Japanese beetles

As is usual this time of year, we've been picking Japanese beetles.  We feed a lot of them to the chickens, but since we have a small flock, there are sometimes more beetles than they can eat.  That got me thinking-could I preserve them to feed in the winter?  I'm pretty sure freezing would work, as my daughter likes to put them in the freezer to make "chicken popsicles" to give them when it's hot, but I'm not sure I want much freezer space taken up by bugs.  I'm wondering if it would work to dry them out in the oven.  That's what happens to the silkworm pupae I give them.
Any thoughts?