Festive Tiger Beetle

Cicindela scutellaris — the festive tiger beetle — is one of the most COLOR-VARIABLE tiger beetles in North America and one of about 220 species in genus Cicindela (the tiger beetles — among the fastest running arthropods on Earth, see also six-spotted tiger beetle in the Wild Files). The species is widespread across all of central and southern North America from southern Canada south through the central US to Mexico, found in sandy and bare-ground habitats — sandhills, sand dunes, sand pits, sandy roadsides, and other open sandy areas. Adults are 12-15 mm long, with the species' diagnostic ELYTRA COLOR VARIABILITY across the species' range. Different geographic populations display dramatically different elytra coloration: BRILLIANT METALLIC GREEN (eastern US populations — most common variant); BRILLIANT METALLIC BLUE (northeastern US populations and some midwestern populations); BRILLIANT METALLIC PURPLE (some Texas and southwestern populations); BRILLIANT METALLIC RED (some midwestern populations); BRILLIANT METALLIC COPPER (some Great Plains populations); and combinations of these colors (e.g., copper-and-green, purple-and-green, blue-and-green). The geographic color variation is one of the most-cited examples of REGIONAL POLYMORPHISM in NA Coleoptera and is a flagship subject of modern studies of structural-color evolution. The colors are created by STRUCTURAL COLORATION — multiple microscopic layers in the elytral cuticle that scatter and interfere with incoming light through thin-film interference effects. Different layer thicknesses produce different colors; geographic variants have evolved different layer arrangements that produce different perceived colors. The species is one of the most-photographed tiger beetles in NA macro nature photography because of the dramatic geographic color variation. Festive tiger beetles share the typical Cicindela tiger beetle biology (already covered in detail for the six-spotted tiger beetle in the Wild Files): exceptional running speed (the species sprints across sandy substrates after small prey, briefly going TEMPORARILY BLIND during peak velocity), large forward-facing eyes for visual hunting, sickle-like jaws for prey capture. Larvae live in vertical burrows in sandy soil and ambush passing arthropods. The species is harmless to humans and is a flagship subject of modern textbook discussions of regional color polymorphism and structural color evolution.