Many people associate Australia with Spiders and many people avoid this beautiful country due to the fear of their venomous bite. However, no mortality has been registered due to a spider bite in Australia since 1979. There was one suspicious death following the bite of a Redback spider back in 2016 but the circumstances remain unclear as to the treatment that followed.
The Australian fauna contains so many types of spiders, ranging from small, very colorful and harmless specimens such as peacock spiders (genus Maratus) to gigantic but relatively quiet Huntsman (Sparassidae family) to the Golden silk orb-weaver (genus Nephila).
Of approximately 10,000 species present in Australia (around 2700 officially described) only a few families of these spiders are potentially dangerous to humans. The vast majority are in fact harmless and it is known as a “dry bite” or “blank bite” when a spider bites but does not inject venom.
The two most problematic groups are those commonly known as the Funnel web spiders (which includes 3 kinds of spiders) and the Redback spiders. Then come the Mouse spiders who can also cause serious envenomations although a bite has never been lethal.
Where to find spiders in Australia?
Due to the diversity of arachnids in the country, you can find spiders everywhere in Australia. Some families, however, are more localised than others. Although, depending on their way of life there is still very little chance of crossing them.
The funnel web spiders prefer temperate and humid climates and they live most of the time in burrows. In Australia they are only found in the southeastern part of the country, from South Australia to Queensland via Victoria, New South Wales and Tasmania. You won’t find them in the dry and arid zones.
On the other hand, huntsman and wolf-spiders are found all over the country. They like to wander at night, so this is when you are most likely to cross them. Redbacks also adapt to many climates. They never leave their canvas and generally weave them in dry areas, away from daylight.
Funnel Web spider
The funnel web spiders are native of Australia, they belong to the family of Atracidae which includes 3 genera. The 2 most infamous (and the most dangerous) belong to the genus Hadronyche (31 species) and Atrax (3 species). These two genera contain the most dangerous species of spiders. By a curious chance of evolution, their venom is particularly active on primates. Interestingly, they are almost harmless to mammals like dogs or cats.
The most dangerous of these species is the Atrax robustus, known as Sydney funnel web spider. As the name describes, this species lives more or less within a 100 km radius of Sydney. The venom of the male is about 5 times more toxic than that of the female and during the spring and summer, the males leave their shelters in search of a female during the night. That is why many people in Sydney’s suburbs find them in and around their homes at this time. They can even survive in water, often up to several hours if they inadvertently fall into a pool for example. Atrax robustus spiders were to blame for 13 deaths prior to the invention of antivenom in 1980.
These spiders prefer moist, dark places like forest floors.
Their habitat differs depending on the species. The burrow can be found on a decaying tree for example, but also found on the edge of a rock on the ground. The spider forms a kind of silk funnel usually surrounded by streaks that serve as “alarms” so when prey lands, they vibrate, alerting the spider that lunch has arrived. Note that other types of spiders such as Trapdoor spiders also use funnel burrows for this reason.
They are “mygalomorphae” spiders, generally black or dark brown and very shiny in appearance. Depending on the species they can reach between 7 and 8 cm in length with females being larger than males.
One of the peculiarities of funnel web spiders is their aggressive reaction when they feel threatened. They instantly adopt a “warrior” posture where they raise their 2 pairs of front legs showing off their hooks (chelicères) while letting drops of venom escape as a threat.
The Redback (Latrodectus hasselti) is somewhat of an Australian icon! There are about 2000 Redback bites reported every year. Even though she possesses a very powerful venom with a lot of unwanted and painful symptoms, there have not been direct and proven moralities following a bite for a very long time. Antivenom has been around since 1956. Note, only females are dangerous, males are much smaller and even if they have venom they are considered harmless.
The Redback belongs to the genus Latrodectus, which includes a multitude of species around the world including the American black widow. There is even a species present in Europe known as the Mediterranean black widow or the Malmignate (Latrodectus tredecimguttatus) as it is known in Europe.
They can be found in most Australian terrain though prefer to weaves their canvas in hidden and protected places. That’s why they are so common around homes and are most likely to be seen indoors. They are particularly fond of the dark corners of garages, attics or outside homes. These spiders are nocturnal so will stay sheltered at the bottom of their nest during the day then patiently stay on their web while waiting for the arrival of prey at night.
Females are small black or dark brown with a very distinctive red-orange line on the back of the abdomen. They also have an orange-red mark on the ventral part of the abdomen. Young females are brown instead of black and in addition to the red line, they may also have white lines on the abdomen but as they age, this turns black and the white lines disappear.
The Huntsman spider species belong to the Sparassidae family. They are the nightmare of all arachnophobes in Australia. This is because they can be extremely large depending on the species and have very long legs. Their venom is not dangerous to humans but because of their size, the bite can still be very painful. Despite their size, they are capable of slipping into small nooks and crannies and have been the cause of car accidents in the past after surprising drivers by hiding behind the sunshade or running on the dashboard! These spiders are not at all aggressive and they will only bite to defend themselves if provoked.
The Huntsman is found all over Australia.
They are nocturnal and spend all day hidden in crevices, behind the bark of the trees or in the dark recesses in houses. At night, they come out of their shelters to start hunting.
The leg length of these spiders are disproportionate to their body – heightening their alarming appearance. Depending on the species, they can be brown, grey or greenish shades!
The largest specimens are found on the east coast, and some can reach about twenty centimetres from one end to another!
Even though their venom is not considered dangerous, people may become infected with a bite because of the bacteria on the spider’s hooks.
White tailed spider & Daddy-long-legs
In Australia, white-tailed spiders (Lampona cylindrata and Lampona murina) are considered dangerous. It is believed that their venom could induce skin infections such as necrosis. On the other hand, however, more and more studies tend to prove that there is no direct link between the venom of its spiders and the possible reactions following bites. Although they may be impressive and a popular belief surrounds them about being dangerous they are actually extremely rare.
Finally, the biggest urban legend about spiders in Australia, the so-called danger of “Daddy-long-legs” spiders (Pholcus phalangioides.) It is believed, that they are the most venomous of all spiders, simply because they feed on the Redback! These are the famously common spiders that can be found in the corners of most homes around the world, but are in fact harmless to humans. The fangs of this spider are incapable of piercing human skin. In fact, they are handy to have in your home as they are your biggest allies against mosquitoes!
As mentioned the spiders in Australia are so diverse, it’s impossible to discuss them all in this one article. It is likely that when travelling in the country you will come across at least one. The most common are certainly the wolf spiders, which are smaller but similar to the huntsman or the impressive golden silk orb-weavers which are constantly in the center of their very large golden silk webs. There are also amazing species like the tiny and colorful peacock spiders who perform a unique, seductive dance:
Keep in mind that Redbacks can also be very common in some places. Do not panic, however, as bites are rare. If by chance you are bitten by one of them and you think you are a victim of envenomation, seek medical help immediately and you will recover quickly. Note, like most medical expenses in Australia, this kind of treatment can be very expensive for a simple bite so for this reason (and many others) ensure you have travel insurance before your trip!
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