Kingdom: Animalia
Phylum: Arthropoda
Class: Arachnida
Order: Araneae
Suborder: Araneomorphae
Family: Araneidae
Genus: Poecilopachys
Species: Poecilopachys australasia
Common name: Two Spined Spider, Madonna spider ((given the resemblance to the singer's iconic 90s costume)

The nocturnal two spined spiders is an immigrant from Australia and have been recorded in New Zealand since the early 1970s. 
The female Poecilopachys australasia is about 9 mm in length and when mature has two white horn-like ‘spines. Yellow and white bands and some red-brown markings are visible. Large body hairs on an adult female gradually disappear as she approaches maturity. The two spined spider is found in gardens on shrubs, often on citrus trees. By day, the spider will hide under leaves, emerging at night to construct a cartwheel-shaped web.
The egg sac of the two spined spider is spindle-shaped.

The male is much smaller (2.5 mm - 3 mm in length) and looks very different. Adult males lack the pair of large abdominal spurs and the bright colours that characterize the adult females. They look so different that they were first thought to be a different species.

Despite the small size of the two spined spider, it is capable of capturing moths and other insects several times its own size. Two spined spiders are regarded as harmless to humans.

Photo of a mature female. Growing up to 9 mm in length. The male (photograph below) is only 2 mm in length.
Poecilopachys australasia Two spined spider-029.jpg

The tiny male 2 mm in body length.
Male Two-spined Spider Poecilopachys australasia-004.JPG

The photo below shows the vast difference in size between the male and a female.
Female and male Poecilopachys australasia final.jpg

Hemale Poecilopachys australasia Two spined spider-003.JPG

Poecilopachys australasia Two spined spider-023.JPG

Two Spined spider Poecilopachys Australasia .JPG

Poecilopachys Australasia Two Spined spider-002.JPG

Rear view.
Poecilopachys Australasia Two Spined spider-001.JPG  

The underside of a female.
Hemale Poecilopachys australasia Two spined spider-004.JPG

The spindle-shaped egg sac of the two spined spider, Poecilopachys australasia1-Two Spined spiders egg case.jpg

Thanks to Wikipedia for text and Information: