You usually can see flea beetles. What if anything do you see on the bottom of the leaves. Look for the culprits at night. Bt is only for caterpillars. Neem Oil is a contact killer and is excellent on eggs and mites. This could possibly be mites but this is something I would use spinosad on first and if that didn't work use the Neem. Using these as a preventative also kills your beneficial insects. I never spray anything until I see damage, otherwise, it is just a waste of time and money spraying for something that isn't there and probably won't be there. This damage didn't happen all at once, it took some time. Inspect closely more often. I think the damage was done while these leaves were closer to the ground and pill bugs got to them.
Uh oh. That is a cucumber beetle. He didn't do the origional damage shown but spray spinosad ASAP. These are really bad guys. Spray both sides of the leaves if you can.
Keep a close eye on the damaged leaves and see if any more damage occurs and especially watch the new leaves. It's a good thing it is happening now instead of during the blooming period.
I looked again at the cucumber beetle picture and saw what caused the original damage which you took care of with the Captain Jacks. It was cabbage looper caterpillars. You can see the dried out carcass of one of them.
Not really. Insects and caterpillars are attracted to weak or stressed plants. There are many reasons for this but in any case, a successful garden MUST be carefully observed on a daily basis and the gardener MUST know what is going on. I inspect every plant in my garden on a daily basis. When you have learned what to look for you can inspect a plant in about 10 seconds. You will soon learn what to look for whether it be from caterpillars or insects or fungus or a virus or some nutritional issue. I had some cabbage loopers on one plant of Portuguese Kale about 2 weeks ago. I walked by and saw a few small holes in one of the leaves. I know holes in leaves aren't normal so I looked on the bottom of the leaf and saw the looper happily munching away so I go mix up a pint of Bt and spray all of my Portuguese Kale plants whether they needed it or not. As of today there isn't an insect or caterpillar of any type to be found and the damage to that one kale leaf was minimal at worst. I rarely have to use anything in my garden but by being vigilant I can stop any problem before it gets serious.
I don't know for sure but to me, it seemed that your ground cherry has a yellowish tinge to it. If so it is lacking nitrogen and that is probably why the loopers got to it. Take some pics of all your plants and I will try to help you diagnose any problems you may have.
