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RedBack Spider



A1 Pest Control

Specialising in spider treatment in Sydney, Australia. We also control termites, cockroaches, and low toxic pest control

We specialise in low toxic treatments in Sydney, Australia. We control all spiders, cockroaches, and termite inspections
Address: 33 Bella Vista Drive Bella Vista
Mobile: 0417 251 911
Email: [email protected]
Manager: Bruce Gow

A1 Pest Control services the Sydney Metro area. The services provided range from pest management, termite inspections, general pest treatments, termite management programs including termite treatment and pre-purchase inspections.

Phone: 0417 251 911
Email: [email protected]

Redbacks And Spider Control

Redback spiders and their control. A1 Pest Control services the Sydney Metro area, the services provided range from general pest treatments in domestic and commercial premises, red back spiders, termite management programs including termite inspection and pre-purchase inspections.


Spider Control Information

(Latrodectus hasselti) Family Theridiidae
Redback spiders are prolific throughout Australia but are less common in colder regions such as Melbourne. In Sydney, they are very common in populated areas, usually hiding in rubbish, leaf litter and under pot plants. Hundreds of bites are reported each year but less than 30 percent require antivenom treatment. Before the antivenom was available, Red back spider bites caused about a dozen known deaths until Dr Straun Sutherland discovered the cure.

In a 13 year period (1963-1976) over 2000 cases of Red Back Spider bite were reported to the Commonwealth Serum Laboratories (Sutherland and Trinca 1978); many more bites are reported to doctors, hospitals, and poison information centres throughout Australia. Because the bite can be potentially dangerous it is wise to be informed about the Redback Spider, its habits and behaviour.

Prior to the introduction of the specific antivenom in 1956, 13 deaths in Australia were caused by its bite.

Only female Redbacks usually bite people – the males are too small. Redback spiders are typically entirely black, except for a broad red band down the back of the body and a red hourglass-shaped mark underneath. Large females may span a 50 cent coin, but males are much smaller. Immature spiders do not have the typical colouring. They are not native to the area, but are common in Sydney and are sometimes seen around houses on the range.

Redbacks build anywhere out of the direct effects of the weather – on buildings, in parks, under steps, in corners, grass, junk piles,, under window sills, around pot plants. They are generally timid except when an object is placed in the web, or when tending young or eggs in the nest. Only the female is large enough to effectively bite people. They are highly venomous.

Redback Spiders belong to the genus Latrodectus or sometimes they are known as “widow spiders”. Worldwide there are many species of widow spiders including the Black Widow Spider (L. mactans) of North America.

First aid for bites

Pressure bandaging is not recommended for Redback bite as this can aggravate the pain. Because the venom molecules are large, they can take some hours to be transported from the bitten area via the lymphatic system and into the blood stream. Medical attention should be sought if a bite is suspected. Cold packs or cold water may help relieve pain.

They are members of the Latrodectus genus. Other members of this species include the Black Widow Spider (L. mactans) and Brown Widow Spider (Latrodectus geometricus) which is is native to South Africa. Brown Widows are also known as Grey Widow, Geometric Button spider and Brown Button. Brown Widow of North America(L. indistinctus), and the katipo (L. katipo) which is found ony in New Zealand. Redback spiders are distributed throughout Australia, and have adapted well to an urban environment. They are common in sheds and garages, under houses, in industrial areas and in outside toilets. The venom acts directly on the nerves, resulting in release and subsequent depletion of neurotransmitters.

Bites by this spider represent the commonest envenomation requiring treatment in Australia, particularly over the summer months. More than 250 cases receive antivenom each year. Perhaps ten times as many cases are mild or unrecognized and do not receive antivenom (a.k.a. antivenin or antivenene. Males appear to be more frequently affected than females, probably in relation to occupational exposure. The spider is usually easily identified by the presence of a red, orange or brownish stripe on its abdomen. Only the female is considered dangerous, and it is generally a retiring spider, biting only defensively. Bites are typically sustained when the spider is disturbed in the garden or shed, in clothing (especially footwear) or even when it is sat upon. Bites to the limbs comprise approximately 75% of cases. The male is very small, only about 3 mm in diameter, and his fangs are unable to penetrate the skin.

Symptoms and Signs of Bites

The time course and the actual symptoms are highly variable, but progression of the illness is generally slow, and symptoms may persist for weeks after an untreated bite. The acute symptoms include:

1. Immediate pain at the bite site +/- erythema and swelling .
2. Pain progressing to involve the entire limb
3. Painful or tender regional lymph nodes.
4. Sweating, sometimes affecting only the bitten limb initially, and sometimes over bizarre distributions distal to the bite site
5. Nausea, vomiting, abdominal pain
6. Headache
7. Migratory arthralgia
8. Fever
9. Restlessness and insomnia
10. Hypertension

Treatment of Bites

Sutherland (1983) recommends that no special first aid be applied because as the venom is slow acting and localising it may intensify the pain at the bite site. Pest control firms now receive training in the treatment of the bites as part of their modules for pest management. The best action is to transport the person immediately and without panic to medical aid. Serious illness apparently does not develop for at least three hours, so this is plenty of time in most cases to get the victim to hospital where first aid may be administered. In 2144 cases surveyed from 1963-1976 (Sutherland and Trinca 1978), antivenom was administered in most cases.

The exact mechanism(s) by which the toxins produce the observed clinical effects are poorly understood, as is the precise cause of death. No deaths have been reported since 1955, a year before the introduction of redback spider antivenom in Australia. Unusually, antivenom may be effective even if administered several weeks after the bite.

