1. Black winged locusts (Dissosteira species).
a. Hindwings mostly black.
b. Median carina cut by one sulcus.
A. Outer margin of hindwing yellow, tegmina plain or dotted with black.
B. Outer 1/3 of hindwing transparent, tegmina with dark blotches.
2. Flash pattern bandwings (Arphia species).
a. Tegmina without blotches or bands.
b. Hindwings either red, orange, or yellow and with broad fuscous margins.
c. Pronotum with median carina entire or cut by one sulcus.
A. Adults in spring and early summer, inner face of hind femur with two pale bands.
a. Front with an inverted 'Y-shaped' carinula between the frontal carinae. A common species throughout area.
a.’ "Y-shaped" carinula absent, southeastern South Dakota only.
b. Frontal carinae meet at an acute angle dorsad.
Arphia sulphurea
b.’ Frontal carinae juncture broadly rounded and marked by irregular depressions below fastigum.
Arphia simplex
B. Late summer and autumn species, inner face of hind femur usually crossed by one pale band.
a. Inner face of hind femur crossed by one pale band, hindwings red with black spur reaching half way to wing base, widespread species.
a.’ Inner face of hind femur crossed by two pale bands, hindwings yellow to orange, black spur very short, southern South Dakota.
Arphia xanthoptera
3. Clear-winged locusts (Camnula, Encoptolophus, and Chortophaga spp.).
a. Hindwings clear or with blurred color pattern.
b. Median carina cut by one sulcus, no exceptions.
c. Vertex without median ridge– eyes not bulging.
A. Tegmina blotched, hindwings clear.
B. Tegmina with alternating dark and light transverse bands
a. Hind tibiae brown, fastigum wider than long.
a.’ Hind tibiae blue, vertex with fastigum as long or longer than wide.
b. Posterior pronotum with black wedges.
b.’ Posterior pronotum without black wedges.
Encoptolophus subgracilis
C. Tegmina without blotches or bands, hindwing with diffuse yellow and fuscous areas, an early spring species.
4. Big-eyed locusts (Trachyrachys, Derotmema, Metator, Metsobregma and Psinidia).
a. Lateral lobes of pronotum flared outward or pointed (one exception).
b. Hind tibiae yellow, brown, or (most often) blue.
c. Median carina cut by two sulci.
d. Pronotum rugose or tuberculate (one exception).
e. Usually appear "big eyed"– eyes usually higher than vertex.
f. Tegmina appear ‘narrow’ in most species including exception of ‘a.’
-- Note: some members of group 7 may appear to fall here.
A. Lateral lobes of pronotum rounded, tegmina brown, without blotches or transverse bands.
B. Lateral lobes of pronotum flaired outward or pointed, tegmina blotched or with transverse bands.
a. Antennae ensiform.
a.’ Antennae filiform.
b. Tegmina blotched, hindwings yellow or red, cerci of male ‘spoon-shaped.’.
b.’ Tegmina with transverse bands at least on leading edge, hindwings yellow or clear, cerci of male cylindrical.
c. Hindwings clear (northern Great Plains), pronotum with subdorsal carinae.
c.’ Hindwings yellow, pronotum without subdorsal carinae.