Look for signs of squash vine borers. It's kind of late in the season to be seeing them around but, in some places, they have a second generation that hatch in the fall.

Mites and aphids gave systemic disease. Malathion is the killer, but neem oil is the organic insecticide. Bifenthrin won't touch them.

Not unusual for this time of the year. Clear out the squash carcass and plant something quick like radishes or lettuce.

Both your cukes and this squash appear to have been sickly for some time so whatever took them down has been in progress for days at least. Perhaps your "spotty mildew" was much worse than you realized or perhaps you had squash bugs rather than stink bugs. Stink bugs aren't a usual pest for squash and do little damage to them. But squash bugs sure are VERY common and hatch thousands of small nymphs that can easily do this to plants. So you might want to research exactly which bug you had for future reference.

Dave

Stink bugs lay white eggs, squash bugs lay orange eggs. Stink bug nymphs are brown, squash bug nymphs are gray. Stink bugs are much shorter in body than squash bugs and wider in the shoulder than squash bugs plus stink bugs have a point on each shoulder. Stink bugs tend to be loners, squash bugs are often seen in groups. Stink bugs are slow moving most of the time, squash bugs are fast darters.

There are hundreds of photos of both on the web so you can see all the differences.

Stink bug photos

Squash bug photos

Dave

Thank you for those links. It really blows my mind how much bacterial and fungal damage is borne by bugs.

I have/hopefully had a major squash bug infestation on my butternut squash. I had tried spraying with neem, soap spray, but finally had to resort to pyrthrins powder to clear them out. Those things were killing every new bloom and wilting the heck out of the plants. We still get the squash vine borer around this time in Atlanta too. I think they have a few generations each year here. I can't grow any other squash uncovered.

Definitely squash bugs! So likely they are transmitting diseases right?

Yep. and larvae. Spray away!

Squash bugs don't actually transmit disease in the usual sense of that term - they don't carry the disease entity in their mouths and inject it into the plant as some other pests do - but the hatchlings, the hundreds of young nymphs suck so much energy out of the plants that they are much less resistant to any fungal or bacterial diseases already in existence.

And the adults that are in the process of laying the eggs are notoriously immune to many of the common pesticides. So the most effective controls for them, other than row covers, is hand picking, egg patrol and removal, and spraying the nymphs.

Dave