SPIDERS AND HUMANS: FEAR, VENOMOUS ONES, MISINFORMATION

SPIDERS AND HUMANS

Tales of giant spiders date back at least to ancient Greece and Arachne, the half-woman, half-spider figure in Greek mythology. J'ba Fofi is monkey-size spider said to inhabit the Congolese rainforest. Shelob was the monstrous arachnid in "The Lord of the Rings." The giant spider in Harry Potter, called Aragog, was an Acromantula who lived in the Forbidden Forest. [Source: Emma Bryce, Live Science, August 4, 2023]

According to a Greek legend spiders were creating when a seamstress named Arachne challenged the goddess Athena to a contest and then felt ashamed of her boldness and hung herself. Athena felt sorry for her and brought her back to life as a spider and made her noose into a web. Her name was also given to the scientist who study spiders (arachnologists), the fear of them (arachanaphobia) and the class of animals that includes them (Arachnida).

Only about a dozen spider species are known to be harmful to people. Matt Bertone wrote: Although they are generalist predators, apt to eat anything they can catch, spiders regularly capture nuisance pests and even disease-carrying insects — for example, mosquitoes. There’s even a species of jumping spider that prefers to eat blood-filled mosquitoes in African homes. So killing a spider doesn’t just cost the arachnid its life, it may take an important predator out of your home. [Source: Matt Bertone, Extension Associate in Entomology, North Carolina State University, The Conversation, March 12, 2022]

It’s natural to fear spiders. They have lots of legs and almost all are venomous — though the majority of species have venom too weak to cause issues in humans, if their fangs can pierce our skin at all. Even entomologists themselves can fall prey to arachnophobia. I know a few spider researchers who overcame their fear by observing and working with these fascinating creatures. If they can do it, so can you!

Spiders are not out to get you and actually prefer to avoid humans; we are much more dangerous to them than vice versa. Bites from spiders are extremely rare. Although there are a few medically important species like widow spiders and recluses, even their bites are uncommon and rarely cause serious issues.

Spider Silk and Humans

Scientist are trying to produce synthetic materials similar to spider silk for use in space ships, stealth bombers, optical instruments and other purposes. Doctors are examining spider silk to make sutures one-tenth the diameter of current sutures as well as possible artificial ligaments and tendons. Spider silk is too elastic however for bullet proof-vests. It would stop the bullet but not until it stretched to the other side of your body.

Why isn't spider silk produced like silkworm silk? The advantage of silkworm silk is that can be unraveled in one continuous strand and the spider's aggressive and cannibalistic nature makes raising them in numbers difficult.

One Canadian company spins silk similar to that produced by spiders from the milk of genetically engineered goats that look like normal goats. Spider-silk genes were implanted into goat embryos that developed into adults and passed the genetic trait onto their offspring. The advance was made possible because goat udders have similar structure to spider silk-making organs. Spider-silk proteins have also been clone into tobacco and potato plants, which secrete them on their leaves.

Misinformation About Spiders

Arachne and Athena

There is a lot of fear, misunderstandings and misinformation when it comes to spiders. In 2022, more than 60 researchers from around the world collected 5,348 news stories about spider bites, published online from 2010 through 2020 from 81 countries in 40 languages. Oliver Whang wrote in the New York Times: They read through each story, noting whether any had factual errors or emotionally fraught language. The percentage of articles they rated sensationalistic: 43 percent. The percentage of articles that had factual errors: 47 percent. “Even a very local event, like a farmer that is bitten in a small village in Australia, can quickly become a news article that is published in newspapers around the world,” said Stefano Mammola, an ecologist at the National Research Council of Italy who led the research. “I think this really speaks to the mythology and fascination that people have with spiders, that comes with fear,” Catherine Scott, an arachnologist at McGill University, said. “And the lack of good information around them.” [Source: Oliver Whang, New York TimesAugust 26, 2022]

To measure the sensationalism of a story, the group looked for frequent use of emotional words, including “devil,” “killer,” “nasty,” “nightmare” and “terror.” They then counted the errors in the story. Were people calling spiders insects? (They’re arachnids.) Were they exaggerating the danger of a particular spider? Did they get basic spider anatomy wrong? Many of the results, while stark, didn’t shock most of the scientists, who had grown accustomed to this kind of spider news. Whether the widespread fear of spiders came before arachnid sensationalism, or vice versa, the two undoubtedly feed off each other. “Given certain topics, we’d naturally be prone to sensationalism,” Mammola said.

