Length 13–15 mm. Outside marks on first and second antennal segments as heavily pigmented as inside ones; outside mark on first segment never round; tibiae and apex of hind femur with conspicuous dark markings; width of inside dark mark on first antennal segment less than distance between inside and outside marks; no dusky areas on pronotum; fewer than 50 teeth in stridulatory file.
Four-spotted tree cricket—outside marks on first and second antennal segments usually less heavily pigmented than inside marks; outside mark on first segment often round; tibiae and apex of hind femur usually without conspicuous dark markings; more than 47 teeth in stridulatory file. Prairie tree cricket—black marks on second antennal segment confluent, contiguous, or separated by no more than one-third the width of the inside mark.
Fields, roadsides, early successional stages.
Two generations annually; with break between generations in early August. First adults in mid May in Gainesville, Florida, to mid June farther north. Adults occur into Nov. unless killed earlier by frost.
The five herb-inhabiting species of the Oecanthus nigricornis species group—the fast-calling, four-spotted, prairie, black-horned, and Forbes's—are the most commonly encountered and the most difficult to identify tree crickets.