ESSENTIAL READING BEFORE COMMENCEMENT OF COURSE:

by J Gerozisis and P Hadlington - Chapter 13 - Pages 154 to 171.

Chapter 13 – Spiders – arachnid characteristics – structure – identification of sexes – respiration – senses – life cycle – habitats – reproduction – food and feeding – production of silk or web – arachnid venom – spiders – commonly occurring spiders – family idipidae – family lamponidae – family actinopodidae – family hexathelidae – family deinopidae – family scytodidae – family sicariidae – family araneidae – family thomisidae – family clubionidae – family theraphosidae – family desidae – family pholcidae – family theridiidae – family lycosidae – family heteropodidae – family salticidae – spider control and avoidance of bites – symptoms and treatment of spider bites.

Pest Species:

Redback Spider
This spider, builds a web, which is tangled, funnel like upper retreat area from which vertical, sticky catching threads run to ground attachments these nest sites are usually located in a dry sheltered site eg. Under rocks, junk piles, sheds, toilets wood stored in areas, this includes pallets etc. It is worth noting that Redback Spiders are least prevalent in winter months and that only the female spider bites.

Funnel Web Spider
This spider builds its nest in sheltered habitats, eg. In the bush and in gardens. It has irregular silk trip lines, which radiate out from the burrow entrance. This spider will raise its front legs and lunge forward when provoked. It is interesting to note, that this spider can live as long as 3 to 10 years, so pest control is very warranted. Bites are most prevalent in summer/autumn and may be fatal, both male and female are poisonous.

Mouse Spider
This spider builds its nest in burrows with a double or single trapdoor it is often mistaken for a funnel web, only a licensed pest controller can tell the difference and it should be stressed to our customers that they should not try to identify these spiders themselves. It is possible that a bite from this spider may be fatal.

White Tailed Spider
This spider is normally found moving around at night it lives in cracks and crevices, under bark, rocks and in leaf litter and often in and around buildings. This spider attacks and eats other spiders including Black House Spiders. This spider will bite, which is followed by stinging or burning pain, and sometimes-local ulceration, nausea and vomiting.

Black House Spider
This spider is one of the most common found spiders around any building in Australia. It builds its nest almost anywhere; their webs form untidy, lacy silk sheets with funnel like entrances. They are mostly found on tree trunks, logs, rock walls, buildings in particular window frames and wall crevices. This spider is not poisonous, but will give a painful bite, which may lead to nausea, vomiting, sweating.

The cephalothorax bears the eyes, mouthparts and legs whereas the abdomen bears the respiratory openings, reproductive and digestive systems and the spinnerets.

Funnel Web Spiders
The Sydney Funnel-web spider, Atrax robustus, is the best known species.  It is large and black with a body length of up to 20 mm(male) and 30 mm (female).  The cephalothroax is black, shiny and smooth.  Two readily visible spinnerets, each about
3 mm long, are attached to the rear of the abdomen.  Male and female are similar in colour but the male has has a tibial spine on the second pair of legs and slightly swollen end segments on its palps.

This spider is relatively common in Sydney and may be found under rocks or roots and against fences. At times it may fall into swimming pools. The males may sometimes enter houses at night and will often hide in damp washing, face towels or shoes. Generally the females will not be found unless heavy rains have forced them from their burrows.

The initial bite is invariably painful but, in most cases, especially those from females, no general symptoms follow and recovery is uneventful.  With a large amount of venom, as may occur from a male spider bite, general symptoms may occur within 10 minutes.  Early symptoms are nausea and vomiting with abdominal pair, profuse sweating, excess salivation and lacrimation.  Later the patient may sink into a coma with depressed respiration, asphyxia and cardiac arrest.  Infants have died in 15-90 minutes while adults have usually lingered for 30 hours or more.

The introduction of an antivenom and, more recently, a vaccine, should mean that very few deaths will ever occur in the future.

The second well known species is Atrax formidabilis, the Tree-dwelling or North Coast Funnel-web spider, which has been­recorded tor northern N.S.W. and southern Queensland.

This spider nests in holes in trees, sometimes high above ground level, or in crevices in old stumps and logs.  The typical tube leads into the silk-lined home.  This is a much larger species than A. robustus and may have a body length of 50 mm.

Bites of this species have been found to lead to severe effects and one fatality has been reported.  The venom of A. formidabilis is more toxic than that of A. robustus and even the bites of the females are likely to be very dangerous.

Black house Spiders
Baduma insignis is commonly known as the Black House or Window spider. It is a common species of black or brownish-black colour with a furry appearance, sometimes with a bluish sheen. It builds an obvious retreat and surrounding sheet web in the corners of windows, under eaves, in drain-pipes and in clefts of eucalypt trunks. Due to the shape of its web it is sometimes confused with the Funnel-web spider.

