Giant Green Water Beetle

No special status (IUCN 2002).

Adults emerge from May to August.

In Alberta this species is recorded from the southern region. This species ranges from British Columbia to Manitoba (Larson et al. 2000). The southern-most records are from Durango State, Mexico.

Medium size (26.7 to 33.0 mm), elongate body (Larson et al. 2000). Reddish to black - some with metallic green appearance. All margins of pronotum and lateral margins of elytra broadly margined with yellow. Large medial chevron on head. Basal segments of antennae yellow, terminal segments reddish. All pronotal margins broadly yellow - basal margin narrow laterally and broadly expanded medially. Lateral margins of elytra yellow, narrowed and discontinuous at apex. Fore- and middle legs yellow to pale red.

Semi-permanent, saline ponds (Larson et al. 2000). Also in fresh water ponds.

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.

Dytiscus marginicollis, the giant green water beetle, is a species of predaceous diving beetle in the family Dytiscidae. It is found in North America.