What is "veliidae"

Veliidae is a family of predatory insects in the suborder Heteroptera. They are commonly known as riffle bugs, smaller water striders or broad-shouldered water striders because the segment immediately behind the head is wider than the rest of the abdomen, unlike in the typical water striders ( Gerridae), close relatives which are also in superfamily Gerroidea. Unlike some Gerridae, riffle bugs are small, typically about 4.5 mm in length.