stone said:I've seen it before...
As to cause...
Dunno, did you dissect?
Might be a SVB caterpiller inside... They usually don't cause the blooms to drop off, but sometimes happens.
I wouldn't worry, if vine is otherwise healthy.
Shame that you didn't post pic of the vine those came from.
And...
Is it raining there? Enough? Too much?
Weedwhacker said:Squash vine borers don't, to my knowledge at least, affect butternut or other C. moschata squash, due to the fact that they have a solid stem rather than the hollow stems that C. Pepo and C. maxima have.
stone said:
They happily lay eggs on the blooms and fruit... At my house....
Thought I was going to outsmart them by planting solid stem varieties... Didn't work.
if you inspect the hollow stem types, you'll find that SVB often go for fruit and blooms as an easier path than just the stem.