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What spider is this? Is it dangerous to humans?

What spider is this? Is it dangerous to humans?


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What is the species? Is it dangerous to humans?

I chanced upon this beautiful one near our water well. It stood at a height where an adult could accidentally walk through the web and the spider would land on one's face.

As a test, I dropped a piece of leaf onto its web, and the spider jumped to action, checking what it was and it took out the leaf from its web.

Size: Web, almost circular 50 cm diameter. Spider, about 8cm.
Location: Malabar region, Kerala state, south of India


This is most likely a spider from the genus Argiope, which has a few members native to India. See here for a list, I think this is most likely Argiope pulchella, see the image from the Wikipedia:

Wikipedia also says that these spiders hunt insects, but are not dangerous for humans.


It's a St. Andrews Cross Spider (Argiope keyrselingi), and quite common in Australia too.

Thankfully, one of the non-toxic non aggressive spiders. Here are some good sites for further information on them:

A Spider Identification site: http://www.spiders.com.au/st-andrews-spider.html

And the Australian Museum site: http://australianmuseum.net.au/st-andrews-cross-spider


Human fear of spiders draws scientific focus

Female comb-footed spider (family Theridiidae), Enoplognatha ovata. Photographed in the wild at DuPage County, Illinois, USA. Size = 15mm. Credit: Bruce Marlin/Wikipedia/CC BY 3.0

A fear of spiders, arachnophobia, is in our DNA. You don't learn to freeze at the site of these creatures you're born with the fear. Even the sight of hypodermic needles and houseflies does not trigger a similar response. Scientists pin that fear on survival instinct. The theory goes like this: Humans evolved in Africa where being able to spot a spider was of necessity.

Some dangerous spider species may have been common during our evolutionary history. A number of species with potent venoms populated Africa before hominoids and have co-existed there for tens of millions of years. A black widow spider bite in the ancestral world even if not fatal could leave one incapacitated for days or weeks.

Joshua New, Department of Psychology, Barnard College and colleague Tamsin German, wrote "Spiders at the cocktail party: an ancestral threat that surmounts inattentional blindness," which has been published in Evolution and Human Behavior. The paper stated that the human visual system may retain ancestral mechanisms uniquely dedicated to the rapid detection of immediate and specific threats, such as spiders and snakes, which persistently recurred throughout evolutionary time. The authors concluded that "Spiders may be one of a very few evolutionarily-persistent threats that are inherently specified for visual detection and uniquely 'prepared' to capture attention and awareness irrespective of any foreknowledge, personal importance, or task-relevance."

New and German asked their participants to look at abstract shapes and data on computer screens. Among those images were needles and flies. Results, as reported in the Daily Sun: "Of the 252 people reviewed in the study, most recognized the spiders much quicker than other images known to induce fear, such as flies and needles."

Spider images got more attention the viewers spotted them and knew what they were. The authors reported that, "Despite their highly marginalized presentation, iconic spiders were nonetheless detected, localized, and identified by a very large proportion of observers."

Their test, said the authors, made use of the "inattentional blindness paradigm" in which an unexpected, peripheral stimulus is presented coincidentally with a central task-relevant display. Last year, Inside Science turned to the spider study which had been published online. Inside Science described how the study was designed: "To see if there is something special about spiders, the researchers showed people a cross shape that flashed in the middle of a screen for an eighth of a second. The participants' task, as far as they knew, was to judge which of the two bars on the cross was longer. During the first three trials, only the cross appeared. On the fourth trial, another image appeared at the same time. The possible images included a spider, a hypodermic needle, a housefly, and abstract shapes made by rearranging the lines of the spider."

People were asked if they saw anything other than just the cross and, if so, in which part of the screen. They also tried to identify the image by selecting it from a lineup.

New's study reflects a question that scientists have posed before about human reactions to spiders: In 2008, the study "Do infants possess an evolved spider-detection mechanism?" appeared in Cognition. Babies looked at spiders longer than they looked at other images. Authors David Rakison and Jaime Derringer talked about "an evolved predator recognition mechanism that specifies the appearance of recurring threats."

The results, they said, supported the hypothesis that humans "may possess a cognitive mechanism for detecting specific animals that were potentially harmful throughout evolutionary history."

Rakison said in Inside Science that "At least with children, there's very little conflicting evidence that spiders and snakes have some kind of privileged nature in human visual processing."


The Human-Spider Struggle

In April of 2017, researchers Martin Nyffeler and Klaus Birkhofer published a paper in The Science of Nature, a multidisciplinary peer-reviewed science journal, on how much spiders eat every year. The quantity was astonishing: altogether, the global spider community consumes somewhere between 400 and 800 metric tons of insects annually. In other words, as the Washington Post put it, the world’s spiders could eat every human on earth in only 365 days.

