- Author: Kathy Keatley Garvey
Access Wikipedia, and you'll learn they have eight legs, a pair of grasping pincers, and generally, a narrow, segemented tail that's curved over the back and ends with a stinger. They prey primarily on insects and other invertebrates. Their ancestors date back some 435 million years ago.
Scorpions now live on all continents except Antarctica. Scientists have described more than 2,500 described species in 22 families. The most venomous scorpion? That's considered to be "the deathstalker," Leiurus quinquestriatus, belonging to the Buthidae family.
What makes the deathstalker's venom so lethal is a potent cocktail of neurotoxins including chlorotoxin, agitoxin and scyllatoxin. While extremely dangerous, the unique chemical composition and scarcity of its venom also makes it the most valuable liquid (by volume) in the world with an estimated cost of $39 million per gallon. It is prized by the medical community because its properties have been found to be effective in the treatment of cancer, malaria and against bacteria such as tuberculosis.--Guinness Book of World Records.
Most people have never seen a scorpion up close, but visitors did at the Bohart Museum of Entomology display in the Academic Surge Building, 455 Crocker Lane, during the 12th annual UC Davis Biodiversity Museum Day.
Live scorpions, as well as specimens, drew curious looks and scores of questions.
Kat Taylor, a UC Davis freshman majoring in entomology, helped with a display coordinated by the Jason Bond arachnology lab. Bond, an authority on spiders, tarantulas and scorpions (among other arachnids) serves as the Evert and Marion Schlinger Endowed Chair in Insect Systematics, UC Davis Department of Entomology and Nematology, and the associate dean, College of Agricultural and Environmental Sciences.
The Bond lab display included sun scorpions, also known as wind scorpions, order Solifugae; and whip spiders or tailless whip scorpions, order Amblypygi.
Senior insect biosystematist Martin Hauser of the Plant Pest Diagnostics Branch, California Department of Food and Agriculture, and a traditional part of Biodiversity Museum Day, displayed Asian forest scorpions (genus Heterometrus) and two walking sticks (order Phasmida): Extatosoma tiaratum, the Australian spiny walking stick, and Ramulus artemis, a giant Vietnamese stick insect known as "a great thin walking stick."
Visitors marveled when Martin fluoresced a scorpion under ultraviolet light, turning it from an obscure brown to a glowing blue-green.
Scientists have known for more than 60 years that fluorescent compounds in the exoskeletons glow when exposed to UV light.
The 12th annual Biodiversity Museum Day showcased 11 museums and collections: the Anthropology Museum, Arboretum and Public Garden, Bohart Museum of Entomology, Botanical Conservatory, California Raptor Center, Center for Plant Diversity, Nematode Collection, Marine Invertebrate Collection, Museum of Wildlife and Fish Biology, Paleontology Collection and the Phaff Yeast Culture Collection.
BioDiv Day, founded by the Bohart Museum, is traditionally held on Presidents' Day weekend. This year's event, held Feb. 18, drew an estimated 3000, according to chair Tabatha Yang, education and outreach coordinator of the Bohart Museum. The "Super Science Day" is free and family friendly.
The Bohart Museum and the Jason Bond lab are both located in the Academic Surge Building. The Bohart Museum, located in Room 1124 and directed by UC Davis distinguished professor Lynn Kimsey, houses a worldwide collection of eight million insect specimens, plus a live "petting zoo" and a gift shop. The Bohart Museum is open to the public Monday through Thursday, from 8 a.m. to noon and from 1 to 5 p.m.
The next event to see insects and arachnids in the Academic Surge Building? That would Saturday, April 15 during the 109th annual UC Davis Picnic Day. It is free and open to the public.
- Author: Denise Godbout-Avant
Why Are People Scared of Spiders?
One possible reason for people's fear of spiders is they are so different from the rest of nature, which Hollywood and the media have exploited.
Spiders are arachnids, a class of invertebrate creatures, which also includes mites, ticks and scorpions. Unlike insects, arachnids have eight or more legs, with two major body parts (insects have three), a fused head and thorax called the cephalothorax, and the abdomen.
Like mites, ticks and scorpions, most spiders are venomous, using venom to catch/kill their prey. However, the jaws of most spiders are too small to penetrate human skin. Only those spiders whose venom can cause a severe reaction are called “toxic” spiders.
