Hi Elizabeth, 

Thanks for reaching out to the UNH Extension Yard and Garden Infoline. Yes, creating a physical barrier by wrapping cucurbit stems with aluminum foil can be effective, but it should be seen as one part of a multi-pronged strategy to deal with the borers. It's not foolproof because: borers may lay eggs above the foil, eggs can be laid on leaf stalks (petioles) and runners and, as pumpkin vines spread, new susceptible stems develop.

Other control methods include:

-Installing row cover immediately after planting (seal edges as best as possible)
-Remove eggs when found.
-Apply a stem-directed insecticide only during the adult flight period if pressure is high.
-Bury vine nodes to encourage additional rooting.
-Destroy vines after harvest to prevent the insects from overwintering 

Also, rotate crops to different locations each year if possible

Here is a UNH Extension resource on squash vine borer control with more information-

https://extension.unh.edu/resource/managing-squash-vine-borer-problems-new-hampshire-fact-sheet