Attack of the Beetles III

As with recent wars elsewhere, my struggle against the beetles is ongoing, progress has been made, it wouldn't make sense to quit now, and I might have declared victory a bit too soon (see parts I and II).

Enemy #1: Flea beetle
Status: new insurgents!
The tomatoes had outgrown the flea beetle damage and were/are taking off. Also, the upside-down tomato plants had completely avoided the first wave of flea beetles that were attacking all my in-ground plants (guess they couldn't jump that high - ha! outwitted you, didn't I, you little f*ers!) Okay, well, not so fast there, J... perhaps I outwitted them the first time, with help from some diatomaceous earth, but.... they're back! With reinforcements! They're all over my in-ground tomatoes. The beetles have also managed to make it up to my upside-down tomatoes, I assume by hopping up all the squash leaves underneath both plants. You're welcome.
Strategy: Management. Time for some more DE.

Enemy #2: Cucumber beetle
Status: buzzing around but are basically has-beens. However, I fear late-season comeback.
In my last report from the front lines, I gave up on sprays and was resorting to physical blockage involving walls of water with cheesecloth over the top, and row covers. The wall arrangement worked very well until the plants were too big to fit inside. At that point, I fearfully took off the walls/cloth and hoped for the best. The squash won: thankfully, squash is such a fast, strong grower that the beetles couldn't do measurable damage to the plants anymore.

However, the cucumber plants were under heavier attack, suffered more damage before I re-covered them, and probably continued to get eaten after I was forced to uncover them because they were getting too big, too, for the wall/cloth contraption. The covers allowed both plants to recover a bit and put on new growth, which I think was key to their survival. They are survivors! As shown in the last post, I harvested 2 lovely cucumbers from my Marketmore plant this week. Still no Armenian yard-longs, but I think I saw some babies on there a few days ago.
Lessons Learned:
1)cuc beetles can do terrible damage to really small plants. Physical covers like walls of water, cheesecloth or row cover material are the only good way to protect small plants from them. Cover your cucumber, melon or squash plant until it is flowering and/or can't fit under the cover anymore.
2)I am sure pyrethrin sprays have some efficacy but just aren't worth the cost, effort and potential to kill beneficial insects.
Strategy: feeling sense of impending doom about late-season resurgence of cuc beetle damage, not sure what to do! Come on, cucumbers! Produce! Hurry!