Squash vine borers can make a pretty garden turn ugly in a hurry during the growing season. These pests bore into lower squash vines and essentially girdle the plant and cause it to wilt. There are actually a few things you can do now to help prevent their reoccurrence next season. First off, remove any dead squash plants from the garden because they might contain eggs for next year's population. Till the area where your squash were planted to help expose over wintering populations. See also Yardiac.com's blog on cleaning the soil.
In early spring,apply a pyrethroid insecticide to the soil and emerging squash after they are planted. Rotate squash from one area of the garden to another and plant in a spot where a different vegetable family group was planted. Squash are cucurbits, so plant next in a spot that had tomatoes, peppers, corn, beans, or other non-cucurbits.