Incisalia agustinus iroides

Western Brown Elfin

One of the earliest butterflies to emerge in the new year; I have seen these on hikes in February on rare days when the sun was shining and it was reasonably warm. These overwinter as fully-formed adults in the chysalis, and it is safe for them to emerge at almost any time since they use so many different food plants across several families (inc. Ericaceae, Rhamnaceae, and Rosaceae).

Incisalia augustinus iroides - Western Brown Elfin
The western brown elfin, Callophrys augustinus iroides, is a fairly common spring butterfly in our mountains. I seem to find it mostly on or around species of Ceanothus. West Fork Trail, San Gabriels, March 5, 2007.
Callophrys augustinus iroides - Western Brown Elfin
A Western Brown Elfin at Mystic Canyon in the San Gabriels, May 28, 2006.
Callophrys augustinus iroides - Western Brown Elfin
This one was on Ceanothus leucodermis at Keen Camp Summit in the San Jacintos. April 28, 2021.
Caterpillar of Callophrys augustinus iroides - Western Brown Elfin
I photographed larvae on Ceanothus provided by Gordon Pratt for the Joshua Tree book. May 4, 2020.
Original description of Incisalia or Callophrys augustinus iroides - Western Brown Elfin
The original description by Boisduval from 1852. This was in the journal Annales de la Société entomologique de France.

©Dennis Walker