Atlantis fritillary

On the upper side of the forewing the outer margin is a solid black border from the apex almost to the inner angle. On the upper side of the hindwing the outer margin is an almost solid black border at the outer angle, becoming progressively lighter as it approaches the anal angle.

2″ to 2¾″

Aphrodite fritillary (Argynnis aphrodite) black border is shorter, less black, or not present. There is an “extra” black spot at the base of the forewing below the forewing cell.

Great spangled fritillary (Argynnis cybele) is larger. The margins of both wings are orange.

Silver-bordered fritillary (Boloria selene) is smaller. There is a submarginal row of spots within the solid black border.

Mid-June to late August

Leaves of violets

Nectar of flowers, especially those in the composite (Asteraceae) family

Sources

7, 21, 29, 30, 71, 75, 82, 83.

Common

Subgenus

Speyeria

A recent analysis of the tribe Argynnini (Simonsen et al., 2006), based on previously published morphological and new mitochondrial DNA data, resulted in a reclassification of the entire tribe. The study found no reason to split the “larger fritillaries” into a large number of genera, and proposed uniting them all in the genus Argynnis. The genus Speyeria is therefore included as a subgenus. A later study of mostly North American butterflies (Zhang, et al., 2020), based on genomic sequencing, supported moving Speyeria to a subgenus of Argynnis. The move has not been universally accepted. Zhang suggests that the reasons are historic, not scientific:

Several generations of American naturalists were raised being accustomed to the name Speyeria and are less familiar with the name Argynnis, thus being resistant to abandoning Speyeria as a genus name.

Atlantis Fritillary (Argynnis atlantis)
Andree Reno Sanborn

Atlantis Fritillary
Damienf77's channel

Atlantis Fritillary (Argynnis atlantis)
AdrianB

Spinning Fritillary Butterfly on an Echinacea Flower
arachphotobia