Spiders

Did you know the male Sydney Funnel-web spider is the world’s most venomous spider?

SPIDERS

Spiders are not insects!

Spiders belong to the class Arachnida along with ticks, mites, scorpions and harvestmen. They have eight jointed legs and their bodies have two distinct segments; Cephalothorax (fused head and thorax region) and Abdomen. Their legs and body may be heavily or sparsely clothed with hair. The male spider is usually smaller than the female of the same species, and its legs are longer than the female’s. Most spiders have three or four pairs of eyes, situated on the sides and top of the cephalothorax, although some have only one or two pairs. 

After fertilisation, the male is often caught and consumed by the female. Female spider produces egg sac which is a mass of silken threads enclosing many eggs. Some spiders leave their sacs near their habitats or in burrows. The eggs hatch inside the sac and the young moult once before emerging. Spiderlings disperse, sometimes by ballooning and obtain their own foods. The life cycle of most web-spinning spiders is less than 12 months, but some ground-dwelling spiders develop more slowly and appear to have a life cycle of many years.

Most spiders are nocturnal. During the day, they are seldom seen, unless they are disturbed in their natural environments. When the daylight fades, spiders become active. They leave their burrows or shelters and go out in search of food, or in the case of web-spinning spiders, construct their webs to snare prey. As day breaks, most spiders seek the safety of their shelters again.

Cannibalism is one the main characteristics among spiders. From a very early age, and more frequently when food is short, they kill and eat one another. Spiders are carnivorous, mostly feeding on living or freshly killed insects and other arthropods (spiders, mites, ticks, centipedes, scorpions). Spiders render their prey immobile by injecting it with venom by means of their fangs. Ground-dwelling spiders have been recorded as killing small lizards and other creatures, which then have their body fluids squeezed and sucked from them. Some spiders are able to survive many months without food, particularly during winter when food is scarce and their own metabolic rate is slowed down.

The venom of the spiders is not necessarily poisonous to animals, but some of them are capable of causing death by introducing an extremely toxic substance into the bloodstream of warm-blooded animals including humans. A spider which inflicts a deep wound may introduce bacteria into the bloodstream, causing septicaemia, but this is rare.

Commonly occurring spiders in Australia

World-wide, more than 40,000 species of spiders have been found which about 2000 of them exist in Australia. Spiders are generally classified into two families; Araneomorphae & Mygalomorphae. 

The Araneomorphae; are the kinds of spiders that you most often see around your homes and gardens. They make up approximately 45% of Australian spiders.  In Araneomorphae, the fangs slope towards each other, giving these spiders many more possibilities than Mygalomorphae, which can only bite top down. Unlike Mygalomorphae, which can live for up to 25 years, most Araneomorphae die after about a year.

The Mygalomorphae; make about 13% of Australian spider species. Their fangs are paraxial (pickaxe) and huge. They have poor eyesight. The mating and feeding habits occur in darkness. They normally live in a burrow and capture their prey at or close to the entrance of the burrow. They have long lives which can be up to 25 years in some species.  

Australian Araneomorphae families include:

• Black & Grey House Spiders

Identification

• The Black House Spider is a dark brown to black velvet textured, plump spider. Females up to 18mm and males up to 9mm.
• The Grey House Spider is a lighter grey colour. Females up to 14mm.

Habitat

• Prefers dry habitats in secluded locations.
• Commonly found in window frames, under eaves, gutters, sheds, toilets and among rocks and bark.
• Electric lights attract their prey (flies, mosquitoes, moths and other insects).
• Spins a lacy and messy web

Venom Toxicity

• The bite is poisonous but not lethal.
• Severe pain around the bite site, heavy sweating, muscular pains, vomiting, headaches and dizziness.
• Seek medical attention if serious symptoms appear.

Distribution

• Southern and Eastern Australia

• Garden Orb-weaving Spider

Identification

• Along with 6 families and 340 species belong to Master Weaver Spiders which make up approximately 17% of Australian spider species.
• Rather large abdomen. Plenty hairs over body surface. Dark to light brown in colour with a pattern.
• Females up to 25mm and males up to 10mm.

Habitat

• Often found in garden areas around the home.
• Spin a large circular web of 2m or more, often between buildings and shrubs to snare flying insects.

Venom Toxicity

• They seldom bite and belong to none-aggressive group of spiders. 
• Not toxic.

Distribution

• Australia-wide, commonly in bushland along the eastern coastal areas.

• Huntsman Spider

Identification

• Buff to beige brown colour with dark patches on the body.
• Flattened hairy body. First two pairs of legs are longer than rear two.
• Females are up to 40mm body length and leg span of about 20cm. Males body length are up to 25mm.
• Because of their big hairy body they look scary to people, but they are shy, timid spiders that can move sideways at fast speed when disturbed. 

