Gyrinus plicifer

Gyrinus plicifer belongs to the genus Gyrinus, one of two genera of whirligig beetles occurring in Missouri (the other being Dineutus). Members of Gyrinus are generally smaller than Dineutus species and possess a visible scutellum, whereas Dineutus species have a hidden scutellum. Specific identification of G. plicifer requires examination of ventral characters; the species is distinguished from congeners by features of the male genitalia and other subtle morphological traits.

North America, with confirmed records from British Columbia, Canada. The broader North American range requires additional documentation.

Like other whirligig beetles, G. plicifer likely forms surface aggregations ('rafts') on calm water. These aggregations serve multiple functions: increased predator detection through collective vigilance, and possibly aposematic signaling through chemical defenses from the pygidial glands.

• Dineutus spp.Large whirligig beetles (~12 mm) with hidden scutellum and rounded elytral apices, distinguished from Gyrinus by size and scutellum visibility.
• Gyrinus spp.Congeneric species requiring examination of male genitalia and ventral characters for definitive identification; field separation often not possible.

• aquatic
• surface-dwelling
• aggregation-forming
• North America
• freshwater
• Coleoptera
• Gyrinidae

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Gyrinidae | Beetles In The Bush
• June | 2010 | Beetles In The Bush | Page 2
• Ozark Trail | Beetles In The Bush