WHITE TAILed SPIDER
Venom toxicity - the bite of a white-tail spider may cause nausea and burning pain followed by swelling and itchiness around the site of the bite.
Gangrene - In some rare but dramatic cases, a severe allergic reaction, blistering or ulceration of the skin, similar to gangrene, has been reported in the media and linked to the bite of a white-tail spider.
Proven - However, this cause/effect relationship has not been proven conclusively to the satisfaction of some scientific researchers. Bacterial infection of the wound caused by Mycobacterium ulcerans carried on the fangs of the white-tail spider, 
may be a contributory factor.
In any case, first aid and medical attention should be sought, if bitten, as and when any adverse health effects are observed.
Area of distribution - Australia-wide.
Spider Identification - adult size varies 12 to 20 mm in body length - grey to black in colour with a white section on the end of it's tail.
Habitat - prefers cool moist location - commonly found in garden mulch areas. In summer, it often wanders into buildings, particularly bathrooms, to escape the heat.
MORE INFORMATION
Dangerous Spiders in Australia
DANGEROUS SPIDERS