I have three Catch-can traps about 150 yard from the trees
and those are getting a lot more. This afternoon I emptied
the traps with a yield (!) of maybe four or five hundred
beetles. so it seems that the traps are doing some good
where they are.

When I go to the traps, I first dunk the whole trap and can
in a bucket of soapy water, then empty the wet beetles
into the bucket. They stay there just fine but I've
started to think about how to dispose of them when they
become more numerous. In the past, I've dumped them in a
far corner of the yard but they stink and sometimes crawl
around and I don't like that.

This time, I decided to see what happens if I feed them to
the fish, so I threw the whole bucketful into my pond
(1/4 acre, 10 feet deep, stocked with large-mouth bass
and bluegills). It took a few minutes before anything
happened but the fish did nibble and later got quite a few.
After about five minutes, some of the beetles revived and
flew away (probably less than 10%). For the next fifteen
minutes there was regular feeding, probably by bluegills,
but I have to concede it was anything but a feeding frenzy.
After a while some of the larger bass showed up and
began to do a better job. I didn't stay longer but I'm
going to venture a guess that probably 90% or more of
these beetles were "consumed".

This result seems good enough to me to warrant another
try. I'll try a couple of things different:
1) I'll leave the beetles in the soapy water longer
(this time was only a couple of minutes) in the hope that
more of them will be "drowned". Anyway, does a japanese
beetle drown?
2) I guess I'll try a different time of day to see if
feeding is a little more enthusiastic. This time it was
around 2 PM under a hot sun.

If anyone has suggestions or a story about a similar
experience, I'd like to hear it. Thanks for any help
you may contribute