ecdysis larval-larval ecdysis IDOMAL:0002202 IDOMAL:0002202 The ecdysis between any of the four larval instars. The epidermis can be seen to separate from the cuticle and to secrete new cuticle and bristles beneath it while the tracheal epithelium similarly retracts from the tracheal linings and secretes new cuticular lining around them. A mid-ventral ecdysial line is also found in many species. Movements of the head free it from the old cranium and the dorsal split extends back over the thorax so the peristaltic movements the larva is able to escape from the cast cuticle, sometimes in less than a minute. The old tracheal trunks have broken across just behind their connections to the non-functional spiracles in each segment. idomal_namespace