CPR First Aid

Is the Redback Spider as Deadly as the Black Widow?

The redback spider is a relative of the black widow spider. Redbacks although their venom are potent, they aren't as deadly as black widows. Read on to find more.

While both arachnids, the redback spider and the black widow are poisonous and need antivenom, there is a common misconception that the redback spider is as deadly as the black widow. In reality, while both spiders can cause serious health effects, the black widow is much more venomous. Let’s take a closer look at these two species of spiders, their respective dangers, and how to provide first aid instructions for anyone who may come into contact with either one and suffer from severe pain.

How to Identify a Redback Spider?

The redback spider (Latrodectus hasselti) is a species of venomous spider indigenous to Australia. The adult female redback spider is easily recognised by her slender legs, black body with a prominent red stripe on her abdomen and an hourglass-shaped marking on her lower back. Male redback spiders have a much shorter body length than females. They are often grey or brown. Much like other spiders, they have two small appendages called the palp which they use for reproduction. Young ones have white markings on the upper side of the abdomen.

The Australian Museum have studied and collected these spiders, making them a great source for spider facts and information. Many have turned to Lyn Forster’s “The behavioural ecology of Latrodectus hasselti” study for many insights on the redback spider.


"Redback spider: Female black with red stripe, hourglass mark; males smaller, grey/brown."

Where Are They Usually Seen?

Redback spiders are found throughout Australia. This includes Adelaide CBD, Sydney, and also seen as a Western Australian spider. High concentrations are found in both rural and urban areas. Apart from Australia, it is also seen in New Zealand (the L. katipo), Europe, and Africa.

Their habitats include the particularly common gardens, sheds, garages, and outside toilets. Males usually do not spin spider webs. The female’s web and traplines are built in sheltered locations such as leaf litter, logs, rocks, or crevices. Retreat areas located in the wilderness should take care with these spiders.

For food, these spiders thrive on small lizards and trapdoor spiders. The females also participate in prey-stealing quite often, taking food from other spider webs. They are also capable of capturing larger animals.

Redback spiders in Australia: common in urban and rural areas, often found in gardens and sheds.

Redback Spiders are Venomous

The redback spider is considered to be of medical significance due to the potency of its venom. Bites from these spiders are potentially life-threatening. It can cause significant pain and suffering, respiratory failure and sometimes, death. The venom itself works directly on a person’s nerves, depelting neurotransmitters in the target.

Cases of Redback Spider Bites in Australia Each Year

Bites usually occur when the spider is disturbed or feels threatened. There are around 2,000 cases of redback spider bites recorded each year. Most of these bites occur in the warmer months, with October to April being the peak period.

Redback Spider Bite Symptoms

Redback spider symptoms can vary depending on the severity of the bite. Signs and symptoms of a spider bite infection include:

Reddening of the skin

This is one of the most common signs of a spider bite infection. The area around the bite will become red and inflamed.


Another common sign of a spider bite infection is swelling. The area around the bite will begin to swell and may even blister.


Many people bitten by a spider will experience pain at the site of the bite. The pain may range from mild to severe, lasting for a few hours or days.


Once the venom from the spider’s bite begins to work its way into the skin, it can cause the skin to crust over. It is a sign that the infection is getting worse and needs treatment.


A fever can be another sign of a spider bite infection, especially if the bite is on the face or neck. If you have a fever, you must see a doctor immediately.

Nausea and Vomiting

Nausea and vomiting are two more signs of a spider bite infection. If you experience either of these, it’s important to see a doctor as soon as possible.

Blood Pressure Changes

The venom is also said to increase a person’s blood pressure and a quickened heart rate.


In rare cases, spider bites can cause seizures. If you experience a seizure, seek medical attention immediately. Call triple zero (000)

Reaction to the Venom

In some cases, the venom from a spider bite can cause a serious reaction, even if you’re not allergic to it. Symptoms of a severe reaction include:

If you experience any of these symptoms after being bitten by a redback spider, get medical help immediately. Sometimes, bites from this spider can be fatal if left untreated.

