Ground-Dwelling Spiders


Ground-dwelling spiders make holes in the ground and often live there with silken web material.  Some of these spiders are regarded as poisonous, and in the case of the Sydney and northern rivers funnel web spiders, very poisonous.



Orb-weaving Spider


The spiders that construct webs produce two types of silk.  One type is for the main part of the web structure and is intended to catch or snare flying insects.  It is of a sticky or adhesive material.  The other type forms the guy ropes which are attached to structure or vegetation and it is of a non-adhesive material.  An ‘orb’ web consists of threads radiating from a central point supporting a spiral of sticky web to catch flying insects.  After one night, both the central sticky area and the dry silk need replacing.  After squeezing the body in silk, it leaves it hanging in the web area.  All the orb-weaving spiders are non-poisonous to humans.  They are not aggressive, and have only one generation a year.



Redback Spiders (Latrodectus Hasselti)

The female redback spider is extremely poisonous.  It has a black velvety body with a red stripe on the upper surface of the abdomen.  It makes loose, untidy webs among leaves, rubbish, under houses, in tins, tyres, stacked articles, and outside toilets.  The male spider is very small and harmless, and measures 3mm in length.  The female can be up to 12mm in length.
                                                                                                                    

White-tailed Spider (Lampona Cylindrata)

This is another poisonous spider whose bites can cause pain and have been associated with blistering and necrosis (where the cells on and just below the surface die and become scaly).  It is black with a white patch at the end of its abdomen.  The male is about 12mm while the female can be up to 20mm in length.

This spider is a wanderer and a hunter.  Its main diet is other spiders, including the black house spider.  They are found under bark and logs in the bush.  When it lives in houses, it searches for its prey in the early evening and shelters during the day in bathrooms, on the tops of walls, and in furniture.

 

Huntsman Spider (Isopoda Immonis)

The huntsman spider is not aggressive, but if provoked, its bite can be painful - although no symptoms of poisoning follow.  Its front two pairs of legs are larger than the rear two pairs and its body has a rather flattened appearance.  Its colouring can vary from browns to greys and buff.  It is often mottled.  The huntsman can move sideways.  The male is usually 25mm in size and the female 35mm.  They normally live under the bark of trees during the daytime and emerge at night.  They often enter houses where they are seen on walls.  They are a useful spider in that they feed on insects.

Non-chemical Procedures

It is important to remember that most spiders are not pests, and are an important part of our environment, since they reduce the populations of pest insects.  However, some are poisonous and their bites require medical attention.

  1. Identify spiders found in the house.  Kill only those that are regarded as poisonous to humans.
  2. Take care when using insecticides in gardens as this can cause funnelweb spiders to enter houses.
  3. Wet weather may also cause ground-dwelling spiders to enter houses.  Ground-dwelling spiders are also often found in swimming pools and can be alive even after hours at the bottom of the pool.  Do not remove with the hands.
  4. Carefully inspect all footwear and clothing left outside before dressing, particularly in summer and autumn.
  5. Inspect all toys, clothing, footwear and other articles left outside at night before bringing them into the house.