I really want to plant more vegetables this year but I'm having an awful time with vine borers - I don't use chemicals - does anyone know of preventative measures I could take to lessen or eliminate this problem? Just broke my heart to see all those gourds and squash die on the vine..

There are a number of things you can do to control the Squash Vine Borer starting with floating row covers to keep them away altogether. however, that will require that you hand pollinate to get fruits. Heavy mulches also can help because the adult beetle needs to get to the soil to lay the eggs, and some people will put down hard surface mulches. If you notice the vines wilting and look closely you can find the larva that is the borer and kill that with a wire and then bury that section of the vine and will root and grow more.
Some people wil tell you that since the adult beetles winter over in garden debris you need to clean everything up really good, but since beneficial insects, including those that will eat the Squash Vine Borer, also live in that garden debris you may be creating more of a problem by eliminating that habitat. Some people will tell you to use very broad spectrum poisons which wil also kill off the beneficial insects that will help you control the pests.

Ok, I'll try the floating covers and the heavy mulch - Hopefully that will avoid the larva part, but if not, I'll keep a wire handy! Thanks so much for the advice!!

well actually the squash vine borer is a moth not a beetle, eggs are laid on the undersides of the leaves the stems and the vines and not in the soil, the moth larva does over-winter in the soil, as stated floating row covers will help some, but no bees either, very few insects will be able to catch the SVB moth as it is very quick, and more wasp-like than moth like. benificial nematodes in the soil will cut down on the numbers, also nematodes can be directly injected into the vines to kill the borer.