Euphilotes allyni

El Segundo Blue

Euphilotes allyni is a scarce blue butterfly closely tied to its sole food plant, Eriogonum parvifolium (sea cliff buckwheat). It is federally listed under the Endangered Species Act, and habitat restoration efforts have helped. The type locality is El Segundo, where it flies in the sand dunes where sea cliff buckwheat still has a foothold; it is also present in a few other places, such as a beach in Torrance where it may or may not remain for long.

The El Segundo blue is single brooded, with flights beginning in June or July and lasting through August into September. They don't stray far from their plants. Eggs are laid in the flower heads, larvae feed to maturity and pupate, and they overwinter as chrysalises. In patches of the host buckwheat where the common California buckwheat (E. fasciculatum) also grows, the Bernardino blue may also be present and using that buckwheat as its larval food plant. Neither species of blue will use the other buckwheat except perhaps for nectar. This is why some sightings of El Segundo blues are actually Bernardino blues, so we need to be aware that these butterflies often are flying together. Generally, El Segundo blues are much darker on the underside of the wings.