The separation of adults of these two species is now considered far more difficult than previously thought without dissection so many early records of both species may be somewhat questionable. The larvae can be reliably separated by the colour of their their head and prothoracic plate. In general A.ciliella is larger with relatively shorter antennae and often a pinkish tinge on the underside, especially on the hindwing cilia. The hindwing of A.ciliella has 5 clear and obvious cilial lines whereas A.heracliana usually only has 2 or 3, occasionally A.heracliana with 4 and even 5 cilial lines are reported but they are never as clear as on A.ciliella and do not continue to the base of the hindwing. Any moth not showing a full suite of these identification features should be recorded as Agonopterix heracliana agg. without dissection.