Redback spiders

A redback spider has a red mark on its back.
These spiders are found everywhere in Australia.
Females make a funnel-shaped web.
Redback spiders eat insects.
Their bite is poisonous to people.

Habitat
Redback spiders live in most parts of Australia. The female redback builds a sticky, tangled web in dry, sheltered places. She hides in a funnel-shaped part at the top of the web. Inside logs, under rubble and rubbish, among rocks and in sheds are places where redback spiders can be found. Male redbacks do not build webs.

Appearance and Behaviours
Spiders are not insects, they are arachnids. They have 8 legs (insects have 6 legs).

Female redback spiders have shiny black bodies with an orange or red stripe on the upper abdomen. A female's body is about the size of a large pea. Males are smaller and are brown. Their red markings are often pale. Redback spiders have long, thin legs.

Redback spiders are more common in warmer weather.

Diet
Redback spiders eat insects. Large female redbacks sometimes capture small lizards and will also steal food from the webs of other redback spiders.

Predators
Daddy-long-legs spiders and white-tailed spiders hunt and kill redback spiders.


Life cycle
The male redback spider hangs around near a female's web. He gets the female's attention by showing her his abdomen. This can be dangerous because if she mistakes him for prey she will squirt digestive juices onto him and try to eat him. Many males are eaten as they mate!

Once the female has mated, she can lay several batches of eggs. She produces about 10 white egg sacs, one every 3 weeks or so. Each sac contains approximately 250 eggs. These sacs hang in the web. When they hatch, the tiny, pale-green spiderlings balloon away on silk threads to another place suitable for a nest.

Female redbacks live for about two to three years. Males live for about six or seven months.

A Relative
The Black Widow Spider of the United States is a close relative of the Redback spider.

Danger to humans
Only the female redback bite is dangerous. The poison can make people sick with sweating, vomiting and pain. There is an antivenom for redback bites. No person has died from a redback's bite since the antivenom was discovered.


Redback spiders are not aggressive, and females rarely leave the web. However caution is advised as their bite is very poisonous and could be very dangerous, even fatal, for children or the elderly.

After a bite, the there may be little pain for five minutes, but then it becomes very painful.

First Aid
Anyone bitten by a redback spider should seek medical attention. An antivenene is available and very effective.

Do not bandage the bite, but apply iced water and take simple painkillers.

The best First Aid is prevention!
Manage redback spiders by learning to recognise their webs and the kinds of places they live. Get an adult to destroy the nest and egg sacs. Spraying has only a temporary effect, and kills the natural predators that kill redbacks.

Find more information here:
http://www.austmus.gov.au/factsheets/redback.htm


If you use any part of this, write the source in your bibliography like this:
Redback spiders (2005). [Online], Available:www.kidcyber.com.au

Back to animals

updated August 2007