Numbers
32 spp. in 3 genera in NA
(1)(2)Identification
Aquatic bugs that often swim upside-down. When resting at the surface, body is typically tilted with the head downward. Characteristics
(3)(4):
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 relatively close together--typically separated by less than the width of one eye
Accurate identification of species often requires examining
stridulatory structures and male genitalia.
Keys to genera/species provided in
(5)(1)(6)(7)(8)Habitat
Ponds, freshwater pools and 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
(9)Remarks
May bite if handled carelessly
Dive by holding air trapped in abdominal pockets; can remain submerged for up to 6 hrs
Attracted to artificial lights at night
Males have a
stridulatory apparatus probably used to attract females and communicate during courtship
See Also
Water Boatmen (Corixidae) have rather flat body often with numerous dark cross-lines and scoop-shaped front tarsi
(10) 
