Development of the Prothoracic Spiracles in Larvae of Sarcophaga Bullata (Sarcophagidae: Diptera).

Abstract

At larviposition (0 h) up to 16 h of development the first tracheal metamere was undifferentiated. At 16 h apolysis occurred, and by 18 h the tracheal epithelium was fully differentiated into the spiracle. spiracular chamber and trachea of the second instar. Cuticle secretion commenced at 20 h, and sclerotization was noted between 24 h and 28 h when the first ecdysis occurred. The development of the larval respiratory system during the first instar is discussed in relation to endogenous ecdysteroid titres.