First Aid for The Redback Spider

Despite their small size, redback spiders are venomous, and their bites can be dangerous to humans. Here are the first aid practices for redback spider bites.

  1. Follow DRSABCD
  2. Apply a cold pack to the affected area to help reduce swelling.
  3. Keep the affected person calm and still to prevent the spread of venom.
  4. Seek medical help immediately.

Adelaide first aid training is available at CPR First Aid (RTO NO 21903), a leading provider of compliant and accredited courses all over Australia.

How is the Black Widow Spider Different?

A black widow spider (a common name for different species) is a venomous spider that is found in warm climates throughout the world. For instance, the genus Latrodectus, under the family Theridiidae (which may have a pair of red spots or have no marking at all) is seen as a European spider (the L. tredecimguttatus). It also lives in North America, Texas, Florida, Mexico, Asia, Australia, Africa, and much of South America.

A L. mactans species (southern black widow) was pictured in New Orleans, Louisiana (North American area). There are also two species of black widow spider in Canada, the western black widow and the northern black widow. National Geographic’s website contains pictures of these spiders.

Such species have bodies with a red hourglass design, most male spiders have a pair of red and white stripes on the shiny black sides of the abdomen.

The female black widow venom is notorious and can be dangerous to humans and is known to be 15 times stronger than a rattlesnake ’s venom. It contains neurotoxins that negatively affect the nervous system.

Female black widow spiders are not aggressive and typically only bite humans in self-defence especially when they are protecting their egg sacs or spiderlings. However, their bites can cause serious health problems, so it is crucial to know how to handle and treat a bite victim.

Such species feed on insects by administering digestive enzymes to their bodies. On the other hand, they are also hunted by birds and wasps.

Venomous black widow spider in various warm climates worldwide, like Latrodectus mactans in New Orleans.

Symptoms of a Black Widow Spider Bite

A Black widow spider venom may cause the following signs and symptoms:

  • pain at the bite site
  • swelling
  • redness
  • muscle cramps
  • nausea
  • vomiting
  • sweating
  • difficulty breathing

First Aid for a Black Widow Spider

If a black widow spider bites you, call 000 immediately. In the meantime, there are some first-aid steps that you can take to help ease the pain and swelling.

  1. Apply ice to the area of the bite to help reduce swelling.
  2. If possible, elevate the area of the bite to help reduce swelling.
  3. Gently clean the area of the bite with soap and water.
  4. Take over-the-counter pain medication such as ibuprofen or acetaminophen to help ease pain and swelling.

Envenomation may be applied.

How to Prevent Spider Bites?

The best way to prevent redback spider bites is to avoid contact with the spiders. Wear long pants and long-sleeved shirts if you must work or play in areas where redbacks are present. Be sure to inspect your clothing for spiders before putting it on. Inspect your shoes and any other gear you will take into the area.

Keep an eye out for webs, and shake out any clothing or gear sitting in an area where spiders are present. If you see a spider, do not approach it or try to kill it. Instead, call a professional to remove it.

How to Get Rid of Redback Spiders?

There are a few things you can do to get rid of redback spiders:

  • Remove any food sources they may be feeding on, such as insects or other small animals.
  • Keep your home clean and free of clutter where they can hide.
  • Use a vacuum cleaner to remove them from their hiding places.
  • Seal any cracks or openings in your home that they could use to enter.
  • Apply insecticides around the perimeter of your home and in areas where they are commonly found.

In conclusion, one of the unforeseen incidents that could happen in Australia would be spider bites. People of all ages should be aware of the toxicity of venoms from redback and black widow spider bites. The best practices are avoiding these spider species and calling a professional to get rid of them.

However, if the situation calls for it, training in emergency care can be highly beneficial. Give CPR First Aid a call to get more information about first aid courses at Level 1/174 Gilles St, Adelaide 5000 . We’ll match you with the best certification class tailored for your needs in a convenient training location as per request, taught by fully qualified trainers.



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