Description: It is a large aquatic insect belonging to the family Belostomatidae, easily recognized by its robust, flattened, oval-shaped body, well adapted to aquatic life. Its coloration ranges from brown to dark chestnut, providing effective camouflage among vegetation and the substrate. The forelegs are modified into powerful grasping appendages used to capture prey, while the hind legs function as paddles. It possesses piercing–sucking mouthparts, typical of predatory true bugs.

Geographic distribution: This species is mainly distributed in South America, with records from temperate to subtropical regions. Belostoma dilatatum is associated with continental freshwater systems, where it shows a relatively regular occurrence under suitable environmental conditions.

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 provides shelter and hunting grounds. It tolerates moderate variations in water quality but relies on well-preserved aquatic habitats to complete its life cycle.

Feeding: It is a strictly predatory insect, feeding on aquatic invertebrates, insect larvae, tadpoles, 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 predominantly aquatic habits and often remains motionless among vegetation, using a sit-and-wait hunting strategy. It is capable of swimming rapidly and may fly to disperse to new water bodies when conditions become unfavorable. Activity is mainly nocturnal, when foraging intensity increases.

Reproduction: Reproduction takes place in aquatic environments and involves a distinctive behavior. The female lays the 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: Belostoma dilatatum is not considered globally threatened. Populations are generally stable; however, wetland degradation, water pollution, and hydrological alterations may locally affect its abundance.

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