Spotted Ground Swift Spider

Nyssus coloripes

Nyssus coloripes is one of the fastest spiders in Australia. While running, it waves its two (often orange) forelegs above its body, mimicking the antennae of a wasp.
Orange-legged swift Spider - female (Nyssus coloripes) A fast moving attractive spider with black cephalothorax and abdomen, black and white banded hind legs and orange front legs. The body had white patterns along the sides, a median white line on the cephalothorax and broken white pattern along the midline of the abdomen.
Its behaviour and erratic movements are a mimicry of the pompilid wasp (spider hunters) - the orange legs move up and down like the orange antennae of the wasps. 
This species is seen throughout mainland Australia and Tasmania. Australia,Geotagged,Nyssus coloripes,Spotted Ground Swift Spider,Spring,orange-legged swift spider

Appearance

Male and females are identical and their length varies between 5 and 7 mm. The front legs can be orange, the rest of the body is usually black with white markings. Colour variations, including gold or yellow spots, depend on location and habitat.

Naming

Synonyms:
Supunna picta

Common names:
Wasp-mimicking Swift Spider, Spotted Ground Swift Spider, Fleet Footed Spider, Painted Swift Spider

Distribution

All states of Australia including Tasmania, New Zealand (introduced)

Status

Not at risk

Behavior

The behaviour is clearly mimicry of some pompilid wasp (e.g., Auplopus, Priocnemis) which has orange front legs and black back legs. The sudden movement with trembling front legs, stopping and restarting in erratic directions across the ground, are the same kinds of actions noted by spider wasps (Pompilidae) hunting spiders to provision their nest (Raven, 2015)

Habitat

A few strands of silk behind bark, or other objects, may be a sign of its retreat. It sometimes enters houses where it can be seen in sunny places, running swiftly in bursts up walls and windows.

Food

This spider feeds on ground dwelling insects and spiders.

References:

Some text fragments are auto parsed from Wikipedia.

http://ednieuw.home.xs4all.nl/australian/sacspiders/sacspiders.html
http://www.arachne.org.au/01_cms/details.asp?ID=1807
http://bie.ala.org.au/species/urn:lsid:biodiversity.org.au:afd.taxon:84188b72-3a13-4a2a-b1d1-be8877103162#
Taxonomy
KingdomAnimalia
DivisionArthropoda
ClassArachnida
OrderAraneae
FamilyCorinnidae
GenusNyssus
SpeciesNyssus coloripes
Photographed in
Australia