Other Common Names
Rocky Mountain Dotted Blue
Synonyms and other taxonomic changes
formerly treated as a subspecies of Euphilotes enoptes (i.e. E. e. ancilla)
BugGuide follows the classification of
Opler and Warren and All-Leps in treating
ancilla as a distinct species (see
discussion in Taxonomy Forum)
Numbers
2 subspecies listed at
All-Leps:
E. a. comstocki and
E. a. glaucon
very common in western United States; very rare in Canada
Identification
Adult: male upperside deep blue with wide black borders in United States (lilac blue with narrow black borders in Canada); hindwing orange band usually absent; female brown with variably expressed marginal orange crescent on hindwing; underside of both sexes light bluish-gray with two rows of dark spots near margin of both wings, a row of orange spots between them on hindwing, and many small round spots in central area of both wings; fringe of both wings checkered - white with scattered dark patches
Larva: body color variable but usually pale whitish or yellowish with brown markings, matching color of flowers of foodplant
Range
western United States, south to California and northern New Mexico, north to southern Alberta and Saskatchewan
Habitat
rocky slopes and flats, open woodland, sagebrush, dry prairies
Season
adults fly from April to August in the south (one brood); May to July in the north
Food
larvae feed on flowers and young fruit of various
buckwheat (
Eriogonum) species, especially
Sulphur-flower Buckwheat within its range
adults take nectar from flowers, especially buckwheat (Eriogonum spp.)
Life Cycle
eggs are laid singly on flowers of hostplant; one generation per year; overwinters as a pupa
Internet References
species account including description, biology, flight season, larval and adult food, habitat, US distribution map (nearctica.com)
live adult image by Paul Opler, plus the same text and map as the nearctica.com site above (butterfliesandmoths.org)
pinned adult image plus description of adult and larva, distribution, similar species, larval foodplants, flight season, habitat, remarks (Butterflies of Canada, CBIF)
pinned adult image by G.G. Anweiler, plus habitat, flight season, description, similar species, biology, foodplants, distribution (Strickland Entomological Museum, U. of Alberta)
