Have you tried letting your gardening friends know that you're in need of zucchini? They might welcome another outlet for the excess squash from their gardens! I understand your frustration. Just as the vines are gearing up to produce, the entire vine collapses and dies. The squash vine borer larva is a grublike caterpillar that gets into plant stems. It feeds inside the stem, causing wilting and death of the plant. This borer also attacks pumpkins and winter squash ('Hubbard' is a favorite of the borer; 'Butternut' is less susceptible than other squashes). If you have only a couple of vines, you may be able to keep the borer at bay by handpicking adults and eggs. Adults look like black wasps with orange-red markings. They lay dull red eggs on the main stem near the ground, or on the undersides of leaves. You may be able to prevent egg laying by wrapping stems with aluminum foil or old nylon stockings. Or try using floating row covers to exclude the borer adults from plants. If all else fails, apply an insecticide every 7-10 days, starting when the vines begin to run.