Katipō

Katipō (pronounced or ; Latrodectus katipo) is a species of cobweb spider found only in New Zealand. It is one of many species in the genus Latrodectus and is most closely related to the Australian redback (L. hasseltii). It is venomous to humans, its bite being capable of producing the toxic syndrome latrodectism; symptoms include extreme pain and, potentially, hypertension or seizure. Bites are rare and antivenom is available in some hospitals. The female is in length; the male is . In the South Island and the lower half of the North Island, the female has a distinct red stripe bordered in white on its abdomen; in more northern populations 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 white with black stripes and red hourglass-shaped markings. The katipō is mainly found living in sand dunes close to the seashore. It is found throughout most of coastal New Zealand except the far south and the West Coast. It feeds mainly on ground-dwelling insects, caught in an irregular tangled web spun among dune plants or other debris. After mating, the female katipō produces five or six egg sacs in November or December. The juveniles hatch after 20–25 days, and during January and February they disperse into surrounding plants.…

Katipō (pronounced or ; Latrodectus katipo) is a species of cobweb spider found only in New Zealand. It is one of many species in the genus Latrodectus and is most closely related to the Australian redback (L. hasseltii). It is venomous to humans, its bite being capable of producing the toxic syndrome latrodectism; symptoms include extreme pain and, potentially, hypertension or seizure. Bites are rare and antivenom is available in some hospitals. The female is in length; the male is . In the South Island and the lower half of the North Island, the female has a distinct red stripe bordered in white on its abdomen; in more northern populations 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 white with black stripes and red hourglass-shaped markings. The katipō is mainly found living in sand dunes close to the seashore. It is found throughout most of coastal New Zealand except the far south and the West Coast. It feeds mainly on ground-dwelling insects, caught in an irregular tangled web spun among dune plants or other debris. After mating, the female katipō produces five or six egg sacs in November or December. The juveniles hatch after 20–25 days, and during January and February they disperse into surrounding plants. The common name is from Māori for "night stinger", which is derived from the words (to sting) and (the night). Due to habitat loss, colonisation of their natural habitat by invasive spiders and hybridisation with L. hasseltii, the katipō is listed as "in serious decline" by the New Zealand Threat Classification System. ==Taxonomy== The katipō was reported as early as 1855 as the kātĕpo, but was not formally described in taxonomic literature until 1870, when New Zealand doctor Llewellyn Powell described it as Latrodectus katipo. Swedish arachnologist Tamerlan Thorell later placed it in Latrodectus scelio, a previous name for Latrodectus hasseltii (redback spider). Later, New Zealand arachnologist Arthur Urquhart unknowingly described it again as two species: Theridium melanozantha in 1887 and Theridium zebrinia in 1890. He also described Latrodectus katipo var. atritus, a subspecies of katipō that was fully black in colour. In 1933, Urquhart's two species were later recognised to be the same as L. katipo by American arachnologist Elizabeth Bryant and thus were synonymised. Several taxonomic studies have disagreed over whether to treat L. katipo as a separate species or as a synonym of L. hasseltii with L. atritus as a subspecies. Eventually, it was concluded that L. katipo, together with L. katipo var. atritus, are separate from L. hasseltii. There was further confusion over whether L. katipo and L. katipo var. atritus should be considered separate species due to their very similar morphology but notably different distributions. Although they were designated as separate species for a time, this was clarified when the species was revised again in 2008. In this revision, L. atritus was formally recognised to be the same as L. katipo on the basis of genetic data and thus was synonymised. It was proposed that the colour variation seen between these two groups is a cline, or gradual continuous variation over latitude, and is correlated with mean annual temperature. The katipō is a member of the genus Latrodectus. This genus has a worldwide distribution with notable members such as Latrodectus mactans (black widow spider), Latrodectus geometricus (brown widow spider) and Latrodectus hasseltii (redback spider), to the latter of which the katipō is most closely related. It is a member of the family Theridiidae, which are commonly known as cobweb spiders or comb-footed spiders. ==Distribution and habitat== The katipō is only found in New Zealand. In the North Island it is found throughout the West Coast from North Cape to Wellington. On