robust conehead
Neoconocephalus robustus (Scudder 1862)

green male
yellow male
stridulatory area

20 s of calling song [1.69MB]; male from Washington Co., Ohio; 23.8C. (WTL195-33)

Waveform of 5 s of calling at 23.8°C (from WTL195-33). Peak frequency 7 kHz.
Click on first half of waveform to hear graphed song.
Click on second half of waveform to expand last 0.2 s.

Identification:  Large (length 53-74 mm). Cone immaculate beneath or with transverse black mark near tip. Ovipositor 1.0-1.1 times length of hind femur. Width of stridulatory area (as measured in drawing above) greater than 4.9 mm. Male pronotal length less than 1.8 times rear width (as in drawing above).

Habitat:  Tall, rank vegetation such as moist upland prairies, cornfields, wet areas behind coastal dunes, and the edges of saltmarshes.

Season:  July–Sept; N. Fla. data.

Song:  A very loud continuous buzz that can be heard under favorable conditions at least 500 m away. At a distance it has a whining quality, while up close it is dominated by an intense, low-pitched hum.

Song data:  Excel worksheet and chart (from spectrographic analyses).

Similar species:  N. bivocatus has the ovipositor more than 1.2 times length of hind femur; width of stridulatory area less than 4.9 mm. N. velox matures earlier in the year and has the ovipositor shorter than the hind femur; male pronotal length greater than 1.8 times rear width. N. palustris is smaller and its ovipositor is shorter than its hind femur.

Remarks:  The apparently disjunct California population is of unknown origin. N. robustus is a strong flier, as is N. triops, the other conehead that occurs in California. During calling, the thorax of N. robustus is as much as 27 F (15 C) above the ambient temperature (Heath and Josephson 1970). Differences in ambient temperature influence its wingstroke rate but less so than in other katydids.

More information:  subfamily Copiphorinae, genus Neoconocephalus

References:  Nutting 1953, Walker et al. 1974, Deily and Schul 2004.

Nomenclature:  OSF (Orthoptera Species File Online)