Caelifera (short-horned hoppers): Males with flattened or round cerci that rarely project slightly beyond the abdomen. The abdomen is rounded in posterior view. Females have a pointed abdomen. The point, actually four visible points are the closely appressed valvulae of the right and left, dorsal and ventral parts of the ovipositor. Females have triangular cerci. Note: Earlier instar nymphs (1-2) usually cannot be sexed as the external structures have not developed sufficiently.
C1. Lubber grasshoppers (Romaleidae)
a. Adults flightless and >4 cm in length (applicable to Dakotan species only, variable in southwestern U.S. species).
b. Apex of hind tibiae crowned with six 'claws' (two spurs and a spine on both the inner and outer face).
c. Pronotal and aroliar characters variable.
C2. Bird locusts (Acrididae: Cyrtacanthacridinae)
a. Spur present between bases of forelegs.
b. Meso-sternal lobes longer than wide.
c. Eyes with narrow vertical stripes (living specimens).
d. Arolium 'egg shaped.'
e. Annual immigrants to the northern Great Plains in warmer years with progeny reaching adulthood in delayed frost years.
C3. Spurthroats (Acrididae: Melanoplinae)
a. Spur present between base of forelegs.
b. Meso-sternal lobes wider than long.
c. Eyes mono-colored, speckled, or with horizontal bands (living specimens).
d. Posterior margin of pronotum rounded or broadly angulated.
e. Arolium oblong or 'egg shaped', projecting well beyond claws.
f. Most cropland species belong to this group.
C4. Slantfaced hoppers (Acrididae: Gomphocerinae)
a. Face nearly always strongly slanted in side view.
b. Without ventral spur between forelegs (a small tubercle present in two species).
c. Pronotum with posterior edge evenly rounded (one exception).
d. Hindwings clear (one exception).
e. Arolium small or absent to rounded and projecting beyond claws.
C5. Bandwings (Acrididae: Oedipodinae)
a. Posterior angle of pronotum 90o or less.
b. Spur absent between bases of forelegs.
c. Arolium absent or minute.
d. Tegmina with elevated intercalary vein.
e. Face broadly rounded in side view.
f. Hindwings often brightly colored
C6. Pygmy grasshoppers (Tetrigidae)
a. Pronotum extending back over abdomen.
C7. Pygmy mole crickets (Tridactylidae)
a. Forelegs modified for digging
b. Tarsi of mesothoracic legs two segmented.
c. Adults smaller than 2 cm.