Yup they are smart, they won't eat the salad if they know they are going to get bugs.
At that weight, he can definitely handle a week or two without bugs. He will get hungry enough to eat his salad eventually. Remember, they are smart, they won't let themselves starve to death.
I've used this method to help dozens of stubborn adults start eating their salads. I use it on babies too to a degree to get them started.
It's your choice, but IMO, the health risks of not eating salads for a dragon far outweigh any potential health risk from not eating any insects for a few weeks.
-Brandon