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

Figure 24

Types and sizes of the sensilla of the Naucoridae: Naucorinae ((a) and (b) Naucoris maculatus, (c)–(e) Namtokocoris siamensis, (f) and (g) Neomacrocoris handlirschi). (a) CH2 are numerous and form a collar around the distal edge of the II segment on the ventral side; individual CH2 can be seen on the III segment (lateral view); TRS1 and TRS2 are visible ventrally and dorsally. (b) TRS1 (four) are distributed over the ventral side (V) in one row near the apex of the labium; MPS are less numerous and spread evenly over the IV segment (dorsal view); TRS1 (two) are distributed over the dorsal side (D), in one tuft placed distally on the III segment; COS are situated dorsally on the IV segment. (c) CH2 and CH1 are densely spread over the ventral side of the III and II segments; COS are distributed dorsally over the IV segment. (d) TRS1 (four) are distributed over the dorsal side (D), in one tuft located distally on the III segment; MPS are numerous and spread evenly over the IV segment (dorsal view). (e) TRS1 (four) and TRS2 (two) are distributed over the ventral side (V) in one row near the apex of the labium; PAS2 (no. 1–10) and PIP (no. 11) are distributed on the labial tip. (f) TRS1 (twelve) arc distributed over the dorsal side (D), in one tuft placed distally on the III segment; MPS are less numerous and distributed evenly over the IV segment (dorsal view). (g) Several CH2 are visible on the ventral side of the II segment; less numerous CH3 are present on the II and III segments.