And Then There Were None: Bohart Museum Remembering Xerces Blue Butterfly In Effort to Help Preserve Other Species
June 8, 2011
Tabatha Yang, education and outreach coordinator for the Bohart Museum of Entomology, is wearing the Xerces blue t-shirt. (Photo by Kathy Keatley Garvey)
DAVIS--The Xerces Blue is extinct but scientists at the Bohart Museum of Entomology at the University of California, Davis want to ensure no other butterflies go the way of the dazzling blue butterfly that once thrived in the coastal sand dunes of the San Francisco Peninsula.
They’ve created a t-shirt with a photographic image of one of the last known collected specimens. Lettered above the image on the front of the t-shirt: “And then there were none.” Lettered below the image: “Extinct since 1941, San Francisco, CA.”
The back shows the ventral image of the Xerces Blue (Glaucopsyche xerces) collected in 1939 by entomologist W. Harry Lange (1912-2004), who served on the UC Davis Department of Entomology faculty from 1943 to 1983. The front of the t-shirt shows the dorsal image of a Xerces Blue collected in 1934 by E. Gredet.
“The images (front and back) are from specimens located away in the Bohart collection,” said t-shirt designer Fran Keller, doctoral candidate in entomology based at the Bohart Museum. Davis naturalist-photographer Greg Kareofelas, who has collaborated with Keller on multiple Bohart Museum projects, made the images.
Only a few U.S. museums, including the Bohart Museum, California Academy of Sciences and the Harvard Museum of Natural History, have specimens of that gossamer-winged butterfly (family Lycaenidae), Keller said. The Bohart has five specimens, according to senior museum scientist Steve Heydon.
The species, first described and documented in 1852, was endemic to the San Francisco Peninsula. Scientists believe it became extinct in the early 1940s due to human disturbance: loss of habitat caused by urban development. While netting insects at the Presidio military base on March 23, 1941, Lange unknowingly collected what is now considered the last known specimen. He later reportedly lamented “I always thought there would be more. I was wrong.”
“Some folks have asked us why we created a t-shirt featuring an extinct butterfly,” Keller said. “It not only makes the public aware of the fragility of insects but also shows how much research is still needed to be aware of the interactions between humans and insects and the overall impact his has on the environment.”
“The concept,” Keller said, “is that we will lose what we don’t know we have.”
The T-shirt is available online and at the Bohart Museum, 1124 Academic Surge, California Drive, UC Davis campus.
The Bohart Museum, home of more than seven million insect specimens, houses the seventh largest insect collection in North America and is dedicated to teaching, research and service. Founded in 1946 by UC Davis entomologist Richard M. Bohart and now directed by Lynn Kimsey, UC Davis professor of entomology, the museum aims to educate the public about insect diversity, conservation and preservation as part of its mission.
During his career, Lange collected more than a million insects, depositing them in the UC Davis Entomology Department Museum, later renamed the R. M. Bohart Entomology Museum. Although he retired in 1983 as a UC Davis entomology professor and an Agricultural Experiment Station entomologist, he continued his research.
The butterfly drew its name from the French spelling of "Xerxes," the name of Persian kings Xerxes I and Xerxes II of the fifth century BC.
Lepidopterist J. W. Tilden lamented the loss of the butterfly in an article published in 1956 in the Lepidopterists’ News. It became extinct during or shortly after World War II, he wrote, and was endemic to the coastal sand dune area known as the Sunset District. “Only a few years before, it had been the most characteristic butterfly of the coastal sand dune area known as the Sunset District, but complete settlement of the area left it no habitat to inhabit,” Tilden wrote.
In the 1930s, Xerces Blue “still could be found in the vacant lots of the Sunset District and in the Lake Merced area,” Tilden noted. “Some survived for years in Fort Funston, but these apparently disappeared when the area was bulldozed bare. At present (1956) the former habitat of xerces is almost one hundred percent settled.”
Tilden linked the disappearance of the insect to a species of Lotus (Hosackia), “a low-growing matting type of sand dune plant which could not tolerate disturbance of the soil. In some places, the plant seemed to disappear before the butterfly did.” In its larval stages, the butterfly fed on the plant.
Of the some 700 species of butterflies in the United States, the U.S. Fish and Wildlife Service lists 23 as either endangered or threatened (as of June 7, 2011). Many others are listed as under review, species of concern, or candidates for the endangered or threatened species list.
The Xerces Blue still lives in the namesake of the Xerces Society, a nonprofit organization that protects wildlife through the conservation of invertebrates and their habitat. The organization was founded in 1971, 30 years after the Xerces Blue became extinct.
--Kathy Keatley Garvey
UC Davis Department of Entomology