Figure 20.

Shapes of the labial segments of the Naucoridae. Cheirochelinae, (a)–(d) Cheirochela feana, (e) Gestroiella limnocoroides. (a) Dorsal view (D) of the labium, the shape of the first segment (I), the stylet groove (gr) is opened, the dorsal surface of the second segment (II) is divided into the triangular plate (tp) and the convex plate (cp), in the second segment (II) the stylet groove is closed, the articulation of the dorsal condyle (cd) between the II and III segments, the shape of the intercalary sclerites (is), (b) the shape of the segment on the dorsal and ventral side (D-V), the lateral membrane with the intersegmental sclerit (si), the midventral condyle (cv) on the proximal edge of the first segment is visible, (c) the dorsal view, the conical shape of the fourth segment, the intersegmental membrane (mb), the stylet groove is closed (gr), (d) ventral view of the segments, the connection between the third and fourth segments, the midventral condyle (cv) and the apical plate (ap) are visible, and (e) the view from the dorsal and ventral sides, the first segment with the open stylet groove (gr) and with the midventral condyle (cv) on the distal edge, dorsally the surface of the second segment is divided into the triangular plate (tp) and the concave plate (cp), the articulation of the dorsal condyle (cd), the groove is closed in the II, III, and IV segments, the intercalary sclerites are distinct. Lr: labrum, stb: stylet bundle.