Overview
The Zerene Fritillary (Speyeria zerene) is a magnificent, fast-flying brush-footed butterfly native to the coastal bluffs, montane meadows, and conifer woodlands of western North America. Flaunting broad, glowing orange wings richly checkered with bold black veins and patterns on the upper side, its ventral wings are encrusted with gleaming, mirror-like metallic silver spots that flash like sequins in the Pacific sunshine.
Biology and Physical Characteristics
Speyeria zerene is a medium-to-large fritillary with strong, gliding flight. Its upper wings are a rich, warm tawny-orange adorned with an intricate lattice of black chevron spots and margin bands. The underside of the hindwing is a work of art: a warm cinnamon or chocolate-brown background densely studded with large, rounded metallic silver spots that reflect sunlight like polished mercury.
Behavior and Ecology
An obligate violet specialist, the Zerene Fritillary’s caterpillars feed exclusively on native wild violets, particularly the early blue violet (Viola adunca). After hatching in late summer, the tiny first-instar caterpillar enters immediate diapause without feeding, overwintering beneath dead leaves until spring violet shoots emerge. Adults are powerful flyers that nectar avidly on native dunedelion, goldenrod, and thistle blossoms.
Conservation and Human Impact
Classified globally as Least Concern by the IUCN, Speyeria zerene contains several critically imperiled coastal subspecies, most famously the Oregon Silverspot (S. z. hippolyta), federally listed as threatened due to invasive European beachgrass choking out native coastal violet meadows.
Interesting Factoid
Underneath its wings, the Zerene Fritillary is decorated with dozens of real reflective silver spots that act like tiny mirrors, flashing bright pulses of sunlight to startle predatory birds when the butterfly opens and closes its wings.