6 s of calling song; from a recording made by Nancy Collins of a male calling at 24.8°, Lower Rio Grande Valley, Texas; used by permission.
Click on sound bar to hear graphed song.
Sound spectrogram of 2 s of calling at 24.8°C (edited from recording above). Dominant frequency 4.3 kHz.
Song at 25°C:
Continuous trill at ca 43 p/s. This is faster than O. quadripunctatus, slower than O. argentinus, and much slower than O. celerinictus.
Length 15–17 mm. For antennal markings and the general appearance of male, female, and juvenile, see images above. As noted below under Similar Species, the place of calling may be the simplest means of distinguishing this Oecanthus from its close relatives. If the pulse rate of a song and the temperature at which the song was produced are known, the species may be identified by its song.
"Three other species of the Oecanthus nigricornis species group, argentinus, quadripunctatus and celerinictus, also occur in extreme southern Texas. These species, however, are not known to occur high in trees. Unlike O. walkeri, neither O. quadripunctatus nor O. celerinictus have black on the antennae or limbs. Although O. argentinus does have black on the antennae and limbs, it does not have a creamy white ventral abdomen." (N. Collins)
"Found on Seep Willow (Baccharis salicipholia), Tepejuage (Leucaena iveruienta) and Sugar Hackberry (Celtis laevigata) trees. Generally heard singing 8 - 20 feet high. The lowest individuals were found 4 feet above ground level on a Seep Willow sapling." (N. Collins)
"Second stage instars through adults encountered in May in extreme southern Texas. Second generation offspring of collected individuals emerged in captivity in late July, and ultimately mated in early October. No subsequent generations were raised." (N. Collins)