This is exactly what some people have been worried about.

Humans have long had irrational feelings for (and homicidal tendencies toward) spiders. On the one hand, we worship spiders as symbols of wisdom and creativity (think Spider Woman, a helper and protector of humans in southwestern Native American cultures or Anansi, the West African trickster appearing in fables told throughout the African diaspora). On the other hand, we have stories such as Arachnophobia and tales of tarantism, a medieval phenomenon in which one supposed victim of a “tarantula” bite (in actuality, tarantulas are a species of wolf spider whose venom is not harmful to humans) would find a “cure” through a fit of dancing the tarantella, setting off mass hysteria as additional “victims” joined the dance, sometimes overwhelming entire towns.

Why are spiders so terror-inducing for some of us? Scientists, too, have been bugged by this question. Multiple studies in 1980s Europe documented that spiders were one of the top five most feared animals, but they’ve struggled to definitively explain why so many people find spiders so terrifying. Broadly speaking, decades of dueling journal articles have established two schools of thought on the origins of spider phobias: a biologically based reaction, transmitted genetically from our ancestors as a survival mechanism, or a disgust-driven response tied to our individual tolerance for dirty, and potentially diseased, environments and objects. It’s essentially “spiders are dangerous” versus “spiders are gross.” In both cases, this is a matter of perception, not reality—only 0.01 percent of the 40,000 species of spiders in the world are dangerous to humans, and evidence suggests spiders do not transmit disease to humans.

No consensus exists on the theories proposed by either camp. One 2017 study found that babies negatively respond to snakes and spiders, suggesting an intrinsic, biologically based fear, but other researchers are quick to point out that if we’re evolving fears to protect ourselves, we should be similarly terrified of wasps (which, surprisingly, we aren’t). Graham C. L. Davey, an emeritus professor of psychology at the University of Sussex who researches anxiety and worry, has noted that fear of spiders does correspond to a greater disgust response to other “gross” animals—slugs, leeches, cockroaches, etc.—and this forms the basis for the counterargument to the innate-fear theory. Davey points out that this association is stronger in some cultures than others. Medieval Europeans, for example, associated spiders with transmission of disease, but if their belief was a rationalization of an innate, biologically induced fear of spiders, we’d expect it to be more universal across cultures. In fact, in many other areas of the world, spiders are viewed neutrally, or even positively, including in areas that actually do have a number of extremely dangerous spiders, like South America.

Although we can’t find scientific consensus on why humanity has a long-standing fear of spiders, we have gleaned some insights into what exactly makes spiders so unnerving. In 1996, psychology researchers from Flinders University of South Australia surveyed 192 volunteer subjects, mapping fear of spiders against four qualities—“disgust,” “dangerousness,” “unpredictability,” and “uncontrollability”—that make an individual feel vulnerable. They found that fear of spiders correlates strongly with all four “vulnerability variables.”

In other words, the spider is icky, the spider might be venomous, the spider might crawl up your arm, and if the spider wants to bite you, the spider is going to bite you—an all-encompassing nightmare spider experience. Or as my husband, a noted spider hater, puts it: “They’re so small. They could be on me and I don’t even know it. They could go inside my mouth.” (Spiders almost certainly do not want to go inside your mouth, even when you are sleeping.)

It is possible for people to overcome their arachnophobia. One doctor I spoke to said that educating people about arachnid biology is an effective technique, particularly when paired with gradual exposure to spiders in various states of living and captivity. But not fearing something is not the same as liking it. And some people do like spiders. “I had a traditionally geeky childhood,” says science fiction and fantasy author Adrian Tchaikovsky, who won the Arthur C. Clarke award for 2015’s Children of Time, about a planet of hyper-evolved spiders. That interest in science fiction, fantasy, and other realms of the uncool resulted in Tchaikovsky’s being “somewhat estranged from others,” and led him to develop an affinity for animals that were similarly cast out, like spiders, snakes, and insects. Tchaikovsky’s readers appreciate his own appreciation of arachnids. In addition to Children of Time, his series Shadows of the Apt and his 2016 novel Spiderlight focus on insects and spiders—and the author worked with zoologists to ensure that spiders were presented accurately in Children of Time (well, aside from evolving human-level intelligence and growing much closer in size to people).

