These species recently came up when someone contacted me with an identification question, so in light of my poor record of posting blog articles lately (it's crunch time with my book!) I thought I'd throw together my summaries of the two species groups ("Dotted" and "Square-spotted" blues) with descriptions of the two most common species in our area.
Columbia Blue (Euphilotes columbiae)
This species was originally thought to be a subspecies of Dotted Blue (E. enoptes), but analysis by Andrew Warren (Butterflies of Oregon, 2005) discovered that it is a separate species. Columbia Blue ranges across the eastern slopes of the Cascades in WA and OR, and scattered parts of E WA and NE OR. Dotted Blue ranges across most of CA, parts of NV and AZ, and scattered populations in W and Central OR and S WA.
Description
Wingspan: 16 to 20 mm
Male: dusky blue dorsal with gray-brown border and white fringe. Whitish-gray ventral covered in numerous round black spots; submarginal row of orange crescents, rarely forming a solid band.
Description
Wingspan: 16 to 20 mm
Male: dusky blue dorsal with gray-brown border and white fringe. Whitish-gray ventral covered in numerous round black spots; submarginal row of orange crescents, rarely forming a solid band.
Female: warm brown dorsal color may be dusted with blue; orange submedian band on DHW.
Egg: pale greenish-white.
Larva: first instar is greenish-yellow, second and third instars are gray-green speckled with black, final instar varies from gray-green to pale cream, often with rose-red markings.
Pupa: honey brown.
Similar Species
Cascadia Blue (E. "battoides") has squarish black spots and is associated with Parsley Desert Buckwheat (Eriog. heracleoides). Other blue species that have a VHW marginal row of orange (Northern, Anna's, Melissa's, and Lupine blues) all have scintillae (sparkling blue-green scales on the marginal row of black spots). Worn individuals should be carefully inspected in bright light for any remaining reflective scales from the scintillae.
Egg: pale greenish-white.
Larva: first instar is greenish-yellow, second and third instars are gray-green speckled with black, final instar varies from gray-green to pale cream, often with rose-red markings.
Pupa: honey brown.
Similar Species
Cascadia Blue (E. "battoides") has squarish black spots and is associated with Parsley Desert Buckwheat (Eriog. heracleoides). Other blue species that have a VHW marginal row of orange (Northern, Anna's, Melissa's, and Lupine blues) all have scintillae (sparkling blue-green scales on the marginal row of black spots). Worn individuals should be carefully inspected in bright light for any remaining reflective scales from the scintillae.
Habitat & Biology
Habitat: wherever host buckwheat grows, primarily in shrub-steppe canyons, meadows, and edges of pine forests.
Overwintering stage: pupa.
Larval host: Northern Buckwheat (Eriogonum compositum) and Tall Buckwheat (E. elatum).
Adult food source: primarily buckwheat, yarrow and rabbitbrush; males frequently visit mud and occasionally damp fire pits.
Habitat: wherever host buckwheat grows, primarily in shrub-steppe canyons, meadows, and edges of pine forests.
Overwintering stage: pupa.
Larval host: Northern Buckwheat (Eriogonum compositum) and Tall Buckwheat (E. elatum).
Adult food source: primarily buckwheat, yarrow and rabbitbrush; males frequently visit mud and occasionally damp fire pits.
The taxonomy of this group is currently being revised; recent studies indicate that the Square-spotted Blue (Euphilotes battoides) is actually made up of previously-undescribed species, each specializing on different buckwheats (Eriogonum spp.). The Cascadia Blue is very common in WA and OR and is nearly always on Parsley Desert Buckwheat (Eriog. heracleoides), it is also suspected to sometimes use Douglas' Buckwheat (Eriog. douglasii). The Summit Blue (E. glaucon) is the only Euphilotes species found to feed on Sulphur-flower Buckwheat (Eriog. umbellatum), but is also occasionally found with Cascadia Blue on Parsley Desert Buckwheat, where it usually flies earlier than the Cascadia Blue. A possible third species feeds solely on Round-headed Desert Buckwheat (Eriog. sphaerocephalum) and is found in E Kittitas County and W Grant County in WA.
Description
Wingspan: 16 to 20 mm
Male: dusky blue dorsal with gray-brown border and white fringe, usually with small orange patch near trailing edge of DHW. Whitish-gray ventral covered in numerous squarish black spots; submarginal row of orange crescents, sometimes forming a solid band.
Wingspan: 16 to 20 mm
Male: dusky blue dorsal with gray-brown border and white fringe, usually with small orange patch near trailing edge of DHW. Whitish-gray ventral covered in numerous squarish black spots; submarginal row of orange crescents, sometimes forming a solid band.
Female: warm brown dorsal color may be dusted with blue; orange submedian band on DHW.
Egg: pale greenish-white.
Larva: greenish-yellow first instar, red and white second instar, third instar similar but slightly darker, final instar varies from gray-green to reddish with pale and dark green and/or red markings.
Pupa: honey brown.
Similar Species
Columbia Blue (E. columbiae) has round black spots and is associated with Northern (Eriogonum compositum) and Tall (E. elatum) buckwheats. Other blue species that have a VHW marginal row of orange (Northern, Anna's, Melissa's, and Lupine blues) all have scintillae (sparkling blue-green scales on the marginal row of black spots). Worn individuals should be carefully inspected in bright light for any remaining reflective scales from the scintillae.
Egg: pale greenish-white.
Larva: greenish-yellow first instar, red and white second instar, third instar similar but slightly darker, final instar varies from gray-green to reddish with pale and dark green and/or red markings.
Pupa: honey brown.
Similar Species
Columbia Blue (E. columbiae) has round black spots and is associated with Northern (Eriogonum compositum) and Tall (E. elatum) buckwheats. Other blue species that have a VHW marginal row of orange (Northern, Anna's, Melissa's, and Lupine blues) all have scintillae (sparkling blue-green scales on the marginal row of black spots). Worn individuals should be carefully inspected in bright light for any remaining reflective scales from the scintillae.
Habitat & Biology
Habitat: wherever host buckwheat grows, primarily in shrub-steppe canyons and meadows.
Overwintering stage: pupa.
Larval host: Parsley Desert Buckwheat (Eriogonum heracleoides).
Adult food source: primarily buckwheat, yarrow and rabbitbrush; males frequently visit mud and occasionally damp fire pits.
Habitat: wherever host buckwheat grows, primarily in shrub-steppe canyons and meadows.
Overwintering stage: pupa.
Larval host: Parsley Desert Buckwheat (Eriogonum heracleoides).
Adult food source: primarily buckwheat, yarrow and rabbitbrush; males frequently visit mud and occasionally damp fire pits.
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| Comparison of Columbia (Euphilotes columbiae) and Cascadia (Euphilotes "battoides") blues |
