Genus Lethocerus

6 species in North America (nearctica.com)

large: up to 65 mm

body elongate; front legs raptorial, twice as thick as other legs, usually held in front of head, and used for grasping prey; middle and hind legs point toward rear and are used for swimming; forewings brown, leathery, held flat against abdomen

forewings cover all of abdomen except for two tube-like appendages at posterior end that function in breathing atmospheric air which is then stored in a bubble beneath the wings while swimming underwater

most of North America

ponds and shallow margins of lakes containing submerged or emergent vegetation

nymphs and adults eat aquatic arthropods, snails, small fish, salamanders, frog and toad tadpoles and adults

During spring and early summer, eggs are laid near or in water attached to aquatic plants, stones, leaves or rotting branches. The eggs are brownish-gray, 4-5 mm long, laid in rows. Usually 100 are found in each group, hatching in about 2 weeks. The nymphs look very similar to adults but lack wings and are much smaller; they molt 5 times before becoming adults.

Overwinters as an adult in mud at bottom of pond or lake margin.

May bite if handled. Adults are attracted to light and are sometimes found on the ground under streetlights.

Belostoma species are much smaller (20-30 mm) with less elongate bodies

adult drawing of L. americanus plus description, biology, common name references, and other info (H. Goble and T. Young, U. of Guelph, Ontario)

adult image of L. americanus by Bastiaan Drees, plus other info (Texas A&M U.)

adult image of unidentified Lethocerus species (U. of Minnesota)

adult image of L. americanus by Stephanie Boucher, plus other info (McGill U., Quebec)

nymph and adult images of L. americanus (Insects of Quebec)

adult image of unidentified Lethocerus species (U. of Saskatchewan)