Introduction

An immigrant from Australia, these nocturnal spiders have been recorded in New Zealand since the early 1970s. The common name is the Two spined Spider. The female is about 8 mm in length and when mature has two spines or horns. The females can be commonly found on the undersides of citrus tree leaves during the day The male, lacks horns and is much smaller (2.5 mm - 3 mm in length) and looks very different. So different that it was first thought to be a different species and was named Cyrtarachne setosa

Colouration and Body hair

Bright colours characterize the adult females and various descriptions have been given. 1. The upper surface of the female's abdomen is yellow and olive with two white horn-like ‘spines' that give this spider its common name. Yellow and white bands and some red-brown markings are also visible (Te Papa, New Zealand). 2. The female has two dorsal yellow and cream abdominal spines. The anterior (front) of the abdomen has a broad band of cream and yellow, an upward pointing chevron marking against a red/yellow background of the posterior abdomen.

Mating Behaviour

In an Auckland garden, four males were observed gathering around the female while the female stroked one, which was directly in front of her, with her legs. However no actual transfer of sperm was observed.

The Male

There are many photographs available of the more beautiful females but very few photographs of the much smaller and more difficult to find males. Adult males lack the pair of large abdominal spurs and the bright colours that characterize the adult females (see the ref for a picture of a male)