Dytiscus circumcinctus    



habitat
Permanent and temporary ponds (Larson et al. 2000). Associated with aquatic macrophytes.

seasonality
All teneral specimens from late July.

identification
Large (27.5 to 34.0 mm), elongate body (Larson et al. 2000). Brown to black - some with green appearance. Ring of yellow around inner margin of eye. All pronotal margins bordered with yellow. Lateral margin of elytra yellow and narrowing to apex. Yellow or reddish ventral surface, expect thoracic sclerites margins narrowly brown-black and metasternum medially and metacoxa dark red. Pale abdominal sterna, with basal margins of first through third sterna narrowly brown-black. Yellow or yellow-reddish legs, brown-black dorsal surface of tibia.

life history
Overwinter as adults in permanent waters (Larson et al. 2000). Late fall or early spring mating. Univoltine (Aiken and Wilkinson 1985). Strong swimmers, hind legs move together while swimming. Adults attracted to lights.

conservation
No special status (IUCN 2002).

diet info
Predatory - active swimmers (Larson et al. 2000). Invertebrate and fish larvae prey. Larvae are predators of mayfly (Ephemeroptera) nymphs, isopods (Isopoda) and caddisflies (Trichoptera) (Johansson and Nilsson 1992).

range
Holarctic (Larson et al. 2000). This species is recorded from most of Alberta. This species ranges from Alaska to Maine, and as far south as Washington, Iowa and North Carolina. Also known from Great Britain to Kamchatka, records from peninsular Italy (Nardi and Maltzeff 2001).

people
species page authorEdgar, M.2003 
species page editorShpeley, D.2004 

quick link
http://entomology.museums.ualberta.ca/searching_species_details.php?s=4257

 

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