Chrysobothris viridiceps

The most reliable field character is the uninterrupted elytral costa that completely divides the posterior fovea—unique among C. femorata species-group members. Males are readily identified by their bright green face and distinctive bicolored antennae with yellow apical portions. Females require closer examination but share the divided fovea character; they differ from other species by subtle combinations of pygidial impression depth, elytral margin shape, and frons callosity form. Microscopic examination may be needed for confident female identification. The species is smaller than C. shawnee and C. rugosiceps, with which it shares oak associations.

Adults measure 7–13 mm in length. The body exhibits metallic coloration typical of the genus. Males have a bright green frons (face), for which the species is named, and uniquely within the C. femorata species-group, bicolored antennal segments with yellow outer portions and bright metallic green inner portions. Females lack the green face and have more uniformly reddish antennae. Both sexes possess a diagnostic uninterrupted costa (raised narrow ridge) that completely bisects the posterior elytral fovea (rounded pit); in all other C. femorata group species, this costa is interrupted by the fovea. Females tend to be more reddish on legs, antennae, and face compared to males.

Hardwood forests, particularly those containing oak species. Adults are found on dead branches of host trees. Within oak habitats, the species shows a preference for the smallest dead branches compared to other oak-associated congeners.

Eastern United States and southern Canada, west to the Continental Divide. Documented from Manitoba, Ontario, and Québec in Canada. The range overlaps broadly with other members of the C. femorata species-group.

Larvae bore into and feed on dead wood of host plants. Adults have been observed on dead branches of Quercus alba (white oak).

• Quercus - primary hostprimarily associated with oak species
• Carya - secondary hostreared from hickory
• Prosopis - secondary hostreared from mesquite
• Ulmus - secondary hostreared from elm

Complete metamorphosis with egg, larval, pupal, and adult stages. Larvae are wood-borers that develop in dead branches of host trees. Specific timing of emergence and voltinism have not been documented.

Adults are diurnal and active on exposed dead branches in sunny conditions. They rely on cryptic coloration for predator avoidance and exhibit flash coloration (brilliant metallic blue-green dorsal segments exposed in flight) when disturbed. The large, multifaceted eyes are presumed to function in predator detection.

As a primary decomposer of dead oak branches, contributes to nutrient cycling in hardwood forest ecosystems. Part of a guild of closely related species that partition host resources by branch size, potentially reducing interspecific competition.

Not considered a significant economic pest. Distinguished from C. femorata sensu stricto, which is an important pest of ornamental and fruit trees. The species has contributed to taxonomic understanding of a historically problematic species complex.

• Chrysobothris caddoSimilar size and metallic coloration; distinguished by joined (not separated) post-median elytral foveae and different host association (primarily Celtis, not Quercus)
• Chrysobothris quadriimpressaAlso oak-associated; distinguished by shallowly impressed pygidium and preference for larger branches
• Chrysobothris rugosicepsOak-associated but larger; distinguished by strongly quadrate last antennal segment and preference for very large branches and upper trunk
• Chrysobothris shawneeOak-associated but largest in group (9–18 mm); distinguished by larger bronze-black frons callosities and preference for large trunks and stumps
• Chrysobothris femorataFormerly confused with C. viridiceps; distinguished by straight (not arcuate) posteriolateral elytral margins and reddish (not bronze) elytral tips, and association with stressed living trees of various genera rather than dead oak branches

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Chrysobothris viridiceps | Beetles In The Bush
• Introducing Chrysobothris caddo | Beetles In The Bush
• Oklahoma | Beetles In The Bush | Page 9