Key to the Genus ofNotonecta Linnaeus (1758) of Michigan
Adapted fromHungerford 1933 andHilsenhoff 1984

1. Keel of the 4th abdominal sternite bare, thehairs confined to the sides (picture) - 2

Keel of the 4th abdominal sternite not bare - 3


2. Scutellum entirely dark - N .insulata

Scutellum entirely light yellowish or only partially with darkmarkings -
N.borealis

3. Female (picture) with last abdominal sternite large, but stronglyconstricted before the tip (picture); male (picture) with digitateprolongation of genital capsule (picture); hemelytra with irregularpattern of black and orange marks (picture) -
N. irrorata

Female (picture) with last abdominal sternite not large, not stronglyconstricted just before the tip (picture); Male (picture) withgenital capsule without digitate prolongation (picture); hemelytrawith large white areas, never with orange - 5

4. Mesotrochanter angulate or produced into a tooth or stoutspinelike process (picture)-
N.lunata

Mesotrochanter rounded posteriorly, or nearly so (picture) -
N. undulata