North American hosts approximately fifty blue butterfly species, a subfamily (Polyommatinae) of butterflies in the larger Lycaenidae family.
Polyommatinae diversity continues to the genera level, with the fifty or so North American species categorized into thirteen genera.
Changing human demographic and development patterns over time placed stress on North American blue butterfly diversity. In fact, of the nineteen different butterfly species listed as either threatened or endangered under the Endangered Species Act, seven of those species are blue butterflies, including the Fender's Blue butterfly.
Western and Eastern Tailed-Blue
Euphilotes (Dotted/Spotted Blues)
Fender's Blue Butterfly
Types of Butterflies
Some genera, such as Hemiargus, get represented by only one species, the Ceraunus Blue (Hemiargus ceraunus).
The underside of the wings, shown above, may or may not have an orange border around the black spots on the hind wing.
Reakirt's Blue (Echinargus isola), another of the single species genera, inhabits grasslands, riparian areas and desert regions of the Midwest, south through Texas, and the lower Rocky Mountain states.
The first image in the composite on the right highlights some small characteristic black spots on the bottom of the wings.
Unlike some of the endangered blue butterflies, Reakirt's are a fairly adaptable species.
The caterpillars feed on a variety of plants in the pea family, making it easier for them to move, if change comes to any one particular ecosystem hosting their food sources.
The Cassius Blue (Leptotes cassius), one of two native Leptotes species, inhabits Southeast grasslands.
Smaller than average for a blue, with two brightly colored eye spots on the wing's edge, their quick and erratic flight pattern provides the first field identification clue of its presence.
The Larvae feed on a variety of plants including members of the pea and leadwort families. Adults nectar on a variety of flowers.
Polyommatinae genera need not contain a small number of species. Native North American Euphilotes and Plebejus species each number in the dozen range.
The final image in the composite represents one of the eight North American Azure butterfly species (genus Celastrina).
Chevron marks along the wing edges indicates a Spring Azure.
The more geographically limited species, the Arrowhead Blue (Glaucopsyche piasus), easily gets identified by its distinct gray and white wing pattern.
While unevenly distributed, their range extends throughout higher elevation areas of the West.
Like so many of the blue butterflies, lupines serve as the host plant for the caterpillars. The video at the top of the page includes a short clip of an Arrowhead blue specimen
The silvery blue butterfly (Glaucopsyche lygdamus) spreads its wings across most of North America.
The side wing pattern characterized by white, circled spots, helps identify it.
The top view of the female shown in the bottom picture highlights its white bordered wings.
The top side of the male silvery blue's wings show a lighter shade of blue surrounded by a dark border.
Silvery Blues tend to fly spring through summer, depending on elevation, with mountain populations tending to fly during the summer.
The links in the box at the top of the page point to articles with more detailed coverage of four additional Polyommatinae genera.
© 2007-2012 Patricia A. Michaels