After work by researchers who analyzed songs of tree crickets in multiple states, it is now generally accepted that greenish tree crickets with dark on the antennae, head, pronotum and/or limbs - that are west of Ohio - are Forbes' tree crickets.

(This much black rules out Prairie tree cricket)

...but cannot rule out Oecanthus nigricornis. The two species cannot be accurately ID'd by sight alone -- they both range in color from mostly green to a lot of black.

The only way to determine species is by the pulse rate of the singing male's song. Forbes' rate is much faster than that of Nigricornis.

Moved from ID Request.