- 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.