Status:  uncommon resident

Flights:  1, Apr-Jul

Distribution/known sites in Monterey County:  central and southern Santa Lucia Range: Arroyo Seco, Chew’s Ridge, Partington Creek, Bottcher’s Gap, Cone Peak Rd.; in Gabilans, Fremont Pk.

Habitats:  open woodland, grassy hillsides, sagebrush flats; coastal dunes?

Host plants: lupines, esp. perennials; each pop. uses just one sp. (monophagous)

Adult foodactive mud-puddler; flower nectar from Eriogonum, various composites

Conservation: Mission blue (missionensis) endangered on San Bruno Mountain, San Francisco, CA.


  1.   like some other blues, forms isolated colonies one step from extinction - many are endangered (16 recognized ssp.)

  2.   mission blue P.i. missionensis found in SF foothills & San Mateo Co

  3.   fems. select lupine sp. with hairiest leaves

  4.   larva produce a sugary secretion eaten by ants that protect them

  5.   male usually violet-blue above; fem. brown, varying blue


Boisduval’s blue Plebejus icarioides

Life history facts

egg: laid on new growth of host plant

larva: feeds first on leaves, then flowers and seed pods

pupa:  2nd stage hibernates

adult:  males patrol during day near host plants for females

nectaring on black sage