Figures 6.11. Growth and development in a marine midge, Telmatogeton (Diptera: Chironomidae), showing increases in:
(a) head capsule length; (b) mandible length; and (c) body length between the four larval instars (I–IV). The dots and horizontal lines above each histogram represent the means and standard deviations of measurements for each instar. Note that the lengths of the sclerotized head and mandible fall into discrete size classes representing each instar, whereas body length is an unreliable indicator of instar number, especially for separating the third- and fourth-instar larvae.