Fourth instar larval types of Chironomus

Several larval types are recognised, based on the presence or absence of lateral and ventral tubules (VT) of the 10th and 11th abdominal segments.    The following classifications are based on Proulx et al.(2013).

The categories are:
                Lacking lateral and ventral tubules:
                    salinarius (Fig. 9)

                Lacking lateral tubules on segment 10:
                    halophilus - anterior VT very short or absent, posterior VT short, less than width of segment (Fig. 8).
                    bathophilus - moderate to long, essentially straight VT, greater than width of segment.
                    fluviatilis - VT slightly curved and coming to a point at ends.
                    thummi - long, anterior VT with 'elbows', posterior VT coiled (Figs. 6 & 7).

                Possessing lateral tubules on segment 10:
                    reductus - lacking ventral tubules.
                    semireductus - short straight or slightly curved VT, less than width of segment.
                    melanotus - moderate to long, essentially straight VT.
                    plumosus - long; anterior VT with 'elbows', posterior VT coiled (Figs. 4 & 5).