four-spotted tree cricket
Oecanthus quadripunctatus Beutenmuller 1894

mating pair
mating pair
antennal markings

20 s of calling song; male from Nelson Co., Ky.; 25.8C. (WTL582-79b)

20 s of calling song; dwarf-form male from Marin Co., Calif.; from tarweed; 25.1C. (WTL582-59c [=MLNS 119653])
  Sound spectrogram
 Click on sound bar to hear graphed song.
Sound spectrogram of 2 s of calling at 25.8°C (from WTL582-79b). Dominant frequency 4.2 kHz.
Click on last 0.5 s to expand its spectrographic image.

Identification:  Length 13–15 mm (Bay Area, California, 10–14 mm). 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.

Habitat:   Open areas, including roadsides, old fields, and crops. Mostly on herbaceous plants but males sometimes call from the lower limbs of trees or shrubs.

Season:  One generation annually in the north with adults occurring from late July or August until frost. Two or more generations annually in the south with first generation adults appearing in May near Gainesville, Florida, and in June near Raleigh, North Carolina. In Gainesville, adults occur through December. Farther south in Florida, adults occur year round.

Song at 25°C:  A continuous trill at 41 p/s; carrier frequency 3.9 kHz.

Song data:  See Walker 1963.

Similar species:  Fast-calling tree cricket—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; fewer than 50 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.

Remarks:  The five herb-inhabiting species of the Oecanthus nigricornis species group—the four-spotted, prairie, black-horned, Forbes's, and fast-calling—are the most commonly encountered and the most difficult to identify tree crickets.

More information:  genus Oecanthus, subfamily Oecanthinae.

References and Links:  Fulton 1915, 1926a; Prestwich & Walker 1981; Walker 1963, 1967; Walker & Rentz 1967. Collins 2010-date.

Nomenclature:  OSF (Orthoptera Species File Online).