Who would have imagined that a small, flying insect, incapable of distinguishing Evening Primrose from Filaree, would be responsible for putting Walker Basin on the map?

The last remaining colony of the Kern Primrose Sphinx Moth—once thought to be extinct—will soon become the focus of a concerted effort aimed at ensuring the species' survival. This drab, but unusual moth is believed to exist nowhere else on Earth except a small plot of land in Walker Basin.

An article by Jill Hoffmann in the November 3, 2001 edition of the Bakersfield Californian reported that the U.S. Fish and Wildlife Service recently awarded $1 million for the conservation of endangered and threatened species in Kern County. The funding is part of a $5 million allocation to California and Nevada under the Land Acquisition and Habitat Conservation Planning Program.

"One species expected to benefit is the federally threatened Kern primrose sphinx moth, which was believed to be extinct until a sighting in 1991 in Walker Basin," Hoffmann wrote. "An $800,000 grant will be used to purchase 300 to 400 acres of privately held land in Walker Basin that houses the only known colony of the moths.

"The agency hopes to protect the existing colony and establish an additional three colonies in the area."

The Kern Primrose Sphinx Moth (Euproserpinus euterpe), has a wingspan of 1 ¾ to 2 1/8 inches, with the topside of the fore wing brown and black with transverse lines throughout. The hind wing is white with a black outer margin, and is also black where it meets the thorax.

Unlike most moths, the Kern Primrose Sphinx is active during daytime rather than at night, preferring to fly while the weather is warm and before afternoon winds begin. Its routine includes basking on warm earth and rodent burrows. When the air is moving, the moth will move to a more sheltered area.

Photos of the Kern Primrose Sphinx Moth can be viewed at several Internet websites, including
http://www.npsc.nbs.gov/resource/distr/lepid/moths/usa/1057.htm
and http://www.calflora.org/cgi/img_query?seq_num=23270&one=T, or by using a search engine such as http://www.google.com.

The lifecycle of the Primrose Sphinx is very much confined. The female moth lays light green eggs on the underside of leaves of either Evening Primrose (Onagraceae) or Filaree (Erodium cicutarium). Larvae emerge from the eggs a few days later to begin feeding on the flowers. Unfortunately, if the eggs are laid on Filaree instead of Evening Primrose, the larvae will not survive, as Filaree does not provide the nutritional support required.

When the caterpillars are full grown, they pupate in burrows found in pastures and fallow barley fields while completing the transition to adulthood.

A single brood of the Kern Primrose Sphinx Moth takes flight each year, normally between February and April, although this can be affected by local weather conditions. The peak period for flight usually occurs during the second and third week of March.

Until 1974, the Kern Primrose Sphinx Moth was thought to be extinct, but the discovery of the sole remaining Walker Basin colony revived hopes for the survival of the species. Unfortunately, its demise can be hastened through overcollection and habitat destruction.

Butterflies and moths both belong to the genus Lepidoptera; hence, butterfly and moth collectors are known as Lepidopterists.

Butterflies, in general, are brightly colored, as opposed to the mottled, drab appearance of most moths. Whereas most butterflies prefer the light of day, moths are primarily nocturnal, with the Primrose Sphinx among the exceptions. Moths have bulky, hairy bodies, while butterflies are slender and free of hair. The caterpillars and pupae of moths and butterflies are virtually indistinguishable.

Most serious Lepidopterists are environmentally conscious and would not presume to collect a specimen of an endangered species such as the Kern Primrose Sphinx. However, profit motives could drive unscrupulous collectors to do otherwise. In many parts of the World, poaching of butterflies and moths is organized, professional and often involves expensive expeditions including the use of helicopters for quick transportation to and from remote collection sites. Poachers will use any trick or technique imaginable to obtain their prey, including ultraviolet light, baited traps and clear-cutting. It's not uncommon for professional poachers to hire locals to do the dirty work, which places them on a par with those who see national forest lands as suitable for clandestine marijuana farming.

As a result of pressure on threatened resources, it is often necessary to take extra steps to protect the habitat of endangered species. What is publicly known thus far is that the Kern Primrose Sphinx Moth occupies several hundred acres of privately owned land somewhere in Walker Basin. Presumably, very few people know the exact whereabouts of the acreage, although that could change depending on how the land transaction occurs. The information made available concerning the federal grant does not specify what entity will own the land, who will manage it, or how the preserve will be protected.

Details have not yet been made public concerning the specific management plan for the project, but it is presumed to include the development of propagation techniques necessary to establish additional colonies. These could include measures to encourage the spread of the host Evening Primrose and other food sources in the preserve, while discouraging the spread of Filaree. Although technically a weed and non-native species, Filaree provides an important nutritional source for cattle during its growing season each year. At best, it can be controlled through prescribed burns or cultivation, but is very difficult to eradicate.

The 1991 sighting of a Kern Primrose Sphinx Moth in Walker Basin—the first such sighting in 20 years—provided Lepidopterists with hope that the species could be saved and revived. Now, a decade later, funds have been allocated toward that end. With proper management, the right conditions, a measure of luck, and at least a few surviving specimens, the Kern Primrose Sphinx Moth could one day multiply and thrive in its natural environment, Walker Basin.

Information for this article was collected from websites operated by the Bakersfield Californian, University of California (Berkeley), Northern Prairie Wildlife Research Center (U.S. Geological Survey), and the U.S. Fish and Wildlife Service. The author welcomes comment from parties active in the current effort to protect the Kern Primrose Sphinx Moth.

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