The puparium is clearly that of an agromyzid; just check Papp and Černý: Agromyzidae of Hungary, I -IV (the last part has been submitted but not yet printed) if there is another possibility or not.
Well, the puparium is empty, but the rear spiracula are indeed two-coloured. This, however, is only described as striking, but not as distinctive for this species - so I am not sure if the presence of that feature does exclude other species
