Regal Fritillary (Speyeria idalia occidentalis) is endangered in the states of Michigan, New York, Ohio, and Wisconsin, threatened in Illinois, and is a species of concerns in Iowa, Minnesota, Missouri, Oklahoma, and Pennsylvania. Their scattered populations are small and quickly declining east of the Mississippi.
The host plants are Violets, including the Atlantic Birdsfoot Violet (Viola pedata) and the Prairie Viotet (Viola pedatifida). The loss of natural tall-grass prairies and meadows has contributed to the decreased populations of the Regal Fritillary.
Photo credit: Thomas Bentley