This green/yellow/black combination fits with O. forbesi/O. nigricornis. This nymph has less black, but there is darkness of it's developing wings. Also, the speckling pattern on the abdomen is a match for O. forbesi/O. nigricornis. It is generally accepted that green tree crickets with black on the antennae, head, pronotum and limbs west of Ohio are Oecanthus forbesi. In the far northeast of the U.S. or southeast of Canada these tree crickets have generally been found to be O. nigricornis. Oecanthus forbesi begins occurring the closer to Ohio they are found. The two species are indistinguishable by visual inspection. Some O. forbesi can have lots of deep black; some O. nigricornis can be entirely green -- and vice versa. Both species often have yellowish heads and pronotums.