I checked my spaghetti squash this afternoon and, sure enough, there are SVB eggs all over it.... I even think I might have a few larva already in it... I'm going to check them tonight with a flashlight. If I find any larva, I'll definitely inject the BT.I inject the BT. Sounds crazy but it works! Mix it up and use a larger gauge needle with he big syringes so you can put a lot in mixture start at base do every three inches or to about a foot up. Now I have zucchini etc all summer. I know some people may not be comfortable with this but it works for me. I do it every week or sometime seven more if the SVB is bad that year. Good luck!
I did spray everything really well with a couple of coats of kaolin clay, after also spraying them with horticulture oil. I figure the oil works well for smothering overwintering eggs, why wouldn't it work against SVB eggs? Of course, I did remove any I could find... The oil was just in case I missed any... I'll continue to check them for larva in the next few days. Plus it's going to rain AGAIN next week so I'll have to redo the kaolin clay afterwards...