Genus Lethocerus

L. griseus is often treated in the genus Benacus (1) (2)

5 spp. in our area(3)

40-75 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

Keys to species provided in(3)(4)(1)(5)

most of NA(3)

ponds and shallow margins of lakes containing submerged or emergent vegetation

Adults are attracted to light and are sometimes found on the ground under streetlights. During the breeding season, when the adults fly around looking for mates and for places to breed, they often get disoriented by electric lights and end up circling them in large numbers. This can lead to mass invasions of artificially lit outdoor spaces near water. (See this newspaper article about one mass invasion in the Tampa Bay area, Florida)

Any animal small enough to grab with their front legs: aquatic arthropods, snails, small fish, tadpoles, frogs, small birds. Once they have a hold on their prey, they inject enzymes with their strong beaks that kill the prey and start the digestion process. Once the insides are broken down, they suck the liquid out with their beaks.

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. (H. Goble and T. Young, U. of Guelph)

Adults breathe air through a snorkel-like breathing tube at the tip of the abdomen and tend to float at the surface or hide in shallow areas within reach of the surface.

Like most predatory bugs, these have a very painful bite. If you're wading or swimming in their habitat, closed-toe footwear is a good idea just in case you step on one.

Belostoma species are much smaller (15-30 mm) and less elongate