I cannot see anything on them with the naked eye

This is happening at night to select sprouts

Pathogens don't take bites out of leaf margins or scrape off the leaf surface. Go out at night with a flash light and see what's going on after dark..

Agreed. Damage is on top of the leaves which I found interesting. I have not found anything yet but it could be very hard to see.

Hasn't this happened in before to you in previous years? I don't know but this is weird.

What fertilizers, chemicals, and poisons do you use? You might be overdoing things trying to do good.

Fish fertilizer and I mulch with pine needles for the past 10 years. Last night at 7pm a cucumber sprout pushed up, it was not open. This is it this morning. I had sevin on this spot 3 days ago - another sprout got hit.

I am geetting married in my backyard 8/26/23. I am growing sunflowers along the walk - 90-100 days to flowering. They get killed as fast as I can plant them.

This is in an area by my wood deck, other plants 30 feet away are not hit. Also whatever it is picks certain sunflowers. I have planted a few kinds in a patter - meaning alternating type 1, type 2, type 1, type 2 etc. and some get skipped over and a certain kind hit. The point is the tiny bugs move several feet. No idea how sevin did not kill them. I also put down diatomaceous earth last night around and on all leaves, still get hit. Several more that opened 2 days ago get hit every night despite sevin. I know sevin only lasts a day - I put it down in the evening. This is a disaster. I check at night but cannot see anything they could be to tiny or flee when I come.

Robert the tiny bites like this is new. Noting in planters is affected.

I do not overdo it with chemicals or fertilizer, I use them very sparingly.

Also note whatever it is is so small it does not bite through leaves, it scrapes them.

My first pest suspect would be tiny/baby slugs. A few beer traps placed near the plants should catch them at night, might be worth the try to see. I'd describe how to set up beer traps but you probably know how to do it.

Interesting slugs, maybe. I have always had slugs and if I had this problem it was very isolated and rare, not like now. I hand pick slugs often, including at night with headlamp. I also use sluggo and sevin occasionally. I do not think it is them but I will keep it in mind.

A new development, one that just popped out had damage, I am pretty sure it got hit a little in the ground before it emerged - or it got hit literally within an hour or two. I am in my garden all day:)

You could try individual cloches over seeds when you sow them. Use the cut off top of a plastic bottle. But make sure you check the soil around the seed before putting the cloche on.

What about growing transplants so you can wait until they're a bit bigger and tougher before putting them in the ground?

And tiny baby snails and slugs can be as small as a grain of sand, so they can get to a seedling as it's coming up in the top layer of soil.

I plant so many thing, it would be a lot of work transplanting, and growing. I would prefer not too. Today was my first day with no new noticeable issues. Meaning sprouts are not getting hammered overnight. I am sure there are still some pests but not near as many.

Still confused why they die so quickly, but do you think the problem is less when it gets warmer? It has been on the cool this May, and even with no freezes, these are seedlings that prefer warm temps over 60 F. Cool temps may make the seedlings weaker.

They die from the bug bites, for sure.