Red-back Spider Latrodectus hasseltii

Spider of Victoria series

Identification

The female Red-back Spider is easily recognised because of her distinctive body colours and shape. The body has a characteristically pea-shaped abdomen and the legs are long and slender. The upper side of the abdomen usually has a broad red stripe, while the underneath always has an hourglass-shaped red mark. Juvenile females have white markings on the abdomen. The female’s body is about 10 mm long, excluding the legs.

A female Red-back Spider

A female Red-back Spider (black and white illustration)
Illustrator: Graham Milledge / Source: Museum Victoria

The male Red-back Spider is much smaller than the female – only about 4 mm – and it is rarely seen. The body is light brown, with no red markings, but there are white marks on the upperside of the abdomen and a pale hourglass mark underneath.

The Red-back Spider makes a web to catch its prey. It consists of a tangled array of sticky catching lines attached to the surroundings.

A female Red-back Spider at its web

A female Red-back Spider at its web
Photographer: Graham Milledge. Source: Museum Victoria

Habitat and biology

This spider is commonly found outdoors around human habitation in such places as rubbish, litter, old tins and containers, under and on steps of the veranda, 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 (e.g. 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 10 pale yellow egg sacs, each with approximately 250 eggs. Females may live for two to three years, and males for about 90 days.

Bites

The bite is highly venomous. It is characterised by intense localised pain around the bite site. Other symptoms may include sweating, muscular weakness, loss of coordination and, in severe cases nausea, vomiting, convulsions, etc. Antivenom is available.

The following description of the signs and symptoms of envenomation is quoted with permission from Australian Animal Toxins, by Struan Sutherland (Oxford University Press, 1983).

‘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 centimetres 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 have developed in some cases. These include 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” are not uncommon.’

Further Reading

Brunnet, B. 1994. The Silken Web – A Natural History of Australian Spiders. Reed Books: Melbourne.

Lindsey, T. 1998. Spiders of Australia. New Holland Publishers: Sydney.

Walker, K. L., Yen, A. L. and Milledge, G. A. 2003. Spiders and Scorpions commonly found in Victoria. Royal Society of Victoria: Melbourne.

Comments (50)

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A, Trinity 4 January, 2010 22:49
Is there anyone you know of that collects the females, if so I have one for them plus egg sack... i'm not keen on killing her as she is a magnificant speciman but need her removed and the CSL don't take them anymore?
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Discovery Centre 6 January, 2010 15:00

Hi. Currently, the Live Exhibits team don’t need any Red-Backed Spiders. Perhaps try contacting the Australian Venom Research Unit at Melbourne University http://www.avru.org/index.html

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julia 11 January, 2010 12:06
thanks for your web page I have been around my front garden only to find hugeamount of red back spiders with these were also small and large whiteback spiders the same as the red backs when I say small I mean smaller than a pin head thankyou for your information and photo
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Geoff Cutter 8 July, 2010 18:02
The first picture of the red-back spider on this infosheet has no red in it.
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Discovery Centre 10 July, 2010 10:58

Hi All, we have been getting a few comments and questions as to why the Red-back spider shown on this infosheet has no red on its abdomen. The reason is that the first image shown is a scientific illustration and is done in black and white.

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Jenn D 21 July, 2010 14:29
I know the top pic was done in black and white but I found a spider that looks almost identical to the pic( black with a white stripe about 2 mm big) I live in ontario but this was the only pic I could find that looked like it. Are there any spiders that resemble the red-back spider with white markings?
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Discovery Centre 23 July, 2010 15:15

Hi Jenn, Museum Victoria's expertise lies more in spiders found in south-eastern Australia. I'm not sure if you are contacting us from Ontario, Canada or Ontario, New Zealand. You could try the Natural History Museum in your country who should have knowledge of local spiders. Or if you can safely obtain an image of the spider please feel free to send it to discoverycentre@museum.vic.gov.au and we will see if we know it.

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Karina 2 August, 2010 08:06
I live in North Carolina USA and I found one of this spiders under my porch, I'm really sure is a female because is a large spider. I am really worried that there may be more of them out there. Anyone knows hot to get rid or kill them?
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Discovery Centre 4 August, 2010 10:21

Hi Karina, probably the best thing to do is to contact your local Natural History Museum in North Carolina and see if they can provide a positive identification for you. Spiders have no interest in people and will not come looking to bite them for no reason. Bites usually occur when people accidentally put their hands in the webs or stand on them.

