It is hard to kill borers since they are inside the stems. If they reach the crown of the plant, it is likely done for. I fight borers in a few ways. First, I usually plant squash in small groupings a good distance apart from one another, like 50 feet or further. Secondly, I do succession plantings, as the borers have periods during the summer when they are more or less active. Squash planted during a low active period may get overlooked. Lastly, sometimes I cover the young plants with mesh cloth or screen covers to keep the adults away until the squash plant has reached good size. That way, even if the vines get borers, the plants will have a few weeks of production before the borers do too much damage.
The borer adult is a large black wasp with an orange band around its rear segment. If you see them when they are active, the wasps can usually be swatted.
Eclectic gardening style, drawing from 45 years of interest and experience. Mostly plant in raised beds and containers primarily using intensive gardening techniques.