Red-back Spider
Latrodectus hasseltii

Family: Theridiidae  ID: Thorell, 1870

Habitat and Biology
This spider is commonly found outdoors around human habitation, in such places as rubbish, litter, old tins, containers, under and on steps of the verandah, and on or under the seats of outdoor toilets! Storage stacks and disused furniture will encourage the breeding of this spider. In nature, it occurs under logs, bark, sides of rocks, etc. As the spider rarely leaves its web, humans are not likely to be bitten unless some part of the body (eg. the hand) is put into the web. Always check before moving items that have been stored outdoors for some time. Wear gloves when cleaning up rubbish areas. The female produces up to ten pale-yellow egg sacs, each with approximately 250 eggs. Females may live for two to three years, males about 90 days.

Male: Usually without red markings. Body light brown with white markings on upperside of abdomen, and pale hour-glass marking on underside.
Female: Body and legs dark brown to black. Characteristic red hour-glass marking on underside of abdomen, usually also with broad, red stripe on upperside of rear half of abdomen; red stripe sometimes broken. Juveniles recognised by white markings on abdomen.

Characteristic pea-shaped abdomen, long slender legs, males much smaller than females. For more information, see the Queensland Museum Spider Page.

Body Length
Male: 4mm
Female: 10mm

Web type
Tangled web with sticky catching attached to substrate.

The bite is highly venomous and characterised by intense localised pain at and around the bite site. Other symptoms may include sweating, muscular weakness, loss of co-ordination and, in severe cases nausea, vomiting, convulsions, etc. The following envenomation description is from The Australian Animal Toxins by Struan Sutherland, 1983. Signs and Symptoms: The normal sequence of events after a bite is as follows. A sharp pin-pricking pain is almost invariable. Usually the bite site becomes hot, erythema and oedema develop rapidly. Localized sweating often occurs. The swelling is generally limited to an area of several cm in radius from the bite site; occasionally it is extreme. Approximately five minutes after the bite, intense local pain commences and increases in severity and distribution. In most cases, pain is the predominant symptom; the patient is sometimes distraught and even hysterical because of its intensity. Movement of the affected limb often significantly increases the pain. About thirty minutes after the bite, pain and swelling are often experienced in the regional lymph nodes. If abdominal pain occurs, it is worse when the lower extremities or genitals were bitten, probably due to lymph node involvement. Sometimes severe pain develops in parts remote from the bite site, for example, in an opposite limb or the opposite side of the trunk. Uncommon, even bizarre, signs and symptoms developed in some cases. There were tetanic spasms, tingling in the teeth, swelling of the tongue, bite site infection, convulsions, excessive thirst, severe diarrhoea, anaphylactic reaction to the venom, blotchy rash on face, haemoptysis, dyspnoea, dysuria, severe trismus, persistent anorexia, periorbital oedema and/or conjunctivas. Patchy areas of what was described as `bizarre sweating' were not uncommon. For additional information see