My squash vines look like they are split or have been eatin by something whats going on?

I planted my squash in a raised bed and am training on a trellis but the plants grew about 3 inches and now it looks like the stems are split or something has eatin into it.

My squash vines look like they are split or have been eatin by something whats going on?
Go to this link and scroll down to "squash":



http://hgic.clemson.edu/factsheets/HGIC2...
Reply:Squash borers. I use Sevin. It is the "safest" pesticide I have found. Just check the residual days before harvesing.
Reply:agree, borers. You can do "surgery" on the plants; locate nasty worm, smoosh. http://search.yahoo.com/search?p=squash+...