New Butterfly Species in the Southwest: The Orange-Barred Sulfur (Phoebis philea)
David F. Marriott, Director of The Monarch Program, spotted a different looking yellow sulfur butterfly near a Cassia plant at The Monarch Program Facility in Encinitas, California in mid-July 2004. He noticed the flight pattern and size of the butterfly was different than the common cloudless sulfur (Phoebis senna). It reminded him of the flight pattern he saw of the orange-barred sulfur (Phoebis philea) while leading Monarch Tours to Central Mexico (Michoacan) — a long flap, flap, and gliding “V” pattern. The butterfly was confirmed as an orange-barred sulfur on July 24th 2004. Life stages were photographed and field specimens were collected to document the presence of the butterfly in San Diego County.
This species remained flying through the autumn and were noticed again in the spring of 2005. They continued breeding in the wild and inside The Monarch Program’s Butterfly Vivarium through the summer and autumn. Recently, 23 January 2006, a wild female orange-barred sulfur was observed ovipositing on flowery senna (Cassia corymbosa) at the facility in Encinitas.
After numerous generations totaling a flight period of 19 months, the butterfly should now be considered a transient resident of the Southwest. It is a tropical butterfly that is slowly making a new home because of changing climate and flora conditions. Perhaps a cold winter may effect the population someday.
These are the first records recorded for the orange-barred sulfur to breed in the far Southwest (west of eastern Arizona and New Mexico’s southern borders). Butterfly expert and author John Emmel has one record of a worn female ovipositing on Cassia in the backyard of lepidopterist Robert J. Ford on 23 September 1983 in Bundy Canyon, Sun City, Riverside County. Otherwise, this is our first encounter of this stunning yellow and orange butterfly to reside in Southern California.
The appearance of this species in San Diego County has been confirmed by Brian Banker (amateur lepidopterist), John F. Emmel (author, lepidopertist), Bill Howell (Biologist, amateur lepidoperist), and Christian Manion (amateur lepidopterist). Scientist Ken Davenport has called this the most important butterfly discovery in 50 years.