Spiders in the World and California
Spiders have been around a long time – fossilized spiders have been found in 318-million-year-old rock. Today there are about 40,000 types of spiders in the world, on every continent except Antarctica. They range in size from a miniscule 0.02 inches (0.5 mm) to hairy tarantulas up to 3.5 inches (90 mm).
- California has quite a few tarantula species, none of which are venomous. They tend to be long-lived, and use silk to line their underground burrows.
- Orb weaver spiders are often large and colorful. Along with their distinctive, sizeable, elaborate webs they are easy to spot. Their venom is harmless to humans.
- Sheet web spiders are small brown spiders who build messy sheets of webbing, often on the ground. Their venom is harmless to humans.
- Cellar spiders, aka “daddy long legs” initially came from Europe, have long skinny legs, and often hang upside down. Their venom does not harm humans.
- Wolf spiders are free ranging predators who don't build webs and are harmless to humans.
Only four species of spiders in the world are really dangerous to humans: Sydney tunnel web spider (Australia), Brazilian wandering spider (Brazil), African sand spider, and widow spiders (global).
California's widow spider is the well-known adult female western Black widow (Latrodectus hesperus).
Their web is sticky, irregular and tough-stranded. During WWII widow silk was used to make the crosshairs in gunsights. Widespread in California, with as many as 20-30 per urban/suburban property, Black widows are found in the holes, crevices, trash, and clutter of human structures. Her distinctive shiny black body with a bright red hourglass on the underside of the abdomen is a warning signal to others which makes her easy to identify and thus avoid.
Misinformation on Spider Bites
Most spider bites cause no reaction or as much harm as a bee sting or mosquito bite. According to Spider Physiology and Behavior, Volume 41, there were only about 100 recorded deaths from spider bites globally during the entire 20th century! The last death by spider bite in California was in 1976 (due to septicemia). Other arthropod bites, including ticks, fleas, bees, wasps, bedbugs, mosquitoes, deer flies and horse flies, may be mistaken for spider bites.
A bite from black widow venom can cause fever, cramping muscle and joint aches, but it does not cause sores. But they are shy and reluctant to bite; when they do bite, it is often dry (no venom). On the rare occasion someone is injected with their venom, there is an effective antivenom available.
Brown Recluse Spiders
Management
Beneficial Spiders
Spiders are extremely beneficial due to being important predators of pest species. They are often the most important biological control of pests in and around homes, yards, gardens and agriculture. It is estimated that spiders eat 800 million tons of bugs a year. According to Norman Platnick of New York's American Museum of Natural History, “Spiders are primary controllers of insects. Without spiders, all of our crops would be consumed by those pests” and we could face famine.
I have always scooped up spiders I find in my home to carry them outside and will continue to do so. I am removing the spiders from my Halloween décor, since I do not want to continue misrepresenting these valuable creatures.
Resources
- UC Davis Dr. Lynn Kimsey's talk on spiders via UC IPM Urban & Community Webinars: https://www.youtube.com/watch?v=b6ExDP5wNVw
- UC IPM Natural Enemies Gallery https://www2.ipm.ucanr.edu/natural-enemies/spiders/
- UC IPM Quick Tips Card http://ipm.ucanr.edu/PMG/PESTNOTES/pn7442.html#SPIDER
- UC Riverside https://spiders.ucr.edu
- https://www.livescience.com/22122-types-of-spiders.html
- Author: Kathy Keatley Garvey
Annie is a pet scorpion belonging to Emma Jochim, a second-year doctoral student n the Jason Bond lab, UC Davis Department of Entomology and Nematology.
"She's an Anuroctonus pococki so I call her 'Annie' for short!" said Jochim. "The common name is 'Californian swollen stinger scorpion' because they have an extra 'bulb' on their telson that most scorpions don't, so I think that's pretty neat about this species. I haven't tried to handle her because she seems pretty aggressive--stinging crickets/roaches as soon as I put them in front of her and attacking water when I pour some in her enclosure."
Jochim's labmate, Xavier Zahnle, found the scorpion while he was collecting millipedes "and brought her back to me so I'm not sure how old she is but I've had her for a year and a half."
Emma holds a bachelor's degree in biology, with a minor in geology and chemistry, from Millsaps College, Jackson, Miss., where she graduated summa cum laude. Her honors thesis: "Species Delimitation of Vaejovis Scorpions from the Santa Catalina Mountains Using Genetic, Morphological, and Geographical Data." While a student at Millsaps College, her outreach activities including sharing her knowledge of tarantulas, scorpions and vinegaroons at the Mississippi Museum of Natural Science.