Eating Spiders

Spiders are eaten in many places. It has been said that Nephilia spider tastes like a potato. Skoeun, a town near Phnom Penh, is famous for its spider brochettes. The mildly-toxic two-inch- long spiders are caught in the nearby forests, dipped in flour and powered peanuts and fried. Sold for about 20 cents a stick, they are served in restaurants and hawked from trays to passing motorists. One customer at a spider restaurant told the Phnom Penh Post. "It's not as tasty as cricket, but it could be good if you eat it with wine." Another said, "It's nice, it tastes good. They clean the stomach.”

Heidi Fuller-Love wrote in the Los Angeles Times, “Skun is home to Cambodia's largest concentration of tarantulas. Tthe market stands were piled high with fried crickets, grilled locusts and braised a-pings, as the beleaguered arachnids are known locally. All around me school kids and old women were buying the spiders. They are black, hairy, as big as a hand and, at 50 cents each, didn't come cheap. "We fry them to destroy the poison, then dip them in garlic and salt," a vendor said.[Source: Heidi Fuller-Love, Los Angeles Times, November 20, 2011 ^^^]

“Steeling myself for the big one, I browsed the stands, sampling crickets (bland and crunchy) and locusts (meaty and the legs stick between the teeth) before buying a bag of tarantulas. Shutting my eyes, I dipped my hand in the bag, pulled off a leg and nibbled. Surprisingly, once the initial revulsion wore off, the taste was not so bad. The texture of the a-ping was rough and crispy like a pork crackling, but inside it was tender and fatty and tasted a bit like cod. "The head is the best bit," said an old woman, with half a spider in her hand, half in her mouth. I decided to take her word for it and offered her the rest of my bag. She accepted gratefully and made short shrift of the three arachnids inside. ^^^

Studying Spiders

Spiderlogist capture their specimens with a plastic straw-like tube. When the scientist see a spider, he or she sucks on the straw. A "strategically placed nylon swatch" captures the prey and keeps it from zipping down the scientists's throat. Corn starch is sprayed onto webs so that scientist can observe their structure and shape with breaking the threads.

SpiderPharm is a company that raises black widows brown recluses, tarantulas and other poisonous spiders for their venom. Roderick MacKinnon, the winner of the 2003 Nobel Prize in chemistry, uses tarantula and scorpion venom to study potassium ion channels in cells.

Spider expert Jonathon Coddington works at the Smithsonian’s Museum of Natural History. Spider expert Fritz Vollrath occasionally takes spiders to a sychotron in Grenoble, France and places the spider on a little platform and hooks its thread to tiny reels that pull the thread out of the spiders body .at different speeds. The synchoton produces high energy X-rays that can be analyzed to give insights into how the silk and silk making glands respond to different stimuli.

Venomous Spiders

There are 200 kinds of poisonous spider. Some spider venoms make hole in cell membranes causing the cells to die. Most are designed to paralyze prey rather than kill it. That way prey remains fresh until it is eaten. Almost all spider have venoms which affect their prey, but is rarely harmful to humans. The fact that some spider venom is harmful to humans is a coincidence. Among these are the venoms produced by tarantulas, black widows and brown recluses.

A black widow bite can cause severe pain and muscle spasms. Brown recluse venom degrades tissue and produces a gangrene-like wound. Funnel spider venom leads to trembling, increased blood pressure and vomiting. Tarantula venom can inhibit the movement in signal-carrying ions in cell channels, resulting in numbing, paralysis, convulsions, high blood pressure, cardiac arrhythmia. Most victims of black widow or tarantula bites are advised to wash the wound with soap, place ice on it and take aspirin or acetaminophen. Brown spider bites, which attack tissue and cause necrotic lesions, require a trip to hospital

Wandering spiders (Phoneutria spp.) have some of the most potent venom on Earth. They get their name from their nighttime visits to the jungle floor to find prey. A wandering spider (family Ctenidae) usually consumes katydids on the forest floor in the rainforests of South America. Spider bites from this species are dangerous yet rarely fatal because of the small quantity of venom injected and available antivenom treatments.

