Status:  rare resident? stray?

Flights:  1-2, Feb - Aug?

Distribution/known sites in Monterey County:  known only from Nacimiento Summit and south county near Bradley/Lake San Antonio.

Habitats:  dry canyons, hillsides, chaparral, woodland openings

Host plants:  Douglas’ rattleweed (Astragalus douglasii)

Adult foodthistle and mint blossoms on dry hillsides

Conservationnone required


  1.   formerly lumped w/Queen Alexandra’s sulphur

  2.   flight slower, higher than clouded sulphur

  3.   black borders very narrow esp. on male HW; fem. paler yellow w/black borders less distinct or reduced/absent


Harford’s sulphur   Colias harfordii

Life history facts

egg: laid singly on underside of leaves

larva: eats leaves

pupa: hibernate

adult:  males patrol open areas for receptive females

awaiting photo