black widow
Black widow spider
Latrodectus mactans, the Southern black widow, is a highly venomous species of spider in the genus Latrodectus. They are well known for the distinctive black and red coloring of the female of the species and for the fact that she will occasionally eat her mate after reproduction. The species is...
and other venomous spiders in the genus Latrodectus. It is a cosmopolitan species found in many parts of the world, including 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...
, Australasia
Australasia
Australasia is a region of Oceania comprising Australia, New Zealand, the island of New Guinea, and neighbouring islands in the Pacific Ocean. The term was coined by Charles de Brosses in Histoire des navigations aux terres australes...
, and 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...
.
Description
Like black widows, the female S. grossa is 6-10.5 mm in length, and dark colored, with a round, bulbous abdomen. Typical coloration ranges from purplish-brown to black, with light-colored markings. Unlike black widows, redbacks, and other Latrodectus species, the S. grossa does not have a bright red hourglass pattern or any other bright markings. Like many spiders, the male is sometimes smaller; But can many times be nearly as long as the females. It measures 4.1-10.0mm in length, and is thinner than the female. The two sexes are colored similarly, however the sexually mature male almost always has lighter, more reddish coloured legs than the female.The S. grossa sheds up to six instars before reaching full growth. They can go several months without feeding, provided they have access to water.
A well fed female can lay 3 or more egg sacs each year, in which each egg sac typically contains between 40 - 100 eggs. The mother can often be observed watching her eggs for hours, even days at a time once the eggs start changing color and grow close to hatching. At normal household temp/humidity, and egg will usually hatch within a month of being laid. The spiderlings are independent from time of hatch.
Female S. grossa spiders can live up to six years; the typical lifespan for the male is 1-1.5 years. Males often die shortly after mating.
Habitat and range
As is common with other members of the family Theridiidae, S. grossa 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 pose a danger. They are not aggressive, and most injuries to humans are due to defensive bites delivered when a spider gets unintentionally squeezed or pinched. It is possible that some bites may result when a spider mistakes a finger thrust into its web for its normal prey, but ordinarily intrusion by any large creature will cause these spiders to flee.S. grossa 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 Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
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...
.
A related species, commonly found in North America, is Steatoda borealis. This spider is similar to S. grossa in shape, but slightly smaller, and is generally found in colder climates. This spider can be identified by colored markings on the dorsal side of its abdomen, rather than on the ventral side.
Medical significance
The bite of S. grossa is known to be medically significant in humans, however without any long-lasting effects. Symptoms of bites include blistering at the site of the bite, and/or a general malaiseMalaise
Malaise is a feeling of general discomfort or uneasiness, of being "out of sorts", often the first indication of an infection or other disease. Malaise is often defined in medicinal research as a "general feeling of being unwell"...
lasting for several days. The Latrodectus antivenom has been shown to be effective at treating bites from Steatoda grossa, after it was mistakenly administered to a S. grossa bite victim who was erroneously believed to have bitten by the far more dangerous redback. These spiders are known for preying on true black widows, redback spiders, and 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...
s, in areas where the species share a common range.
Trivia
A specimen of S. grossa, painted with blue and red stripes, was used as the spider which bit Peter ParkerSpider-Man
Spider-Man is a fictional Marvel Comics superhero. The character was created by writer-editor Stan Lee and writer-artist Steve Ditko. He first appeared in Amazing Fantasy #15...
in the Sam Raimi
Sam Raimi
Samuel Marshall "Sam" Raimi is an American film director, producer, actor and writer. He is best known for directing cult horror films like the Evil Dead series, Darkman and Drag Me to Hell, as well as the blockbuster Spider-Man films and the producer of the successful TV series Hercules: The...
-directed Spider-Man
Spider-Man (film)
Spider-Man is a 2002 American superhero film, the first in the Spider-Man film series based on the fictional Marvel Comics character Spider-Man. It was directed by Sam Raimi and written by David Koepp...
film, released in 2002.