Comparative Analysis and Systematic Mapping of the Labial Sensilla in the Nepomorpha (Heteroptera: Insecta)

Figure 4

Types and sizes of the trichoid sensilla of the Nepomorpha. (a) TRS1 trichoid sensillum, long, TRS2 trichoid sensillum, short; these sensilla are placed dorsally near the apex of the labium at the fourth segment; in the broken shank of the sensillum, a hole (ap) is visible, and it displays a dendrite running to the tip of the sensillum. (b) TRS1, TRS2 trichoid sensilla; these are individually placed dorsally near the apex of the labium in one row. (c) TRS1, TRS2 trichoid sensilla; these are placed ventrally, near the apex of the labium. (d) TRS1, TRS2 trichoid sensilla; they are placed dorsally on the third labial segment.