Veliidae

Definition

A family of small, gregarious predatory true bugs (Hemiptera: Heteroptera: Gerromorpha) characterized by a pronotum distinctly broader than the rest of the abdomen, giving them the common name "broad-shouldered water striders." Members occupy the air-water interface of streams, rivers, and shorelines, where they prey on small invertebrates trapped in the surface film. The family includes the subfamilies Veliinae, Microveliinae, Rhagoveliinae, and others, with Rhagovelia species notable for occupying faster-flowing riffle habitats.

Etymology

From the genus Velia (Latin, possibly from Greek velos "sail" or referring to swift movement) + -idae (family suffix).

Example

Veliids such as Rhagovelia can be distinguished from the larger Gerridae (common water striders) by their compact, broad-shouldered body form and preference for turbulent, oxygenated stream margins rather than still water.

Synonyms

• riffle bugs
• small water striders
• broad-shouldered water striders

Related Terms

• Gerridae
• Gerromorpha
• Heteroptera
• Hemiptera
• surface film
• neuston
• rheophilic

Usage Notes

Veliidae are often confused with Gerridae (water striders) due to similar habitat and locomotion on water surfaces, but veliids are generally smaller, more compact, with a pronotum that is conspicuously wider than the abdomen base. The family is strictly aquatic in habitat but typically occupies faster, more turbulent water than gerrids. Species of Rhagovelia are sometimes distinguished as "ripple bugs" for their association with broken water surfaces.