Spider Bites

tarantula walking on a tourist arm, peru

Jim was strolling the Peruvian Amazon forest and came across this cute little Tarantula. According to the local guide they don’t bite unless crushed so pick them up very carefully. . . unless they have a red spot on their backs. Those you don’t touch.

Spider Bites – Avoid and Treat

Of around 50, 000 species of spider only a very few are dangerous to humans, although arachnophobia is not without some basis, with several animals that can cause death or at least very nasty, long lasting wounds and excruciating pain from their venom.

Some people react badly to bites that others would shrug off easily. However spider bites are generally rare and hardly ever fatal, especially with access to anti-venom. They are nowhere near as dangerous as venomous snakes.

Avoiding Spider Bites

Many spiders are nocturnal so beware the witching hour, and take care especially of:

• Clothing – from storage, or left on the floor where creepies can crawl in, particularly shoes and gloves. Check and shake out.

• Sleeping – in hi risk areas keep bedding off of floors and walls allowing animals access only from the supports. Check bedding and bags before getting in.

• Domains – attics, wood piles, storage sheds, garages and other cluttered places are a favoured domains for arachnids. Crops and plants also harbour the Black Widow.

• Traps – if you suspect there are killer spiders about, put down glue traps against walls behind the toilet, in cupboards, attics etc, and wear gloves when doing a clearance.

Australia is the place for dangerous wildlife – here are two scary beasts

Funnel-Web Spider

Australian Victorian funnel-web spider

Victorian funnel-web spider, Australia.

This is the most poisonous spider in the world. The bite is strong enough to pierce a fingernail and the venom will generally kill a man in a day if antivenom is not available. From 1927 -1980 seventeen people lost their lives due to funnel web spider bites. The male is particularly dangerous; on occasion it enters houses looking for a mate and is quite aggressive, though its large size means it is more likely to be seen.

Sydney funnel web spider, Atrax Robustus. Sputniktilt

Sydney funnel web spider, Atrax Robustus. Photo by Sputniktilt

The Funnel Web  is the most poisonous spider in the world. The Sydney species, from .5 inch – 2 inches long (1cm – 5cm)  is fond of the Sydney region (aren’t we all?) out as far as the Blue Mountains and likes to go walkabout at night during the cool conditions. In the daytime they build tunnel traps in moist places.

The bite from male fangs is strong enough to pierce a fingernail and the venom will can kill a person in a day if anti-venom is not available. From 1927 -1980 seventeen people lost their lives due to funnel-web spider bites. The male is particularly dangerous as it wanders randomly during mating season and may enter houses and backyards looking for a mate.  It is quite aggressive, and rears up on its hind legs when threatened, showing its fangs. However, due to its large size it is easier to see than smaller spiders. Children are especially vulnerable.

Funnel-Web bite symptoms

Pain, swelling, redness, numbness at site and around mouth. Nausea, vomiting, stomach pain, breathing difficulties, muscle spasms.

Funnel-Web bite treatment

• try to kill the insect for ID purposes: don’t panic, very few people die of spider bite.
• reassure victim and keep him still.
• quickly wrap a light bandage above and below the wound (if you can’t get two fingers under the bandage, it’s too tight).
• remove any jewellery or tight fitting clothing.
• Immobilize/splint the bitten area and keep it at heart level (gravity-neutral) if possible. Too high causes venom to travel to the heart, too low causes more swelling.
• Do not drink alcohol, or take any medicine or food.
• Take victim to medical facilities urgently. Inform them in advance of the spider’s identity if possible.

australia redback spider with eggsac and prey

Australia Redback spider with egg sac and dinner.

Another of Australia’s deadly creatures; while without the fangs of the funnel web, this one is tricky as it commonly lives within houses and sheds right across the continent. Not often fatal, but several hundred bites a year do occur and antivenom is recommended for safety purposes.

Symptoms

Pain, swelling, redness and sweating. Nausea, vomiting, stomach pain. Heavy sweating and swollen glands in armpits or groin.

Treatment

• try to kill the spider for ID purposes: don’t panic, very few people die of redback spider bites.
• put a cool pack on the bite area (e. g. frozen peas wrapped in a kitchen towel)
• take victim to hospital.

USA has two spiders which are considered life-threatening

Brown Recluse

Brown Recluse spider bites

Also known as the ‘fiddleback’ or brown fiddler due to violin-shaped markings on its back, the Brown Recluse found in the central and southern US, bordered by the Rocky Mountains, the Gulf Coast and the Great Lakes. The bite though rarely fatal, may cause necrosis – long term tissue meltdown – and the wound may be problematic for years. Read about my spider melting-flesh experience in Papua New Guinea

Symptoms

Little initial pain is replaced over several hours or days by intense pain and may be followed by: headaches, fever, skin rash, nausea, vomiting, muscle spasms, renal failure and coma.
A halo may form around the bite site. Tissue destruction may continue for up to six weeks.

Treatment

• wrap a light bandage above and below the bite site(if you can’t get two fingers under the bandage, it’s too tight).
• put a cool pack on the bite area (e. g. frozen peas wrapped in a kitchen towel)
• remove any jewellery or tight fitting clothing.
• Immobilize/splint the bitten area and keep it at heart level (gravity-neutral) if possible. Too high causes venom to travel to the heart, too low causes more swelling.
• Do not drink alcohol, or take any medicine or food.
• Take victim to hospital. Inform them in advance of the spider’s identity if possible.

• Or…cut a slab of fresh papaya and tape it to the wound. Refresh daily!

Black Widow

Brown widow spider, Latrodectus geometricus underside, LA, USA. Mfield

OK so this one is this underside of a Brown Widow spider – same Latrodectus family – found in  LA, US. Photo by Mfield

Widow spiders are a large family known scientifically as Latrodectus which includes the Australian Redback as seen further up the page. The female eats the male after mating, thus the name, tho’ smart males will check the female’s chemical output to check if she has eaten a decent meal before making a courtship dance and attempting intercourse. Yes guys, fools rush in…Spend a little time to get to know her first.

The Black (or Brown) Widow is a nocturnal stay-at-home animal and not aggressive. Her web lacks shape and she prefers outdoor locations – such as plants – unless the weather is particularly cold or dry.

She’s shiny black, with an hourglass shape on the underside of her abdomen. Her babies are white or yellowish.
Her venom is 15 times as toxic as a rattler, but only a tiny amount is injected so it’s not as dangerous as other animals. Still, about one percent of Black Widow bites are fatal – usually in the elderly or very young.

Black Widows can also be found in Canada, Mexico and South West Europe.

Symptoms

The bite is not painful and may not be noticed until later, when muscular, feet or stomach pains occur. Other symptoms are heavy sweating, swollen eyelids, erratic saliva production and difficulty in breathing. Healthy adults will recover in two or three days, though the old (60+) or young (-16) may need hospital treatment.

Treatment

• clean the bite site
• put a cool pack on the bite area (e. g. frozen peas wrapped in a kitchen towel)
• keep the limb at heart level (gravity-neutral) if possible. Too high causes venom to travel to the heart, too low causes more swelling.
• take a pain killer if required.

South America has several dangerous spiders

Brazilian Wandering Spider – a large one which travels Amazonian forest floors away from a web, is highly aggressive and can kill children.

Tarantulas – the largest spiders, have venom but generally only equivalent to a strong bee sting and they do not attack unless crushed. See photo at top.