Deliberations on the External Morphology and Modification of the Labial Segments in the Nepomorpha (Heteroptera: Insecta) with Notes on the Phylogenetic Characteristics

Figure 32

Shapes of the labial segments of the Notonectidae. Notonectinae. (a)–(d) Enithares bergrothi. (a) Dorsal view of the shape of the segments (I, II, III and IV), the first segment is wide, the stylet groove is covered by the labrum, the shape and size of the reduced intercalary sclerites, the stylet groove (gr) in the III and IV segments is closed, (b) dorsal view (V) of the segments in detail, the second segment is divided dorsally into the triangular plate (tp) and the convex plate (cp), the articulation between the II and III segments is visible, (c) ventral view (V), the shape of the segments, the midventral condyle on the proximal edge of the fourth segment is visible, the trapezoidal apical plate can be observed, the membranes (mb) are visible, and (d) lateral view, the first segment is narrower ventrally than dorsally, the second segment is narrower dorsally than ventrally, the intersegmental sclerites can be observed. Lr: labrum.