Both these species are polymorphic and their identification may have been over simplified in the past. The main difference between them is in their life cycle with A.laterana being univoltine in August and September feeding on a wide variety of foodplants and A.comariana being bivoltine in June/July and August to October on a small number of foodplants none of which overlap with the previous species. A.laterana averages slightly larger than A.comariana but there is some overlap so any specimens taken in June or July with a wing length <7mm should be A.comariana and any taken from August to October with a wing length >8.5mm should be A.laterana. If there is any doubt at all they should be recorded as Acleris laterana/comariana.