Do I need to apply an adhesive to the 1.5" pipe that the studor mini vent will be going on? It fits well when placed on the pipe but is there a need to have an adhesive?

Yes! You should prime and cement the AAV to the raiser. This is done so that no sewer gas can escape. FYI,
The reason it fits snug is because the female fitting has a slight taper and they bind. Regards, Tom

I would suggest yes, the AAV comes with threaded end, see the images below, Thanks.

John