When I plant radishes around my zucchini and cucumbers, I notice a marked difference in the amount of squash vine borers (the icky worm you mentioned above) along with cucumber beetles (the bug I suspect of killing your cucumbers). Were the cucumber wilted down and looking dead, by the way?

What I do to control these issues is a combination of companion planting (like you did) with regular applications (about every 7-10 days from sprouting) of both diatomaceous earth and neem oil. The earth goes around the mounds and vines on the actual soil/not on the plant! The oil can be sprayed on both the plant and ground. It deters bugs and, conveniently, is also anti-fungal.

Also, upon finding borers (worms), and lot of people simply take and knife, slit open the area of entry, and extract the worm. Then, a good rub with alcohol never hurts and top that part of the vine with clean soil, so that it can heal up...

Hope this helps for next year.

p.s. I planted an heirloom zucchini called Costata Romanesco this year that had great tasting fruit and did well against squash vine borer. They were sprawling, huge plants with stems of thorns almost, so I think this helped keep a lot of borers away. When I did find one here or there, the plant still held up to it quite well-producing and looking healthful. High Mowing Seeds sells this variety.

Yes, the cucumbers were wilted and dying. My zuchini is dead and I sprayed some neem on the squash today. I see some small bugs that are black and yellow and they fly. Is this also killing my plants??? Where do the worms come from? I don't see anything crawling along the ground. Thanks again for your help.

Those worm come from eggs laid on the plant by the squash vine borer moth, which actually looks like a fat wasp, but is actually a moth. Its real pretty , and you might see it during the day flying around. It lays small reddish brown disk shaped eggs on your plants. I pick them off my plants daily. Its a pain. Try checking your main stem for eggs, and as the plant gets bigger mound soil up to cover the main stem. Then just keep an eye out for the eggs or better yet kill the moths if you see them. Use a fly swatter or badminton racket.

Squash Vine Borer - my nemesis.

What the adults look like.

They killed my cucumbers too.

Here is a link that might be useful: DFW Gardener

Hi my cukes up and died too. I have never had a problem before. I grow them in large containers with fresh organic mix and they were growing like crazy one day and then started with powdery mildew and then wilting and then, dead! I never found any bugs, but a couple of the stems were almost rotten.
Sharon

Hey Chuckby,

In case you don't know by now, the yellow and black bugs are probably striped or dotted cucumber beetles. In my view, they are the worst pest a garden lover can have, though I'm sure others may have something to say about that.

I kill cucumber beetles on site, as they carry the bacteria in their gut that causes wilt of cucumbers and melons. One has to clean the hands after doing so too, since the bacteria is probably spread by means of squeezing. I also never dispose of the little body in my garden.

In any case, use of diatomaceous earth in combination with Neem early in the season usually helps. Adults at the end of their life cycle often lay eggs near new sprouts causing for what you're seeing now late season. Natural pyrethrin spray also helps once one is in the throws of having beetles and worms.

Hope this helps...

p.s. the diatomaceous earth is what really helps with beetle eggs. When they hatch, they have to make their way through it if one is applying it every 7-10 days, which often causes them to die early on. D. Earth is also a natural substance mined from the earth just like chalk or things of this nature and is approved for organic and natural gardening...!