Redback spiders, also known as jockey spiders, are members of the widely distributed Latrodectus genus, or widow spiders. Redback spiders are distributed throughout Australia, and have adapted well to an urban environment. They are common in sheds and garages, under houses, in industrial areas and in outside toilets. The venom acts directly on the nerves, resulting in release and subsequent depletion of neurotransmitters.
Juvenile redback spider showing incomplete red stripe on abdomen.
Bites by this spider represent the commonest envenomation requiring treatment in Australia, particularly over the summer months. More than 250 cases receive antivenom each year. Perhaps ten times as many cases are mild or unrecognized and do not receive antivenom. Males appear to be more frequently affected than females, probably in relation to occupational exposure. The spider is usually easily identified by the presence of a red, orange or brownish stripe on its abdomen.