In my area there is a first wave of them in mid to late May. These are the surviving ones who over-wintered. They go directly after seedlings of the cucumber-squash-melon family. After they eat your young seedlings, they bury in the ground around the roots and lay eggs for a hatch about a month later.
I dust the seedlings with some Sevin. There are perhaps something else that would work, but it must work instantly as these buggers ruin the seedlings very quickly.

There are any number of controls available for cucumber beetles. They range from strong chemical pesticides thru various organic controls down to simple cultural practices. It all depends on how aggressive you wish to be.

Personally I find delayed planting and simple insect barrier row covers to be sufficient in early spring and one of the organic sprays like Pyola or Neem plus some yellow sticky traps to be sufficient later in the season.

The article linked below covers all aspects of CB control, their life cycle, and includes pics of the various varieties.

Hope this helps.

Dave

Here is a link that might be useful: Cucumber Beetles

I try several approaches.

One group of cucumbers are covered with agribon 15 row cover and hoops made from PVC pipe. I cover 3 sides with dirt and the fourth with a heavy pipe so I can remove it and inspect he plants, water, etc. I used the Diva variety as it is parthenocopic and does not need bees to pollinate the flowers.

I have also kept several this year uncovered but sprayed with Kaolin clay. I have 25 pounds of the Kaolin and need less than 1 cup per year so if anyone lives in the area they are welcome to have some.

My sticky yellow traps have not caught any yet but I have seen a few of the bugs around the garden but not near the cukes.

I never see a single cucumber beetle in the spring, but come August, there are thousands of them.

I suspect the key to control is getting them in the spring, but I'm so far not sucessful in this.

Dave,

Thanks for the link. That is the most comprehensive, most useful information I have seen on controlling this destructive pest.

Jim

ltilton, The first wave is rather small. For mine, I would guess 100 from the dead buggers on the cantaloupe leaves. They arrived the very day I was setting out the last of the cantaloupes. one landed on my arm and that clued me in to them.

I have cucurbits scattered around in many locations so it is not so simple as spreading a couple row covers.

Wayne, so what do you use to control them?

After several years fighting them, I placed my cucumbers in vertical trellis inside a screen house we made. Squashes and melons under row cover until they start to flower. Beetles still come, but they do not kill squashes and melons, and their wave is usually passing very fast, when they can't get to the cucumbers. I am planting Little Leaf and Adam cucumbers - they do not require pollinators. There are many more varieties that do not require pollination.