Yes, you will need insurance on a 49cc Zuma in Minnesota. In MN all mopeds must be legally registered in order to operate on a public street or highway and all mopeds operated on the streets and highways must have Liability insurance.
In Minnesota mopeds (or motorized bicycles) have a piston displacement of 50cc or less, two-brake horsepower or less, and are not able to go faster than 30 mph on a level surface, as defined by Minnesota lawmakers in MN Statute 168.002 subdivision 20. If a vehicle exceeds any of these categories, it will likely be classified as a motorcycle and different rules will apply.
If you have a driver's license, you are legally allowed to drive a moped. If you do not, you will need to obtain a moped operator's permit from the MN Department of Motor Vehicles. Applicants must be at least 15 years old. You can read more about Moped laws under section 169.223 of the Minnesota Statutes.
Insurance laws are under MN Statute 65B.48 and in part states that every owner of a motor vehicle of a type which is required to be registered or licensed or is principally garaged in this state shall maintain during the period in which operation or use is contemplated a plan of reparation security under provisions approved by the commissioner, insuring against loss resulting from liability imposed by law for injury and property damage sustained by any person arising out of the ownership, maintenance, operation or use of the vehicle.
Moped drivers in Minnesota need to carry liability insurance, but riders of electric-assisted bicycles do not. Mopeds must be titled at registered at a Driver and Vehicle Services location, much in the same manner as a car. All moped registrations expire in February. The license plate displays the month of expiration sticker and a year validation sticker.