Numbers
2 subfamilies, with 32 spp. in 3 genera in NA
(1)(2) and 400 spp. in 11 genera worldwide
(3)Identification
Aquatic bugs that often swim upside-down. When resting at the surface, body is typically tilted with the head downward. Characteristics
(4)(5):
hind legs modified for swimming, with long hairs
front legs not scoop-like (unlike in Corixidae)
dorsum convex, V-shaped when viewed from tip of abdomen
wings clear, tips without veins
eyes typically separated by less than the width of one eye
Species identification often requires examining
stridulatory structures and male genitalia.
Keys to genera/species in
(6)(1)(7)(8)(9)(10)Habitat
Ponds, freshwater pools, slow flowing streams
Food
Prey on other aquatic insects and sometimes on small vertebrates; nymphs often cannibalistic
Life Cycle
Elongated white eggs are cemented to underwater plant stems and hatch in a few weeks; first-generation adults appear in July; often 2 generations a year
(11)Remarks
May bite if handled carelessly
Dive by holding air trapped in abdominal pockets; can remain submerged for up to 6 hrs
Come to lights; may invade swimming pools and become a nuisance
Males stridulate probably as part of courtship
See Also
Corixidae have rather flat body (often cross-streaked with dark lines) and scoop-shaped front tarsi
(12), and swim dorsal side up