Question: I'm looking for something people from rural area would use, especially when they refer to that person's inability to adapt to the country life.

Answer: 
[Townie](http://www.collinsdictionary.com/dictionary/english/townie) is the obvious answer, but *tourist* or *tripper* often carry overtones of scorn and 'urban, squat and full of guile'. (I knew a young girl who, left in a car for half an hour, hid under the seat because she was afraid of the trippers.)
In Cornwall, UK they are often referred to as *[grockles](http://www.oxforddictionaries.com/words/what-is-the-origin-of-the-word-grockle)*, though this refers more to 'tourists' than specifically town dwellers (after all, there *are* some towns in Cornwall...)