Not septoria.

Do the white things move?
Do they damage the leaves in any way.
Any treatments, etc., applied recently? If so, what?

Do they move? Lol, no they don't move. Very little change if any to the leaves other than the obvious spots that you see in the pic. I have about 60 hills of this particular variety and there is spots on ever hill but nothing on the other varieties what so ever.

And no treatments applied at all.

Can you answer a couple questions? The photo is good, but doesn't give the kind of information as seeing it first hand. Are there dents or divots under these spots? Does the leaf tissue look thinner or light show through the spots? Is there any browning around them? What do they look like on the reverse side of the leaf?

Well, I emailed pictures to the U of MN plant pathology clinic and without doing a sample diagnosis they feel pretty certain that it is Ozone damage that is occurring on my pumpkin plants.

Ozone damage? what? If it is divots it looks like bugs. If it was watermelon it would be Moon and Stars.

Here is a link that might be useful: Seed Saving Class in MN

No, it is definitely not bugs. I can post more recent pictures soon showing that it has progressed into more of a pattern on the leaves vs spots. There is pictures online showing Ozone Damage on pumpkin plants and it looks very similar to what my plants look like now. So based on those pictures I think their diagnosis is correct as to the Ozone Damage.

The reason I asked if there were divots on the leaf, is because there is a similar type of appearance to leaves worked upon by the four lined plant bug. I grew mums commercially for many years and one year had a good deal of damage to the crop, seemingly overnight, on a few benches, having never seen the insects on the plants I scouted regularly. The plant inspector was shown the material (entymologist) and identified it as four line plant bug aftermath. Sure enough, after scouting the crop, I found them. I am seeing them this year in my vegetable garden and suspect the pressure is high this year. I'm not saying your crop doesn't reflect ozone damage, but I've heard that diagnosis applied to plants before by experts and had it not be so. Is there a manufacturing facility nearby? I was a grower for a nursery once and pinpointed some foliar damage by industrial fumes on a particularly susceptible line of plants.

.. Ozone huh? I don't see how that could be possible unless someone is using an ozone generator in the immediate vicinity..

I would lean more towards insect damage myself..

Also, if it were ozone it wouldn't selectively affect a single variety (I would think) .. It seems that variety is more prone to whatever you have going on.. Hopefully someone with more knowledge in pumpkins will come along to help you out.. Good luck! =)

Btw - this is septoria leaf spot:

No, there is no divots. When you see the plants first hand it does not have the appearance of insects being present. The Ozone Damage is what I'm going with based on what I see first hand and the pictures I have seen online. I actually wondered about Ozone Damage even before I contacted the clinic because I had seen pictures before online.

Well, that's plumb scary. Yeah, pumpkins are particularly ozone sensitive and resistance to damage will vary within a particular crop. Will be curious to see if the other varieties of pumpkin you have planted will exhibit the same response. If not, guess you'll know which ones to plant next year. Do you think the vines will hang in there long enough for the fruits to mature?

Yeah, as of yet they look like they will. Actually August 22nd is the maturity date from when I planted for this variety according to seed catalog but we had a wet, cool June so things got delayed a bit because of it so I'm guessing at least 2 weeks after that date until they are ready. I will try and get some updated pics posted and put them on a separate post as Ozone Damage.