See the first picture there, on the left? That's the culprit! And it turns out to be the "Cucumber Beetle" that you see listed several times below.
Here's the bad news - not much to do about cucumber beetles. Two non-chemical solutions I read about are to plant radishes nearby (seeds already purchased yesterday - regular old red ones, and also white daikon radish, because two websites specifically mentioned white radishes) and also to lay aluminum foil (or some other reflective material) around the base of the affected plants. I plan on trying both of these. We may begin eating radishes as a result! And, since it never hurts, I am going to use some of our cayenne pepper crop to make a spicy spray that may deter these pests.
RECIPES FOR SPICY SPRAY TO DETER PESTS:
- hot peppers, chopped up, with seeds
- Murphy's oil soap
- water to thin slightly
As you can see, this is a rather imprecise recipe with no quantities. The heat of the peppers supposedly deters bugs, and the Murphy's oil soap helps it to coat the leaves. You spray it on the undersides of leafy plants (like Swiss chard). What we have done in the past is mix this stuff up and let it sit for a day or so. Depending on your spray bottle, the seeds might be a problem, so you may need to strain it. I have no idea about the effectiveness of this, but it is cheap to make and worth a try!
I will let you know if I am able to keep this problem at bay. I don't take kindly to invaders.