"Annie" will be just one of the live animals displayed in the Bohart Museum of Entomology/Jason Bond booth in the Conference Center. The Bond section also will include a live trapdoor spider (genus Hebestatis), a tarantula and millipedes, as well as specimens.
Doctoral candidate Lacie Newton of the Bond lab is coordinating the arachnid/myriapod section. Jason Bond, her major professor, is the Evert and Marion Schlinger Endowed Chair in Insect Systematics, UC Davis Department of Entomology and Nematology, and associate dean, College of Agricultural and Environmental Sciences.
"And there will be a small interactive station where people will be able to use props that mimic an insect flying into a web and learn more about the sensory structures that spiders have to detect those vibrations," Newton said.
Eleven Museums, Collections. Scientists from a total of 11 museums or collections will staff booths in the Conference Center. Represented will be the Arboretum and Public Garden, UC Davis Bee Haven, Bohart Museum of Entomology, Botanical Conservatory, California Raptor Center, Center for Plant Diversity, Department of Anthropology Museum, Museum of Wildlife and Fish Biology, Nematode Collection, Paleontology Collection, and the Phaff Yeast Culture Collection. Visitors can sign up at the Conference Center for tours of several of the museums or collections. (See news story)
The UC Davis Biodiversity Museum Day is traditionally held on the Saturday of Presidents' Day weekend. However, last year's event was virtual, and this year's event is centrally located in an exposition. For more information, access the UC Davis Biodiversity Museum Day website and/or connect with Instagram,Twitter, and Facebook.
Bohart Fact Sheets on Scorpions. Lynn Kimsey, director of the Bohart Museum and UC Davis distinguished professor of entomology, has published two Fact Sheets about scorpions on the Bohart website.
Scorpions are arachnids, Kimsey writes, "and like all arachnids, they have eight legs, although it looks like ten, and a body divided into two regions, the cephalothorax (the head plus thorax) and the abdomen...The scorpion exoskeleton is different from that of similar groups. Something about it causes scorpions to fluoresce bright blue to green under ultraviolet light. So in the desert its easy to find them at night with a black light."
Kimsey describes scorpions as "nocturnal predators. During the day they hide under stones, logs or boards, or in cracks and holes in the ground. They prey on ground-dwelling insects and other small animals. Scorpions will occasionally wander into homes, particularly in new housing developments. New housing developments often encroach upon the scorpions' normal habitat and as a result these animals will blunder into homes searching for prey and shelter. Within several years, scorpions will no longer live in these areas because of the lack of suitable habitat and prey."
"The majority of California scorpion species average about 2 inches long as adults, however, some exotic species can be as long as 6 inches. Scorpions occur throughout the milder parts of California, including the Sierra foothills and the coastal mountains. Most of the species of scorpions in California pose no more threat to humans than do ordinary bees and wasps."
How long do they live? "Adult scorpions generally live two to three years," Kimsey relates. "They do not begin producing young until they are nearly a year old. Females produce between 20 and 30 live young at a time. Young scorpions are carried on the female's back for the first 5-15 days of life."
Read the two scorpion posts on the Bohart Museum website: one on scorpions in general and the other on sun scorpions. Sun scorpions, or solfugids, are distantly related to both scorpions and spiders.
- Author: Kathy Keatley Garvey
Logan, a visitor at the Bohart Museum of Entomology's recent open house on spiders and other arachnids, wowed the crowd with his knowledge of scorpions.
“Logan is only in kindergarten but he was showing his mom our arachnid drawer and describing the differences between the Emperor Scorpion, Pandinus imperator, and the Dictator Scorpion, Pandinus dictator,” said Bohart associate and scorpion scientist Wade Spencer, an undergraduate student at Bohart Museum. “Thankfully, he wasn't at all shy when I asked him to repeat what he had just said to the crowd.”
“He loved sharing his knowledge with those interested,” Spencer said. “And his mom is an arachnid saint as she supports his endeavors even while she still gets the willies from just looking at them. She told me she finds it important to keep her cool so that he may never lose his enthusiasm.”
The Bohart Museum's three-hour open house included a presentation on spiders by Jason Bond, the Evert and Marion Schlinger Endowed Chair in Insect Systematics, UC Davis Department of Entomology and Nematology. Scientists in both the Bond lab and the Bohart lab led arachnid activities, including "Eat Like a Spider" and "Catch a Moth."
