Help identifying this hitchhiking critter!

I am setting up a new 5 gallon shrimp tank and purchased some java moss from an Amazon vendor. While examining the moss prior to a 1:20 bleach dip I found this "worm", larva. It was about 1/2 inch, 1.27cm in length. Can anyone identify it for me? ....I placed him in the bleach dip for 5 minutes and it did not kill him!
Thanks, Pete