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Species Euphilotes ancilla - Ancilla Blue - Hodges#4367.4

Rocky Mountain Dotted-Blue - Euphilotes ancilla Lupine Blues - Euphilotes ancilla - male - female Euphilotes of some type - Euphilotes ancilla - female Blue - Euphilotes ancilla Another butterfly - Euphilotes ancilla Ancilla Blue at Rocky Mountain National Park - Euphilotes ancilla Euphilotes ancilla - male Euphilotes ancilla - male
Show images of: caterpillars · adults · both
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Lepidoptera (Butterflies and Moths)
Superfamily Papilionoidea (Butterflies and Skippers)
Family Lycaenidae (Blues, Coppers, Hairstreaks, Harvesters)
Subfamily Polyommatinae (Blues)
Genus Euphilotes
Species ancilla (Ancilla Blue - Hodges#4367.4)
Hodges Number
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)
2 subspecies listed at All-Leps: E. a. comstocki and E. a. glaucon
very common in western United States; very rare in Canada
wingspan 16-25 mm
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
western United States, south to California and northern New Mexico, north to southern Alberta and Saskatchewan
rocky slopes and flats, open woodland, sagebrush, dry prairies
adults fly from April to August in the south (one brood); May to July in the north
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 (
live adult image by Paul Opler, plus the same text and map as the site above (
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)