It is a bit late for seedcorn maggots to be a problem. Soils are warm enough. The chipped look of the seeds look more like damage from a rodent or bird. 

Damage from rodents on emerged corn would be nibbling that takes out the whole seedling. Bird damage on emerged corn would feature plants pulled from the ground and littered around as they go for the seed and fresh soft white tissue around it.

Any powerlines near by? I have watched seagulls watch me seed a pumpkin plot and then swoop down when I got in my car.

There is a family of Killdeer in that field, so you could be right. I did find a few dead bugs at the site. Do you think it could be one of these. Some of the kernels of corn are hollowed out as if a small bug got inside. 

Killdeer mostly eat bugs.

The picture of the bug on the knife is a lightning bug larva. They eat worms, slugs, and snails. The other two are ground beetles. Most ground beetles are predators of other bugs, and small weed seeds. Good things.

However, the small one could be the slender seedcorn beetle, which can switch from eating bus eggs to cornseed if the conditions are wet and emergence is delayed. This does not happen routinely.

https://extension.entm.purdue.edu/fieldcropsipm/insects/corn-seedcorn-beetle.php

What percent of the stand is gone? What ingredients are in your seed treatment?

First planting very little corn came up, I would say only 10%.  Second planting after spraying, approx 75% came up. Not sure what is on the corn seed for treatment, red stuff, if that is what you mean by "seed treatment".

Yes, the red stuff. It is important to know what's on your seed. Sometimes it's just a fungicide. Other times it's a fungicide and insecticide. If it did not have an insecticide on them, then it is more likely a seedcorn maggot or seedcorn beetle problem. The other thing it could be is wireworm, which is worse in fields the first year after they've been fallow or pasture. Wireworms eat seed, roots, and also burrow into emerged plant stalks, and kill them that way too. On the plants that emerged and died, could you see any holes in them?

What is your field history? When did you plant, and what were temps/rainfall like in the time between planting and your discovery of the poor germ?

This 1/4 acre field has been a vegetable garden for over 20 years. Each year I admen the soil with 5 to 6 yards of compost (dead leaves from the city's composing site) or horse manure.
I planted 1June2020, weather was dry and warm.  I watered just the rows of seeds not the whole field. I continue to water every 2nd or 3rd day. Noticed the seeds being disturb 5days after planting. Each time I watered I would see more and more seed disturb/eaten and it not coming up. The seed was a couple of years old so I tested it along with three other lots of seeds for germination. The best lot I planted adjacent to the first planting after spraying it with Sevin.  Plant that on 11June202.  On 16June I noticed the seed still being eaten but more seed was coming out of the ground.
 I seen the wireworm in roots of other plants.  What should I used to get rid of it?  Do you think the bugs are coming from the compost or the horse manure? 
Only saw a few plants that emerged and died but it appears to me that something was digging at the roots.  I thought it was a skunk digging looking for a grub at the base of the corn stalk.  If I find another I will take a better look for holes.

Without a field history of long-term grass, I doubt wireworm was the problem. More likely seedcorn maggot, and when you found them they had already left.

They really like laying eggs in rotting stuff, like a recently killed cover crop, or compost, or manure. So, we generally recommend fall applying those types of amendments. Or, working in the cover crop and amendments at least two weeks before planting so the flies can do their thing before the crop goes in.

Sevin may have helped kill adult flies laying eggs. But, perhaps it is more likely that the second planting was just better timed. The maggots have three generations. This year, the first generation of egg-laying peaked around 1 May, and the second generation of egg-laying peaked around June 14. You planted sort of in between those, but they could still have been effected.

Soil temperatures also play an important role in seedcorn maggot development. Once soil temperatures at 4 inches reaches a maximum of 70 F for about four days in a row, the likelihood of maggot damage gets much lower. According to the weather station in Romeo, soil temps were not reliably over 70 F until 19 June. So, they were probably still out there.

Seeded crops are more likely to experience damage than transplants. Seed treatments such as Cruiser (thiamethoxam), diazinon, FarMore FI400 (thiamethoxam plus fungicides) and Poncho (permethrin) are somewhat common seed treatments for vegetables. Because sweet corn is so close to field corn, there are probably other products that I just can’t think of that are labeled for field corn with sweet corn as an add-on.

For banded or in-furrow application, or as a chemigation through drip tape, you can use Admire (imidacloprid), Capture LFR (bifenthrin), Platinum (thiamethoxam), Sivanto (flupyradifurone), and Verimark (chlorantraniliprole). For just a banded application, you can use Entrust (spinosad) or Mustang Maxx (zeta-cypermethrin), or Sevin (carbaryl).

Never use a banded or furrow spray if your seed was already treated with an insecticide. This double dose is not necessary and later hurts bees.