Black house spider

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Black house spider
Black house spider03.jpg
female
AustralianMuseum spider specimen 66.JPG
male
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Arachnida
Order: Araneae
Family: Desidae
Genus: Badumna
Species: B. insignis
Binomial name
Badumna insignis
L. Koch, 1872
Synonyms

Amaurobius insignis Koch, L. 1872
Amaurobius australiensis Strand, E. 1913
Amaurobius robustus Koch, L. 1872
Amaurobius praecalvus Simon, E. 1906

The black house spider (Badumna insignis) is a common species of cribellate Australian spider, found throughout much of Australia and New Zealand. A closely related species, variously called the brown house spider[1] or the grey house spider (Badumna longinquus), has a similar distribution. It is also known as the common black spider.

Ludwig Carl Christian Koch described the black house spider in 1872.[2]

Description[edit]

B. insignis is a dark, robust spider, the female growing up to 18mm, with a 30mm legspan. As with most spiders, the males are smaller (10mm), and have longer legs in relation to their body size. In both sexes the carapace and legs are dark brown to black, and the abdomen is charcoal grey with a dorsal pattern of light markings (sometimes indistinct) and a dense covering of fine, velvety hair. B. longinquus is slightly smaller (14mm) with a greyish carapace and red-brown legs.

Distribution and habitat[edit]

Black and grey house spiders are widely distributed throughout Australia and New Zealand. In natural habitat, they are usually found on rough-barked trees, whereas inside buildings they are often found in corners, around windows and doorways, or other light sources that may attract prey insects. B. longinquus may be found in similar locations, but is more often found outdoors.

Habits, mating and reproduction[edit]

The webs of both B. insignis and B. longinquus are a messy-looking construct of irregular sail-like shapes. There is a funnel-shaped, silken retreat, usually in the middle or corner of the web, where the spider spends most of its time waiting for prey. The female spider never leaves the web unless forced to. They seem quite attached to their location, rarely changing the position of their webs and because of this, old webs can be quite messy, often with small objects or dust stuck in them. At night the spider comes out to repair and add to the web, often just adding new silk over the old.

Black house spider in its web

Males, when ready to mate, go in search of females. The male plucks the web of the female to attract her attention. Once the male has made sure that the female will be receptive, he will approach and inseminate her with his palps. They may then stay together for several days, and may mate again several times.

The female constructs several white silk egg sacs, which are secured within the web retreat. The female stays with the eggs until they hatch. The spiderlings then disperse. Occasionally the young spiders stay in the web of the mother for some time, catching the smaller prey that the larger spider would ignore.

Predators include the White-tailed spider, as well as parasitic wasps and flies.

Bite[edit]

Black house spiders are venomous, but are not considered dangerous. They are timid and bites from them are infrequent. The bite may be excruciatingly painful and cause local swelling. Symptoms such as nausea, vomiting, sweating and giddiness are occasionally recorded. In a few cases, skin lesions (arachnogenic necrosis) have developed after multiple bites.

References[edit]

  1. ^ http://www.terrain.net.nz/friends-of-te-henui-group/spiders/grey-house-spide.html
  2. ^ Department of Sustainability, Environment, Water, Population and Communities (20 June 2012). "Species Badumna insignis L. Koch, 1872". Australian Faunal Directory. Canberra, Australian Capital Territory: Australian Government. Retrieved 2 October 2013. 

External links[edit]