Don't know what kind of worm you've got there, but here's a link to Christy's Worm Hitchhiker Reference Library...
http://www.canreef.com/vbulletin/showthread.php?t=22163
BTW, how often do you clean your foams? I have foam in my 802s and 402s. They get cleaned weekly. Have never found worms in them during cleaning, knock on wood
