New Zealand has 1157 described spider species, with an estimated total fauna of 2000 species. [1] [2] [3] Over 97 per cent are endemic, and the rest have been introduced through human activities or were natural wind-borne introductions. [1] [3]
The New Zealand spider with the largest leg span is the Nelson cave spider ( Spelungula cavernicola ), with a leg span of up to 13 centimetres (5.1 in) and a 3 centimetres (1.2 in) body length.
The Australian white-tailed spider, first recorded in New Zealand in 1886, has been falsely attributed as the cause of many necrotising spider bites. [4]
The flat huntsman spider ( Delena cancerides ), also from Australia, and called the Avondale spider in New Zealand, was accidentally introduced in the early 1920s, possibly in shipments of hardwood logs used for railway sleepers. [5] The huntsman spiders, which are considered harmless to humans, have been collected for use in at least two films.
Very few New Zealand spiders have bites that can cause significant injury to humans, and of these, only one – the katipō – is endemic. Katipō bites have been known to cause systemic effects, such as hypertension, seizure, or coma, though no deaths as a result of katipō bites have been recorded for over 200 years. Its more dangerous close relative, the venomous Australian redback spider, has established a foothold in some parts of New Zealand, notably in Taranaki and Central Otago. [6]
There are four spiders in the genus Dolomedes (the fishing spiders), species which have adapted to hunt on the surface of water.
Three of the fishing spiders are widespread on the two main islands of New Zealand. Dolomedes aquaticus grows up to 7 centimetres (2.8 in) across and specialises in open, unforested riverbanks, and lives under rocks within 5 metres (16 ft) of the river. Another species of similar size, Dolomedes dondalei , specialises in forested riverbanks and is also widespread on the mainland. The third and most common species, Dolomedes minor , is not restricted to rivers. Known as the nursery web spider, it makes white nursery webs on shrubs, but is still capable of fishing behaviour. The largest of the New Zealand fishing spiders is Dolomedes schauinslandi and occurs on South East and Mangere islands in the Chatham Islands. [7]
Spider species in New Zealand include:
Huntsman spiders, members of the family Sparassidae, catch their prey by hunting rather than in webs. They are also called giant crab spiders because of their size and appearance. Larger species sometimes are referred to as wood spiders, because of their preference for woody places. In southern Africa the genus Palystes are known as rain spiders or lizard-eating spiders. Commonly, they are confused with baboon spiders from the Mygalomorphae infraorder, which are not closely related.
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, the diversity of species is much greater. A member of the family Theridiidae, this genus contains 34 species, which include several North American "black widows". Besides these, North America also has the red widow Latrodectus bishopi and the brown widow Latrodectus geometricus, which, in addition to North America, has a much wider geographic distribution. Elsewhere, others include the European black widow, the Australian redback spider and the closely related New Zealand katipō, several different species in Southern Africa that can be called button spiders, and the South American black-widow spiders. Species vary widely in size. In most cases, the females are dark-coloured and can be readily identified by reddish markings on the central underside (ventral) abdomen, which are often hourglass-shaped.
The redback spider, also known as the Australian black widow, is a species of highly venomous spider believed to originate in Australia but now, Southeast Asia and New Zealand, with colonies elsewhere outside Australia. It is a member of the cosmopolitan genus Latrodectus, the widow spiders. The adult female is easily recognised by her spherical black body with a prominent red stripe on the upper side of her abdomen and an hourglass-shaped red/orange streak on the underside. Females usually have a body length of about 10 millimetres (0.4 in), while the male is much smaller, being only 3–4 mm (0.12–0.16 in) long.
Delena cancerides, the communal huntsman, flat huntsman or social huntsman, is a large, brown huntsman spider native to Australia. It has been introduced to New Zealand, where it is sometimes known as the Avondale spider. This was the species used in the Australian movie Napoleon and widely in Arachnophobia, and all films depict them as having a deadly venomous bite, but they are generally considered harmless to humans in real-life. It was first described by Charles Athanase Walckenaer in 1837.
