Rhinolaemus Steel 1954:143

Thomas, Michael C., 2016, A revision of the genus Rhinolaemus Steel (Coleoptera: Laemophloeidae), Insecta Mundi 2016 (505), pp. 1-17 : 2-3

Rhinolaemus Steel 1954:143

Diagnosis. Individuals of this genus can be distinguished from those of other laemophloeid genera by a combination of the following character states: Head usually rostrate; labrum deeply emarginate in males; mandibles elongate; anterior coxal cavities closed posteriorly, intercoxal process truncate; dorsal surface clothed with conspicuous, stout, reclinate setae; elytra maculate, with both cuticle and setae bicolored; abdominal segment VII modified to form claspers with peg setae.

Description. Steel (1954:143) provided a very detailed generic description, which is reproduced below, with alterations (in italics) to take into account knowledge of the male sex and additional species, and figure references to the current paper are added:

Dorsal surface with conspicuous pubescence composed of thick, recumbent setae ( Fig. 1–10). Body with a dorsal color pattern ( Fig. 1–4). Head not distinctly ( Fig. 9 ) or moderately produced in front of the eyes as a short, broad, flattened rostrum; rostrum longer and narrower in females of some species ( Fig. 5–8 , 10 ), the clypeus a little produced and broadly emarginate anteriorly ( Fig. 12 ). The eyes rather large, not very coarsely faceted. Ventral head sutures (“gular” sutures) present as two short, well marked, slightly converging lines which commence at about the level of the posterior margins of the eyes and end, each in a small fovea, a little in front of the level of the middle of the eyes.

Antennae with the first segment long, more or less club-shaped, inserted in cavities at the sides of the head; antennal insertions broadly exposed dorsally ( Fig. 12 ) or concealed ( Fig. 9–10 ).

Labrum prominent, slightly transverse, narrowed towards front, the sides almost straight, the front margin, rounded in females ( Fig. 5, 7 , 9 ), deeply emarginate in males ( Fig. 12 ); dorsal surface with a few scattered fine setae, the front margin with a dense fringe of finer shorter setae. Mandibles long and slender ( Fig. 12 ), lightly curved apically, bifid at tip (seen from the side), just behind apex with a small rounded tooth and a little behind this a smaller, more pointed one; prostheca and molar area well developed, the latter filelike. Inner lobe of maxilla [lacinia] very narrow, of the normal form for the subfamily, the outer [galea] much longer and broader, internally (in front of inner lobe) with a dense fringe of fine setae which are longer towards the front, external margin with a few long fine setae. Maxillary palpi very long, the first segment distinctly longer than broad, the second much longer, widened apically, the third a little shorter than the second, widened apically, the fourth slightly longer than the third, somewhat fusiform, rounded apically ( Fig. 16 ). Labium chitinized, as long as broad, broadest at about middle, the anterior margin broadly, somewhat triangularly, emarginate, the sides straight between the anterior margin and the widest part; anterior margin with a few rather long fine setae. Labial palpi very long, the first segment subquadrate, the second considerably longer, slightly curved, rounded apically, the third a little shorter than the second, rounded apically ( Fig. 15 ). Mentum strongly transverse.

Pronotum with lateral margins evenly curved ( Fig. 5–8 ) or obtusely dentate ( Fig. 9-10 ); sublateral lines represented by a strongly elevated ridge, without an accompanying groove ( Fig. 24 ). Prosternal process broad, truncate or slightly emarginate, the anterior coxal cavities closed behind (seen from below) ( Fig. 17 ), separated by nearly three times their maximum width (seen from below). Intermediate and posterior coxae as broadly separated as the anterior ( Fig. 19 ).

Scutellum distinct, transverse, obtusely pointed behind ( Fig. 15 ).

Elytra completely covering the abdomen. Discrimen almost attains anterior edge of metasternum. First visible abdominal sternite long, a little more than twice as long as the second, the intercoxal portion broad, lightly rounded in front, the second to fourth about equal in length, the fifth distinctly longer, nearly twice as long as the fourth ( Fig. 19 ).

Legs rather long. Tarsi with the first segment very short, hardly visible from above, the second much longer, longer than the third, the third slightly longer than the fourth, the fifth about as long as the remainder. Tarsal formula 5–5– 4 in males, 5–5– 5 in females.

Male genitalia ( Fig. 20–23 , 26, 27 ) with parameres not or slightly separated; basal piece of tegmen with paired, posteriorly directed, rounded, setose projections, as in Placonotus Macleay ( Thomas 1984b) ; tip of median lobe abruptly expanded; internal sac with fibrous armature; sternite and tergite of abdominal segment VIII modified to form claspers, with peg setae ( Fig. 25 ).

Figures

Figures 9–11. Rhinolaemus tuberculatus. 9) Female. 10) Male. 11) Illustration of holotype (Grouvelle 1878).

Figures 5–8. Rhinolaemus spp., head and pronotum. 5) R. maculatus, female holotype. 6) R. maculatus, male. 7) R. niueensis, female. 8) R. niueensis, male.

Figures 12–15. Rhinolaemus niueensis, SEM photomicrographs. 12) Head, dorsal. 13) Puncturation of head. 14) Antennal club antennomeres. 15) Elytra.

Figures 16–19. Rhinolaemus niueensis, SEM photomicrographs. 16) Head, ventral. 17) Mesocoxa. 18) Pro- and mesosternum. 19) Metasternum and abdomen.

Figures 24–27. Rhinolaemus niueensis. 24) Pronotum, SEM photomicrograph. 25) Abdominal segment VII. 26) Male genitalia. 27) Parameres and apex of median lobe.

Figures 20–23. Rhinolaemus spp., male genitalia. 20) R. maculatus. 21) R. maculatus, parameres and apex of median lobe. 22) R. tuberculatus, genitalia. 23) R. tuberculatus, parameres and apex of median lobe.