Red Katipo
| Red Katipo | ||||||||||||
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Red Katipo, female |
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| Scientific name | ||||||||||||
| Latrodectus katipo | ||||||||||||
| Powell , 1871 |
The red katipo ( Latrodectus katipo ), often just called katipo , is a spider belonging to the family of canopy web spiders . It belongs to the New Zealand species of the genus of real widows .
description
The females of the species reach a body length of about 8 millimeters and the leg span is about 32 millimeters. They have a spherical abdomen the size of a pea. The legs are slender and black in young animals and later turn brown. The abdomen has a red-orange, angular stripe with a white-orange or red border, which extends to the spinnerets . The underside is black with a red spot and shows the hourglass markings common in real widows, but this markings may be missing in some females. The species belongs to the widow spider species whose basic color is matt instead of glossy black.
The males are much smaller, about one sixth the size of the females. They also differ in their coloring. Males and young animals are brown in color with a predominantly white belly, with irregular red-orange, diamond-shaped markings.
Occurrence and habitat
The Katipo is endemic to New Zealand. In the North Island it is common along the west coast between Wellington and the North Cape . It also occurs occasionally on the east coast. It is still relatively common on the Great Barrier Island . On the South Island their distribution area extends from north to south on the eastern coast to Dunedin , on the western coast to Greymouth . This southern limit of distribution is related to the lower average temperatures in southern New Zealand. The spider's eggs need a temperature of more than 17 ° C in order to develop.
As a rule, the Katipo lives in the dune landscapes near the beaches. It builds its irregular net of hoods on plants of the species Desmoschoenus spiralis and on common beach grass ( Ammophila arenaria ). But the animals also build nets on driftwood or in rubbish, for example empty cans and bottles. The net is shaped like a hammock and is colored white or yellow.
Way of life
The species feeds on insects of all kinds. Amphibians are not spurned either.
The mating season is between August and September and the male is looking for a female. If it has found a female, it goes onto the net and makes it vibrate. The female initially reacts aggressively and chases the male away. The courtship consists of the male jumping over and over and pulling the net. When the female becomes docile, she lets the male onto the net and hangs upside down so the male can insert the palps into the female's genital opening and transfer the seeds. Unlike many other species, the females do not eat the males after mating. The female produces 5 to 6 egg cocoons. The eggs are round and just about the size of a mustard seed. They wear a transparent purple. Mismatches with the closely related red-backed spider ( L. hasselti ) are known.
The Katipo has hardly any natural enemies to speak of. So far only one parasitic wasp species has been observed that feed on the eggs of the katipo.
Danger
Unlike ex. the closely related white widow ( Latrodectus pallidus ) in North Africa and the Middle East or the also closely related southern black widow ( Latrodectus mactans ) in the USA , the red katipo is rarely found in its area of distribution. It is assumed that only 50 populations remain on the North Island and 8 populations on the South Island of New Zealand. The spider is classified as "endangered" in the red list . The decline in populations has to do with the increased use of the coasts by humans, because the Katipo habitats are rarely further than a few hundred meters from the beach. This habitat is endangered by:
- Recreational activities such as the use of beach buggies and off-road vehicles
- Development of cities and settlements
- Expansion of the areas used for agriculture and forestry
- Cultivation of non-native plants that the entire biological communities change
In addition, the Katipo seems to be displaced by a competitor, the imported False Katipo ( Steatoda capensis ). The false katipo prefers similar habitats , but has less specialized demands on their habitat. It provides offspring twice a year, in spring and early summer, while the native Katipo only once a year.
The species was even threatened with extinction. It was protected by the Wildlife Act 1953 in 2010 .
Bite accidents and toxicity
Like all widow species, the Red Katipo is not aggressive. It only bites when it is startled or attacked, first the Katipo goes into a defensive position, if this is of no use, it bombarded it with threads, if it is still irritated it can bite. Females guarding their egg cocoons bite immediately if they are disturbed. The main components of the poison are neurotoxin and alpha-latrotoxin . The bite triggers goosebumps and local pain. You also get headaches , fever , hypertension and tremors . This lasts for 24 hours. However, a visit to the doctor soon can help. In exceptional cases, coma , pulmonary edema , respiratory failure and local skin infections can occur.
Taxonomy and systematics
Latrodectus katipo was described by L. Powell in 1871.
The Katipo was often confused with the Steatoda capensis, which is also common in New Zealand . This led to the name False Katipo (English: False Katipo ) for this species belonging to the fat spiders . A relative of the Katipo, which also belongs to the real widows , is the red-backed spider ( Latrodectus hasselti ) introduced from Australia .
Black Katipo
The black katipo, which was established in 1890 by Arthur T. Urquhart as a subspecies Latrodectus katipo atritus and in 1995 as a separate species Latrodectus atritus , is a color variant of the Katipo. Today it is no longer recognized as a separate species. Apart from the coloration, the black color morph shows no distinguishing features from the red Katipo. Experiments in the laboratory have shown that there are no crossing barriers. Couples, consisting of black and red Katipo, were able to produce offspring together. There is also no molecular biological evidence of a genetic split between the two groups. The color variant is created depending on the geographical latitude and the temperature.
gallery
Overhead view of a groomed female at the Auckland War Memorial Museum
Frontal view of a female
Lateral view of a female
Rear view of a female on driftwood
literature
- Roy Alexander Harrison: Katipo Spider . In: Alexander Hare McLintock (Ed.): An Encyclopaedia of New Zealand . Wellington 1966 ( online [accessed December 15, 2015]).
Web links
Red Katipo in the World Spider Catalog
- Hilary Ann Riordan: Species Profile: Katipo spider. In: Canterbury Nature. Lincoln University, July 2005, accessed November 25, 2015 .
Individual evidence
- ^ A b Brian Patrick: Conservation status of the New Zealand red katipo spider (Latrodectus katipo Powell, 1871) . Science for Conservation, 194, 2002 full text (PDF, English; 262 kB)
- ^ ER McCutcheon : Distribution of the katipo spiders (Araneae: Theridiidae) of New Zealand . In: The New Zealand Entomologist . Vo. 6, No. 2 , 1976, p. 204 (English, online [PDF; 57 kB ; accessed on May 11, 2019]).
- ^ A b L. Forster: The behavioral ecology of Latrodectus hasselti (Thorell), the Australian redback spider (Araneae: Theridiidae): a review. Records of the Western Australian Museum, Supplement 52, pp. 13-24, 1995, p. 23
- ↑ Simon Collins: It's poisonous, but it's ours - DoC seeks aid for spider. New Zealand Herald, January 14, 2005
- ^ Virgil Evetts: The Life Around Us: Enter amazing world of NZ's spiders . New Zealand Herald, January 11, 2008
- ↑ James Griffiths: Katipo threatened by changes to coastal sand dunes. ( Memento of October 11, 2007 in the Internet Archive ) Royal Forest and Bird Protection Society of New Zealand
- ^ L. Powell: On Latrodectus (katipo), the poisonous spider of New Zealand. Transactions of the New Zealand Inst., 3, pp. 56-59, 1871
- ^ AT Urquhart: Descriptions of new species of Araneidae. Transactions of the New Zealand Inst., 22, pp. 239-266, 1890
- ^ Cor J. Vink, Phil J. Sirvid, Jagoba Malumbres-Olarte, James W. Griffiths, Pierre Paquin and Adrian M. Paterson: Species status and conservation issues of New Zealand's endemic Latrodectus spider species (Araneae: Theridiidae). Invertebrate Systematics, 22, 6, pp. 589-604, 2008, p. 599 doi: 10.1071 / IS08027