If you can’t appreciate spiders for their outsider status, you can at least admit they have a lot going for them, ecologically speaking. Spiders should be kept alive to destroy other, even less appealing, insects in both small spaces (your bathroom) and large properties (farms). Dr. Alan Cady of Miami University—whose affection for spiders accompanied a general childhood interest in science and zoology—is currently researching how spiders can be used as biological pest control for crops. Using other animals for this purpose has not worked in the past (famously, the cane toads introduced to protect sugarcane plantations from beetles in Australia both failed to protect the sugarcane harvest and disrupted the local ecosystem) but in Cady’s previous studies, he has proved the capacity existing native spider populations have for eating unwanted insects. Creating refugia, areas where a species can survive through unfavorable conditions, for spiders in cornfields has resulted in statistically significant increases in crop yields, presenting a potential low-cost, pesticide-free method of protecting young crops.

I’m not afraid of spiders, to be honest. Growing up, the onset of fall meant a home invasion of wolf spiders. The walls weren’t crawling with them, but you’d try to retrieve a pan from a lower cabinet or visit the laundry room late at night and—surprise!—a big boy, America’s largest wolf spider, suddenly right in front of you. I never managed to squash them (sorry, Spider Grandmother), because not only were they fast, they were extremely determined to get away from me. And that, I realized, was the heart of it the spiders, as fear-inducing as they could be, just wanted to get away from the giant noisy things with weirdly reduced numbers of eyes. They’re just different, and a little misunderstood, which is something we can all relate to (at least sometimes). Plus, they eat mosquitoes, which are unquestionably the worst animals on earth.


What spider is this? Is it dangerous to humans? - Biology

Danger time - the mature male funnel-web spider will wander around during hot humid nights, looking for a mate, and is known to enter homes, footwear, clothing, washing and swimming pools where they can survive several days under water. It is highly aggressive when disturbed or cornered and is able to inflict multiple bites, with its "flick-knife" hardened fangs. People also find funnel-web spiders wandering around the garden or in the home after heavy rain or nearby earthworks. An anti-venom is available in most major hospitals and ambulance vehicles in "funnel-web country". First aid and medical attention (ambulance) should be sought as soon as possible, if bitten.

Spider Identification - an adult male 25 mm - female 30 mm in body length - shiny black in colour with a dark purplish brown abdomen- reddish hairs. Unique attributes include it's long spinnerets, that is , the 2 appendages on the end of the abdomen and the male has a spur on 2 of it's legs - refer to illustration on left.

Area of distribution - the Sydney Funnel-Web Spider is a ground dweller in moist soil areas along much of the eastern coastal area of New South Wales and Victoria.

The Blue Mountains Funnel-Web Spider is found mainly in the Blue Mountains area, as far west as the Bathurst - Orange region and occasionally in the Sydney basin.

The Northern Tree Funnel-Web Spider is found in south-eastern Queensland and northern New South Wales as far south as the Hunter Valley region.

Red-Back Spiders. highly venomous - can be deadly

Area of distribution - Australia-wide.

Spider Identification - size varies greatly - the male can be tiny, with the abdomen of the female growing to the size of a large pea. Red-Back Spiders do NOT always have a "red" marking.

Habitat - prefers dry habitats - often found in out-houses, letter boxes, undersides of seats, in rubbish, such as empty cans, in the sub floor and other dark areas. Electric lights attract their prey - moths, flies, mosquitoes and other insects.

White-tailed Spiders: venomous - dangerous?

Area of distribution - Australia-wide.

Spider Identification - adult size varies 12 to 20 mm in body length - grey to black in colour with a white section on the end of it's tail - as illustrated.

Habitat - prefers cool moist location - commonly found in garden mulch areas. In summer, it often wanders into buildings, particularly bathrooms, to escape the heat.

Mouse Spiders. venomous - painful bite

Area of distribution - Australia-wide.

Spider Identification - a medium to large spider of up to 35 mm in body length. The male Mouse Spider often has a bright red head and elongated fangs.

The Mouse Spider is often mistaken for the Funnel-Web Spider. The main differences being the Funnel-Web has much longer spinnerets (the 2 appendages on the end of the abdomen) and the male funnel-web has a spur on it's second leg - as illustrated above.

Habitat - Mouse spiders are ground dwellers with burrows of more than 1 metre deep. The male often wanders about during the day on open ground, especially after rain, in search of females.

Black House Spiders. venomous - nausea


Venom toxicity - the bite of the Black House Spider is poisonous but not lethal. Certain people bitten experience severe pain around the bite site, heavy sweating, muscular pains, vomiting, headaches and giddiness. First aid and medical attention (ambulance) should be sought as soon as possible.

Area of distribution - Australia-wide.

Spider Identification - adults are about 15 mm in body length and of a dark brown to black velvet textured appearance.

Habitat - this spider spins a lacy, messy web and is prefers dry habitats in secluded locations. It is commonly found in window framing, under eaves, gutters, in brickwork, sheds, toilets and among rocks and bark. Electric lights attract their prey - moths, flies, mosquitoes and other insects.

