Species Lethocerus americanus - Giant Water Bug

Electric Light Bug

Toe Biter

Fish Killer

Lethocerus americanum (alternate spelling)

described in 1847 by Leidy, who originally placed it in genus Belostoma

one of 6 species in this genus in North America listed at nearctica.com

very large: adult up to 65 mm

see Lethocerus page for general characteristics of genus

in L. americanus, anterior margin of eye is bulging, posterior margin of eye is perpendicular to body axis, and eye is globose or almost spherical; outer margin of hind tibia almost straight; width of first hind tarsal segment less than or equal to least interocular distance

L. americanus also has a groove in the anterior margin of the fore femur, but this feature is rarely visible in photos

see distinguishing characteristics of other species in "See also" section below

most of North America

ponds and shallow margins of lakes containing submerged or emergent vegetation

spring through fall

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.

in L. griseus, anterior margin of eye is evenly curved, posterior margin of eye is at an oblique angle to body axis, and eye is broadly triangular with rounded corners; outer margin of hind tibia broadly curved; width of first hind tarsal segment greater than least interocular distance [all of these features are visible in the close-up image of L. griseus by schming here]

L. griseus also has no groove in the anterior margin of the fore femur, but this feature is rarely visible in photos

in L. uhleri, the middle and hind legs are distinctly banded (see U. of Florida image)

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

live adult image - eating adult Pacific Tree Frog [Hyla regilla] (Mike Benard, mister-toad.com)

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

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

nymph and adult images (Insects of Quebec)

key to species of Lethocerus and Belostoma in Michigan (Ethan Bright, U. of Michigan)

key to species of Belostomatidae in Florida, plus photos (Paul Choate, U. of Florida)

author, date, and original genus (nearctica.com)