Dwarf spider (Ostearius melanopygius)

Kingdom: Animalia
Phylum: Arthropoda
Class: Arachnida
Order: Araneae
Suborder:  Araneomorphae
Superfamily: Araneoidea
Family:  Linyphiidae
Subfamily:  Erigoninae (Dwarf Spiders)
Genus: Ostearius
Species: O. melanopygius
Binomial name: Ostearius melanopygius

Ostearius melanopygius is a cosmopolitan dwarf spider and is found in many parts of the world. This spider may have first been described from NZ before anywhere else. It is often associated with man-made objects which have allowed it to establish itself in many countries from Europe to Africa, Brazil, Hawaii and Australia and New Zealand.
Its uniformly orange-red abdomen is its most distinctive characteristic. There are no other spiders with a similar appearance. An Ostearius melanopygius male has a 2mm body length which is smaller than the female with a 3mm body length. They have a small web and can be found resting under a great variety of surfaces. They are too small to harm humans.

Visit   http://www.bumblebee.org/invertebrates/Araneae.htm  for details of a spiders anatomy.

Photo of Ostearius melanopygius showing its narrow pedicel (waist)
Ostearius melanopygius 3mm body-001.JPG 

Photo of the underside of this spider in its near invisible web. One strand can be seen top left
Ostearius melanopygius 3mm body dwarf spider.JPG

Ostearius melanopygius 4 .JPG

 Ostearius melanopygius 3mm body.JPG 
Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0/