The katipō is an endangered species of spider native to New Zealand. It is one of many species in the genus Latrodectus, such as the Australian redback, and the North American black widow. The species is venomous to humans, capable of delivering a potentially dangerous bite. It is a small to medium-sized spider, with the female having a round black or brown pea-sized body. Red katipō females found in the South Island and the lower half of the North Island, are always black, and their abdomen has a distinctive red stripe bordered in white. In black katipō females found in the upper half of the North Island, this stripe is absent, pale, yellow, or replaced with cream-coloured blotches. These two forms were previously thought to be separate species. The male is much smaller than the female and quite different in appearance: white with black stripes and red diamond-shaped markings. Katipō are mainly found living in sand dunes close to the seashore. They are found throughout most of coastal New Zealand except the far south and west. Katipō feed mainly on ground dwelling insects, caught in an irregular tangled web spun amongst dune plants or other debris.
Dolomedes is a genus of large spiders of the family Pisauridae. They are also known as fishing spiders, raft spiders, dock spiders or wharf spiders. Almost all Dolomedes species are semiaquatic, with the exception of the tree-dwelling D. albineus of the southeastern United States. Many species have a striking pale stripe down each side of the body.
The spider genus Steatoda, in the family Theridiidae, includes about 120 recognized species, distributed around the world. One common name is cupboard spider, for many species build their webs in dark, sheltered, undisturbed places around the house or garden, in sheds and garages, under garden, in compost bins, and the like. Signs of the cupboard spider include small white spots of spider droppings, like small splashes of paint, on the floor underneath the web.
Periegops is a genus of spiders with six eyes instead of the usual eight. It is the only genus in its family (Periegopidae) and has three described species. It was long considered to be a member of Sicariidae or Segestriidae until Raymond Forster elevated it to the family level in 1995.
Latrodectism is the illness caused by the bite of Latrodectus spiders. Pain, muscle rigidity, vomiting, and sweating are the symptoms of latrodectism.
Spelungula is a monotypic genus of South Pacific large-clawed spiders containing the single species, Spelungula cavernicola, or the Nelson cave spider.
Dolomedes minor is a spider in the family Pisauridae that is endemic to New Zealand, where it is known as the nursery web spider.
Steatoda capensis is a spider originating from South Africa. Its common names include the black cobweb spider, brown house spider, cupboard spider and due to its similarities to the katipō spider it is commonly known as the false katipō in New Zealand. Common throughout Southern Africa, it has been introduced into other countries and is now present in Australia and throughout New Zealand. It is a small spider, usually an all-over shiny black. It may have a small bright red, orange, or yellow patch near the tip of the abdomen along with a crescent shaped band near the front of the abdomen.
Dolomedes aquaticus is a species of fishing spider that lives and hunts along the gravel banks of unforested New Zealand rivers. It prefer open riverbanks where it typically lives under rocks, usually less than 5 metres away from the river. Its colouring allows it to camouflage against river stones. Normally nocturnal, it will sit and wait for prey after dark, and can survive for short periods under the water.
Trite planiceps, commonly known as the black-headed jumping spider, is a common jumping spider (Salticidae) endemic to New Zealand and one of about 150 species of jumping spiders in New Zealand.
Dolomedes tenebrosus or dark fishing spider is a fishing spider found in the United States and Canada.
Australia has a number of highly venomous spiders, including the Sydney funnel-web spider, its relatives in the family Hexathelidae, and the redback spider, whose bites can be extremely painful and have historically been linked with deaths in medical records. Most Australian spiders do not have venom that is considered to be dangerously toxic. No deaths caused by spider bites in Australia have been substantiated by a coronial inquest since 1979. There are sensationalised news reports regarding Australian spiders that fail to cite evidence. A Field Guide to Spiders of Australia published by CSIRO Publishing in 2017 featuring around 836 species illustrated with photographs of live animals, around 381 genera and 78 families, introduced significant updates to taxonomy from Ramirez, Wheeler and Dmitrov.
Dolomedes schauinslandi or the Rangatira spider is a large spider of the family Pisauridae. It is only found on South East Island (Rangatira), Houruakopara and Mangere Islands in the Chatham Islands, New Zealand. It is one of New Zealand's largest and rarest spiders.
Dolomedes dondalei is a species of large fishing spider endemic to the main islands of New Zealand. It is a nocturnal hunter, feeling the water surface for vibrations, and catches insects and even small fishes – the only New Zealand Dolomedes species able to do so.