SPIDERS

Redback

Long shiny legs a small mid-section & large bulbous black abdomen which usually has a broad orange, red or scarlet dorsal stripe. The underside of the female also bears a bright red mark in the shape of an hour glass. Completely black forms are also found. Male spiders are a tiny 3-4 mm, compared to the large female 12-15 mm. These spiders show little aggression and, if threatened, curl up & fall to the ground.

Habitat

Redbacks prefer dry habitats ranging from forests to deserts. They make a loose web in rubbish or debris, and males will surround a female in her web. Around households Redbacks can be found in letterboxes, under seats, garden furniture, around pot plants, and in sheds. In areas where Funnel-webs & Trapdoors are found, Redbacks will frequently ensnare & devour these wandering male spiders.

Very toxic. Males do not bite as there fangs are too small to penetrate human skin, but the bite from a female is very painful & can be fatal. However there have not been any fatalities since 1956, when an effective antivenin was developed but this spider must always be treated with caution. Most Redback bites occur when the spider is accidentally picked up or trapped against the hand or body when cleaning out rubbish from a workshop or garden.

Symptoms

• Stinging sensation at bite although no sign may be evident
• Swelling around bite & paleness; pain & tenderness
• Pain in lower limbs due to absorption of venom in lymphatic system
• Patient shows shock symptoms: pallor, weakness, profuse sweating – sometimes only round bite site, nausea & vomiting
• Some cases show paralysis of lower limbs

Treatment

• Keep patient as still & calm as possible
• Remove tight clothing & make patient comfortable
• Apply cold pack to the bite being careful not to freeze tissue (wrap ice pack in towel)
• Seek medical assistance promptly

 White Tail

Cigar shaped body that varies from grey to plum to black depending on the age of the spider & when it last moulted. Its legs may also be red-brown to black, also depending on its age. The adult has an outstanding patch of white on the dorsal tip of its abdomen. Juvenile spiders have a series of light patches on the top of the abdomen which deepen with each moult until they disappear leaving only the distinctive white ‘tail’. Female spiders measure 12 – 20 mm & the slimmer male spiders measure 5 – 12 mm. These nocturnal open range hunters are not aggressive but like many other spiders will bite if touched or placed on the body inside clothing

Habitat

White-tailed spiders prefer cool places. Outside they can be found under the bark of trees where it builds a temporary tubular retreat sac. Often they can be found in doors particularly in bath rooms where it is cool as well as in bedrooms under clothing left on floors & they have even been found in beds.

Toxicity

Although dangerous, the bite is not lethal. Severe illness & localized pain may be experienced as well as blistering & tissue necrosis. The venom of a white tail contains flesh dissolving enzymes & a microscopic organism, Mycobacterium ulcerans, which is what, can cause necrotic (ulcerous) sores.

Symptoms

• Clearly visible puncture mark
• Burning local pain sometimes followed by blistering & ulceration, however the symptoms have no predictable pattern
• The speed of tissue damage & of other symptoms varies widely. Ulceration may begin with surface blistering or a darkening of flesh beneath the bite
• Reaction can be rapid & painful, with violent vomiting & diarrhoea, or gradual with relatively little pain
• If necrosis spreads extensively, the only way to retard damage is to remove the dead tissue & scrape around it. It is thought that the digestive enzyme that causes this damage can renew itself

Treatment

• L-Cysteine ointment can counteract the necrotic effect of the venom
• Aloe Vera in ointment or fresh leaf form can also greatly help to neutralize the effects of the bite; apply generously over wound 3-4 times a day until it heals
• Seek medical assistance as soon as possible

 Black House spider

Robust build with large abdomen, dark brown to black with black legs. The female is a medium sized spider measuring up to 18mm long; the male is only 9mm. There fangs are not obvious but move pincer wise. Their web is a mat with an obvious, roughly round, entrance hole & the spider will wait for an insect to become ensnared. Not an aggressive spider.

Habitat

In the wild they construct their webs in the loose bark of trees, but in & around buildings they make their webs in window frames, in corners, under eaves, in fact any place they have security. These spiders are frequently attacked & devoured by the white-tailed spider.

Toxicity

Toxic. The bite of the Black House spider is poisonous but not lethal. There bites cause some pain & swelling, but the patient soon recovers. Medical advice should always be sought as there may be an allergic reaction.

Huntsman

Huntsman are also known as Triantelope, Tarantulas or Giant Crab spiders because of their rapid sideways scuttling gait. They generally have a hairy flattened body structure & their front two pair of legs is longer than their back two pair of legs. Some species are quite large, the female being about 40 – 45 mm long & 160 mm across outstretched legs & the male only slightly less. Despite their fearsome appearance
these nocturnal hunters are not an aggressive spider.

Habitat

The natural habitat of Huntsman is under the loose bark of trees but they will often enter houses & may be found on walls. If threatened these spiders can & will squeeze into cracks & crevices where no other animal can.

Toxicity

Not toxic. Although a large Huntsman can give a painful bite, most species are entirely harmless to humans.