Description: It is one of the largest aquatic insects, belonging to the family Belostomatidae, characterized by a long, robust, and strongly dorsoventrally flattened body, well adapted to aquatic environments. Its coloration ranges from brown to dark chestnut, often with lighter margins, providing effective camouflage among vegetation and the substrate. The forelegs are powerful and raptorial, specialized for capturing prey, while the hind legs function as efficient paddles. It has piercing–sucking mouthparts, typical of predatory true bugs.

Geographic distribution: The species is widely distributed in South America, with records mainly from tropical and subtropical regions. Lethocerus annulipes is associated with continental freshwater systems, where it shows a relatively common occurrence in well-preserved habitats.

Habitat: It inhabits lakes, ponds, pools, slow-moving streams, and temporary freshwater bodies, both natural and artificial. It prefers calm waters with abundant aquatic vegetation, which provide shelter and suitable hunting grounds. It tolerates moderate environmental variation but depends on structurally complex aquatic ecosystems.

Feeding: It is a strictly predatory insect, feeding on aquatic invertebrates, insect larvae, tadpoles, small amphibians, and small fish. Prey are seized with the forelegs and injected with digestive enzymes through the rostrum, after which the liquefied tissues are consumed. It plays an important role as a population regulator within aquatic ecosystems.

Behavior: It exhibits mostly aquatic habits and an ambush strategy, remaining motionless among vegetation while waiting for prey. It is a powerful swimmer and can also fly, allowing dispersal to new water bodies, especially at night. Activity is predominantly nocturnal, when predatory behavior increases.

Reproduction: Reproduction takes place in aquatic environments and involves a distinctive behavior. Females lay eggs on the male’s back, where they are carried and protected until hatching, ensuring proper oxygenation and reducing predation. Nymphs are aquatic and undergo several molts before reaching adulthood, maintaining similar habits throughout development.

Conservation status: Lethocerus annulipes is not considered globally threatened. Populations are generally stable; however, wetland loss, water pollution, and hydrological alterations may locally affect its abundance.

Author of this compilation: EcoRegistros – 12/12/2025