Unlike most praying mantises that have a single region of auditory sen
sitivity, species in the genus Creobroter have equally sensitive heari
ng at 2-4 and at 25-50 kHz and and are relatively insensitivity at 10-
15 kHz - they have a W-shaped audiogram. Ultrasonic sensitivity origin
ates from an auditory organ in the ventral midline of the metathorax t
hat closely resembles the ear of other mantises. Ablation experiments
demonstrate that low frequency sensitivity derives from a serially hom
ologous mesothoracic auditory organ. Extracellular recordings suggest
that these two ears operate largely, if not entirely, independently of
one another in the thorax. The low frequency response has a longer la
tency, more action potentials per stimulus, and different patterns of
change with increasing SPL than the high frequency response. Separate
interneurons mediate responses in the two frequency ranges, but our ev
idence suggests that they are two serially homologous sets of cells. N
either auditory organ shows any physiological evidence of directional
sensitivity. Ultrasound triggers a set of behaviors in flying hymenopo
did mantises much like those in other mantises, but the behavioral sig
nificance of low frequency hearing in these animals is still unknown.