Dytiscus harrisii Kirby 1837

No special status (IUCN 2002)

Adults emerge from July to September.

In Alberta, recorded in the northern, central and southerwestern regions. This species ranges from Alaska to Newfoundland, as far south as Washington, Nebraska and Pennsylvania (Larson et al. 2000). Generally rare in western parts of range, most abundant in Great Lakes region.

Large (32.4 to 39.0mm), broad body (Larson et al. 2000). Dark brown to black - some with green appearance. Small chevron between eyes. Ventral surface of head yellow. Prosternum pale at lateral margins, brown-black medially. All margins of pronotum broadly yellow. Middle and hind legs brown-black with reddish basal portions, forelegs reddish anteriorly and brown-black posteriorly.

Shallow, warm permanent ponds, sedge marshes, beaver ponds and slow streams.

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.

Predatory - active swimmers (Larson et al. 2000). Invertebrate and fish larvae prey. Records of larval preference for caddisfly (Trichoptera) prey (LeClair et al. 1986).