I think it is slugs. I have seen this happen in my garden, and I second the idea of going out at night with a flashlight. Small slugs don't always leave visible trails. Birds are also a possibility. Sluggo should help with slugs/snails (and is available in an organic version). Netting will help with the birds. I now always sprinkle sluggo around seedlings, and cover all my beds with netting until the seedlings get a little bigger. I use 4x8 foot raised beds, and have netting tents that sit right on top of them.

I always thought that they only carried 1 or 2 fruits per vine to ripeness. I don't think the vines have the nutrients to ripen all those potential fruits, so they are unneeded backups. But maybe I'm mistaken, it's only my second season growing winter squashes.

In spring and early summer they pick caterpillars for their young, in late fall, they are all collecting as much nectar as they can get. They will swarm on cowpea nodes, on compost piles containing watermelon, fruit, anything sweet, in the fall. You might want to make sure that your wasps are not yellow jackets, which hover from side to side as they land. Yellow jackets will become aggressive to protect the nest or even a food source. So if a little kid bumps a nest by mistake there could be disaster. I had to burn out a yellow jacket nest this summer and then in fall the survivors swarmed a compost pile full of overripe melons and aggressively protected it. My neighbors have small children, so I sprayed the compost with Sevin and dusted it with borax. The survivors moved to swarming on the cowpeas, so I sprayed the cowpeas with Sevin and hung a soda bottle trap half full of watermelon juice with a dash of dishsoap on the trellis. When I took the vines down, the survivors moved back to the compost pile. I'd almost rather have caterpillars. In fact I did have caterpillars, in the beans and in the peppers, never seen them in either plant before. I wonder what they were.

I agree with Annie on the interchangeable part....but I prefer hubbard to butternut. There really are lots of varieties of winter squash....all of them with subtle differences. I find acorn stringy, butternut a little dense, some delicata a little watery, hubbard HUGE and sometimes stringy, Marina del chioggia has a bit of a smokey taste....and I am still searching for the elusive galleux....said to be the sweetest and most delectable. And it must be, a friend gave me one and I left it outside for a bit as a fall decoration and the critters ate it up!! In spite of stringy, watery etc...I love all winter squashes!!