Area of distribution - Australia-wide.

Spider Identification - an adult is 15 mm to 30 mm in body length - mottled grey to brown in colour, with a distinct Union Jack impression on it's back. The female carries it's young on it's back.

Habitat - this spider is a ground dweller, with a burrow retreat. It has a roving nocturnal lifestyle to hunt their prey and can move very rapidly when disturbed. Commonly found around the home, in garden areas with a silk lined burrow, sometimes with a lid or covered by leaf litter or grass woven with silk as a little fence around the rim of the burrow.

Trap-Door Spiders. low risk - non-aggressive

Area of distribution - Australia-wide.

Spider Identification - an adult is about 35 mm in body length - brown to dark brown in colour - heavily covered with fine hairs. The male has distinct boxing glove-shaped palps, that is, the two "sensory feelers" at front of it's head.

Habitat - this spider is a ground dweller, with a burrow retreat lined with silk of up to 250 mm in depth and around 25 mm in width - prefers nesting in drier exposed locations - often has a wafer-like lid on the burrow entrance. Trap-Door Spiders are commonly found in the drier open ground areas around the home.

Orb-Weaving Spiders. low risk - non-aggressive


Venom toxicity - the bite of Orb-Weaving Spiders is of low risk (not toxic) to humans. They are a non-aggressive group of spiders. Seldom bite. Be careful not to walk into their webs at night - the fright of this spider crawling over one's face can be terrifying and may cause a heart attack, particularly to the susceptible over 40 year olds.

Area of distribution - Australia-wide, particularly common in bushland along the eastern coastal areas.

Spider Identification - an adult is about 20 mm to 30 mm in body length - has a bulbous abdomen - often colorful - dark to light brown pattern. The common Golden Orb-Weaver Spider has a purplish bulbous abdomen with fine hairs.

Habitat - often found in summer in garden areas around the home - they spin a large circular web of 2 metres or more, often between buildings and shrubs, to snare flying insects, such as, flies and mosquitoes.

St Andrews Cross Spiders. low risk - non-aggressive



Venom toxicity - the bite of the St Andrews Cross is of low risk (non-toxic) to humans. They are a non-aggressive group of spiders.

Area of distribution - Australia-wide.

Spider Identification - adult 5 to 15 mm in body length - abdomen striped yellow and brown - as illustrated. The St Andrews Cross Spider usually sits, upside down, in the middle of it's web forming a cross - as illustrated.

Habitat - this spider is a web-weaver usually found in summer in garden areas around the home. It is considered beneficial as it spins a large web to snare flying insects, such as flies and mosquitoes.

Huntsman Spiders. low risk - non-aggressive


Venom toxicity - the bite of Huntsman Spiders is of low risk (non toxic) to humans. They are a non-aggressive group of spiders. However, a large individual can give a painful bite. Beware in summer when the female Huntsman Spider is guarding her egg sacs or young.

Area of distribution - Australia-wide.

Spider Identification - an adult varies greatly around 15 mm in body length - has long legs - the diameter of an adult including legs may reach 45 mm - the first 2 pairs of legs are longer than rear two - it is hairy - buff to beige brown in colour, with dark patches on the body.

Habitat - a hunter that prefers to live under the flaking bark of trees, under flat rocks and under eaves or within roof spaces of buildings. The Huntsman Spider often wanders into homes and is found perched on a wall. It is a shy, timid spider that can move sideways at lighting-fast speed when disturbed.


Spider Myths

As the only spider specialist in a large metropolitan area, I get many spider inquiries from the general public. Since I'm mentioned on the Internet as a spider specialist, some of the public inquiries come from distant places. When I lecture on spiders, adult and child audiences always have questions and comments. So do casual acquaintances when they learn that I work with spiders.

These people's concerns come from a widespread and surprisingly uniform set of assumptions and "general knowledge" about spiders. And almost all of this widespread spider information is false!

I don't really expect that the following, by itself, will make much headway against the flood of spider misinformation. However, I hope that those curious about spiders who find their way here will absorb enough information to ask me some new questions instead of the same old ones. I can hope, can't I?

Questions and Comments. For general spider information go to our resources page . To suggest improvements or additions, or to ask a question, please contact me . But if you hope to show that any of the following myths is actually true, please be prepared with verifiable evidence including actual specimens…


Venomous Hobo Spider Bites May Be Not So Toxic After All

Whether the bites of the hobo spider are toxic to people has been a matter of scientific debate, but a new study suggests the spider's venom may be less harmful than many people think.