Spencer and fellow Bohart associate and entomology undergraduate student Lohit Garikipati, tabled the scorpion display. The guests asked questions, gingerly touched them, and took cell phone photos.
Spencer currently has 37 scorpions of various species. Scorpions are venomous, not poisonous, he pointed out. As Professor Bond said in his talk: "Poisonous is what you eat it make you sick. Venomous means it takes toxin and it injects it into you."
"Fun fact about scorpions, Spencer said, "is that all of them are safe to eat as none of them are poisonous (toxins ingested or absorbed), but all of them (as far as we know) are venomous (containing poison(s) which are injected by some means)."
"I use the term 'medically significant' because it has the most potent venoms we know of, but I refrain and even discourage the use of the term 'dangerous' when describing scorpions and other venomous creatures," Spencer said. "It's often our own carelessness which makes them dangerous. If you live in in scorpion country, shake out your boots if you leave them outside and buy a $20 UV flashlight on Amazon. Those are simple ways to detect them and avoid being stung."
Spencer said he handles "my little Leiurus q. to show just how gentle and adorable she is so that people can have visual confirmation to back my claim that there is no such thing as a dangerous scorpion--though it should be clear I am not saying they're cuddly or friendly like a puppy. I advocate for them to be treated with caution and respect.
The UC Davis student attributes his interest in scorpions to his great-grandmother.
"My great-grandmother would always take me on afternoon picnics in the Big Tujunga Canyon Wash, a mostly dry river bed in the San Gabriel mountains in my home town of Sunland. She was a naturalist at heart and taught me about the native plants, geology, birds, mammals, reptiles, amphibians, and my favorite: the bugs. If ever we encountered a scorpion, she would stop and show me, but wouldn't kill them. Instead, starting when I was 3, she taught me that they were nothing to fear and showed me how to gently handle them. I've handled thousands ever since and not once been stung."
"I'm often asked why I'm not stung, and my response is always the same: 'It's not a cat!' By that, I mean, there's no risk of it randomly attacking me. I have scars all over my body from dogs and cats."
Spencer loves scorpions for three primary reasons:
- "Knowing their ancestors were the first animals on land about 450 million years ago."
- "Many of their venoms are being studied for use in shrinking brain tumors, sending fluorescent dyes to tumors with such specificities as to view 200 cancerous cell clusters--whereas MRIs can view 500,000 cell clusters. And some--to regulate insulin, treat arthritis, and antimicrobial components--have been used in mice with MRSA (methicillin resistant Staphylococcus aureas), completely curing them in 4 days."
- "Working with them directly and seeing how many people we have helped get over their fears has me simply head-over-heels for them."
The scorpion display drew the interest of adults and children alike. Three Brownie Girl Scouts from Vacaville giggled and comforted one another when they experienced the "Virtual Reality Spiders" demonstration conducted by medical entomologist Geoffrey Attardo, assistant professor, UC Davis Department of Entomology and Nematology. But not so the scorpion display.
"When it came to the live stuff, the girls (Kendl Macklin, 7, Jayda Navarette, 8, and Keira Yu, 8) were more calm than nervous," said Spencer, adding "I thanked them for their bravery and showing the adults that there was nothing to fear."
The Bohart Museum, directed by Lynn Kimsey, UC Davis professor of entomology, is located in Room 1124 of the Academic Surge Building on Crocker Lane. It houses nearly 8 million insect specimens, a gift shop, and a live "petting zoo" of Madagascar hissing cockroaches, stick insects or walking sticks, and tarantulas. The insect museum is open to the public Monday through Thursday, from 9 a.m. to noon, and from 1 to 5 p.m.
- Author: Kathy Keatley Garvey
“You're never too far away from a spider; a spider is always watching you," Professor Jason Bond told the crowd at his town-hall presentation at the Bohart Museum of Entomology open house on arachnids.
“If you look at the statistics, you have a 60 to 75 percent chance there's a spider in your bathroom and a slightly higher percent chance there are spiders in your bedroom," said Bond, the Evert and Marion Schlinger Endowed Chair in Insect Systematics, UC Davis Department of Entomology and Nematology. "They are always there. There are lots of them on the planet. They're absolutely everywhere."
Bond presented a 10-minute, family-friendly talk on spiders, enthralling the crowd. They ranged in age from toddlers to senior citizens.