The Brazilian wandering spiders is regarded as th world’s second most deadly venomous spider. It can grow up to five centimeters in body length, roughly the length of an adult's index finger, making them relatively big for a spide. During the day, they like to hide in banana plants and can find their way into banana shipments that travel to other parts of the world. They sometimes take shelter in the nooks and crannies of houses or cars and administer a nasty bite if threatened or touched. Females have more toxic venom than males, and a bite can lead to raised blood pressure, fever, vomiting, sweating and breathing difficulties. In some extreme cases, it can lead to paralysis, respiratory arrest and death, if left untreated

Recluse spiders (Loxosceles) are also known as brown spiders, fiddle-backs, violin spiders, and reapers, They are venomous spiders whose bite, which sometimes produces a characteristic set of symptoms known as loxoscelism, in which a dusky, shallow open sore forms as the skin around the bite dies (necrosis). It is the only known spider type that causes necrosis in humans. the Chilean recluse spider is regarded as the world’s third most venomous spider. As its name suggests, it is mainly found in Chile but it also has been seen in some parts of the U.S. and in Brazil. The bite can cause tissue damage which can take months to heal and can leave behind visible scars. In very rare cases, the toxins from a bite can lead to kidney failure and, very occasionally, can result in death. Chilean recluse spider are very similar to brown recluse spiders, the world’s fourth most venomous spider. They primarily reside in North America, and quite shy and retiring as their name suggests. You aren't likely to be bitten by one unless you accidentally step on it or touch it.

Australian redback spiders are regarded as the world’s fifth most venomous spider. They are black with a red stripe on their back, and are less than five centimeters (two inches) in length and and have a one centimeter (half inch) body. They produce venom equivalent to a bad bee sting that in some cases makes people sick for a couple of days. No one has died from a redback bite in Australia since the antitoxin was developed in 1956. Redbacks are very common and few people have ever been seriously hurt by them. A popular schoolyard goes" "There was a redback on my toilet seat when I was there last night. I didn't see it in the dark, but boy I felts its bite.” One Australian journalist told the Washington Post, "It's impossible to live in Australia and not see them. They're fairly timid spiders...But Japan is in a panic. The whole thing is hilarious." [Source: Kevin Sullivan and Mary Jordan, the Washington Post]

Funnel Web Spiders — the World’s Deadliest Spiders

The funnel web spider is recognized as the deadliest spider in the world. Native to Australia, its venom contains 40 different toxic proteins, according to Mount Sinai School of Medicine. This spider was responsible for several human deaths in the Sydney area, but no deaths have been reported from a funnel web spider in Australia since 1980. [Source: Olivia Munson, USA TODAY, February 26, 2023]

Native to Australia and New Zealand, atrax spiders, which include the funnel web spider, are said to be "very large, very poisonous, very aggressive; lunges at prey or in self defense...Bite: painful...may include muscle spasm, profuse sweating, high blood pressure, fluid in lungs, coma."

According to the BBC the funnel-web spider is also one of the most aggressive and deadliest creatures on Earth. It is incredibly defensive, and because of this can bite several times in a single attack. The bite itself is very painful, and symptoms can arise quickly. If a bite is left untreated it can lead to serious illness and even death. Children are especially susceptible to bites and must be taken to hospital as soon as possible if bitten. [Source: James Cutmore, BBC, November 2, 2024]

Black Widow Spiders

The black widow spider (Latrodectus Hesperus) can be identified by a red hourglass marking on it belly. Its venom is more potent that of a rattlesnake. Still death occurs at most to a few people a year in part because the amounts of venom the spider injects is relatively low. Symptoms include chills, breathing difficulty and muscle cramps. An antivenin has been developed. Widow spiders get a bad rap for their bites, which can be very painful to humans but rarely cause death. The species like to weave their haphazard cobwebs in urban and suburban environments and often come into contact with humans

Matt DiSanto wrote: Black widow spiders are usually found in dark and undisturbed places, including under stones, in stumps or woodpiles, in dark corners of barns and garages and other undisturbed cavities, such as vacant animal burrows. They typically make their webs outdoors in undisturbed areas or indoor non-living spaces such as garages, Skvarla says. Unlike some other species, their webs are often skimpy and unorganized. [Source: Matt DiSanto, State College Centre Daily Times, October 25, 2023]

Black widow bites come primarily from adult female spiders, and especially those protecting an egg sac, Penn State Extension notes. At first, bites appear painless before symptoms arrive an hour or two later, usually including any of the following: nausea, chills, slight fever, raised blood pressure, retention of urine, burning sensation of the skin, fatigue, motor disturbances, breathing difficulty, constipation and muscle aches, particularly in the abdomen.

