Synonyms and other taxonomic changes
Circotettix Scudder, 1877. Genotype: Oedipoda undulata
Aerochoreutes Rehn, 1921. Genotype: Oedipoda carliniana
Closely similar to Trimerotropis. Distinguished primarily by shape of wings and strongly thickened annal veins of hind wings. Most species have the tegmina very wide (not narrowing noticeably or even widening toward the end). The hind wings of most are exceptionally wide, with the outer margin somewhat undulate, and the apex somewhat elongated into a short lobe. [C. maculatus is not distinguishable from Trimerotropis by these traits, but has a buzzing crepitation and blackish wings that make it immediately recognizable when seen.]
Western North America, primarily in the United States, but also into southern western Canada, and perhaps barely into northernmost Mexico.
Almost universally favoring exposed rocky or eroded areas, usually sloping, and often steeply sloping.
All species overwinter as eggs, with adults most common in summer into autumn.
This genus is extremely closely related to Trimerotropis, and several species now included in that genus may soon be moved to Circotettix based on cytological and molecular studies (a number of those have at times been placed within Circotettix in the past). At least one species (C. maculatus) is a misfit within this genus, as it compares poorly with the others in wing shape and venation. However, it also seems out of place among Trimerotropis as currently defined.
The "species" C. rabula, coconino, crotalum, splendidus, shastanus, & undulatus are all very closely related to one-another, and there is evidence that where two of them meet, they may intergrade. This implies that at least some of them (and perhaps all of them) are biologically members of the same species. This is particularly notable in the two pairs C. coconino / C. rabula and C. undulatus / C. shastanus, neither of which can be neetly divided in the field.
Most Circotettix are conspicuous by their extremely loud buzzing (plus snapping in several species) crepitation and the high flight displays put on by the males (and sometimes females). M. maculatus is not as loud as the others, but buzzes in a similar manner.