Tasmania is home to a varied population of spiders, confirming that the island state does indeed have its share of arachnids. The cooler, temperate climate does not deter a wide range of species from flourishing in both natural and urban environments. While Australian spiders often cause alarm, the danger level in Tasmania is generally less pronounced than on the mainland, with fewer species posing a significant medical threat. Most encountered spiders are harmless and play a beneficial role in the ecosystem.
Common Spiders of Tasmania
The Huntsman Spider, such as the Flat Huntsman, is one of the most frequently observed groups. These large spiders have a body length of 2 to 3 centimeters and a leg span that can be much wider, making them highly visible. Huntsmen actively hunt insects and arthropods rather than building webs, and are commonly found under loose bark or wandering indoors. Despite their intimidating size, they are timid, and their bite typically causes only minor, temporary symptoms.
The Wolf Spider is another common resident, with the Garden Wolf Spider (Tasmanicosa godeffroyi) being widespread. These robust, hairy spiders are typically brown or grey, ranging from 1.2 to 5 centimeters. Wolf spiders are ground-dwelling hunters, often seen on lawns or among leaf litter. They do not pose a serious risk to humans, and while they may bite if provoked, the venom usually results in only localized pain and mild swelling.
Garden Orb Weavers are prevalent, known for constructing large, intricate, wheel-shaped webs. These stout spiders are usually reddish-brown or grey and typically hang in their webs at night to catch flying insects. They are reluctant to bite, and any symptoms are usually limited to mild local pain and temporary numbness. These species are beneficial for natural pest control and are harmless to people.
Medically Significant Species
The Redback Spider (Latrodectus hasselti) is the most well-known medically significant species in Tasmania, particularly in urban areas. The female is distinctively black with a prominent red or orange stripe on the upper side of her abdomen. Redback bites are frequent during warmer months, causing intense local pain that can spread, sometimes accompanied by sweating and nausea. Antivenom is available for severe cases, and since its introduction, no deaths have been recorded from a Redback bite.
The White-tail Spider (Lampona cylindrata or Lampona murina) is identifiable by its dark, cylindrical body and a distinctive white spot at the tip of its abdomen. These nomadic hunters are often found under bark, rocks, and in clothing or linen indoors. Although historically linked to severe necrotizing ulcers, current research has largely debunked this claim. A bite from a White-tail typically causes only mild to moderate pain, redness, and minor swelling, similar to a bee sting.
Tasmania is home to its own species of Funnel-web Spiders, belonging to the genus Hadronyche, with at least three types known to exist. The endemic Tasmanian Funnel-web is significantly less dangerous to humans than the notorious Sydney Funnel-web (Atrax robustus). While bites should be treated with caution, they are not associated with the life-threatening rapid systemic effects of their Sydney relatives. The venom, while potent, tends to cause severe localized pain rather than the rapid, widespread paralysis characteristic of the Sydney species.
Practical Prevention and Safety
Avoiding spider encounters relies on simple precautions, especially where Redback and White-tail spiders might hide. Shaking out shoes, clothing, and towels before use can dislodge spiders seeking shelter. When gardening or handling materials like firewood or debris, wearing gloves is advisable to prevent accidental contact. Sealing gaps and installing weather-strips on doors also helps reduce the chances of spiders entering the home.
First aid protocol depends on the type of spider involved. For Redback or White-tail bites, the recommended treatment is to wash the area with soap and water and apply a cold pack to manage pain. A pressure immobilization bandage should not be used for these bites, as it can worsen symptoms by concentrating the venom. If a bite is suspected to be from a Funnel-web spider, the immediate first aid is to apply a pressure immobilization bandage to the bitten limb and keep the victim still. In all cases of suspected Redback or Funnel-web bites, or if symptoms worsen, immediate medical attention should be sought.