Is this an army worm? How do I keep them from coring out my young Catasetums?

[flowergardengirl]

This is the third catt that i have found a small worm eating the center out of. I know to keep an eye out for other pests, but these guy seem to be continually showing up and it is driving me nuts. I was able to drive this guy out of hiding by spraying the core with a permethrin spray that I have. It seemed more aggravated (than dying )when it finally crawled out.

Can I give my catts a preventative treatment now? Even with being home the past couple of weeks I somehow managed to miss seeing this guy until it was a decent size. I go back to work in a week and I don't want another one chowing down on another orchid and I miss spotting it until it is too late. I have already lost one plant due to a secondary bacterial infection that it caused. Also, how do I prevent these guys from appearing in future years? Would treating this group with a systemic before they go dormant assist them through the spring before I water them? My Catasetum Pileatum was hit when it was really young before I started watering it out of dormancy, and I think I just got really lucky that an infection didn't spread.

I have attached two pics of the offender. The third is of my catamodes, which happens to be the current victim. The fourth is the Pileatum that was hit this spring.