I would try a different food item if I were you. Try some crickets or something, how large are the locusts are you giving him?
And try meal worms(Don't over do it though because the chitlin in the shell can cause a blockage and prevent him from passing waste) superworms(smaller super worms) some wax worms, but you really want to limit the wax worms, I would just say try to give him more variety than locusts if you can. He will eat if hes hungry though so maybe give it another day and then try. Are you letting them free range btw? If you can I would try let them do that if you are hand feeding, they tend to be a bit shy with eating like that until they get used to you. And maybe try making a feeder where you can set the locus in there and let him get to them from a perch.