Habitat

• Lives under bark during daytime and emerges at night.
• Often enters houses and tends to hide under pictures, curtains and sun visors of cars.

Venom Toxicity

• They are none-aggressive spiders and bite rarely. 
• The bites are not toxic to humans, but might result in localised pain and swelling.

Distribution

• Australia-wide

• Red-Back Spider

Identification

• Females are black with a red strip on their rounded abdomen and their body is approximately 1cm long. 
• Males are rarely seen. Their body is 3-4mm long with less distinct markings.
• Red markings are not always present particularly in those which live primarily in dark areas.
• Females kill males in the process of mating.
• Egg sac contains about 250 eggs.
• Females live for 2-3 years.

Habitat

• They make a messy, tangled web usually in low dry areas.
• Often found in out-houses, outdoor toilets (most bites on male genitals), letter boxes, around barbeques, in rubbish (empty cans), in the subfloor, in rock piles, logs, sheds and other dark areas.
• Electric lights attract their prey (flies, mosquitoes, moths and other insects).

Venom Toxicity

• Highly toxic poison which attacks the nervous system.
• Only a small amount of venom causes headache, nausea, vomiting, abdominal pain, pyrexia, hypertension and in severe cases paralysis and death. 
• Females bite, but Males don’t normally bite. Frequent bites might occur.
• The pain around the bite area can be intensely unbearable. 
• More than 250 cases receive anti-venom in Australia each year.
• No deaths have been reported since 1956 the discovery of anti-venom.
• Seek medical assistance promptly, if bitten. 

Distribution

• Australia-wide

• Saint Andrew’s Cross Spider

Identification

• They have long legs with small cephalothorax. The abdomen striped yellow and brown.
• The male is smaller and paler than female.
• They hang in web with legs in shape of a cross.
• They live for 1 years.

Habitat

• It is a web-weaver species which usually found in summer in garden area around the home.
• It is considered beneficial as it spins a large web to snare flying insects.

Venom Toxicity

• It is a non-aggressive spider and the bite is non-toxic to humans.

Distribution

• Australia-wide

• White tailed Spider

Identification

• The body is cigar-shaped, oval cephalothorax. Grey to black in colour with a white mark on the end of abdomen’s tip.
• Females are up to 20mm in body length and males are tinner up to 12mm.

Habitat

• Prefers cool moist location, commonly found in garden mulch areas. In summer, it often wanders into buildings, particularly bathrooms, to escape the heat.
• They do not live in a permanent web but range nomadically searching for prey (often other spiders).

Venom Toxicity

• Most bites may result in nausea and burning pain followed by local swelling, blistering and itchiness.  
• There’s no scientific satisfaction that the bites of white tailed spiders are the cause of long term necrosis. However, bites combined with associated bacterial (Mycobacterium ulcerans) and/or fungal infection carried on the spider fangs may cause ulcerative skin lesions.  
• In some cases a severe allergic reaction, blistering and ulceration of the skin similar to gangrene has been reported and linked to the bite of this species.  
• Seek medical assistance, if bitten.

Distribution

• Australia-wide, mainly in Southern Australia.

• Wolf Spider

Identification

• Many species of them can be found throughout Australia.
• They are large spiders. The body length of female is up to 25mm.
• They are mottled grey to brown in colour with a distinct Union Jack appearance on their back.
• Females make a round sac which they carry around until spiderlings hatch.
• They move very rapidly when disturbed.
• They live for up to 2 years.  

Habitat

• Most species are wanderers, although some are a ground dweller and build burrows with a trapdoor like lid.
• They are commonly found around the home, in garden areas with a silk lined burrow, sometimes with a lid or covered by leaf litter or grass woven with silk as a little fence around the rim of the burrow.

Venom Toxicity

• Bites are poisonous but not lethal and may result in local pain or itchiness.
• They are non-aggressive spiders, although they bite freely if provoked and should be considered dangerous to children and the elderly.
• Seek medical assistance, if bitten.

Distribution

• Australia-wide.

Australian Mygalomorphae families include:

• Australian tarantulas spider

Identification

• Australian tarantulas are often known as whistling or barking spiders because of the sounds most species can produce.
• They have a large thick body of 6cm in length and leg span of 16cm. The fang is 1cm long.
• They vary in colour from dark chocolate-brown to pale fawn, often with a silvery shine.
• Some species have long hairs on their rear legs.
• They eat other spiders, insects, frogs and lizards.
• Female may live up to 12 years and spend most of her life in her burrow.

Habitat

• Females live in a web-lined burrow in the ground of up to 100cm deep.
• Males often construct silk webs under rocks or logs.
• They may plug their burrows during cold winter months and hot summer days.

