Couplets: 1  2  3  4  5  6  7  8  9  10  

Key to Larvae of Holarctic Blephariceridae: Couplet 9(7)

Posterodorsal margin of cranium with excisions extending to near stemmata...Philorus Kellogg	Posterodorsal margin of cranium entire, usually without excisions; excisions, if present, terminate well posterior of stemmata...10