Spiders

SpidersSpiders belong to a group of animals called Arachnids. They differ from insects as they have eight jointed legs and two main body parts. Male spiders are generally smaller than female spiders of the same species, and male spiders do not tend to spin webs. Spiders are usually solitary, and most are nocturnal – seeking shelter in cracks, crevices or burrows during the day. Almost all spiders are venomous, with some being harmful to humans.

Types of Spiders

Across Australia, there are about 2900 species of spiders, however a few common species are considered pests in urban areas. Throughout Joondalup and the northern suburbs of Perth, most spider problems are caused by:

Black House Spiders

Dark brown / black spider, male 8 - 10mm long, female 15 – 18mm long. Webs mostly found in corners, under eaves or in window frames. Bites are venomous and may cause pain and/or swelling. Medical attention should be sought in case of allergic reaction.

Huntsman Spiders

Large buff coloured spider with dark patches on body, male 15 –25mm long, female 35 – 40mm long. Mostly found under the loose bark of trees, however can be found on walls in houses. Bites are non-toxic however may cause pain. Not aggressive.

Redback Spiders

Black spider, female has a bright red/orange stripe on her abdomen. Male 3 – 4mm long; female 12 – 15mm long. Webs mostly found in cracks, crevices, under fence-capping, behind downpipes, or in sheltered areas such as tins, boxes, outdoor toilets, etc. Male redback spiders do not bite, however bites from the female are extremely venomous and have been known to cause serious illness and even death. In the event of a female redback bite, apply an icepack to the bitten area and seek immediate medical attention.

White Tailed Spiders

Dark grey / black spider with a white spot on the end of its abdomen, male 5 – 8mm long, female 12 – 15mm long. Mostly found under the loose bark of trees, however often found inside homes on walls, in bathrooms, hidden in clothing and/or bedding. Bites are venomous and may cause pain and/or ulceration in the area of the bite. Some cases of tissue necrosis have also been reported. In the event of a whitetail spider bite, apply an icepack to the bitten area and seek medical attention if symptoms persist.

Problems caused by Spiders

The greatest problem caused by spiders is their ability to inflict painful and/or dangerous bites. Most spider bites result in little more than localised swelling or irritation, however some spiders have venom that is toxic to humans. Throughout Joondalup and the northern suburbs of Perth, the most dangerous spiders are the Red back and White Tail and bites received by either of these spiers should receive immediate medical attention, however WA Pestsaway recommends all spider bites be monitored closely and medical attention sought if symptoms persist.

If you have concerns about spiders, please call WA Pestsaway on 0419 374 374