Venom Toxicity

• Australian tarantulas spider is a non-aggressive species, but it can inflict a painful bite if provoked.
• Severe illness may result with nausea and vomiting for 6 to 8 hours from bites.
• Seek medical attention if symptoms persist. Collect spider for a positive identification.

Distribution

• Australia-wide. Habitats ranging from rainforest to desert.

• Funnel web spider

Identification

• There are 35 different species of Funnel-Web Spiders in Australia.
• Female’s body is 30mm long and male’s is 25mm. Their overall size is 6-7cm including leg span. 
• They are shiny black in colour with a dark purplish brown abdomen and reddish hairs.
• The males have a spur on the 2nd set of legs.
• Their spinnerets (the silk-spinning organ of a spider on the underside of the abdomen) are distinctly long.
• They live for 3-5 years.

Habitat

• They burrow in moist, cool and sheltered areas under rocks and logs.
• Females live in burrows.
• Males are wanderers. They will wander around during hot humid nights, looking for a mate and wander around the garden or in the home after heavy rain or near earthworks.
• It is also known to enter homes, footwear, clothing and swimming pools where they can survive several days under water.
• The Sydney Funnel-Web Spider is a ground dweller in moist soil areas.

Venom Toxicity

• The Sydney Funnel-Web Spider is one of the world’s most deadly spider.
• Both the male and female Sydney Funnel-Web spiders carry Atraxotoxin which is one of the world’s most dangerous toxins. Males are more toxic than females.
• It is highly aggressive when disturbed or cornered and is able to inflict multiple bites with its hardened fangs.
• The Blue Mountains Funnel-Web and Northern Tree Funnel-Web Spiders are also highly venomous.
• Seek medical assistance promptly, if bitten. 

Distribution

• Generally found in Eastern portion of Australia. 

• Mouse Spider

Identification

• Female body is up to 35mm long. Her legs are shorter than the male’s of the same species.
• Male is smaller and often has a bright red head with elongated fangs.
• They live for 1-3 years.

Habitat

• Females are ground dwellers with burrows of more than 1m deep.
• The male often wanders about during the day on open ground particularly after rain and in search of females.

Venom Toxicity

• Toxic venom. Fangs are strong and bite may be painful.
• They are not aggressive and few biting incidents have been recorded.
• Bites are treated with funnel web spider anti-venom.
• Seek medical assistance promptly, if bitten. 

Distribution

• Australia-wide

• Trapdoor spider

Identification

• There are many different species of Trapdoor Spider in Australia.
• They are brown to dark brown in colour and heavily covered with fine hairs.
• The male has distinct boxing-glove shaped palps (two sensory feelers at the front of head).
• Females are up to 35mm body length and males 20mm.
• They live for 1-3 years.

Habitat

• It is a ground dwellers species with a burrow lined with silk up to 250mm in depth and around 25mm in width. 
• They prefer nesting in drier locations and often plug the entrance of the burrow with a wafer-like silken lid or other objects such as leaves or litter.
• Females live in burrow for up to 20 years.
• Males are wanderers.

Venom Toxicity

• It is a non-aggressive spider and the bite is non-toxic to humans.
• They rarely bite, but if so it can be painful with local swelling.

Distribution

• Australia-wide

Housekeeping Preventative Measures & Control Tips

• Seal off all entry points; inspect and repair any ill-fitting, warped or broken doors and windows, check for and repair rips or tears in screens. This service is provided by BUGZOFF upon request.
• Keep the screens closed all the time if the door and windows are open.
• Seal off the interior/exterior gaps, cracks and crevices. Check for and repair cracks in the foundation, loose siding, skirting boards, floor boards, missing roof shingles, and gaps around incoming utility lines, including pipes, electric and cable wiring. This service is provided by BUGZOFF upon request.
• Eliminate spiders’ food sources; to get rid of spiders, get rid of your other bugs. Spiders eat other insects, so reducing the other insects around your home will reduce their food sources, and spiders will be less interested in hanging around.
• Keep your house clean. The state of hygiene and sanitation in and around buildings influences the likelihood of infestation by insects and consequently spiders; vacuum, sweep and mop regularly, empty trash regularly. 
• Check your boxes, plants, and firewood before bringing it into the home to ensure that spiders are not hitching a ride.
• Reduce or eliminate piles of papers, boxes, bags, and other clutter to reduce potential harbourage areas.
• Keep firewood and logs away from the home. Clean up leaves and other organic debris from around the yard. Trim back any trees and shrubs that contact the home.
• Trim back any trees, shrubs or ivy the contact home walls to eliminate insects harbourage. 
• Reduce the insects that attract the spiders by replacing standard mercury vapour lights with high-pressure sodium vapour or halogen lights. Very simple; yellow lights instead of white ones. Although it is common to place lights on exterior walls near doors, it is better to place the light farther away, using pole lights when possible, with the light shining toward the door for safety.