Conocephalus is a huge genus of several hundred species worldwide. In my experience they inhabit damp habitats of dense herbaceous vegetation, swales inland, salt marshes along coasts, meadows of grass and sedge. The common name of meadow katydids seems apt. As katydids go they are smallish, elegantly delicate, and they occur at very high densities in these swales. The males are day stridulators singing mostly within a metre of each other.
The first species I ever encountered was Conocephalus fasciatus, stridulating in a field on a sunny afternoon south of Ithaca in upstate New York. I was trying to find an animal to study for my 'digger' (Post Hole Digger Ph.D.). Bob Pipher, a friend brought a heterodyning device with which to listen for ultrasonics. Over the earphones at 40 kHz came a long buzzing interspersed with many ticks. It took a long time to locate the source.