They are good as a staple for a 13 month. Keep in mind they are rather high in protein though. Roaches may be a better route for a staple.
A wide variety of feeders is better then just one type of feeder. :wink:
Don't get my previous post wrong. As Brandon said they are a great staple. For this particular instance though, I personally would feed them in a varied diet at a higher rate then most other feeders being incorporated. This is why, 64% protein at an age of 13 months may not be the best overall. If the dragon was so close to full grown this determination would be different.
I would buy a small amount of the feeder you want to try first just to be sure he likes them lol. I purchased phoenix worms and my little one wouldn't even look at them...then when he did grab one two days later he spit it back out without even hurting the worm...*sigh*
You still want to dust with a multivitamin two times a week.
And for safe measures, you might still want to dust with calcium once or twice a week or so.