With black widows and brown recluse spiders, hobo spiders are listed by the Centers for Disease Control and Prevention as one of the three venomous spiders that can be found in the United States, that can be dangerous. In some cases, hobo spider bites have caused necrosis, which is the death of cells or tissue, according to a 1996 report from the CDC.

However, researchers have questioned for years whether there is actually sufficient evidence that hobo spider venom can indeed cause necrotic skin lesions, and how dangerous to humans these spiders really are. Moreover, hobo spiders are considered innocuous in Europe, and previous research comparing the venom of American and European members of the species did not find significant differences between the two. [Creepy, Crawly & Incredible: Photos of Spiders]

"There is a psychological thing about spiders, that people just want to believe that spiders are doing the damage," said study author Richard Vetter, an arachnologist at the University of California, Riverside. People may readily conclude that a spider caused an injury they actually incurred from something else, he said.

Venomous bites

Hobo spiders are moderately large, measuring about a quarter-inch to a half-inch (7 to 14 millimeters) in body length, with a 1- to 2-inch (27 to 45 mm) leg span. The brown and grey spiders are native to Europe, and were probably introduced into the Seattle area in the 1920s or early 1930s. They have since spread through the Pacific northwest. The spiders build funnel-shaped webs in dark, moist areas, and are fast runners &mdash moving up to 3 feet (1 meter) per second.

In the new study, Vetter and his colleagues examined 33 reported, verified spider bites that occurred in Oregon over three years. Different spider species perpetrated the bites, with one coming from a hobo spider.

The researchers examined the symptoms of the spider bite victims. Unlike some previous studies on spider bites, the researchers looked only at reports in which people actually caught the spiders that bit them, and submitted the eight-legged beasts as evidence.

It turned out that none of the spider bites in the sample, including the one inflicted by the hobo spider, resulted in dermonecrosis &mdash the death of skin cells. The victim of the hobo spider suffered only pain, redness and twitching.

"Spiders are a very handy scapegoat to blame all the time" because, historically, people have had a negative view of spiders, Vetter told Live Science.

At the outset of the study, the researchers had wanted to look at a series of cases of hobo spider bites. But over the three-year period, the researchers found only one such report. And while this may not necessarily mean that hobo spiders rarely bite people, there is not sufficient evidence to prove that they are "common biters," either, Vetter said.

A handy culprit?

Previous reports of hobo spider bites have cited largely circumstantial evidence, with people reporting bites without providing evidence they were actually bitten by a hobo spider, or any spider at all, the researchers said. People may blame other medical conditions, for instance, skin conditions, on spider bites.

"Spider bite diagnoses are very handy diagnoses for a lot of doctors," Vetter said. "They can't be proven wrong, and 90 percent of everything heals by itself anyway."

Other researchers agreed with the idea that hobo spiders are not dangerous.

"I actually believe that it's not at all a real thing that the hobo spiders" have bites that can kill human skin tissue, said Christopher Buddle, an arachnologist at McGill University, who was not involved in the study. "I think it has largely been almost a hoax," he told Live Science.

The new study, which gathered data on the bites of a range of species of spiders, was quite valuable, because researchers don't know much about the potential medical importance of a lot of these species, Buddle said.

The fact that the researchers found just one case of a hobo spider bite, and no evidence of skin necrosis is interesting in itself, Buddle said. That result "suggests that maybe the fear around the hobo spider has really been overblown," he said.

The few previous reports of hobo spider bites also failed to show evidence of skin necrosis, Buddle said. "There is a lot of fear around spiders that gets proliferated online and in the media that's just not warranted," he said.


How to Manage Pests


Mature adults of Zoropsis spinimana are long-legged spiders with bodies about 1/2 to 5/8 inch long and leg span of 1 to 1 1/4 inch. A female is shown here.


A female Zoropsis spinimana spider. A male spider will have a relatively smaller abdomen and longer legs. Spines occurring on the undersurface of the leg are visible as small hairs jutting from the lateral portion of the legs.

In the mid-1990s, Zoropsis spinimana, a large spider from the Mediterranean region, started showing up in homes around the San Francisco Bay area. It has since become well established around the southern, eastern, and northern portions of the Bay and has become a permanent member of the California spider population. Although the known distribution is not very extensive, this spider does inhabit a part of the state that is densely populated by humans and Zoropsis is routinely found in homes, causing concern among the people who encounter it. However, it is harmless to people. This Pest Note was prepared to provide information regarding this non-native resident.

The first California reports of Zoropsis spinimana were from the Sunnyvale area in Santa Clara County in 1992. Since then the spider has mostly spread north and east around the San Francisco Bay area with specimens found throughout Santa Clara, San Mateo, Alameda, Marin, and Santa Cruz Counties. Scientists at the California Academy of Sciences in San Francisco are tracking the spider&rsquos spread. So far, Zoropsis spinimana seems to be found only in and around human dwellings. However, it is also possible that this spider is establishing itself in natural vegetation areas.

