Spiders

Australia has both venomous and non-venomous species of spiders to humans. As with snakes, treat all spider bites as venomous unless proven otherwise.

DEADLY AND DANGEROUS

Funnel webs have extremely venomous bites. They are among the most deadly spiders in the world, however, fatalities are extremely low since the development of effective and readily available antivenoms.

Mouse spiders are also up there. According to the Australian Museum: “Some mouse spiders have a very toxic venom which is potentially as dangerous as that of the Sydney Funnel-web Spider… Because of their potential toxicity to humans, first aid treatment should be provided as recommended for funnel-web spider envenomation. Fortunately, funnel-web spider antivenom has proven effective in cases of mouse spider bite”.

Redbacks are common across Australian and readily found in urban areas. Although only the female bite is dangerous to humans, more than 250 antivenoms are administered a year over the summer months.

Funnel web spiders (Atracinae)

Male funnel web spider. Photo credit: Sputniktilt via commons.wikimedia.org / CC BY-SA 3.0

Female funnel web spider. Photo credit: Sputniktilt via commons.wikimedia.org / CC BY-SA 3.0

Mouse spiders (Missulena)

Male mouse spider. Photo credit: Friends of Chiltern Mt Pilot National Park via Foter.com / CC BY-NC-SA

Female mouse spider. Photo credit: ron_n_beths pics via Foter.com / CC BY-NC

Redback spider (Latrodectus hasselti)

Redback spider. Photo credit: Bill & Mark Bell via Foter.com / CC BY-NC-SA

VENOMOUS – PAINFUL BITE

Black house spider (Badumna insignis)

Black House spider. Photo credit: Bill & Mark Bell via Foter.com / CC BY-NC-SA

LOW RISK SPIDERS

Wolf spiders (Lycosidae)
Wolf spiders rarely bite, especially if left unhandled. They are common around houses, but low risk to humans.

Wolf spider. Photo credit: Tone Killick via Foter.com / CC BY-NC-SA

Trap door spiders (Ctenizidae)

Trap door spider. Photo credit: GregGilbert1 via Foter.com / CC BY

Garden orb weaving spider (Eriophora transmarina)

Garden orb weaving spider. Photo credit: Misenus1 via Foter.com / CC BY-NC-SA

St Andrew’s Cross spiders (Argiope)

St Andrew’s Cross female spider. Photo credit: James Niland via Foter.com / CC BY

Golden orb weaver (Nephila)

Photo credit: BRJ INC. via Foter.com / CC BY-NC-ND

Huntsman spiders (Sparassidae)

Huntsman spider. Photo credit: eliotc via Foter.com / CC BY-NC

White-tail spiders (Lampona)
A common misconception is that white tailed spiders have a deadly bite and cause skin necrosis. Yet, their venom is non-lethal. In some cases, bacterial infection is the biggest source of danger to people that have been bitten.

White tail spider. Photo credit: No Middle Name via Foter.com / CC BY-NC-SA

The NSW government has this advice for avoiding funnel web and redback spider bites:

• Keep your garden free of rubble and rubbish where spiders can hide.
• Wear shoes, gloves and long sleeved shirt when working in the garden.
• Check shoes and households items for spiders.

For bushwalkers, we recommend:

• Take care if moving rocks or logs.
• Wear shoes around campsite, especially at dusk and dawn when it’s harder to see.
• Check shoes and anything else left out for spiders and insects before use.

In general, we split Australian spiders into three medically relevant groups and treat accordingly: big black spiders (funnel webs, mouse spiders), redback spiders and all other spiders.

General signs and symptoms of spider bites include:

• Sharp pain at bite site
• Profuse sweating
• Nausea, vomiting and abdominal pain.

Additional signs and symptoms of a Funnel web spider bite:

• Copious secretion of saliva
• Muscular twitching and breathing difficulty
• Small hairs stand on end
• Numbness around mouth
• Copious tears
• Disorientation
• Fast pulse
• Markedly increased blood pressure
• Confusion leading to unconsciousness.

Additional signs and symptoms of a red-back spider bite:

• Intense local pain which increases and spreads
• Small hairs stand on end
• Patchy sweating
• Headache
• Muscle weakness or spasms.

Possible signs and symptoms of other spider bites:

• Burning sensation
• Swelling
• Blistering.

St John Ambulance makes the following management recommendations:

1. Follow DRSABCD .
2. Lie the patient down.
3. Calm and reassure the patient.
4. Apply management for:

• Funnel-web / Mouse spider
  • If on a limb, apply a broad crepe bandage over the bite site as soon as possible.
  • Apply a heavy crepe or elasticised roller bandage starting just above the fingers or toes of the bitten limb, and move upwards on the limb as far as can be reached (include the bite). Apply firmly without stopping blood supply to the limb.
  • Immobilise the injured limb with splints and ensure the patient does not move.
  • Ensure an ambulance (000) has been called or emergency beacon activated.

• Red-back spider
  • Apply an icepack (cold compress) to the bitten area to lessen pain.
  • Seek medical attention if patient develops severe symptoms.

• Other spider bites
  • Wash with soap and water .
  • Apply ice pack (cold compress) to relieve the pain.
  • Seek medical attention if patient develops severe symptoms.

Special thanks to Fran Van Den Berg for reviewing and contributing to this article:
FRAN VAN DEN BERG
Citizen Science Officer
National Parks Association of NSW