Notonecta irrorata

Adult Notonecta irrorata has the triangular, boat-shaped body typical of the genus Notonecta, with a keel-like dorsal surface adapted for rapid upside-down swimming. The species can be distinguished from water boatmen (family Corixidae) by its triangular cross-section versus the flattened body of Corixidae, and by its shorter unmodified front legs versus the spoon-shaped tarsal segments of water boatmen used for scooping food.

Freshwater aquatic environments including ponds and slow-moving streams; occupies open water rather than bottom substrates. Has been observed in artificial water environments including fountains and swimming pools.

Native to North America; documented in the eastern Nearctic region including Mississippi and Missouri, USA, and Vermont.

Predator; feeds on mosquito larvae and other small aquatic insects.

Swims upside-down using long, oar-like hind legs modified for rowing. Adults are capable of flight and can disperse between water bodies. Exhibits diurnal activity patterns and is rarely attracted to lights at night. Surfaces to take in air using hydrophobic hairs around the rear end and along the middle of the underside of the abdomen, which trap air for underwater respiration.

Predator in aquatic food webs that affects mosquito population dynamics through both consumptive effects on larvae and non-consumptive effects on mosquito oviposition behavior.

Presence in ponds and pools can reduce mosquito populations by repelling Culex oviposition; adults may bite if handled, causing pain comparable to a wasp sting.

• Corixidae (water boatmen)Superficially similar oval body shape and aquatic habitat, but water boatmen have flattened bodies (versus triangular), spoon-shaped front legs for feeding (versus unmodified), and are primarily detritivores that cruise the bottom (versus predatory backswimmers in open water).
• Notonecta glauca (European backswimmer)Congeneric species with similar morphology and behavior; N. irrorata is distinguished by its North American distribution.

• aquatic
• predator
• mosquito control
• dispersal
• Hemiptera
• Notonectidae
• North America

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Oedemeridae | Beetles In The Bush
• Buprestidae type specimens at Fundación Miguel Lillo, Argentina | Beetles In The Bush
• Bug Eric: Backswimmer or Water Boatman?
• A hump‐shaped relationship between isolation and abundance ofNotonecta irroratacolonists in aquatic mesocosms
• Geographic variation in Culex oviposition habitat selection responses to a predator, Notonecta irrorata