The Red Back Spider is one of Australia’s best known spiders; it earned much of its reputation through `a large proportion of the recorded bites having been sustained in outdoor privies’ (Taylor and Murray 1946). That activity, wrongly attributed to the male, was immortalised in Slim Newton’s 1972 hit song, “The Redback on the toilet seat”

There was a Redback on the toilet seat when I was there last night.
I didn’t see him in the dark but, boy, I felt his bite”

They occur throughout Australia but are most common where the natural environment has been disturbed, such as settled or urban areas. Within natural forest, they are rare to absent. Redback Spiders may not even be native spiders to Australia. They were originally recorded by scientists in around the year 1870.

Their initial bites are often felt but are somewhat painless, although sensitive victims have complained about burning or stinging sensations. Puncture marks from Red-backs are not always obvious. In the majority of bites intense local pain is experienced about five minutes after the bite (Sutherland 1983). According to Weiner (1961), in around forty percent of their bites the symptoms have included localised sweating and muscular weakness, temporary paralysis, muscle soreness, coordination problems, shakes and tremors; in about ten percent of victims have muscle weakness, tiredness, heavy nausea, vomiting, dizziness up to fainting, tachycardia (fast beating of the heart), heart palpitations, large bouts of insomnia, fever, and also frequent muscle spasms were recorded. Some of these symptoms may be a little odd; tetanic spasms, occasional tingling of the teeth, tongue swelling, violent convulsions, abnormal thirst, diarrhoea, periorbital oedema, rashes, shock, sweating, amongst other symptoms. Usually the best indication of bites are a localised sweating in the area where the bite occured.


The web of the Redback Spider is an irregular tangle of fine but strong silk. The back portion of the web forms a funnel (visible from certain angles) where strands of silk are more closely bound. It is here that the spider and egg sacs are found. Many spiders that are similar in shape and colour to Redback Spiders build similar tangled webs; however, those webs are generally weaker and usually the spider rests centrally in the open web.

Location of habitat

It seems that they prefer to build their webs in a way that the edge of the web is exposed to the sun and the middle part is in the shade. Along the outside of the house, they may be found under window sills, under the guttering and eaves, in the corners of windows and doors, amongst pot plants, under and on steps and verandas, and, of course, under the seats of outdoor toilets. Melbourne pest control treatment for these areas include direct removal of spiders and webbing. Inside houses, the possible locations for webs are even more numerous but because the spiders tend to stay near the sun they occur infrequently inside.

Away from houses, Redback Spiders seem more numerous because there are more hiding places; piles of wood, iron, cans, and old machinery are ideal hiding places. Such is the tenacity of the spiders that they build in grass tussocks and the little shelters provided by sods of freshly ploughed fields. Frequently, they are found on and within motor vehicles in use; locations reported are in the handlebars of motorbikes, and on seatbelts and behind the bumper bars of cars.

Life Cycle

Redback spiders may lay their eggs every twenty-five to thirty days. Incredibly, a single spider of this species may end up laying up to around five thousand eggs. The eggs will hatch thirteen to fifteen days after they have been laid (near the start of a rain shower is common). Females may get to maturity in approximately sixty days to one year but average maturity is about four months. The much smaller male spider will mature in around thirty-one hundred adn sixty days, but on the average will mature in around ninety days. Females will live up to 2 or 3 years, but male red backs might only last six or seven months.

Without any food sources, both genders will last around one hundred days.

It is interesting to note that homes that are infested with Black House Spiders are nearly always completely free of Redback Spiders.

Pest Control

This spider has established itself successfully in Australia. It is a hardy spider than can stand high temperatures and prolonged dry periods; it is completely indiscriminate about where it builds its web; and it constructs a deep recluse to maintain its security. How, then, can the spider be controlled? Spraying with insecticides is one possibility. However, like all spiders, they can close off its lung openings and exist for several hours using very little air. Therefore, a safe residual spray will have to be enduring, or else sprays would have to be used in large quantities to have a “blanket effect”. Above ground treatments work therefore reasonably well. But, the spraying must carried out frequently, because the wind may carry in spiderlings (or young spiders) that can re-infest a treated area. So redback spider treatments may need to be repeated about every 4 weeks.

The curiosity of children is often aroused when they see webs and spiders, so if young children are in the area, it is important to pay careful attention to low ledges which are best seen by getting down close to the ground and looking up. Once an area has been thoroughly checked and the spiders and egg sacs destroyed, a weekly casual check and eradication will substantially reduce the numbers of young Redback Spiders establishing themselves.

Redback spiders are most vulnerable in the cool dry winter. Insect food is scarce and the spider is forced to live on available reserves. Watch the sun. Look for areas that are heated throughout the winter’s day or a good part of it. Those are most likely spots because Redbacks need to stay warm and dry. A sustained attack on Redbacks during the winter will ensure a much quieter spring and summer to follow.

Redbacks survive the winter only in areas which have sufficient sun on the web or on the retreat to warm the spider up to about 15-20øC for about an hour or so. Early onset of summer heat and dry conditions will allow early mating and extra generations.

Redbacks are often absent in gardens that are well kept, moist, with much shade, even in Sydney’s summer and are most common around houses that have few shrubs or trees that provide shade.

Our advice for pest control?

Choose A1 pest control spider treatment! If spiders are a problem, call or email us at [email protected] for information on Red-Back spiders & pest control.

Phone: 0417 251 911
Email: [email protected]