Story: Spiders and other arachnids

Page 6. Other arachnids – spider relatives

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Mites

Mites (Acari order) are found in most habitats where animals exist. They are so small that they are often overlooked. The most abundant mites live in the upper layers of the soil, playing an essential role in the breakdown of organic content.

Pseudoscorpions

Pseudoscorpions are small scorpion-like arachnids common throughout New Zealand. They are usually no more than 5 millimetres long, and are often mistaken for baby scorpions. They are predators, and use their pincer-like pedipalps to catch small insects. Unlike scorpions they do not have stinging tails.

Pseudoscorpions are shy and retiring. Sometimes they hide under stones or foliage, but the best way to find them is to sift leaf litter from the forest floor on to a dish, and then wait for them to move.

Harvestmen (daddy-long-legs)

Harvestmen (Opiliones order) seem the most bizarre of all the arachnids. In fact they are the most harmless creatures, being one of the few arachnid groups that do not use venom.

Although native harvestmen are numerous and widespread in New Zealand, the most common is the introduced European species Phalangium opilio (known as daddy-long-legs), found throughout the country. Because they were so common in English fields during the harvest, the group has become known as harvestmen.

New Zealand has a large number of unique species. They are divided into two groups: the suborder Laniatores (short-legged harvestmen) and the suborder Palpatores (long-legged harvestmen).

Short-legged harvestmen are known for their spiny, knobby bodies and stout, spiny pedipalps which are used for grabbing prey. The long-legged harvestmen have very thin legs, about 20 times the length of their body.

The males in the genus Megalopsalis have black bodies and enlarged, two-segmented chelicerae (mouth appendages) that tower above their body like a crane. The females look more colourful, with yellow, brown, green and red patterns on their bodies. For many years each sex was thought to be a separate species.

How to cite this page:

Simon Pollard, 'Spiders and other arachnids - Other arachnids – spider relatives', Te Ara - the Encyclopedia of New Zealand, http://www.TeAra.govt.nz/en/spiders-and-other-arachnids/page-6 (accessed 19 November 2017)

Story by Simon Pollard, published 24 Sep 2007