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Carol S 25 August, 2010 00:10
Can anyone tell me about a spider that has a long narrow body with two distinctive white stripes running down it and long and slender legs.
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Discovery Centre 26 August, 2010 11:08

Hi Carol. Our Victorian Spiders website features a spider gallery and spider search to help identify species local to Victoria. If this doesn't confirm the identification, you can send a specimen or clear photograph to us and we'll attempt to identify the spider for you. Hope this helps!

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Melissa 24 September, 2010 23:07
Hello, I live in Memphis, TN. We have forever those spiders (red and white ones) in my garage. They have gotten as big as 1/2 inch! I know, because I just crushed another one. We see them daily... got used to them... We try to make a "spider check" before our kids touch the toys from our garage. But they don't always listen. (nothing happened so far) The spiders are mostly in the bottom part of our garage door, so that when we open it, they can "fall" in your collar in the neck or hair, freaky, but hasn't happened yet. My trunk door opens right under the garage door. We spray but they are not dying out, because they are way too many in our area. They come back every year. :o( Hope the LORD will spare us with any bites for the next years.
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Giuliano 24 November, 2010 21:54
Recently camping at Lake Albacutya we saw in the drop toilet 9 or so HUGE redbacks. They were at least 15mm from tail to top of head, and 25-30mm in legspan. Their body volume would be 4 times of those I've usually seen. Their red stripe was precisely rectangular as though it had been printed on them. I have seen hundreds of redbacks in Melbourne (I'm a builder) but never this large or with such precise red stripes. Can they vary so much in size and stripe appearance? With thanks.
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Michaela 26 November, 2010 01:23
Hi. I found what lions to be a juvenile redback on my pillow so I sprayed it hoping all was okay. Then I looked on my blanket only to find a small eggsack with about 10 eggs in it, I thought there was supposed to be hundreds? Also could this small redback have laid those eggs? It was about the size of a small finger nail. Not long after however I found another larger but still quite small redback under a broken wall heater. They both resembled the description of a female spider, so all I was wondering is if these small spiders could've laid the eggs and if I should be worried about there being more as they are in my house. Also are bite dangerous for pregnant women
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Jess Smith 2 January, 2011 22:48
hi, I live in Echuca, Victoria and I have a spider hanging from my front veranda. It looks just like a redback spider but much larger and with a stark white stripe. It's body is about 18-20mm and it seems to have a reddish head. There's an egg sac on the pole which looks like a cocoon shape...unlike the redbacks "ball" shape sac. Web is messy with a very long piece of web stretching 1m to another point on the veranda. I've checked your photos and it only seems to match the redback, only white. Hope you can help, the thing scares me :)
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jodie 3 January, 2011 14:48
I was biten by a redback on Saturday, and went straight to hospital with an icepack on it. I was monitored for an hour and the swelling all but disapeared and my BP & Respitory was checked and was fine so was sent home. Later it swelled again, but after ice pack applied it went down. Now its Monday and its red and itcy. I am mostly concerned because Im 9 wks pregnant. The doctor at hospital said it shouldnt affect the baby. Is this right?
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Discovery Centre 5 January, 2011 09:58
Hi Jodie, the Museum is not involved in researching spider venom and it's effects. The best thing to do is keep in touch with your doctor or you may want to contact the Australian Venom Research Unit. Best of Luck.
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Discovery Centre 5 January, 2011 10:08
Hi Jess, if you have a digital camera and can safely obtain some good quality images please feel free to send them to discoverycentre@museum.vic.gov.au and we will try and identify the spider.
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John McC 26 January, 2011 19:43
Carol S on 25 Aug 2019 asked if anyone can anyone tell her about a spider that has a long narrow body with two distinctive white stripes running down it and long and slender legs. I have captured a spider similar to the one described above however after taking some images of the spider and zooming in on the images, I see that it has a white backround with and orange tinge on its oblong body and a thin white line down the centre with circular dots (10) on either side of the line. The colour of the spider legs and sides of its body is black with orange bands on its legs. This spider was found in the same area as a red back. Could it be a male redback spider?
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Discovery Centre 27 January, 2011 16:11
Hi John and Carol - these both sound interesting, but we aren't able to suggest an identification without seeing the spider ourselves - feel free to send any images you have to us via the Contact Us link at the bottom of the page and we will do our best to identify the spider
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Catherine 3 March, 2011 08:40
I live in Berwick Vic and we have a spider that looks like the red back but the body would be the size of a 20cent piece with a white stripe not red. We tried to take a photo but it seems to be nocturnal so we can't get enough light on it. It has a large web spanned between two large bushes ( 80cm in width) any advice on where to find information. Have tried all the common web sites.
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Discovery Centre 5 March, 2011 11:21
Hi Catherine, from your description it may be a Garden Orb-weaver, probably from the genus Eriophora. There are a number of different species in this genus and they can be very variable in appearance. This link is to a website showing one species from this genus and you can see one of the variations is a striped form.   
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Maria 18 March, 2011 11:28
Hi. There is a PhD student in the office next to mine that has a red back in a transparent plastic box. The student argues that the plastic box is a ´good´ environment for this kind of spiders as they live in pretty small places and do not need to hunt. I just feel bad that the poor spider lives under such artificial conditions, is there any possible action to be taken to free the spider? Thanks
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Discovery Centre 19 March, 2011 14:02
Hi Maria, it is likely that as long as the spider has access to food and air it is probably not going to be too concerned about the fact that it is in a container. If you feel strongly about it you will have to have a chat to your colleague and convince him or her to let the spider go outside.
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Caren J 23 March, 2011 10:22
I found a red back spider in my garden this morning. It is first time I saw such spider and so I mistaken it Black Widow. I killed it because I was panicked. I will email the photo to MuseumVictoria later.
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Amanda 21 May, 2011 03:13
I was cleaning in my kitchen and went to pull out a chair at the table where I came upon a Redback Female... As I am researching the spider, I only read that they are Australian. No where have I seen anything about them being native to the United States, much less in Northeast Tennessee! Are these spiders commonly found in the US at all? If so, is Tennessee one of the areas? I am just concerned because I know they are venomous and I have 2 young children who would have not thought twice about capturing this spider and making her a pet if they had found it first!!! It's even more concerning to me that it was IN my house... AT my dinner table!
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Kristin Cox 21 June, 2011 09:22
I walked by my kitchen sink this morning and found a white back female!!! I thought it was posinous... and I guess I was right!
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heather 29 June, 2011 17:24
I was going to my bathroom today and I found this black spider with two white dots, almost dimond shaped. I tried killing it but it got away. I want to know what I need to do I have two kids and a dog plus me and my husband. Please someone help I can't sleep cause I'm worried about it biting me please help.
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Bill 30 June, 2011 19:05
how big can a red-back spider get? I live in Geelong and they are everywhere in my garage and shed but there are also a lot of dead huntsman's. could the red-backs be responsible?
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Discovery Centre 1 July, 2011 11:56