IDENTIFICATION AND BIOLOGY

Mature adults of Zoropsis spinimana are long-legged spiders about 1/2 to 5/8 inch in body length and with a leg span of 1 to 1 1/4 inches. Females have slightly larger bodies and shorter legs than males. For the most part, the Zoropsis spider is a typical brown spider of varying shades of brown mixed with little black markings over most of its body. In many respects, it resembles a wolf spider. One distinctive mark is a longitudinal, black mark with several outward flares on the central top surface of the abdomen, near the cephalothorax (the part of the spider to which the legs attach). Be aware that there are some species of wolf spiders that also have a black mark in this area but most often, the wolf spider mark is diamond-shaped with only one flare at the center. Zoropsis spiders also differ from wolf spiders in the eye arrangement. Zoropsis eyes are restricted to the front edge of the cephalothorax in wolf spiders the eyes are spread across the front third of the cephalothorax. Zoropsis spinimana can be distinguished from other common household spiders by these features: its abdomen is elongate (never globular) and it is never found in orb webs hanging between trees or on porches.

Zoropsis spinimana is a hunting spider (like wolf spiders), meaning it does not spin a web or use silk to subdue prey. Its silk is used primarily by the female to cover her egg sac. Like other spiders, its diet is primarily insects. Little information is available about the biology of this spider.

Most specimens that have been submitted for identification are mature males and females this means that people are finding wandering spiders that are searching for mates or roaming in search of food or for other reasons. Mature specimens have been found from September to May and are commonly encountered throughout the winter. It is not known where the immature spiders spend the summers or if this spider requires more than one season to mature.

Despite the fact that this spider is large enough to be intimidating, Zoropsis spinimana is harmless. No spider in this genus is known to be medically important and there are no verified accounts of bites by this spider causing any significant medical problems.

MANAGEMENT

Zoropsis spiders are harmless and control of them is unnecessary. The ones you encounter will be wandering adults so there is little you can do to prevent them from showing up in your home. If you feel you must do something, general spider preventive measures include reducing the clutter around your home, which eliminates hiding places that spiders find attractive. Adding weather-stripping around the base of doors will help keep spiders and insects from entering your home. It is unlikely that you will encounter more than one of these spiders at once Zoropsis spiders do not appear in groups or invade in large numbers. Capturing and placing the spider outside will probably end your arachnid encounter and will not increase the probability of running into the spider later on. You can remove a spider from your home by placing a jar over it and slipping a piece of paper under the jar so that it seals off the opening of the jar when it is lifted up.

REFERENCES

Griswold, C. E., and D. Ubick. 2001. Zoropsidae: a spider family newly introduced to the USA (Araneae, Entelegynae, Lycosoidea). J. Arachnology 29:111-113.

Vetter, R. S. 2007. Pest Notes: Spiders. Oakland: Univ. Calif. Agric. Nat. Res. Publ. 7442.

PUBLICATION INFORMATION

Pest Notes: Zoropsis spinimana

Authors: R. S. Vetter, Entomology, UC Riverside D. Ubick, Entomology, California Academy of Sciences, San Francisco.

Produced by University of California Statewide IPM Program

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Statewide IPM Program, Agriculture and Natural Resources, University of California
All contents copyright © 2019 The Regents of the University of California. All rights reserved.


9 thoughts on &ldquo Why are So Many People Afraid of Spiders? &rdquo

There were a lot of different theories for why people are afraid of spiders, one that I found interesting and never even thought of that that your website also mentions is the idea that spiders used to be more of a threat to humans in earlier times. I would definitely agree that the media has made the fear of spiders worse and makes people think spiders are scarier than they actually are. They are usually portrayed as evil and dangerous in movies, and even on television they will really on show and talk about the dangerous spiders. While these programs on networks like Discovery are correct, it could lead someone to believe that a lot more spiders are dangerous than what actually is true.

I’ll first admit that for my entire life I have been afraid of spiders. I like how you use meta-analysis in your post and talked about different studies about spiders. I guess you’re right spiders do move around weirdly, but I don’t think that’s the main reason why people are scared of them. Another interesting point that you bring up is the fact that in some parts of the world people aren’t scared of spiders. I found this article and it talks about how elementary school children think that spiders are dangerous. I feel that TV is to blame for many people being misinformed about Spiders. Here the is the article I was talking about, definitely check it out.
http://www.newstatesman.com/sci-tech/2014/01/why-are-we-afraid-spiders

Hi Claire, thanks for your reply that was a really interesting perspective to read. Your psychology professor did the typical progression for getting over a fear, by basically trying to get you to slowly realize that the spider is not as scary as it seems and trying to get you to realize that the fear was all in your head. Were you able to do all of the different steps without an increase in heart rate? If not, at what point were you no longer able to maintain a normal heart rate? Was holding the spider torturous from the very beginning or was it after a certain amount of time that it became torturous? Would you say that your arachnophobia is manageable? Like are you able to go outside and not worry about spiders unless you come into contact with one? That’s interesting that you have a good idea where the fear came from, seems like it’s a combination of learning to hate them from other people as well as a traumatic experience when you were young. Yes, I have seen a picture of a wolf spider before, those spiders are huge!

