We are all generally familiar with spiders having 8 legs and usually associated with webs but there are hundreds of different species; some that should concern us and others that cause no harm. There are those few though that give the spider a bad reputation, that will show signs of aggression and whose bites cause be painful and at times fatal. These varieties of spiders can have a serious impact on your home and family – spider control strategies can help remove these.
White-tailed Spider – Lampona cylindrata
The white-tailed spider has a long cigar-shaped, dark grey abdomen with a creamy-white speck on the tip. The legs usually have a brownish hue. A large female may reach up to 20mm in body length, males around 12mm. The female white-tail lays around 80-100 pink eggs in a silk sack and guards the ‘nest’ until the spiderlings emerge. On hatching, the little spiders disperse to find their first meal. The white-tailed spider’s main prey is other spiders. It is an active hunter, stalking the spiders while they are in their own webs. The black house spider in particular is a favorite food item.
White-tailed spiders are found in cool dark areas such as under bark, leaf-litter, etc. It will readily utilise buildings and is common in private houses but is not often seen because the web is small and temporary and the spider is most active at night. They are slow moving spiders which wander great distances looking for prey.
White-tailed spiders are known to bite humans and effects may include local pain, a red mark, local swelling and itchiness; rarely nausea, vomiting,malaise or headache may occur. Ulcers and necrosis have been attributed to the bites, but a scientific study by Isbister and Gray (2003) showed these were probably caused by something else, as the study of 130 white-tailed spider bites found no necrotic ulcers or confirmed infections.
Red Back spiders – Latrodectus hasselti
Red Back spiders favor dark, secluded areas such as crevices and cool bricks. They thrive primarily in temperate zones and are known to be abundant in the South East of Queensland.
Redback females earned their less know name here in Australia of Black widow, for killing and eat males after mating. This behavior does occur, as it often does in many spider species. However, the males are not always eaten and often survive to mate again.
The redback contributes to the balance of the ecosystem by consuming insects such as flies and mosquitoes. It also controls crop pest populations, feeding on pests that defoliate plants, including locusts, grasshoppers, beetles and caterpillars.
Signs of a Red Back Infestation
Red back produce messy, irregular webs. Webs usually are located near ground level and under a protected ledge such as under garden furniture or wood piles. The female with the iconic red hourglass marking also indicates their presence.
Female redback spiders can attack humans when they are provoked. The venom of the redback spider is comprised of neurotoxins that affect the nervous system.
The initial bite of the Red back is only like a pinprick, However, within a few hours extreme pain, cramping and nausea commonly occur. Pain and cramping can spread rapidly to the arms, legs, chest, back and abdomen. Swelling is often experienced in the extremities. In severe cases, victims may experience delirium. Other general symptoms include restlessness, panic attacks, heavy breathing, difficultly speaking and profuse sweating. Symptoms may diminish within two to three days. However, some symptoms may continue for much longer after recovery.
Harm inflicted by the red back spider can be fatal. The young, elderly and those with high blood pressure are particularly susceptible though. Most people recover with medical treatment which can include antivenin injections.
Funnel-webs – Atrax robustus
Funnel-webs are large black spiders with a shiny head/thorax. The body may range from 1.5 cm up to more than 5 cm long depending on the species.
Female funnel-web spiders are stockier than males, with shorter legs and a bigger abdomen, which may be brown or bluish. The eyes are small and closely grouped, the fang bases extend horizontally from the front of the head and the long fangs lie parallel underneath (do not check this on a live spider!).
Funnel-web spiders live in burrows in sheltered positions in the ground, or in stumps, tree trunks or ferns above the ground. Their burrows are lined with a sock of opaque white silk and several strong strands of silk radiating from the entrance.
Funnel-web spider venom is highly toxic and all species should be considered potentially dangerous.
Female funnel-web spiders are long-lived, possibly up to 20 years. They are rarely seen except during tree felling, excavation or landscaping work. Female funnel-web spiders are sedentary and pass their entire lives inside the burrow, only venturing out momentarily to grab passing prey. Prey consists of insects and small vertebrates such as lizards and frogs.
They mainly occur along the coast and mountain regions from Gladstone in the north to southern Tasmania.
Isolated species occur in the Mount Lofty Ranges and Eyre Peninsula of South Australia, and in the mountains of North Queensland. The Sydney funnel-web spider is found within about 100 km of the city.In the tropics and subtropics, they favour rainforests and higher altitudes, but in southern states they also live in drier eucalypt forests and woodlands, as well as snow country.
