A massive aquatic predatory bug — up to 3 inches. They lurk in shallows ambushing fish, tadpoles, and even small ducklings. Their bite is among the most painful insect bites.

Also called: Giant Water Bug, Toe-Biter, Electric Light Bug, Alligator Tick

Native status: Native; widespread; multiple US species

§ Quick facts

SizeBody 4–12 cm (1.6–4.7 in)
Weight3–8 g
LifespanWild 1–2 years
OrderHemiptera
FamilyBelostomatidae

§ Encyclopedia

Lethocerus americanus, sometimes called the electric light bug, toe biter or fish killer, is a giant water bug in the family Belostomatidae, native to southern Canada and the United States. It typically has a length around 5–6 cm (2.0–2.4 in). It was originally classified as a species in the genus Belostoma.

Source: Wikipedia — Lethocerus americanus Licensed under CC BY-SA 4.0

§ Identification

Field marks. Large flat brown to dark gray insect with grasping mantis-like forelegs; piercing beak; two air-breathing tubes at the abdomen tip; powerful swimming hind legs.

Similar species. Other Belostomatidae species (different sizes). Some beetle species (different mouthparts, life cycles).

Voice. N/A

§ Diet & behavior

Diet. Aquatic insects, snails, tadpoles, small fish, occasional small turtles and amphibians.

Behavior. Largest true bug in North America. Voracious aquatic predator with grasping forelegs and dagger-like beak that injects toxic saliva to immobilize prey and digest it externally. Bite ("toe-biter") to humans is intensely painful but harmless — sometimes ranks as one of the most painful insect bites in North America. In some species (Lethocerus, Belostoma), females cement eggs onto males' backs; males carry and aerate the eggs until hatching. Adults are strong fliers attracted to lights, often appearing far from water.

§ Range

Across North America

§ Habitat

Ponds, slow streams, marshes

§ Threats

Wetland loss, water pollution, light pollution (drowns them at lights at night).

§ Conservation status

According to the IUCN Red List, the giant water bug is currently classified as Least Concern.

§ What helps

Maintain wetland habitats. Reduce night lights near water. Don't handle.

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§ Further reading

§ Sources cited

  • BugGuide
  • University of Florida IFAS
  • Audubon Insect and Spider Guide