Arachnid Facts Katipo

In the Maori language Katipo means night stinger, and it is the name given to a species of poisonous arachnid. The katipo is the only venomous creature in New Zealand and a bite will give rise to a condition known as latrodectism.

Shortly after the bite, a person’s blood pressure will increase. A general feeling of weakness and aching within the muscles may be experienced along with abdominal cramps and excessive perspiration. In severe cases, seizure, tachycardia and coma may become apparent. Bites are rare, and although they are known to have been fatal, a death has not been reported for more than a century. For this reason, New Zealanders have become much less fearful of the katipo. At least they were up until May of the year 2010 when a Katipo bit the penis of a 22 year old Canadian tourist as he sunbathed naked. Although the victim became ill, like all human recipients of katipo bites, he was treated with anti-venom medication and therefore he fully recovered.

Physical characteristics

Related to the Australian red back spider and the North American black widow, the Latrodectus Katipo is native to New Zealand and it exists only in this country. It is a small spider. The body of the mature female measures approximately 6 – 8 mm. The leg span can reach 32 mm. As with most species of arachnid, the male is smaller at around 4 mm in length. Only the female of this species is physically able to bite a human. The male cannot achieve it because the fangs are too small.

The female has a globular shaped abdomen that is black and shiny in appearance. An orange or red stripe in a diamond chain pattern is apparent along the center of the body.

The abdomen of the male is the same shape and comprises of patches of white with black streaks at the sides. As with the female, the colorful characteristic stripe runs down the back.

Habitat

The katipo lives within the sand dunes mainly along the coastal areas of the southern half of New Zealand’s North Island, and on the northern half of the South Island. It may also be found in places where the dunes stretch inland. This species will spin its webs among the dune vegetation, under driftwood, across the stones, and within human trash such as empty cartons and cans.

Hunting

Capable of trapping and killing insects far larger and heavier than its own body, the katipo will usually prey on beetles, flies, moths, and other arachnids. The hunting behavior of the male and the female is more or less the same, although the female tends to be more ferocious due to her larger size.

Once the prey becomes trapped in the katipo’s web, the spider spins more silk and throws it across the victim. The prey is killed only when it is immobilized. It is then kept within the web until the katipo is ready to eat. It is not unusual to see more than half a dozen insects hanging in the katipo web at any one time.

Breeding

Unlike some other species of arachnid, the female very rarely eats the male after mating. The egg sacs, each measuring approximately 12 mm in diameter will appear in November or December. The female will make between one to three egg sacs and will lay between 70 – 90 eggs in each. She will hang the sacs within the web and continue to protect them by spinning more silk over and around them. The female closely guards her egg sacs and after around six weeks, and during the months of January and February the spiderlings begin to hatch.

The katipo is now an endangered species of arachnid. Only a few thousand remain and most live on New Zealand’s North Island. The greatest threat to this spider is human activity. The development of housing projects in sand dune areas, off road vehicles and the removal of driftwood are likely to further threaten the existence of the katipo.