Posts Tagged: Alexander Nguyen
Scorpions--to fear or to revere?
The Bohart Museum of Entomology's open house last Sunday drew visitors of all ages who marveled at the scorpions glowing under ultraviolet light.
UC Davis entomology major Alexander Nguyen flashed a UV light on the critters as his audience watched in amazement.
Most--but not all--of the world's scorpions glow under ultraviolet light, says Lynn Kimsey, director of the Bohart Museum, which houses more than seven million insect specimens.
Scorpions are not insects, but arachnids, the same as spiders. Ranging in size from 9 mm to 21 mm, scorpions have eight legs (arachnid alert!) and grasping claws that help conquer their prey. But it's their venom that kills. And all scorpions possess venom.
UC Davis entomologist Bruce Hammock and his lab made the news back in 2003 when they published a study that showed that scorpions produce two venoms: a pre-venom to deter predators and immobilize small prey, and then the good stuff, the powerful venom that's meant to kill.
It's like saving the best for last or waiting for the venom glands to pump and reload, so to speak.
So, why do they glow?
Scientists believe it's because of the fluorescent material found in the scorpion's hard outer covering.
"The fact that they glow serves no physiological function," said Bohart senior museum scientist Steve Heydon. "It's probably a quirk of chemical makeup."
Great quote..."a quirk of chemical makeup."
Scorpion glowing under ultraviolet light at the Bohart Museum of Entomology. (Photo by Kathy Keatley Garvey)
UC Davis entomology undergraduate student Alexander Nguyen flashes a UV light on a scorpion, as Professor Demosthenes Pappagianis, M.D., Ph.D., of Medical Microbiology and Immunology, watches. (Photo by Kathy Keatley Garvey)
Most scorpions glow under an ultraviolet light, but now a discovery on Alcatraz Island reveals that a certain species of millipedes will, too.
Forensic entomologist Robert Kimsey of the UC Davis Department of Entomology, who does fly research on Alcatraz, said that bait laced with a non-toxic fluorescent dye to estimate the rat population in February yielded the expected result: the glow of rat urine and feces.
But something else was glowing nearby: millipedes.
Had they consumed some of the rat bait?
No. An experiment at the Bohart Museum of Entomology on the UC Davis campus showed that these millipedes (Xystocheir dissecta (Wood) glow under black lights, just like scorpions.
Lynn Kimsey, director of the Bohart Museum and a professor of entomology at UC Davis, said the species is a relatively abundant species in the Bay Area. “This particular species of millipedes glowed all along, but nobody was paying any attention to it,” she said.
She suspects that the millipedes on Alcatraz Island originated from soil transported over from the nearby Angel Island when “The Rock” was just that—rock with little or no soil.
Meanwhile, if you attend the Bohart Museum's open house from 1 to 4 p.m. on Sunday, June 3 at 1124 Academic Surge, California Drive, you'll see scorpions and millipedes glowing.
And there's something else to draw you in: a special live display of the California dogface butterfly by naturalist/photographer Greg Kareofelas of Davis. If all goes as planned, an adult will emerge from its chrysalis. If this doesn't happen (well, you can't tell a buttterfly when to emerge!) you can watch the life cycle on his PowerPoint presentation, to run continuously throughout the open house.
And, you can ask Kareofelas all about the California dogface butterfly (Zerene eurydice), which, by the way, is close to royalty--it's California's designated state insect.
This millipede (Xystocheir dissecta) glows under ultraviolet light. Alexander Nguyen of the UC Davis Entomology Club captured this image on Alcatraz, during one of UC Davis forensic entomologist Robert Kimsey's field trips.