fritillaries

The size of North American fritillaries ranges from the smallest, such as the meadow and silver-bordered fritillaries with wingspans no more than 2 inches, to the largest, including the regal and great spangled fritillaries reaching up to 4 inches. The wing uppersides are mostly orange with black spots, lines, and dashes. The term fritillary means “dice-box”, and it refers to the checkerboard-like pattern of black spots. The antennae are expanded at the tip into broad, flattened clubs.

Sources

7, 24, 27, 30, 71, 82.

U.S. Fish and Wildlife Service (Service). 2023. Species Status Assessment Report for the Regal Fritillary: Eastern Subspecies (Argynnis idalia idalia) and Western Subspecies (A. i. occidentalis). Version 1.0. 288 pp.

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.

In essence, the 2006 study by Simonson et al., supported by later genomic evidence, is gaining acceptance in the taxonomic community, leading to the placement of Speyeria as a subgenus of Argynnis. However, this change has not been universally adopted across all online resources.

Fritillary (Argynnini)
Andrée Reno Sanborn

"Fritillary Butterflies" filmed by Dan W. Andree
May 5, 2025