Although I did not examined the function of the oral tube, the presence of a concave area covered by long filamentous cells on the lower labium near the mouth is consistent with the idea that the tube is involved in feeding.
EF = external fold; LL = lower labium; UL = upper labium; R = tooth ridge; ras = m.
citri nymph, showing the extended tip of the stylets (st) and the partially retracted/looped part of the stylets (rs): cg, clypeal groove, cl, clypeus; lb, labium
; lbl & lb2, labial segments 1 & 2; rs, retracted/looped stylets ; so, stylet-holding organ.
This sensillum is short and protrudes slightly above the surface of the labium. This type has been identified in the Belostomatidae (Belostoma flumineum, Figures 11(b) and 11(c); Hydrocyrius colombiae Figures 12(a) and 12(b); Lethocerus deyrollei, Figures 14(b) and 14(c)) and Appasus major (Table 2).
They are distributed on the surfaces of the first, second, and third segment, but not on the fourth segment of the labium.
Large (50-100 [micro]m) (TRS1) and short (1.0-49 [micro]m) (TRS2) trichoid sensilla are placed on the dorsal side on the fourth segment of the labium (Figures 4(a) and 4(b)).
punjabensis was more closely related to Riazocoris (with both the above species) because it shared with both taxa the synapomorphic characters of long labium which atleast reaches to metacoxae, scutellum not regularly gradually tapering apically but with a well marked apical lobe separated by a visible constriction and ninth paratergites much longer in the female ovipositor, distinctly passing beyond the medially fused posterior margin of eighth paratergites.
The unique presently described new generic taxon is however quite different from both the above specific taxa of Riazocoris in having the autapomorphics of remarkably longer labium which reaches the third abdomoinal sternum, metathracic scent auricle much shorter, reduced with markedly subacute apex, connexiva more or less entirely concealed (apparently without shining black patches), without short colourless corial patch on either side and general body coloration drab, dark brown, not with a metallic sheen.
The morphological and anatomical structures of the labium in the individual representatives of the Nepomorpha have been subject of observation and interpretation for a number of years [9, 21, 26-29].
These changes have been preserved as various modifications and forms of particular structures of the labium and would provide an interesting source for comprehensive studies.
Labium brown, lighter on anterior margin, darker laterally; 0.70 long, 0.64 wide.
Labium light brown, yellowish at anterior margin; 0.60 long, 0.52 wide.