Common NameGiant green water beetle
SeasonalityAdults emerge from May to August.
IdentificationMedium 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.