“Small children and the elderly are more susceptible to the venom due to their smaller body mass or generally frailer condition, so are more likely to have adverse or severe effects,” Skvarla wrote. “So, a bite is certainly not a pleasant experience, but it’s usually not as bad or threatening as most people perceive them to be.”

Though a rare black widow bite is frightening, it is unlikely to turn fatal, researchers say. The 2021 National Poison Data System report from America’s Poison Centers reported zero fatalities following 1,004 black widow bites. Some people may wind up facing more complications from an allergic reaction to antivenin — a treatment for black widow bites developed from horse serum — than a bite on its own, Skvarla wrote.

According to Gizmodo: Black widow spiders across the southern United States are getting eaten up by brown widows, their lesser-known cousins, according to research investigating the relationship between the two arachnids. Three species of black widow are native to the United States; brown widows are believed to be native to Africa but are now present on all continents but Antarctica. While black widows are a shy spider species — only getting aggressive when they are pinched or pressed — brown widows seek out black widows to bite. Bit(e) by bit(e), in a pattern first noticed a decade ago, the black widow spiders are being displaced by the interlopers according to a study published in March 2023 in the Annals of the Entomological Society of America by a team led by spider biologist Louis Coticchio. [Source: Isaac Schultz, Gizmodo, March 13, 2023]

Theatened Spiders and the Arachnid Trade

Describing a stroll through Costa Rica’s Area de Conservacion Guanacaste rainforest, evolutionary ecologist Daniel Janzen in 2019 wrote: “Gone are the spiderwebs that decades back entangled those leaves. Gone is the nighttime sparkle in the leaves reflected from thousands of lycosid spider eyes.” [Source Julia Janicki, Gloria Dickie, Simon Scarr and Jitesh Chowdhury, Reuters. December 6, 2022]

Otherwise it is difficult to gauge how threatened spiders and arachnids are because there is relatively little research on the subject. In a paper published in Communications Biology in May 2022, a team led by Alice Hughes, a conservation biologist at the University of Hong Kong, addressed the largely unregulated trade of arachnids by analyzing the online sales listings of more than 1,200 species of spiders, scorpions and other arachnids. Just two percent of them are subject to international trade regulations, the researchers said. “Arachnids are being massively traded,” Hughes said. “And it seems to be going completely under the radar.” To learn about the scale of the global arachnid trade, the authors of the paper used a handful of search terms — “spider,” “scorpion,” “arachnid” — in nine languages to identify websites that might be selling the animals.

Emily Anthes wrote in the New York Times: Many organisms in the arachnid marketplace appear to have been caught in the wild rather than bred in captivity, the study found, and the ecological impact of their harvest remains unknown. “They’re just being removed willy-nilly in large numbers,” said Anne Danielson-Francois, an arachnologist and behavioral ecologist at the University of Michigan-Dearborn who was not involved in the new research. She added, “They’re not this unlimited resource.” [Source: Emily Anthes, New York Times May 22, 2022]

There’s a large and growing demand for invertebrates, experts said, and arachnids make popular pets. They are a cinch to ship — “You can literally mail an envelope of little spiderlings” Hughes said — and many species are relatively easy to care for. “They don’t bark, they don’t need to go for walks — you can set up a simple arachnid in a 5-gallon tank on your shelf,” said Ernest Cooper, an independent wildlife-trade expert in Canada. “They have fascinating behaviors. Some have bright colors.”

Image Sources: Wikimedia Commons

Text Sources: Mostly National Geographic articles. Also David Attenborough books, Livescience, New York Times, Washington Post, Los Angeles Times, Smithsonian magazine, Natural History magazine, Discover magazine, The New Yorker, Time, Newsweek, Reuters, AP, AFP, Lonely Planet Guides, and various books and other publications.

Last updated December 2024