Home / Gossamer-Winged (Lycaenidae) / El Segundo Blue (Euphilotes battoides allyni)

El Segundo Blue (Euphilotes battoides allyni)

The El Segundo Blue butterfly is a rare and captivating species indigenous to the El Segundo dunes in Los Angeles County, California. This delicate butterfly is confined to a mere 3200 acres, making its conservation a priority. With its striking blue wings and unique lifecycle, the El Segundo Blue is a fascinating subject for enthusiasts and conservationists alike.

Scientific Classification

  • Family: Lycaenidae
  • Genus: Euphilotes
  • Scientific Name: Euphilotes battoides allyni


Primarily found in the coastal regions of Southern California, the El Segundo Blue has been classified as an endangered species due to its limited habitat and specific ecological requirements. Efforts are ongoing to preserve and protect the remaining populations, especially given the butterfly’s dependence on coastal buckwheat for its lifecycle. The proximity of their habitat to urban areas, such as the Los Angeles International Airport, underscores the challenges and importance of conservation initiatives.

Description and Identification


The larval stage of the El Segundo Blue butterfly includes four instars before it matures into a pupa. During this phase, the caterpillar exhibits polymorphism, displaying colors ranging from pure white to dull yellow. Some caterpillars may even present a dull red or maroon body adorned with white or yellow markings.


The pupa stage of the El Segundo Blue remains relatively undocumented regarding color and specific appearance. However, it is known that the pupa forms at the base of a leaf and remains there until it transforms into an adult butterfly.

Adult Butterfly

Sexual Dimorphism: In the El Segundo Blue butterfly, sexual dimorphism is evident. Males and females can be distinguished by their coloration and certain physical traits.

Color and Appearance: When the wings are open, the butterfly displays a bright blue with black spots and an orange band. When the wings are closed, a light bluish hue with rows of black dots can be seen on both sides. Males typically have a darker blue tinge on the upper side, while females are predominantly brown.

Average Wingspan: The wingspan of the El Segundo Blue ranges from 20 to 25 mm (0.8 to 1 inch), making it a relatively small butterfly.

Flight Pattern: The flight pattern of the El Segundo Blue butterfly is not extensively documented. However, it is known to be a low-flying butterfly, often seen fluttering close to its host plants.


The eggs of the El Segundo Blue are laid on the flowers of coastal buckwheat. They typically hatch within three to five days, continuing the butterfly’s close association with this plant throughout its lifecycle.

Quick Facts

DistributionLos Angeles County from the Palos Verdes Peninsula in the north to the Ballona Wetlands; also observed in Santa Barbara County, California.
HabitatEl Segundo dunes.
Lifespan of AdultsBetween 2 and 7 days.
Host PlantsEriogonum parvifolium (coastal buckwheat).
Adult DietWild buckwheat nectar.

How to Identify El Segundo Blue?

Identifying the El Segundo Blue butterfly involves observing several distinctive features. When in flight, look for a small butterfly with a bright blue upper wing surface in males and a brownish hue in females. The underside of the wings in both sexes has a light blue color with rows of black dots. During the caterpillar stage, their polymorphic colors can range from white to yellow, and occasionally red or maroon with distinctive markings. The presence of coastal buckwheat plants in the vicinity is also a strong indicator of their habitat, as this plant is crucial for their lifecycle from egg to adult. Observing these specific characteristics can help in correctly identifying this endangered species.

Did You Know?

  • The El Segundo Blue butterfly has been designated as an endangered species, with only three colonies currently known to exist.
  • The El Segundo Blue Butterfly Reserve, located adjacent to Los Angeles International Airport (LAX), was established to protect and preserve this delicate species.
  • In efforts to support their population, certain beach cities have replaced the invasive ice plant with native coastal buckwheat to provide nectar sources for these butterflies.
  • Despite its small size, the El Segundo Blue butterfly plays a significant role in the local ecosystem, particularly in pollinating coastal buckwheat.


The El Segundo Blue butterfly is a symbol of the delicate balance within our ecosystems and the importance of targeted conservation efforts. With its limited distribution and specific habitat needs, the preservation of this species requires ongoing dedication and public awareness. By understanding and protecting the El Segundo Blue, we contribute to the broader goal of biodiversity conservation and the health of our natural environments.

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Scientific Classification

  • Family: Lycaenidae
  • Genus: Euphilotes
  • Scientific Name: Euphilotes battoides allyni
Published by Avatar on June 27, 2019.
Last Updated: May 30, 2024. ✅ Verified by: Butterfly Team