I have extreme arachnophobia, so this article was very interesting for me to read, but only after shivering and having to get past the first image in your post. My psychology teacher last year attempted to rid me of my chronic fear. Every day, I would spend 30 seconds staring at a picture of a spider and measured my heart rate. After being able to look at the spider picture for that long and having my heart rate be normal, we would progress to one minute and again measure how my heart rate would increase. This would continue to touching a picture of a spider for a period of time, having a spider in a plastic case in the corner of the room, having the plastic case on my desk, and eventually, at the end of the semester, being able to hold the spider in my hand without an increase in heart rate, ridding me of my fear. This strategy did not work for me. Needless to say, I still hate spiders. I got to the point where it was on my desk and could not handle it for an entire class period. Having to touch the spider was torturous, and my teachers plan and experiment failed, but I’m sure this approach works on some people and is an effective way to get over your arachnophobia. I also know where my fear stems from. Like you wrote about in your post, I know where my fear stems from. When I was a child, both of my older sisters were deathly afraid of spiders, influencing my view of them to be deathly scary insects. Also, when I was a baby, I was crawling after a Wolf Spider thinking it was a toy (I do not suggest googling that too see one), and my mother scooped me away screaming. So I believe those events are what made me fear spiders so much today, plus, they are just freaky, hairy, and have six too many eyes. I have tried to cure my fear as your post suggests with no success. However, this post was very interesting for me to read and it can help a lot of other people! It’s important to know where your fear stems from, and different ways it can be cured.
-Claire

Catherine, I do not mind spiders at all but I will still kill them most of the time if they are in the house. Just because that seems like the normal thing to do and just not wanting bugs in general in the house. I found it really interesting that the fact that spiders have two more legs than insects is a big reason why people don’t like them and are fearful of them. I thought the biggest reason by far was the fear of getting bit by them, but that doesn’t seem like a huge concern. This article also says a big reason for the fear is “their angular shaped legs, dark colors and the fact they move unpredictably are all things we are hard-wired to fear. He said studies have shown that people tend to dislike angular shapes and prefer curved ones, have bad associations with dark colors, and prefer creatures we feel we can ‘understand’” (Cohen 2012). It’s interesting how humans can be ‘hard-wired’ to fear certain things.

Michael, I have actually felt a similar sensation before, I knew exactly what you meant when I started reading it. When I was younger I would sometimes get the feeling that ants were crawling on me before falling asleep. I don’t really have an explanation for this, obviously it was just in my mind and not actually happening but I don’t think I used to be scared of ants or anything. So I’m not sure why I experienced this tingling sensation unless there was another reason for it. I tried searching for an article that could explain this, but did not find anything that made sense for me.

This is a great blog, because i do in fact think many people are scared of spiders. I have never liked spiders, but i am usually one to get rid of them shall we say. My mom has always told me they are more scared of me, because i am like a giant to them but i can never shake the feeling of just letting them go. However, i can never seem to get rid of the creepy 8 legged ones that come out of the drain in the sink or in the shower. The way they crawl gives me the chills, especially when they are in the same shower i shower in everyday to get clean. You say that spiders use to be more dangerous to humans in ancient times, but as far as i am concerned, they will always be dangerous to me.

Throughout my entire life I have been petrified of spiders. No matter how big or small whenever one crosses my path I immediately get the chills and feel a tingling sensation going down my body. To some degree I feel as though I have Morgellons Disease, which is the feeling of bugs crawling on you. Here is an link to an article that goes more into detail about it. Click Here


New Translucent Spider Discovered Living in Muddy Indiana Cave

Scientists have discovered a new species of sheet-weaving spider , and it only dwells in one cave in southern Indiana. A s its name suggests, this spider spins flat, tightly-woven, horizontal webs. There are thousands of species of sheet-weavers, and you’ve probably walked through one of their webs by accident some point.

“In the morning when there’s dew on the grass, and you see the little horizontal webs—those are sheet webs,” Marc Milne told Gizmodo. Milne is an arachnologist at the University of Indianapolis who identified the new spider in Indiana.

