Species Speyeria atlantis - Atlantis Fritillary - Hodges#4459

4459

Argynnis atlantis W. H. Edwards, 1862. Type locality: Catskill Mountains, New York

Also included as subspecies or synonyms are the following names:

note: Dryas atlantis beani W. Barnes & Benjamin, 1926. Type locality: Banff, Alberta. The specimen currently illustrated as the holotype on Butterflies of America is actually the unsilvered lectotype specimen of S. [hesperis] irene, though the label shown is the correct one for beani. However, the actual specimen is illustrated by Dunford, 2007: 117 (bearing the same label), and looks like a specimen of S. atlantis. In practice the name is generally applied to a type (or more than one type?) of insect that seems related to helena on one hand, but often looks identical to eastern S. atlantis ssp. atlantis on the other. It is often distinctly reddish below, with silvered spots. See identification comments below, and under this section in the Hesperis Fritillary (Speyeria hesperis).

wingspan 50-70 mm in United States; 50-64 mm in Canada

Adult: Forewing upperside is orange (male) or yellowish orange shaded darker brown toward base (female), has prominent but often small black spot below discal cell, and outer border is usually almost entirely blackish (sometimes not as much so on hind wing); dark pattern above tends to be crisp relatively thin with individual spots not much run together as compared to most other species (especially noticeable in males). Males have parallel veins an lower half of front wing prominently scaled black. Apex of forewing not as rounded as usual in similar S. hesperis, with outer margin tending to be more closely perpendicular to inner (lower) margin), making wings average more "squared" in appearance. Underside with disk and border of hind wing, and dark portions near apex of forewing usually dark grayish, purplish, or chocolate brown (sometimes dark reddish brown); with pale hindwing submarginal band clearly defined, filling most of space between outer and inner pale spot rows, and crossed by clearly but narrowly darkened veins. Silver spots below always silvered. Under side of forewings usually mostly of similar (but paler) color to upper side, and not distinctly darker pinkish toward base.

Easily distinguished from other species in East by gray living eye color (reddish or brownish in other species), and by smaller size. S. cybele usually lacks the dark spot near the lower margin of the wing below the discal cell. S. aphrodite lacks the prominent dark scaling along the veins in males, and usually has the pale submarginal band of the lower hind wing narrower and less sharply defined or even completely obscured by dark coloring.

In West several species are confusing, but S. egleis and S. hesperis are most similar. They both have the dark pattern usually less crisp and more run-together, submarginal pale band on lower HW often narrower and less crisply defined (varies though), and the wing shape is somewhat different (most obvious in spread specimens). Both (particularly S. hesperis) usually have the wing borders less solidly dark and invaded by orange color (especially males). S. egleis has the humeral lobe of the hind wing (visible on lower side) narrower and less prominent, and is usually a lighter shade of brown. S. hesperis is usually distinctly more reddish below, often with light spots not silvered (cream to pale yellow), and in far south (New Mexico & Arizona) often has brownish eyes. The under forewing of S. hesperis usually has more prominent pale cream patches between veins toward apex of forewings, and is more likely to have rich pinkish coloring on this same surface.

Larva: variable; most often with body light grayish to reddish brown with a slightly diagonal pattern of broken black stripes. Spines usually brownish, often partly black. Head somewhat darker but lighter on top (often reddish on top). Sometimes dark part of pattern is more dominant and they may appear more blackish over-all.

Newfoundland to British Columbia and Northwest Territories in Canada. South to Virginia in Appalachians, and south to Utah and New Mexico in Rocky Mountains. Also, in the Black Hills in South Dakota.

Forest openings, upland pastures, bogs, meadows, moist canyons. Nearly always within or close to Aspen and/or moist Conifer forests.

As in all Speyeria, larvae feed on violets (Viola spp.), and adults are avid flower visitors, especially of Composites (family Asteraceae).

Eggs laid in summer on or next to Violets, hatch and overwinter as small larvae. Development continues through spring, with pupal period only lasting roughly two or three weeks. Adults fly from June to late August or early September; most common in June or July (varying somewhat with latitude and elevation.

Aphrodite Fritillary (Speyeria aphrodite) forewing upperside has partly or completely pale terminal band, and hindwing underside is orange in basal two-thirds (compare images of male and female Aphrodite versus Atlantis at CBIF)

Hesperis Fritillary (Speyeria hesperis) see notes on identification under that species.

live adult images (NABA)

pinned adult images plus species account and US range map (nearctica.com)

images of adults and pupa plus species account and Canadian range map (CBIF)

author, date, and original genus (nearctica.com)