Funnel-web spiders are found in:
- New South Wales
- the Australian Capital Territory
- South Australia
Pest status and management
Funnel-web spider venom is highly toxic, and all species should be considered potentially dangerous. Males wander at night, especially during or after rain, and may enter houses.
Bites by males of two large species, the Sydney funnel-web and northern tree funnel-web, have resulted in death.
If you are in a known funnel-web area:
- wear gloves when gardening
- know what a burrow looks like
- wear shoes when walking
- if camping:
- close tent flaps
- carefully shaken out before use, any footwear, clothes and sleeping bags left on the ground overnight, as the spiders hide during the day.
First aid if bitten:
- keep calm
- move only if necessary
- if a limb is bitten, apply pressure bandage to bite area and around limb towards heart
- immobilise limb with a splint
- collect spider specimen (even if squashed)
- seek medical aid as soon as possible
Huntsman Spider – Sparassidae
Huntsman Spider also known as Giant Crab Spider Huntsman spiders are large, long-legged spiders and are mostly grey to brown, sometimes with banded legs. Many huntsman spiders have rather flattened bodies adapted for living in narrow spaces under loose bark or rock crevices. This is aided by their legs which, instead of bending vertically in relation to the body, have the joints twisted so that they spread out forwards and laterally in crab-like fashion.
The female Huntsman produces a flat, oval egg sac of white papery silk, and lays up to 200 eggs. She then places it under bark or a rock, and stands guard over it, without eating, for about three weeks. During this period the female can be quite aggressive and will rear up in a defensive display if provoked. Some species will even carry their egg sac under their bodies while moving about. They will then complete her egg sac and pick it up, leaving the silk ground-sheet behind. Incubation periods vary and are probably influenced by climatic conditions.
Feeding and Diet Food consists of insects and other invertebrates. Feeding Habits arthropod-feeder, carnivorous, insectivorous , can invade homes much to the horror of spider haters because of size and hairy appearance. Bites occur rarely and no known causes of fatalities exist. Some species can inflict a painful bite that may result in local swelling, possible dizziness, vomiting, lethargy, irregular pulse, persistent nausea, vomiting, sweating and a welt like mark at the bite area. In young children the effects can be more exaggerated. The possibility of bacterial infection should be considered when treating any bite. Insufficient information exists on the toxicity of these spiders to state whether they are entirely harmless.
Daddy-long-legs Spider – Pholcidae
Daddy-long-legs spiders are easily recognised by their extremely long, skinny legs and small body. They are cream to pale brown and are around 9mm in size. Some species have darker markings on their legs and abdomen. There are 12 species of Daddy-long-legs.
Daddy-long-legs Spiders are found in most urban areas, in particular houses. They make a thin, tangled web in sheltered positions were they are unlikely to be disturbed, such as under furniture, behind doors, in the corner of the ceilings, in sheds, in garages and under decks. Its successful use of these human-made structures has made it one of the most common spiders in Australia. If the Daddy-long-legs Spider is disturbed in the web it responds by setting up a a very fast, spinning motion, becoming a blur to anyone watching. The Daddy-long-legs Spider feeds on insects and other spiders.
The Daddy-long-legs Spider, Pholcus phalangioides, is found throughout Australia. It is a cosmopolitan species that originates from Europe and was introduced accidently into Australia.
Danger to humans and first aid
There is a persistent belief that the Daddy-long-legs Spider has the most toxic venom of all spiders. However, there is no scientific evidence to back this up. The myth probably grew from observations that the Daddy-long-legs Spider will kill and eat a Redback Spider. However, the venom is not actually that potent, even for insects.
It had been thought that the fangs of this spider were incapable of piercing human skin. Recently, however, it was shown that the tiny fangs (about 0.25 mm) were actually capable of piercing human skin in a test done on the US television show, Mythbusters, but the stinging sensation produced was very short-lived. Most reputable sources, including the University of California, Riverside, still say that this species would never be considered as harmful to humans. However, in the unlikely event of a bite from this species, a positive identification of the spider by an expert should be made and medical attention sought if any reaction persists for more than a short time.
After a thorough inspection of your property to determine the extent and type of spider infestation the Termite Choices technician will determine the best method of treating the problem. The most common treatment will usually involve the application of a pesticide dust to the roof void, in and around cavities of external windows and doors etc, and under the building (if access is available). Very safe synthetic pyrethroids are applied to internal skirtings and other likely harborages. The external perimeter walls, eaves, verandahs, etc and spider webs are all also sprayed. Please leave the spider webs for a couple of weeks before removing to allow the treatment to work fully.
If you are bitten by any spider seek medical advice immediately and call a licensed pest controller for advice on control measures.
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