the east coast of the North Island it occurs irregularly, but it is abundant on Great Barrier Island. In the South Island it is found in coastal regions south to Dunedin on the east coast and south to Greymouth on the west coast. It has been proposed that this southern limit is due to the katipō needing warmer temperatures to allow for the development of their eggs. The red katipō is found south of the western tip of Taranaki on the west coast, and just north of Waipatiki Beach in Hawke's Bay on the east coast. The black katipō are found north of Aotea Harbour in the Waikato region on the west coast, and Waipiro Bay in the Gisbourne region on the east coast. Both forms are found in a transitionary area in between these aforementioned localities. These colour variants are strongly correlated with temperature, one study reporting that the red katipō is found in cooler areas with average temperatures of . In contrast, the black katipō is found in warmer areas with average temperatures of . ==Life history== ===Reproduction=== Once it becomes an adult, the male begins to search for a female with which to mate, possibly being guided by pheromones in female's silk. The male enters the female's web and gently vibrates the silk as he approaches her. The female is usually aggressive at first and will chase the male from the web. The courtship process consists of the male bobbing, plucking and tweaking the web along with periods of cautious approach and being chased by the female. Eventually, she becomes docile and allows him to approach. The male moves to the underside of her abdomen, tapping her rapidly until their abdomens are aligned in the same direction. He then inserts his palps (appendages modified for reproduction) into the female's reproductive tract one at a time. Copulation occurs over 10 to 30 minutes. After mating, the male retreats to groom, which is performed by running his palps and legs through his fangs and wiping them over his body. The male is not eaten by the female unlike some other widow spiders. The female lays its eggs in November or December. The eggs are round, about the size of a mustard seed, and are a transparent, purplish red. They are held together in a cream-coloured, round, ball-shaped egg sac which is about in diameter. The female constructs five or six egg sacs over the next three to four weeks. Each egg sac contains about 70 to 90 fertilised eggs. The egg sacs are hung in the centre of the spider's web and the female spins more silk over them, which becomes covered in sand and conceals them somewhat. The eggs hatch after 20–25 days and continue to develop within the egg sac where they remain until the second instar, at which stage they feed on the wall of the egg sac. After four to six weeks of incubation, during January and February, the juveniles chew their way out of the egg sac. The young spiders then disperse from the web. In one 24-hour study of juveniles, 28% dispersed from the web by ballooning—using air currents to carry themselves away from the nest on a single silk strand. The majority, 61%, used bridging, moving to nearby plants along silk threads, while 11% remained in the nest. Because they are closely related, the male redback is able to successfully interbreed with a female katipō to produce hybrid offspring. However, a male katipō cannot mate with the female redback as the male katipō is heavier than the male redback, and when it approaches the web it triggers a predatory response in the female leading to the male usually being eaten before mating can occur. There is evidence of interbreeding between katipō and redbacks in the wild, one specimen reported to have redback DNA in its maternal lineage. ==Conservation status== Under the New Zealand Threat Classification System, the katipō is listed as "Declining", with the qualifiers of "Climate Impact", "Data Poor: Trend" and "Range Restricted". Several factors have contributed to its decline; the major factors appear to be habitat loss and the declining quality of the remaining habitat. Human interference with the katipō's natural habitat has been occurring for over a century following European settlement of New Zealand. Coastal dune modification resulting from agriculture, forestry, or urban development, along with recreational activities like the use of beach buggies, off-road vehicles, beach horse riding and driftwood collection, have destroyed or changed areas where the katipō lives. The introduction of many invasive plants may have also contributed to the decline of suitable habitat. It has been proposed that surfactants, which are used to improve herbicide efficiency, may pose an additional risk to the katipō. , the false katipō|alt=A spider sitting on a web]] Much of the katipō's habitat is occupied by the invasive spider Steatoda capensis (commonly known in New Zealand as " "), a South African species that became common in New Zealand during the 20th century. Both species can be found sharing the same dune systems or even co-existing under the same piece of