“Folks are always surprised to hear that there are over 48,000 species of spiders that have been described, and there are probably 250,000 actual species on our planet,” said Bond, who researches terrestrial arthropod systematics, evolution and diversity. "So there's this amazing amount of diversity that's out there. The amazing thing is that there's so much left to discover.”
Bond mentioned a new tarantula species discovered in California in 2015 near Folsom Prison and named for country singer Johnny Cash: Aphonopelma johnnycashi. (One of Cash's signature hits is “Folsom Prison Blues.")
“Spiders are found on every continent on our planet except maybe Antarctica,” Bond related. “But if you go into one of the field stations in Antarctica, you'll probably find a spider there that's been brought in on a ship. Spiders can exist in incredibly harsh environments, including some of the driest places on the planet."
It's interesting to compare the numbers, he said. "Compare the 48,000 species to our planet's 9500 species of birds, 5400 species of mammals and 250 species of primates."
“And spiders are incredibly old, that is, the lineage has been around a long time," Bond said. "Fossil evidence shows that the common ancestor of the spider goes back to somewhere around 350 million years ago."
A spider's relatives include such arachnids as scorpions, whip spiders, ticks, mites, sun spiders and harvestmen, the UC Davis professor said, but what makes “spiders really special are their spinnerets. Spiders have the ability to produce silk from these abdominally placed appendages.”
Folks commonly ask if spiders have superpowers. "If you Google that (see http://www.bbc.co.uk/guides/zc472hv), you'll learn that silk as thick as a pencil can stop a passenger jet airline, like a Boeing 747. Silk is incredibly strong.”
Among the "superpowers": spiders can fly, leap and carry heavy weights. Through ballooning, "they can travel thousands of feet in air and travel hundreds, if that not thousands of miles, on air currents," Bond said. "They can leap 50 times their body length. They can carry up to 170 times their weight walking across the ceiling."
"They really are superpowers," Bond told the crowd. "But what really makes them superpowers are the webs they build, the silk they weave. They use silk for all sorts of things--to line their burrows, build trap doors, make things like sheet webs, and entangle prey."
A common misnomer is to call a spider "poisonous." Bond said that "spiders are venomous, not poisonous. Do you know what the difference is? Poisonous is what you eat it make you sick. Venomous means it takes toxin and it injects it into you." Almost all species use venom when they attack and kill their prey.
"Of the 48,000 described species, only about 30 or so are known to be harmful to humans," he said. "There are probably more out there, but most spiders aren't harmful."
Turning to the spider population, Bond estimated that the world spider population weighs 29 million tons. "That's equivalent to 478 Titanics if you were to weigh all these. And the neatest thing about this is they're eating somewhere between 400 to 800 million tons of insect biomass a year. If you took all seven million human adults, and weighed them, that's about 285 million tons. And there's about 70 million tons of children on the planet. So the total weight of humans is about 350 million. If spiders were to consume exclusively humans--they don't consume humans--there would be only enough biomass to sustain spiders for one year."
"Bottom line: Here on planet earth, there are lots of spiders and they're eating lots of things and there's always a spider watching you."
Bohart associates and entomology students Wade Spencer and Lohit Garikipati displayed Spencer's scorpions. Medical entomologist Geoffrey Attardo, assistant professor, UC Davis Department of Entomology and Nematology, set up a virtual reality station. Participants marveled at the 40-foot-tall spiders.
Three members of the Brownie Girl Scout Troop 30477 of Vacaville--Kendl Macklin, 7, Jayda Navarette, 8, and Keira Yu, 8--delighted in participating in all the activities. They especially liked the virtual reality station, gleefully holding onto one another for comfort as they viewed the spiders. One Brownie declined to "eat like a spider"--even though fellow participants assured her "It's just applesauce." Mikah Jarvis, 2, of Davis loved "eating like a spider." Said his parents: "He loves applesauce."
Logan Loss, 6, of Rocklin, who attends John Adams Academy, amazed Spencer with his knowledge of scorpions, gained from watching nature documentaries.
The Bohart Museum of Entomology, home of nearly eight million insect specimens, also houses a gift shop and a live "petting zoo," comprised of Madagascar hissing cockroaches, stick insects and tarantulas. The museum, directed by Lynn Kimsey, professor of entomology at UC Davis, is located in Room 1124 of the Academic Surge Building on Crocker Lane. It is open to the public (free admission) on Mondays through Thursdays from 9 a.m. to noon and from 1 to 5 p.m.