Bites from this spider have been recorded as painful causing sweating, weakness of the limbs, giddiness and vomiting.  There may be large persistent weals of dead tissue around the bite.

White Tailed Spider
The harmful spider of this family is Lampona cylindrata (White-tailed spider), which is widespread in Australia and New Zealand.  It is a small, cylindrical spider with a shiny, pitted cephalothorax, dark reddish-brown legs and a greyish - brown abdomen with a conspicuous white blotch at its tip.

In the bush it is often found under the bark of trees, under stones or in similar crevices.  Inside it prefers dry situations such as under boards or boxes.  It is a nocturnal hunter.

The bite may cause symptoms such as local discolouration, headache, pyrexia, "cold turns" and local itchiness.

This spider is suspected as being one of the species whose bite may cause necrotising arachnidism (tissue death caused by a spider bite). Symptoms may be mild with the necrosis being self-limiting in area and duration but, with severe cases, the skin loss is extensive and irreversible, reaching through all layers of the skin. In such cases, the only way of repairing the damage is to remove the dead tissue and to replace it with grafts of skin form elsewhere on the body. Sometimes fingers and toes have had to be amputated. At the time of writing, there is no known antidote for this condition.

The Red Back Spider
This species is common in Australia and may be found under logs and stones or in shaded hollows of trees and other dry, sheltered situations.  The webs of mature spiders consist of three parts - a retreat funnel, a group of strands and a trap section.  The trap section has a number of sticky threads in contact with the ground and when contacted or broken, the spider emerges to bite and wrap the prey.  The connecting strands may be as long as 2-3 metres.

Around houses, these spiders are commonly found in dry and dark places, such as under boxes or tins, in meter boxes and in outdoor toilets.

The bite of a female Red-back is particularly venomous.  It can cause the death of a child in a few hours and serious illness, or even death, in an adult.  Before the development of an antivenom in the mid - 1950's approximately 5% of recorded bites
proved fatal.  Luckily the Red-back is not an aggressive spider and seldom bites humans.

When disturbed it usually tries to escape or feigns death by curling up and falling to the ground.  Compared to the female, the male is small and harmless.

Symptoms of a Red-back spider bite may include:-

- A relatively painless initial bite, like a pinprick or less;

- Localised skin sweating at the site of the bite;

- Local pain which spreads and intensifies;

- Nausea and/or vomiting, sweating and general muscular weakness;

- The bitten area may swell and develop a skin weal.

Mouse Spiders
They are dark, usually black in colour with varying amounts of red on the fangs and sometimes also on the head.  The abdomen may be bluish.  They have short legs and a broad body and the high head region slopes steeply down to the front of the cephalothroax.

They construct vertical burrows lined with coarse silk with two doors at the entrance.  These doors are oval and may consist of thin silken flaps or solid structures reinforced with soil.  Females and immature spiders stay in their burrows but males may be found roaming on the ground at all times.

It has been established that the venom from these spiders may be very toxic but only one serious envenomation has been recorded with all other bites only causing minor effects. Funnel-web spider antivenom may be effective in serious cases.

identification techniques

spiders are not insects

identifying parts

life cycle

anatomy

families of spiders

NON CHEMICAL CONTROL / CULTURAL CONTROL
In the interest of non-chemically reducing the population of spiders around a particular property, tidying up yards, removing old unused structures (old sheds), cleaning away long-standing rubbish heaps can all help in making the yard less available to spiders. Regular brushing down of webbing is often useful. Where practical, proofing of some industrial buildings can be worthwhile, as can filling cracks and crevices around houses.

SAFETY TO BE CONSIDERED WHEN TREATING FOR SPIDERS
A very important issue concerning spider sprays relates to public health and safety. Spider sprays often require the operator to apply insecticides under eaves, around window tops and other elevated locations.  Because some operators are thoughtless and inconsiderate in their actions, the Department of Industrial Relations and Employment often receives complaints from neighbours about spray drift.
As well as the obvious need for 'extra' personal protective gear that the operator should wear (face shield and respirator) the following points should be borne in mind:
• do not do any outdoor spraying on windy days;
• use equipment that allows you to have an extension wand so that your nozzle is always close to the target site;
• use low pressures because you want large droplets that go where you want them to go (high pressures break the liquid up into tiny particles that will, more easily, drift away from the target).

area of distribution

common breeding sites

habitat areas

Useful website links:

http://www.ipminstitute.org/school_biblio_buildings.htm#Occasional