Black bugs on the underside of cucumber leaves

One of my cucumber plants is not thriving. When I went to inspect it, I found lots of black things that look like tiny bugs stuck to the underside of the leaves: about one millimetre or less in length, roundish in shape and absolutely loads of them.

We've had lots of rain here recently, but I'm pretty sure they're bugs rather than a fungal problem, though they weren't moving.

Apologies for not being able to post a photo. From my terrible description, is anyone able to identify this problem and suggest a solution? I'm guessing rip up the plant and hope for the best for the other two. My courgettes, squash and melons are planted very nearby and so far I haven't spotted the bugs on them.

There's no webbing on the plant and I don't think they're spider mite. When I squash them, there's black goo, no red trails like I usually get with spider mite. Plus, it's been very damp here recently, so not ideal conditions for spider mite.

I haven't seen anything quite like them in images on the Web. The closest is squash bug eggs.

Maybe I'll just rip the plant out and hope for the best. Mr Snoop wouldn't be sorry to see a few fewer cukes, that's for sure.

Thanks Dr. Pepper. I'll get on the case. I've noticed a couple of ladybirds on the plants recently. I'll move them elsewhere and give the plants a spray tomorrow evening and hope for the best.