Status:  fairly common resident

Flights:  1+, Feb-Nov

Distribution/known sites in Monterey County:  widespread 

Habitats:  open: fields, gardens, lawns, deserts, prairies, meadows

Host plants:  legumes. esp. alfalfa (introduced), white clovers, vetches

Adult foodalfalfa, clover, milkweed, many composites; large numbers may puddle for nutrients & moisture

Conservationnone required


  1.   male has UV reflective wings; clouded sulphur, UV absorptive

  2.   range has moved north, but less tolerant of cold than clouded sulphur

  3.   sometimes roosts in small groups

  4.   early (ariadne) and late (autumnalis) indivs often dull yellow, quite small (dark form phenotypes)

  5.   dark scales on basal HW thermoregularity, extends dark form’s daily flight period, enhancing fecundity

  6.   summer form amphidusa bright orange above w/ lavendar overlay

  7.   female yellow/white (alba); distinctive seasonal (diphenism)/sexual (dimorphism) forms may play adaptive role in courtship


Orange sulphur   Colias eurytheme

Life history facts

egg: laid singly on young leaves or flower buds

larva: eat leaves, rest on underside of leaf petioles

pupa: ?

adult:  males patrol for females with rapid flight

male with UV reflective wings