1. Blue or purple striped grasshoppers (Hesperotettix and Aeloplides species).
a. Pronotum with a purple, red, or deep blue median stripe.
b. Cercus of males tapering from base to apex.
c. Tegmina at most only slightly projecting beyond abdomen.
A. Hind femur with a red cross band before knee. Pronotum with a red or purple median stripe which is often white centered.
a. Pronotum strongly rugose, dorsal surface of femur red.
a’. Pronotum weakly rugose on metazona only, pronotum usually with median stripe white centered.
B. Hind femur alternately banded with blue-black and dull yellow, pronotum with a deep blue, pale centered median stripe.
2. Painted grasshopper (Dactylotum bicolor)
a. Black with horn yellow, orange, and blue markings.
b. Flightless species with rounded wings.
3. Short-winged hoppers I (Phoetaliotes, Hypochlora, Campyacantha, Melanoplus species).
a. Flightless species with tegmina less than 1/2 length of abdomen.
b. Tegmina often pointed.
c. Hind tibia blue, green or yellow-brown.
A. Black (post-ocular) stripe extending from behind eye onto pronotum.
a. Hind tibiae green, male cercus broad at base and apex.
Melanoplus gracilis
a’. Hind tibiae blue, male cercus narrowest at apex.
b. Head large, pronotum broadest anteriorly, hind femur horizontally bicolored, male cercus triangular and flattened.
b’. Head 'normal', pronotum broadest posteriorly, hind femur with vertical dark and light bands, male cercus inflated basally.
B. No such black stripe, a dark shade may be present.
a. Powdery green, darker above and a darker lateral stripe, male with furculae short but elevated above suranal plate and pointing inwards.
a’. Olive green flecked with yellow, male furculae small lobes, not projecting above suranal plate, directed outwards.
Campylacantha olivacea
4. Short-winged hoppers II (Melanoplus species).
a. Flightless species with tegmina less than 1/2 length of abdomen.
b. Tegmina often pointed.
c. Hind tibia red, orange, or pink.
A. Hind tibiae pink or orange
a. Dorsal edge of male cercus straight, black post-ocular stripe extending onto metazona, tegmina oval, not extending beyond second abdominal segment.
Melanoplus scudderi
a.’ Dorsal edge of male cercus concave, black post-ocular stripe not extending onto metazona, tegmina oblong, extending to fourth abdominal segment.
Melanoplus walshii
B. Hind tibiae red.
a. Male with furcae at least 1/3 as long as supra-anal plate; tegmina leaf-like with acute apex. Abdominal tergites bicolored, black basad, green distad, sternites bright yellow.
a.’ Male with furcae appearing as small tubercles or tooth-like; tegmina usually rounded, coloration variable.
b. Male cercus > 3x as long as narrowest width.
Melanoplus huroni
b.’ Male cercus < 2x as long as width at mid-point.
Melanoplus discolor
5. ‘Booted’ hoppers (Melanoplus bivittatus and M. differentialis)
a. Cercus of male boot -shaped, with a heel.
b. Dorsal valvula of ovipositor evenly rounded.
c. Furcae demarked as bulges at base of supra-anal plate.
d. Black sulci of pronotum not part of a black post ocular stripe.
e. Large species, males usually over 3 cm., females over 4 cm.
A. Dorsum with two pale stripes, one from each eye onto pronotum and tegmen; hind femur black at apex and dorsum, fading to yellow basad.
B. Dorsum olive green, without pale stripes, hind femur yellow with 'herring-bone' pattern in black.
C. Dorsum black, hind femur yellow with black cross-bands and herring bone pattern.