Family Psephenidae - Water Penny Beetles (original) (raw)

Classification

Kingdom Animalia (Animals)

Phylum Arthropoda (Arthropods)

Subphylum Hexapoda (Hexapods)

Class Insecta (Insects)

Order Coleoptera (Beetles)

Suborder Polyphaga

No Taxon (Series Elateriformia)

Superfamily Dryopoidea

Family Psephenidae (Water Penny Beetles)

Explanation of Names

Psephenidae Lacordaire 1854

Water penny: larvae are flat, often circular

Numbers

16 spp. in 6 genera in our area(1), ~300 spp. in 15 genera total(2)

As of 2024 the family is paraphyletic with Eubrianacinae sister to Callirhipidae and the other taxa sister to Chelonariidae.

Identification

Adults flattened, usually dark:

Larvae aquatic, distinctive, cling to rocks and found more often than adults:

Range

worldwide, most diverse in E. Asia; Eubrianacinae (represented in our area by Eubrianax) are circumpacific, Psepheninae (represented in our area by Psephenus) are primarily a New World group, and Eubriinae (the rest of our genera) are globally distributed(1)

Habitat

Larvae on the underside of rocks of submerged wood in fast-flowing water. Adults on rocks and vegetation along streams.

Season

Adults only in summer(1)

Food

Larvae graze on algae; some are detritivorous(1); adults are short-lived

Life Cycle

semivoltine; larvae overwinter, pupate under riparian substrates or in water(1)

Internet References

Family page (Hammond 2009)

Works Cited

1.	American Beetles, Volume II: Polyphaga: Scarabaeoidea through CurculionoideaArnett, R.H., Jr., M. C. Thomas, P. E. Skelley and J. H. Frank. (eds.). 2002. CRC Press LLC, Boca Raton, FL.