A number of species are associated with thistles, including Scrobipalpa acuminatella. The larva feeds on a lower leaf, in a mine along the midrib which appears brownish from above. Where this extends sideways it leaves pale branches, some of which are filled with blackish frass. Creeping thistle and spear thistle are very common plants in grassland, waysides and wasteground. There should be no shortage of places to look though the larval signs are by no means everywhere.