It's great that you have him, eating greens, athough kind of weird, most WD won't touch vegitables, and rarely fruit. Crickets are no good, mostly they are water and is the WD equivalent of a gummi bear. By worms, I hope your either mean earthworms or Zoophobas, either one of these would make a better staple then the green you are feeding, in fact cutting back the greens to once a month is more appropriate, since the additional fiber can reduce the amount of food that is properly digested. He/she is big enough for small pinkie mice, that's what I would feed him if he/she was mine, three to six a week or whatever he/she would eat, along with the worms. When they become adult size it's good to cut back on feedings, my adults eat two to three fuzzies once a week or every two weeks in the winter time.