Redback spider, alternately known as the Australian black widow, originated in the Southern or Western parts of Australia. Though, at present, it is found throughout Australia and even in New Zealand. It is considered one of the most venomous spiders, with its bites resulting in severe consequences, including fatality.
Size: Female redback spiders are around 0.39 inches (0.99 cm), and males are smaller, measuring 0.11-0.15 inches (0.27-0.38 cm).
Color: Females have a black abdomen with red or orange vertical stripes from top to bottom. The underside of the abdomen has red streaks, resembling a silhouette of an hourglass. The cephalothorax is black. Male spiders have a pale brown body with white markings on the abdomen and an hourglass-like pattern on the undersides.
Other Characteristic Features: The spiders have eight eyes and small fangs. Their chelicerae have venom glands attached to them.
Female spiders make a round and white egg sac and lay around 250 eggs per clutch.
The hatching takes around eight days, but spiderlings stay within the sac for 7-11 days more. During this time, they eat the yolks and go through the molting phase. They finally come out in spring or summer. They can attack each other for cannibalism. They live in their mother’s web for a while and then start building their silken thread. Afterward, they are blown away by the wind, a process known as kiting or ballooning. They have a grey body with some dark spots.
Female spiders make webs every night in no particular pattern with strong and fine silk. The front part of the web is for retreat, both for the spider and eggs in the future. The part that is used for catching prey has sticky silk entrapment. The spiders make the web in between two layers of a surface to secure it.
These spiders are venomous, and their venom comes from the holocrine venom glands. Male spiders are less capable of injecting venom into humans than females. The venom has enzymes, toxins, alpha-latrotoxin, and neurotoxin. Bite from the spider is extremely painful, and it needs medical supervision immediately, lest it could be fatal. To treat such conditions, there is a certain antivenom. Symptoms of a redback spider’s bite are vomiting, nausea, and sweating.
Even for pets, like cats and dogs, the spider bite is dangerous. The venom affects cats more than dogs.
| Other Names | Australian black widow |
| Distribution | Found throughout Australia, New Zealand, countries of South Asia, Belgium, England, Iran, and the United Arab Emirates |
| Habitat | Shrubs, tree hollows, and logs |
| Web Type | Irregular web |
| Venom Fact | Highly venomous |
| Diet | Insects, trapdoor spiders, and snakes |
| Predator | Giant daddy-long-legs spiders, cellar spiders, black house spiders and wasps like redback spider-hunting wasps, and mantid lacewings |
| Lifespan | Females: Around 3 years Males: Around 3 months |
Image Credits: Media.australianmuseum.net.au, Biomedicalsciences.unimelb.edu.au, Media.apnarm.net.au, Images.theconversation.com, Ak0.picdn.net, I.pinimg.com, Thesun.co.uk, Nnimgt-a.akamaihd.net
Redback spider, alternately known as the Australian black widow, originated in the Southern or Western parts of Australia. Though, at present, it is found throughout Australia and even in New Zealand. It is considered one of the most venomous spiders, with its bites resulting in severe consequences, including fatality.
Size: Female redback spiders are around 0.39 inches (0.99 cm), and males are smaller, measuring 0.11-0.15 inches (0.27-0.38 cm).
Color: Females have a black abdomen with red or orange vertical stripes from top to bottom. The underside of the abdomen has red streaks, resembling a silhouette of an hourglass. The cephalothorax is black. Male spiders have a pale brown body with white markings on the abdomen and an hourglass-like pattern on the undersides.
Other Characteristic Features: The spiders have eight eyes and small fangs. Their chelicerae have venom glands attached to them.
Female spiders make a round and white egg sac and lay around 250 eggs per clutch.
The hatching takes around eight days, but spiderlings stay within the sac for 7-11 days more. During this time, they eat the yolks and go through the molting phase. They finally come out in spring or summer. They can attack each other for cannibalism. They live in their mother’s web for a while and then start building their silken thread. Afterward, they are blown away by the wind, a process known as kiting or ballooning. They have a grey body with some dark spots.
Female spiders make webs every night in no particular pattern with strong and fine silk. The front part of the web is for retreat, both for the spider and eggs in the future. The part that is used for catching prey has sticky silk entrapment. The spiders make the web in between two layers of a surface to secure it.
These spiders are venomous, and their venom comes from the holocrine venom glands. Male spiders are less capable of injecting venom into humans than females. The venom has enzymes, toxins, alpha-latrotoxin, and neurotoxin. Bite from the spider is extremely painful, and it needs medical supervision immediately, lest it could be fatal. To treat such conditions, there is a certain antivenom. Symptoms of a redback spider’s bite are vomiting, nausea, and sweating.
Even for pets, like cats and dogs, the spider bite is dangerous. The venom affects cats more than dogs.
| Other Names | Australian black widow |
| Distribution | Found throughout Australia, New Zealand, countries of South Asia, Belgium, England, Iran, and the United Arab Emirates |
| Habitat | Shrubs, tree hollows, and logs |
| Web Type | Irregular web |
| Venom Fact | Highly venomous |
| Diet | Insects, trapdoor spiders, and snakes |
| Predator | Giant daddy-long-legs spiders, cellar spiders, black house spiders and wasps like redback spider-hunting wasps, and mantid lacewings |
| Lifespan | Females: Around 3 years Males: Around 3 months |
Image Credits: Media.australianmuseum.net.au, Biomedicalsciences.unimelb.edu.au, Media.apnarm.net.au, Images.theconversation.com, Ak0.picdn.net, I.pinimg.com, Thesun.co.uk, Nnimgt-a.akamaihd.net
Sahana Kanjilal on September 26, 2019.
Dr. Watuwa James
© 2023 (Spider Identifications). All rights reserved. Reproduction in whole or in part without permission is prohibited.
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