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

Figure 14

Types, sizes, and distribution of the sensilla of the Belostomatinae (Lethocerus deyrollei). (a) TRS2 and TRS1 are placed dorsally (D) near the apex of the labium; the pore (ap) is visible at the end of TRS1. (b) TRS2 (three), TRS1 (four) form a single row dorsally (D), TRS2 (three) and TRS1 (nine) form a tuft ventrally (V), and CUS and PES are numerous on the IV segment. (c) CH3 are spread sparsely on III segment, and COS is situated on segment IV and hidden under IS (intercalary sclerites) of the III segment. (d) CH1, CH2, and CH3 densely cover the dorsal and ventral surfaces of the labium on segments II and III. (e) CH3 and CH2 are less numerous and placed dorsally in a small group on segment III. CH1 are numerous on the dorsal surface of the II segment. (f) PAS1 (no. 1–13) and PIP (no. 14) are distributed apically over sensory fields (SFR, SFL). (g) PIP situated in the lateral positions on SRF and SFR are clearly visible.