Knowing where you live would help a lot in determining when it would be right for you to prune. It's different for different climates. But I don't think this is the right time for hard pruning in most climates. If the tips were eaten off by something just snip off the tip down to the next set of 5 leaves and it should start to grow again.

Doctorant said it best! May I add that before you destroy any native plantings maybe it would be good to see if anyone else would love to have them. I know many in Zone 5 Indiana who would be very anxious to take them off your hands if you want to kill them. That includes me. It is so vibrant and really attracts the butterflies like crazy. If in a very moist and fertile enviorment you can get them to reach 8 feet tall. Their root system really gets thick and the plant does a great job of "grounding itself in". It really holds up the large flower heads it produces. The stems are so strong that you can cut them down in the fall and use them to stake up some of your other tall growers that need staking. Enjoy them for all the benefits they have to offer to our Indiana meadows.

2 weeks is not long enough. Be patient. I use a 55 gallon barrel for a hatchery so the cocoons have time to hatch. Just keep that VC moist and add a sprinkling of corn meal and the babies will work their way to the top. It just takes time for baby worms to get there.

In addition, it can also be a sign of stress. The first azalea I bought was the only red leaved one in a small field of Hino Crimson. It was beautiful! When I got it home to plant, I noticed the trunk had been girdled by a slug. I had just started working at the nursery where it was being grown. I was too embarrassed to bring it back. :-) Mike