Ask-a-Dave's-Gardener: Squash Vine Borer?, 2 by LizFlake

LizFlake wrote:
I\'m in my second year of a veggie garden. Last time SVB got my zucchini and squash plants. I noticed early on that the main vines are cracked/split but I haven\'t seen the moths and I\'ve been treating the plants since we moved them outside. I didn\'t think it would be SVB so soon since these cracks showed up so early. I can\'t figure out why else the vines would be split, but I don\'t notice a lot of frass or other signs of SVB we had last time. The plants aren\'t wilting yet and are getting their first zucchini. Does this look like SVB?