Hi Heather, thanks for enquiry, unfortunately the entomologist needs an image in order to identify the spider you saw at home.  Have a look at the Victorian Spiders website, you may find that you are able to identify the spider yourself

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Richard Collins 18 August, 2011 19:42
Hi there, I was recently cleaning my BBQ cover and noticed two black spiders about 4cm long with red backs (although the back was entirely red and not a red stipe as I have seen with images of red backs).I have a cat that often goes out into our garden - should I be concerned?
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Jenni 28 January, 2012 23:56
Hi, I live in Vermont Vic and had a red back living in my worm farm. Now the red back is gone but I found four spiders that look exactly like it except each one had four white dots in the shape of square on their backs. Does anyone have any ideas what they may be? Unfirtunately I killed them before I thought of taking a pic as they were killing my worms and very fast and scary looking.
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Discovery Centre 30 January, 2012 09:29
Hi Jenni, we cannot conduct an identification without a photograph of the specimen, or the specimen itself. If you kept the dead spiders you are welcome to leave them personally at the Discovery Centre or to post them to us. Please read the identification guidelines on our website for further information.
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Discovery Centre 7 February, 2012 11:17
Hi Sam, the Daddy long-legs spider is capable of killing and eating a Red-back spider, but the presence of Daddy long-legs does not mean that Red-backs will be absent. They may help in keeping numbers down but it is also important to be aware of where Red-backs may establish a web, (under furniture, garden pots, sheds etc) and to then make sure you don't put your hand in it. This link from the Australian Museum offers some tips on minimising Red-back numbers.
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jessica trigwell 19 July, 2012 20:51
My partner has just been bitten but we don't know if the spider is Dangerous or not its completly black with 2 white dots going from Bum to middle with a horizontal line at top of back.. is this spider damgerous?? As my partner now says the area is burning?? Help please
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Kelly 21 February, 2013 11:14
Is there any difference in the strength/potency of a juvenile red back (female) spider bite versus a mature red back spider bite? I was bitten by a juvenile red back a couple years ago and since then have always wondered if they might trigger different reactions, or reactions of varying severity.
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Discovery Centre 23 February, 2013 13:39
Hi Kelly, adult Redback Spiders are capable of producing more venom than juveniles and therefore their bite is more potent. It is also said that adult females are more venomous during the breeding season at the height of summer, when they are producing eggs, than at any other time. Their red stripe also seems to become more obvious at this time, a stronger warning to potential predators. Your reaction to the venom will always be the same, but will vary in intensity depending on the amount of venom injected.

