I am fairly sure he is at the age where he needs more veggies than bugs now.
He is a little on the heavy side, not bad but heavy.
You can feed greens like collard turnip or mustard greens daily and try bell peppers (green,yellow, orange or, red) for color to entice him. At his age to much protein is bad for his liver. You need to really start pushing veggies. Bugs every other day is fine but greens everyday. Leave them in his viv for him to snack on all day.
He definitely needs mostly greens in his diet. 70% of his daily intake should be greens and 30% insects. A good incentive to getting them to eat their veggies is to mix a few worms into their salad. They'll eat the salad trying to get at the worms!