From wikipedia: "A helicopter parent (also called a cosseting parent or simply a cosseter) is a parent who pays extremely close attention to a child's or children's experiences and problems, particularly at educational institutions. Helicopter parents are so named because, like helicopters, they hover overhead." I think that this is a fairly new term. You can also say "over protective", but I'm not sure if this conveys the full extent of the phenomenon.

If the student isn't doing well in his/her studies, the student may need a tutor or a mentor. If the parents elected to personally monitor the student's every move they might fail to solve the underlying problem of insufficient preparation or lack of interest in the college subjects. I would call the parents behavior "meddling" or "interfering".