Green’s Dictionary of Slang

flyspeck adj.

(US) usu. of a place, small, insignificant.

[US]R.T. Sale Blackstone Rangers 67: ‘[S]ome little flyspeck clothing store, they don’t bother with nothing like that. Extortion is determined according to the volume of weekly business the store does’.
[UK]R. Lloyd Playland 29: He stood on the shoulder of Highway 15 just outside a flyspeck town called Beacon Station.

In compounds

fly speck (isle) (n.) [its relative size compared to Australia]

(Aus.) Tasmania; thus fly-specker/flyspeck n., an inhabitant of Tasmania; fly-speck adj., Tasmanian.

[Aus]Bulletin (Sydney) 12 May 14/4: ‘Tassey’: ‘Flabby P.’ [...] probably refers to what is known in Tasmania as the ‘fern tick.’ Its other Flyspeck name is unprintable. [Ibid.] 13 Oct. 20/2: [T]here is nothing so ferocious as a Flyspeck when it is thoroughly aroused.
[Aus]Sun. Times (Perth) 12 June 2nd sect. 12/5: It’s all very well to denounce land monopoly in the Cabbage Garden and the Fly-speck, but why [...] run a ring-fence around the Commonwealth.
[Aus]Bulletin (Sydney) 23 July 14/3: The genuine old Vandemonian spirit must surely be losing its punch in the Flyspeck.
[Aus]Baker Popular Dict. Aus. Sl. (2nd edn) 75: The speck, Tasmania. Also, ‘the Fly Speck’.