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

Figure 12

Types, sizes, and distribution of the sensilla of the Belostomatinae (Hydrocyrius colombiae). (a) TRS1 (four), TRS2 (three) form one row and are placed dorsally (D) near the apex of the labium; sensory fields (SFR, SFL); CUS and PES, placed dorsally, are numerous and unevenly distributed on segment IV. (b) CUS and PES (magnified). (c) CH3 are sparsely and unevenly distributed, dorsal view of segment III, several CH2 grouped near the labial groove. (d) CH2 are numerous, placed on the dorsal side, on segment II. (e) TRS1, TRS2 are distributed ventrally (V); CUS, PES, and CH3 are sparsely and unevenly distributed ventrally on the IV segment. (f) CH1 are visible at the base of segment II on the ventral side, CH2 are densely arranged along the surface of the second segment, and CH3 are slightly visible and unevenly distributed over segment II.