Pre-scutellar callus: = post-alar callus: q.v.
Pre-scutellar rows: in Diptera, short rows of small bristles in front of the scutellum.
Press: =filator; q.v.
Pressure plate: a structure at base of pulvillus, which exerts a pressure on the sole of the pad.
Pre-sutural bristles: in Diptera, in a trigonate depression at outer ends of transverse suture, near dorso-pleural suture.
Pre-sutural inter-alar bristle: the single bristle of the interalar series, situated before the transverse suture.
Primaries: the anterior or fore-wings.
Primitive: simple in character; of an early or ancient type.
Principal sector: in Odonata, extends from its point of separation From the median sector to the outer margin, at or just below the apex:= media 1 (Comst.).
Principal sulcus: in Orthoptera, a transverse impression of the prothorax, at or behind the middle.