driftwood. There is evidence that displacement of the katipō is occurring due to the ability of S. capensis to quickly recolonise areas from which the katipō has become displaced after storms or other dune modifications. Furthermore, S. capensis breeds year-round, produces more offspring, and lives in a greater range of habitats, leading to greater pressure on the katipō's survival. A 2025 study comparing the movement ecology of adult male katipō and S. capensis from overlapping populations collected at Te Ariā Beach in Auckland found that male S. capensis were significantly more exploratory than katipō in laboratory conditions. S. capensis emerged more readily into a maze arena and explored a greater area, while katipō were more reclusive. In running tests, S. capensis completed the track faster and without stopping, whereas katipō would occasionally freeze — a behaviour consistent with an anti-predator crouching response. Both species showed similar climbing performance. The researchers concluded that the higher exploratory behaviour of S. capensis may facilitate their rapid recolonisation of vacant microhabitats in sand dunes left open by storm damage or human disturbance, potentially contributing to the displacement of katipō. In 2010, the katipō was one of a dozen previously unprotected species of invertebrate given full protection under the 1953 Wildlife Act, noted as "iconic, vulnerable to harm, and in serious decline". Under the Act, killing an absolutely-protected species such as the katipō is punishable by a fine or even imprisonment. It has been proposed that restoration of sand dune habitat, including the replacing of marram grass ( ) with native dune plants, would provide more suitable habitat for the katipō to conserve their populations. Reducing activities that damage sand dunes, such as off-road driving and rubbish dumping, may also protect the species. ==Toxicology== The katipō has venom that is medically significant in humans, meaning it has the potential to cause serious injury or death. Antivenom is available in some hospitals to treat bites. No deaths due to the bite have been recorded in medical settings. The incidence of bites is low as it is a shy, non-aggressive spider. Their narrow range, diminishing population, and human awareness of where they live means humans rarely encounter katipō. The katipō will only bite defensively. If the female is with an egg sac it will remain close by it and be more aggressive. Envenomation from bites of the katipō cause effects known as latrodectism. The venoms of all Latrodectus spiders are thought to contain similar components with the neurotoxin α-latrotoxin being the main agent responsible. One study reported that only the female is capable of biting humans. Māori legends recall deaths due to bites. One legend states that a group of Māori camped out at the mouth of the Whanganui River were bitten overnight, and two died. In Māori tradition, katipō bite victims would be treated by bathing them in hot water or covering the bite wound in red ochre, which supposedly reduced swelling and pain. Alternatively they would also cover the victim in smoke. Bites are very rare, 23 of the 37 known hospitalisations for spider bites between 1967 and 1976 in New Zealand being attributed to katipō bites. The most recent reported katipō bites ( ) were to a Canadian tourist in 2010 and a kayaker in 2012, both of whom survived. ===Symptoms=== The symptoms of a katipō bite are considered to be extremely similar to the bite of L. hasselti. The bite may be initially painful, but it sometimes only feels like a pin prick or mild burning sensation. Within an hour victims generally develop more severe local pain with local sweating and sometimes piloerection (goosebumps). Pain, swelling and redness spread away from the site. Less commonly, systemic envenoming is heralded by swollen or tender regional lymph nodes; associated features include malaise, nausea, vomiting, abdominal or chest pain, generalised sweating, headache, fever and hypertension. The duration of effects can range from a few hours to days, with severe pain persisting for over 24 hours after being bitten in some cases. ===Treatment=== Treatment is based on the severity of the bite; only oral analgesics being needed in less severe cases or parenteral analgesics being used in more severe cases. If symptoms do not resolve, then redback antivenom may be used, which can neutralise the katipō venom. Stocks of the antivenom are available in some New Zealand hospitals. Unlike some other antivenoms, it is not limited to patients with signs of severe, systemic envenoming. Opioids and benzodiazepines can be used as an initial treatment for latrodectism. ==References== ==External links== Spider Olympics – interview with katipō researcher James Roberts on RNZ Saturday Morning, 18 October 2025 Katipō spider on the website of the Museum of New Zealand Te Papa Tongarewa Katipō discussed on RadioNZ Critter of the Week show, 15 April 2016

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