El Segundo Butterfly

Euphilotes battoides allyni


Photo by: Larry Orsak

Photo by: Larry Orsak

Named for the dune system that it inhabits, the El Segundo blue has found its home increasingly coveted by humans. One of the last populations lives adjacent to the Los Angeles International Airport in California. The airport’s construction, oil refining, sand mining and urban development have all claimed large portions of its dune system habitat.

The development threats to the El Segundo blue’s habitat have been largely halted. The butterfly now persists on three fragments of habitat, the L.A. airport site being the largest of these. However, there are other threats, as well. Invasive species out compete the coastal buckwheat (Eriogonum), the butterfly’s host plant, and several of the introduced plants actually act to stabilize the dune system, which inhibits the success of the host plant.


The El Segundo blue is in the family Lycaenidae (gossamer wings). A small butterfly, it is usually less than 2.5 cm (1 in.) across. The dorsal wing coloration is blue, with the males a brighter blue than the females. The ventral side is gray, with bold, square-shaped spots and a series of orange spots on the hindwing that appear merged into a single band of color.

Life History

As with all species in the genus Euphilotes, the El Segundo blue spends virtually its entire life cycle in intimate association with the flowerheads of some species of buckwheat. The El Segundo blue emerges during summer when the flowers of its host plant, seacliff buckwheat (Eriogonum parviflorum), open. The adult life of these butterflies is relatively short, lasting only a few days during which they mate and lay eggs. The eggs hatch within a week or so of their deposition. The larvae feed on the flower heads of the host plant for approximately one month before they molt to their pupal stage. Then when the next summer arrives the cycle begins anew.


The El Segundo blue historically resided in El Segundo sand dunes, whose active area historically covered about 4.5 square miles (1295 hectares, 3200 acres), including interrupted extensions to the north into what is present-day Ocean Park, and southerly to Malaga Cove in Palos Verdes. The butterfly is now restricted to three locations in what is left of those dunes.

Conservation Status

In order to ensure the future of the El Segundo blue, the U.S. Fish and Wildlife Service (USFWS), as well as officials from the L.A. Airport and Standard Oil have undertaken important dune management programs which focus on removing exotic plants and reestablishing the sites’ native vegetation. The Urban Wildlands Group, Inc. is also working at one site.

The butterfly’s populations are considered stable to increasing in two protected reserve areas. In the third occupied area, Malaga Cove, the status is unknown but likely decreasing due to continued degradation of the habitat. The Ballona recovery unit remains unoccupied. Throughout the range of the animal, other suitable habitat areas identified in the recovery plan remain unoccupied.

Conservation Needs

Working with landowners

The Urban Wildlands Group, Inc. has applied to the USFWS for an enhancement of survival permit and safe harbor agreement for approximately two acres of bluff habitat on private property in Los Angeles County, California.


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 El Segundo blue;
  • corresponding or meeting with the biologists managing current El Segundo blue sites;
  • visiting El Segundo blue 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 sites or use in captive breeding programs; and
  • writing letters to decision makers to ensure that the El Segundo blue receives adequate resources and protection.


Insufficient information available at time of publication.

Captive Rearing

Several sites are currently being examined for their potential as reintroduction sites for the species.

Recovery Plan

Recovery Plan for the El Segundo blue butterfly (13.4MB pdf), September 28, 1998

The 1998 recovery plan is very thorough and includes specific downlisting criteria. The recovery objective is to downlist the species from endangered status to threatened status. The El Segundo blue butterfly can be considered for reclassification to threatened status when:

  • At least one secure population in each of the four Recovery Units (RUs) – Ballona, Airport Dunes, El Segundo, and Torrance – are permanently protected and managed. The population that inhabits the Airport Dunes contains the largest population of the butterfly and is one the most likely to survive disease, predators, parasites, and other perturbations. Accordingly, the Airport Dunes must be one of the protected populations.
  • Each of the four populations are managed to maintain coastal dune habitat dominated by local native species including coastal buckwheat (Eriogonum parvifolium).
  • As determined by a scientifically credible monitoring plan, each of the four populations must exhibit a statistically significant upward trend (based on transect counts) for at least 10 years (approximately 10 butterfly generations). Population management in each Recovery Unit must ensure that discrete population growth rates (lambdas) are maintained at or above 1.0.
  • A program is initiated to inform the public about the El Segundo blue butterfly and its habitat.

Recovery Priorities

Protect and restore occupied and suitable habitat in each of the four Recovery Units (Ballona, Airport Dunes, El Segundo, and Torrance).

  • The most important requirement for the survival of these species is preventing activities that reduce populations by destroying or damaging El Segundo dunes habitat. Control of invasive exotic pest plants is also of utmost importance.
  • To successfully implement this step the occupied and potential habitat in the RUs must be mapped through time to show trends in key parameters. Ownership information must be compiled for occupied and potential habitat areas and the willingness of landowners to participate in recovery of the El Segundo blue butterfly must be determined. Habitat identified through this process should then be protected and management plans should be developed and implemented for each site.

Determine ecological requirements, population constraints and management needs of the El Segundo blue butterfly.

  • Determine methods of introducing butterflies into suitable habitat or to augment extant populations.
  • To accomplish this task the methods for captive breeding, rearing and release of the El Segundo blue butterfly must be determined. Then specific locations for reintroductions must be identified and El Segundo blue must be released as appropriate.

Monitor the status of the El Segundo blue butterfly and its habitat.

  • To accomplish this task monitoring guidelines and techniques for tracking population status and habitat trends must be developed and a monitoring program must be implemented at each RU.

Raise public awareness about the El Segundo blue and its habitat by conducting public outreach and education programs.

More Info

  • USFWS contact: Alison Anderson at the Service’s Carlsbad Fish and Wildlife Office, 2730 Loker Avenue West, Carlsbad, California, 92008. Telephone: (760) 431-9440.
  • Urban Wildlands Group, Inc.: Travis Longcore, P.O. Box 24020, Los Angeles, CA 90024-0020, Phone (310) 247-9719, longcore@urbanwildlands.org


  • Arnold, R.A., 1983. Ecological studies of six endangered butterflies (Lepidoptera: Lycaenidae): Island biogeography, patch dynamics, and design of habitat preserves. University of California Publications in Entomology 99: 1-161.
  • Mattoni, R.H.T. l988. Captive propagation of California endangered butterflies. Report to California Department Fish and Game. Contract C-1456.
  • Mattoni, R.H.T. l989. The Euphilotes battoides complex: Recognition of a species and description of a new subspecies. Jr. Res. Lepid. 27: 173-185.
  • Mattoni, R.H.T. 1990. Habitat evaluation and species diversity on the LAX El Segundo sand dunes. Report to the LAX board of airport commissioners.
  • Mattoni, R.H.T. 1990a. Unnatural acts: succession on the El Segundo sand dunes in California. Proc. Soc. Ecol. Restoration and Management.
  • Oppewall, J. C., 1976. The saving of the El Segundo blue. Atala 3(2): 25-28.
  • U.C. Berkeley, Essig Museum of Entomology. Californias Endangered Insects El Segundo blue page
  • USFWS Federal Register documents for the El Segundo Blue butterfly

Comments are closed.