''Parasteatoda tepidariorum'', the common house spider or American house spider, is a

spider Spiders (order (biology), order Araneae) are air-breathing arthropods that have eight limbs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude spider silk, silk. They are the largest order of arachnids and ran ...

species of the genus ''

Parasteatoda ''Parasteatoda'' is a genus of Theridiidae, comb-footed spiders that was first described by Allan Frost Archer in 1946. The name is a combination of the Ancient Greek "wikt:παρά, para-" (), meaning "near" or "next to", and the theridiid genus ...

'' with a cosmopolitan distribution. Common house spiders are

synanthropic A synanthrope (from ancient Greek σύν ''sýn'' "together, with" and ἄνθρωπος ''ánthrōpos'' "man") is an organism that evolved to live near humans and benefit from human settlements and their environmental modifications (see also ...

and live in and near human dwellings. Their prey mechanism is similar to that of the other cobweb spiders: the spider follows disturbances transmitted along the web to entangle and then paralyze its prey, which usually consists of household insects and other invertebrates (often considered as pests).

Description

Appearance

Common house spiders are variable in color from tan to nearly black, frequently with patterns of differing shades on their body. Females are generally between long, and males are generally between long. They can be an inch (2.5 cm) or more across with legs outspread. The average female body mass is about 37.7 mg. ''P. tepidariorum'' is similar in body shape to

widow spider ''Latrodectus'' is a broadly distributed genus of spiders with several species that are commonly known as the true widows. This group is composed of those often loosely called black widow spiders, brown widow spiders, and similar spiders. However ...

s. Males have a less bulbous abdomen than females. Common house spiders' size and coloration allow the spiders to blend into the background and escape notice.

Life cycle

This species can live for more than a year after reaching maturity. Females suspend their

egg sac Spiders (order (biology), order Araneae) are air-breathing arthropods that have eight limbs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude spider silk, silk. They are the largest order of arachnids and ran ...

s in their webs; the spherical egg sacs have a tan papery outer layer. Females produce clutches containing mean of 149 eggs. Each egg measures about 0.59 mm in diameter and weighs around 0.12 mg. The spiderlings remain in the mother's web for several days after coming out of the egg sac.

Diet and predation

Common house spiders usually feed on small insects and household pests. If the prey is too agile, the spider will try shooting web at it from a distance before pulling the thread toward itself. Bigger females can also attract baby

skink Skinks are a type of lizard belonging to the family (biology), family Scincidae, a family in the Taxonomic rank, infraorder Scincomorpha. With more than 1,500 described species across 100 different taxonomic genera, the family Scincidae is one o ...

s inside their web by leaving fly remains hanging in it. Once its food dries out, the spider usually drops it to the floor in order to free space in its web, instead of destroying and rebuilding it or changing its location. Three spider species usually prey upon them: the pirate spiders of the genus ''

Mimetus ''Mimetus'' is a genus of pirate spiders in the family Mimetidae. They are found worldwide. Description Members of this genus resemble the comb-footed spiders, Theridiidae, due to their globular abdomen. The upper side of this bears curved bris ...

'' (

Mimetidae Pirate spiders, members of the family Mimetidae, are araneomorph spiders which typically feed on other spiders. The family Mimetidae contains roughly 200 species divided among 12 genera, of which ''Mimetus'' and '' Ero'' are the most common. Mi ...

), as well as two

jumping spider Jumping spiders are a group of spiders that constitute the family (biology), family Salticidae. , this family contained over 600 species description, described genus, genera and over 6,000 described species, making it the largest family of spide ...

species – ''

Phidippus ''Phidippus'' is a genus in the family Salticidae (jumping spiders). Some of the largest jumping spiders inhabit this genus, and many species are characterized by their brilliant, iridescent green chelicerae. ''Phidippus'' is distributed almost ...

variegatus'' and ''

Platycryptus undatus ''Platycryptus undatus'', also called the tan or familiar jumping spider, is a species of jumping spider (family Salticidae), native to North America.

''. The latter one often falls prey to its own food when it gets trapped in the tangling web after missing the jump on its target. The assassin bug ''

Stenolemus lanipes ''Stenolemus lanipes'' is a species of thread-legged bug ( Emesinae). This species feeds on spiders, especially spiderlings of ''Parasteatoda tepidariorum ''Parasteatoda tepidariorum'', the common house spider or American house spider, is a ...

'' (

Emesinae The Emesinae, or thread-legged bugs, are a subfamily of the Reduviidae (i.e., assassin bugs). They are conspicuously different from the other reduviids by their very slender body form. They are stalking, predatory insects that can be collected on ...

) apparently feeds exclusively on spiderlings of this species, but can also become prey of the adult spider.

Behavior

Interaction with other spiders

A male and female often share the same web for long periods, and several females often build their webs in close proximity. However, females will sometimes fight when they encounter each other.

Interaction with humans and predators

As these spiders live in constant proximity to

human Humans (''Homo sapiens'') or modern humans are the most common and widespread species of primate, and the last surviving species of the genus ''Homo''. They are Hominidae, great apes characterized by their Prehistory of nakedness and clothing ...

s, they are not usually aggressive and will even let a human hand approach their web. Common house spiders will bite humans only in self-defense, when grabbed and squeezed. The species' synanthropic habits, however, increase the risk of human bites. Common house spiders possess poor vision and cannot detect any movement more than three to four inches away. If cornered, they will feign death as last resort.

Toxicity

Common house spiders have

neurotoxic Neurotoxicity is a form of toxicity in which a biological, chemical, or physical agent produces an adverse effect on the structure or function of the central and/or peripheral nervous system. It occurs when exposure to a substance – specifical ...

venom. However, their bites are less severe than that of other theridiids and are "not known to be dangerous to humans".common house spider
on the UF / IFAS Featured Creatures Web site.

Subspecies

Subspecies include ''P. tepidariorum australis'' (common gray house spider).

References

External links

* (2000)
''Achaearanea tepidariorum''
at

Animal Diversity Web The Animal Diversity Web (ADW) is a non-profit group that hosts an online database site that collects natural history, classification, species characteristics, conservation biology, and distribution information on species of animals. The website ...

{{Taxonbar, from=Q388278 Theridiidae Spiders described in 1841 Spiders of North America Spiders of South America Spiders of New Zealand Taxa named by Carl Ludwig Koch