Phylum Arthropoda
Class Insecta
Order Coleoptera
Family Elimidae
Common Name Riffle Beetle
Distinguishing Characteristics
Larva of Xenelmis
  • The body is convex, broadly rounded anteriorly, tapering posteriorly from the second abdominal segment.
  • The head is usually concealed by the pronotum when viewed dorsally, although it can be extended from beneath the pronotum.
  • The anterior margin does not have a tooth between the base of the antennae and the clypeus.

    Larva of the Hexacylloepus
  • When viewed dorsally, the head is not concealed by the pronotum
  • There is an inconspicuous tooth between the antennae and the clypeus.
  • Additional Pictures



    QuickTime Movies


    Additional Links



    Merritt, R W., K W. Cummins, and M B. Berg. An Introduction to the Aquatic Insects of North America. Dubuque, Iowa: Kendall/Hunt Company, 2008