 

Angie 18 March, 2013 12:00
I live in southeast queensland and found a big spider with a large white stripe on its back (similar to red back stripe only white). It was about the size of a Huntsman. Can anyone tell me what it is?
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Elizabeth 5 May, 2013 15:55
Hello, thank you so much for your informative website. I am hoping you might have some thoughts on the spider I encountered in our (light, bright, well trafficked) hallway today. It was black with an elongated abdomen (rather than pea shaped) with a red stripe. There was also a red stripe on its underside. I have seen red-backs before and it didn't look like one, but the red stripe was quite pronounced and in the same place as it would be on a redback. Stupidly, my lizard brain had me smashing it to smithereens before my human brain realised it was unusual and that I should really try identify it. There was no sticky redback web - indeed, the web was quite minimal. On another subject, I've noticed a number of people seeking information about first aid for spider bites. Might I suggest that you put a banner headline advising of best places for people to call to get immediate information about first aid. Thanks Elizabeth
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Discovery Centre 7 May, 2013 14:20

Hi Elizabeth,

Unfortunately without an image it is impossible to provide an accurate ID, however you could try browsing the Spiders of Australia website to try to identify it yourself. A red-back can have the red colouring on both its back and underside, but it usually has a pea shaped body.

SnakesandSpiders.com 8 May, 2013 09:10
I found this site recently that may help in identifying the spider from the previous post (Elizabeth)it also has what a person that has just been bitten needs to do. http://www.snakesandspiders.com/category/spider-bite-first-aid/
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Karen 1 June, 2013 09:12
I was visiting a friend the other day and she told me she had been bitten by a spider that looked like a redback only bigger with a white stripe. She was airlifted to Brisbane Hospital where she flatlined. She was revived by medical staff and thankfully is alive and welltoday. This took place in Hervey Bay QLD. There were many more spiders like that in the local area!!!! Could have been because of extreme drought conditions.
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james 5 June, 2013 10:50
wow!
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Sarah 5 June, 2013 20:52
Hi. My partner,myself and our 4 month old live in one room At the moment, so all our stuff is pretty much crammed in one room. Yesterday I found a redback guarding its nest in the corner of our room. I am worried for the safety of my baby. What is the likeliness there is more that just the one redback?
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Discovery Centre 18 June, 2013 09:55
Hi Sarah, Red-backs can be locally common but this can depend on a number of factors. They like undisturbed dry areas and you often find them under things like outdoor furniture that hasn't been moved for some time or in sheds etc. The Australian Museum's website has some information on how to minimise spider numbers, (including Red-backs) in the home and garden. 
Lilly 20 October, 2013 23:40
Hi. I was vacuuming my house today when I noticed a spider walking along the tiles. I got a tissue and killed it as it wasn't very big. Once I opened the tissue I realised it was a red back spider. I was wondering, since I found it inside the house walking around freely could there be more inside? I have a 2 year old and a 3 month old. I'm worried that my daughter will come into contact with one without me noticing.
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Amanda 25 February, 2014 00:08
Hi. I found a female red back and have decided to keep her as a pet. I have bought a spider terrarium and I feed her live crickets. She seems very happy and I am fascinated by her. I also have a lot of St Andrews cross spiders in the garden. They are such passive and pretty spiders. Would a St Andrews Cross be bothered living in captivity (a spider terrarium like I have for the red back). I wouldn't want to cause it duress and will leave it if you think it's cruel.
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Adhira 14 March, 2014 22:34
Hi, I live in South Africa and have found a black spider in my house with just one white spot under the abdomen. Can anyone help me identify this spider
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Discovery Centre 15 March, 2014 14:55
Hi Adhira, your best bet is to safely take a good quality picture of the spider and contact your Natural History Museum in South Africa to see if you can send it to them for an identification. 
cliff mcmahon 25 March, 2014 23:22
i have a spider brown with a stand out white stripe across its back. this i don't think is a red back because it's built it's web from a tree to the side of my house in the air. you say a red never leaves it's web. this one goes back in the tree of a day and comes out at night. could you tell me what it is thanking you cliff
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