He may grow ever so slightly more, but he doesn't need live food every day. Some dragons are full sized at his age, even before. Many dragons prefer bugs over salads + their owners give up on offering salad. Once he's settled in for a couple of weeks, cut out the bugs for 3-4 days at a time and offer only salad. He should get hungry enough [ he won't starve ] to accept the greens [ use greens like turnip, mustard, collard, dandelion, kale and some squash, green beans + peppers.
You can also try dropping some greens right on the paper towel when he's expecting his bugs and this may entice him by the movement as they are dropped as well as making the greens stand out against the white.