Kern Primrose Sphinx Moth

Euproserpinus euterpe


Photo by: Larry Orsak

Photo by: Larry Orsak

The current status of the Kern Primrose Sphinx is unknown. Until 1974 this moth had been thought to be extinct. The discovery of a population in southern Kern County, California renewed hopes for its preservation.

An introduced plant is probably partly responsible for this species decline. The plant, filaree (Erodium spp.), is an excellent nectar source for adult moths. Adult females will often lay their eggs on this plant as well. Unfortunately the newly hatched larvae cannot develop on this plant and shortly die. Insect collectors may also pose a threat to this small population. Pesticide or herbicide application could also endanger the moth.


The Kern Primrose sphinx moth (Euproserpinus euterpe) is a day-flying moth in the Sphingidae (sphinx) family. These are small sphinx moths with a wing span of 3 inches from tip to tip. Adult moths have a gray ground color with patterned black and white markings on the forewings. Hindwings are gray to white with black marginal banding. Males are slightly smaller than the females and are difficult to distinguish.

Early instar larvae are green with dark-brown to black heads, legs, lateral spiracles shields, and blunt anal horns. Fourth and fifth instar larvae have red to dark red heads, green to red rust green bodies accented with black areas around spiracles, anal shield, and anal horn. The legs are green and the prolegs (appendages that are not true legs) are red in these mature larvae.

Life History

The light green eggs are laid on a subspecies of the plains evening-primrose (Camissonia contorta epilobiodes) and on filaree (Erodium cicutarium). Larvae emerge from the eggs a few days after oviposition and those on evening-primrose begin to feed on the flowers and apical growth areas of the plant. If eggs are laid on filaree, however, the larvae soon die because this plant does not nutritionally support them.

Adults nectar on a variety of flowering species that occur in the region, including, filaree, California goldfields (Lasthenia californica), baby blue-eyes (Nemophila menziesii) and bicolor lupine (Lupinus bicolor). The adult flight season occurs from the last week in February to the first week of April, with a peak period during the second and third week of March. This time may vary according to the climatic conditions in the region.


Distribution is apparently restricted to a privately owned ranch in the Walker Basin, Kern County. This basin is an agricultural region, with grain and cattle the primary crops. The moth is found in cultivated barley fields or disturbed areas in association with its larval and adult food plants.

Conservation Status

Only one colony is known. The recovery plan’s objective is to protect the known colony and to establish three more secure colonies within Walker Basin. A current proposal to subdivide the property where the only known colony occurs may jeopardize the continued existence of the species. Populations thought to exist outside the type locality have not been located. No new information supporting change in status.

Conservation Needs

Working with landowners

Insufficient information available at time of publication.


Education sheets available at zoological facilities (e.g. zoos, aquariums, botanical gardens with butterflies, butterfly houses, natural history museums) or events at which BFCI partners participate are a valuable way to disseminate information about imperiled butterflies.

When schools and other youth organizations study biodiversity and species extinctions they typically use examples of charismatic megafauna (e.g. bald eagles) or exotic creatures from the tropics. However, vulnerable species found within the state or ecoregion in which students live provide an excellent opportunity to develop curricular materials with a direct link to the students’ home region. In addition to classroom studies, students may be able to visit sites to see the butterflies, as well as talk to the scientists and land managers involved in the species’ conservation.

Educational activities that school students and community members could do include:

  • studying butterfly (insect) life stages;
  • researching the special habitat needs of the Kern primrose sphinx moth;
  • corresponding or meeting with the biologists managing current Kern primrose sphinx moth sites;
  • visiting Kern primrose sphinx moth sites during adult flight season;
  • visiting captive breeding programs;
  • assisting scientists with on-site habitat management;
  • propagating and growing host plants for planting at butterfly/moth sites or use in captive breeding programs; and
  • writing letters to decision makers to ensure that the Kern primrose sphinx moth receives adequate resources and protection.


This species would benefit from a survey of potential habitat during its flight period (February and March).

Captive Rearing

Insufficient information available at time of publication.

Recovery Plan

Kern Primrose Sphinx Moth Recovery Plan, February 8, 1984.

There has never been a final recovery plan for the Kern primrose sphinx moth. A draft recovery plan was produced in 1984. Much of the information in this plan is outdated but it would be a good starting point to develop a current recovery plan for the species. Although a new population was discovered in 2002 at El Carrizo Plain Natural Area, a survey conducted in 1999 found the population at the Walker Basin to be under the same potential threats.

According to the 1984 draft recovery plan the primary objective for the Kern primrose sphinx moth is to delist the species by protecting the presently known population and establishing three additional secure colonies. A combined total of 5000 acres of habitat must be maintained for 10 years before delisting may be considered.

Recovery Priorities

Recovery may be accomplished through:

  • Utilizing existing laws and regulations (to protect against illegal collecting, i.e. poaching);
  • Protecting and enhancing Kern primrose sphinx moth populations by developing a strategy to minimize larval/pupal mortality (possibly by augmentation of the host plant (Camissonia) through planting seed and/or controlling/removing filaree, an exotic plant, [via controlled grazing, mechanical means or possibly herbicides]), increasing nectar sources, examining limiting factors, and developing a strategy to protect the habitat (e.g., against pesticides, grazing, adverse agricultural practices, etc.);
  • Establishing additional colonies in the Walker Basin. This requires securing habitat for protection from development and developing captive propagation techniques, and;
  • Informing the public about the Kern primrose sphinx moth and its habitat.

More Info

  • USFWS Recovery Coordinator/Contact: Graciela Hinshaw, Carlsbad Fish and Wildlife Office, 2730 Loker Avenue West, Carlsbad, California, 92008. Phone (760) 431-9440.
  • Entomological Consulting Services, Ltd.: Richard Arnold, 104 Mountain View Court, Pleasant Hill, California, 94523-2188. Phone (925) 825-3784.


  • Thelander, C. ed. 1994. Life on the edge: a guide to California’s endangered natural resources. BioSystem Books. Santa Cruz, CA. pp. 442-443.
  • Tukes, P.M. and J.F. Emmel. 1981. The life history and behavior of Euproserpinus euterpe (Sphingidae). Journal of the Lepidoptera Society 35:27-33.
  • U.C. Berkeley, Essig Museum of Entomology. California’s Endangered Insects Kern Primrose Sphinx Moth page.
  • U.S. Fish and Wildlife Service. 1984. Kern Primrose Sphinx Moth Recovery Plan. Portland, Oregon.
  • Sacramento Fish and Wildlife Office Endangered Species Division Kern Primrose Sphinx Moth page
  • U.S. Fish and Wildlife Service , Kern Primrose Sphinx Moth resources

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