We used nematodes, a natural predator. You can buy them online. They kill the larvae of the beetles. Beetles destroyed my entire crop last year; this year, though, we used the nematodes and are getting lots of nice cucumbers. Next year we will try applying before the beetles appear, as that's when it would be most beneficial against the larvae. If you need help finding a supplier let me know.

I know other people who have only a small area of plants kill them by hand; they squish them or pick them off by hand.

My cukes are already dead thanks to the CB's. Now they've moved on to a zuke plant I have. Of course, they prefer the blossoms. Recently I found 8-10 CB's IN a zuke blossom. I sprinkled a very small amount of Rotenone IN the blossom then tilted it sideways over a small pail of soapy water. They crawled out and fell into the soapy water. They did not like the rotenone at all.

I then sprayed the inside of the blossom with the water hose to remove the Rotenone. (since bees also like squash blossoms) In doing so, I wet the straw mulch around the plant. Before long a parade of squash bugs and CB's began to climb onto the zuke to escape the moist surroundings. I squished the CB's and drowned the SB's. Squishing the squash bugs grosses me out too much. ewww...

If anyone knows a better way of removing the CB's from the blossonms, I'd like to hear. I find CB's to be more difficult to catch than squash bugs. They're quick!

Everyday I spray the zuke and the straw mulch around it with a good blast of water. That method probably won't work for you if you don't have straw or a similiar mulch for the buggers to hide in.

Good luck!

I had a terrible time with them a couple years ago. I used Rotenone and / or Sevin. Either one will kill CB. I have stopped using both since then. They do kill off beneficials including bees and worms and can kill off fish if your pesticides run off into a stream or a lake.

If you decide to go that route and use either pesticide, just keep in mind that you will need to hand pollinate your zukes & cukes. I now spray them with soapy water until they drowned. I also squish them sometimes.

Try and rototill your garden in the fall to expose any eggs they have laid. If you do find eggs - squish then.

growingup

I had terrible problems with cuke beetles last year and so did a lot of other people. Oddly, I had no problems at all this year with them.

The link below is a discussion of pretty effective traps for them if you're interested.

Here is a link that might be useful: Cucumber beetle traps