I use a foam called ethafoan for popping bugs and Booby Flies
(www.bishfish.co.nz/articles/boobyfly.htm Ethafoam is basically the foam
used for outdoor mattresses, and comes in a range of colours. I cut out
tubes ( using filed down sections of car arials - yea miss-spent youth) to
get the right diametre. The tube is then threaded onto to hook, and the tube
can be shaped by judicious 'binding' with the thread.

Hope this helps,

--
Tony Bishop
www.bishfish.co.nz
New Zealand