It is nowadays a commonplace to state that every literary genre is a highly selective segment of a broader world of potential representations, and presents itself to the reader as a complete, self-contained model of interpretable mimesis of that particular aspect of reality. Yet this is especially true of bucolic poetry, whose very act of foundation rests on a joint effort, on the part both of the poets and their readers, to ‘conjure up a pre-existing “bucolic” tradition’ in the very same act of ‘founding such a tradition’. Theocritus' pastoral universe has its own bucolic hallmarks: landscape, gods and ‘professional’ accessories such as those required of a rustic life (milk-pails, shepherd's staffs, goatskin-coats and the like) are appropriately paraded and customised, and these hyper-‘realist’ markers are casually made to exist on the same level as the most unrealistic aspects of bucolic life (Theocritus' shepherds sing their time away while occasionally looking after their flocks). But it is especially in later imitators and interpreters that the possibilities of Theocritus' pastoral microcosm become necessities: generic consistency and recognisability are constantly pointed out and alluded to by obsessive repetition and normalisation of Theocritus ‘open’ pastoral world. The aim of the present paper is to read Colluthus' exploitation and, I would say, mobilisation of such a crystallised pastoral world against the background of ancient exegesis on the ‘bucolic problem’. In particular, it will be shown how bucolic criticism and Homererklärung (together with some important Hesiodic elements) are indissolubly intertwined in Colluthus' interpretation and reception of Theocritus' pastoral world. Comprehensiveness in charting Colluthus' critical response to such reading practices will not be attempted here: instead attention will be focused on those passages where Colluthus' scholarly engagement with bucolic generic conventions and their later accretions has a more direct impact on his narrative strategy.