This new sheet-weaver, dubbed Islandiana lewisi, is most likely not dangerous to humans. It’s only about 2 millimeters long and probably eats other small arthropods, like springtails.

“Springtails are like little lunch sacks for spiders. They’re soft and packed with nutrients,” Milne said. “When the springtails hop into the air, they can land and get stuck in these sheet webs.” Though he hasn’t observed it directly, Milne thinks this is what’s happening in Stygeon River Cave where I. lewisi live.

As described in his study published in June in Subterranean Biology, Milne named the new spider lewisi as a nod to his colleague Julian Lewis, an independent isopod taxonomist who first brought his attention to the spiders hiding out in the Indiana cave.

Milne went to see the spiders for himself, and found the cave to be a little treacherous to navigate. “It’s actually a bit of a tight squeeze,” he told Gizmodo. “It’s small and narrow. Y ou have to crawl to get in.”

He added that the cave occasionally floods, leaving it very wet and mucky. But the spiders seemed right at home, spinning their sheet webs between giant, mud-covered boulders. While the spiders had lost some of their pigment and were slightly translucent ( a common trait among light-deprived, cave-dwelling creatures) he noticed their eyes hadn’t shrunk. This le d him to believe the spiders hadn’t occupied the cave as long as many other cave-bound animals we know of—maybe just a few million years as opposed to hundreds of millions of years.

Thought it may seem strange that a new species of spider has been lurking undetected in Indiana, Milne says it’s a misconception that all new spiders are going to be found in sparsely populated areas .

“When people think of new spiders being discovered, they think of the Amazon or the ice underneath Antarctica,” he said. “But even in our backyard, there are a lot of new, undiscovered organisms that we don’t know much about. People think we know everything about the organisms in the Midwest and the United States because we’ve scoured the land, but in reality, we haven’t. A lot of groups are really understudied. Spiders are just one of them.”


Believe it or not, there is no “most poisonous spider” because spiders are venomous, not poisonous. Zoologists and veterinary scientists distinguish “poisonous” from “venomous” depending on the delivery mechanism of their toxins. Since spiders willfully inject toxins, they are considered venomous.

Though the toxicology is complicated, we present the title of most venomous spider in the world so you can justify your fear of all spiders by identifying the deadliest eight-legged creeper.

Atrax robustus, also known as the Sydney funnel web spider, has venom so potent, it can kill in just 15 minutes. While females are normally the fiercer sex among spiders, it’s just the males who possess this wickedly deadly venom.

Sydney Funnel-Web Spiders

Male funnel web spiders only grow to be a couple inches across, but they build their namesake funnel webs up to two feet underground. By digging a hole, and then lining it with sticky silk, they can trap wandering prey and ambush with great effect, all while having a sturdy underground fortress layered with web to retreat into.

Venom

These spiders deliver venom with their large fangs, capable of piercing fingernails and shoe-leather. A bite first causes extreme pain at the site of injection, and within minutes the neurotoxic effects begin to appear. Symptoms include vomiting, profuse sweating, drooling, crying, muscle spasms and an accelerated heart rate with low blood pressure. Though only 10% of severely envenomed patients fall unconscious or into a coma, this outmatches nearly all other spiders in the world.

Bites by the Sydney funnel web spider are considered life-threatening due to the speed at which the venom works. Doctors tell patients to capture and bring the spider in with them to the emergency room if possible.

Though the Atrax robustus’s venom is quite damaging to humans and other primates, it has little effect on other mammals, like rabbits, which are actually used to produce anti-venom.

Intention

It may not surprise you, but to find the world’s most toxic spider, you have to go to Australia, particularly its largest city. Curiously, it seems as though this deadly spider specifically chose the densest human population center on the entire continent to use as its sole habitat. The funnel web spider only lives in about a 60-mile radius around the city, not in the remote Outback of Australia.

A possible reason for the increased toxicity among males, they wander the forest floor and city suburbs looking for a mate. These spiders are also incredibly aggressive towards people, preferring to pounce on a possible predator rather than flee or hide. It’s this increased interaction with people combined with their ornery behavior that has led to their high envenomation rate.

The Deadly Spider Myth

Though the Atrax robustus is the deadliest spider in the world, deadly spiders, in general, are rare. Only 1 in 10 people bitten by Atrax require medical intervention, and since the introduction of anti-venom, not a single person has been killed by this venomous spider. Before that, only 14 deaths were blamed on Atrax.

In comparison, you’re more likely to be struck by lightning than you are to suffer a fatal spider bite and close to 73,000 times more likely to be killed by a human than a spider-related injury.


Watch the video: What to Do When You See a Spider (October 2022).