Trigonopterus fulvicornis (Pascoe)

Riedel, Alexander, 2011, The weevil genus Trigonopterus Fauvel (Coleoptera, Curculionidae) and its synonyms — a taxonomic study on the species tied to its genus-group names, Zootaxa 2977, pp. 1-49 : 12-16

Trigonopterus fulvicornis (Pascoe)

Eurysia fulvicornis Pascoe, 1885: 251 -252. Type locality: “Celebes, Kandari” [SE Sulawesi, Kendari].

( Figs. 33–45 )

Diagnosis. Body ( Fig. 33 ) subpentagonal, black, polished, densely punctate. Rostrum ( Fig. 34 ) with median ridge and pair of submedian ridges, merging on forehead. Disc of pronotum subquadrate, with distinct edges; marginal carina on outside face bordered by deep sulcus. Metafemur dorsally sparsely squamose; ventrally without tooth, anteroventral ridge crenulate; subapically with stridulatory patch. Aedeagus ( Figs. 39–40 ) with long flagellum.

Description. Lectotype, male ( Figs. 33–45 ). Length. Pronotum + elytra 3.0 mm.

Color black, legs dark ferruginous to black, antenna and tarsi ferruginous. Integument of elytra and pronotum polished, punctate, nude; legs with scattered narrow scales.

Habitus subpentagonal, with marked constriction between prothorax and elytra; body in profile dorsally evenly convex. In thanatosis ( Fig. 38 ) legs sticking out from horizontal body plane at ca. 70°; dorsal edge of metafemur distant from elytral edge; tibiae largely left exposed; gaps between legs distinct, especially at base.

Rostrum ( Figs. 34–35 ) ca. 2.5 X as long as wide at base, markedly curved ventrad; in profile dorsal contour markedly convex at base, weakly convex to apex; ventral contour subparallel; dorsally with distinct median ridge and pair of similar submedian ridges, all three merging on forehead; subapically flattening; epistome simple, without tooth, cuticle shining, sculpture shallow.

Head. Eye subrotund, only partly concealed by pronotum when in thanatosis position. Forehead between eyes narrower than rostral base (0.8 X), foveate, eyes bordered by furrow; vertex behind eyes subglabrous.

Antenna inserted somewhat behind middle of rostrum. Scape subequal to articles 1–3 of funicle, fully concealed in rostral channel in thanatosis position.

Pronotum 1.37 X wider than long; sides subparallel, apex and base subtruncate; laterally with traces of weak subapical constriction; disc subquadrate, separated from sides by distinct edges, densely punctate, along submedian line with 15 punctures; interspaces wider than puncture´s diameter, glabrous; sides with postocular lobe angulate, continuous with slightly convex profile of marginal carina; marginal carina on outside face bordered by deep sulcus; antecoxal projection of marginal carina distinct, angulate, directed ventrad; side above procoxa simple, without fovea.

Elytra pyriform, basally subtruncate, 1.20 X longer than wide, 1.30 X wider than base of pronotum, widest in basal 0.29 of elytral length; profile dorsally smoothly convex, 0.56 X as deep as long; striae marked by row of small punctures; flat intervals with row of similar punctures, resulting in confused punctation; interspaces usually much wider than diameter of punctures, glabrous, polished; along basal margin punctures somewhat denser and larger than behind; basally at humerus striae 7 and 8 with denser, deeply impressed punctures, but intervals simple, without any ridge; subapically stria 9 deeply entrenched, furrow containing dense row of punctures; elytral apex simple, jointly evenly rounded, not extended ventrad.

Thoracic venter. Fig. 36 . Procoxa anteriorly punctate; posteroapically with two teeth, nude; mesal face subglabrous, subapically with few deep punctures. Ventral setose fringe of pronotal hypomeron forming distinct receptacle brush; modified setae medially distinctly longer than lateral setae. Mesothoracic receptacle broadly H-shaped with short side-walls; ventrally produced to level of mesocoxal apex; posteriorly nude, microreticulate, dull, with pair of deep, posteriorly open foveae, ventral rim of side walls punctate, with sparse scales. Mesocoxa anteriorly subglabrous, posteriorly punctate, without distinct teeth. Metaventrite medially slightly longer (1.1 X) than exposed part of mesoventrite, disc broadly concave, anteriorly subglabrous, posteriorly microreticulate, dull, with coarse punctures; lateral intercoxal ridge markedly protruding ventrad, in lateral aspect ventrally obliquely truncate; in ventral aspect intercoxal ridges subparallel, posteriorly weakly extending over metacoxa; anterior rim of metacoxal cavity without secondary denticle. Sides of metaventrite glabrous, dorsally surface even with epipleuron, suture bordered by row of punctures, ventrally intercoxal ridge bordered by sickle-shaped, posteriorly punctate costa. Metacoxa in mesal angle with two long setae.

Legs. Femora markedly compressed laterally; with distinct but simple anteroventral ridge overlapping bent tibia; posteroventral ridge less marked but still distinct; without ventral teeth; anteroventral furrow distinct, bordered by fringe of more or less setiform scales. Pro-, meso- and metafemur of similar size, sides subparallel, subapically somewhat bent ventrad. Profemur anteriorly polished, punctate; posteriorly weakly concave, dull, densely coarsely punctate; punctures containing inconspicuous scales; dorsally simple, without scaling. Mesofemur similar to profemur, but posterior surface rather convex, basally polished, at middle and dorsally coarsely punctate, subapically impunctate, microreticulate. Metafemur in repose reaching elytral apex; anterior surface polished, densely punctate, punctures containing each one recumbent scale; anteroventral ridge crenulate; posterior surface largely subglabrous, dull, bordering posteroventral ridge with furrow containing row of squamiferous punctures; subapical posterior surface with distinct stridulatory patch of transverse striation; basal limits of stridulatory patch illdefined; dorsoposterior edge with indistinct row of 9 denticles, dorsal surface with sparse recumbent scales; suture with trochanter oblique with ventral edge. Tibiae with fine longitudinal ridges bordered by rows of dorsad pointing scales; dorsal ridge of metatibia terminating in subapical tooth, apical portion of metatibia thus appearing narrower; dorsal edges of meso- and metatibia with sparse denticles; apex with uncus, without premucro. Anterior setose comb of metatibia subapically following midline of metatibia from base of uncus, ventrally with second parallel row of setae. Tarsi with tarsomere 3 subtrapezoid, anteriorly markedly widened, shape of apical lobes symmetrical; tarsomere 3 ca. 2 X as wide as tarsomere 2, their length subequal; inserted at center of tarsomere 3; tarsomere 5 as long as tarsomere 3; tarsal claws minute.

Abdomen. Ventrite 1 laterally microreticulate, dull, punctate, behind metacoxa with oblique swelling; ventrite 2 laterally and posteriorly microreticulate, dull, punctate. Ventrites 1 and 2 forming common subglabrous concavity; suture between ventrites 1–2 distinct throughout. Ventrites 3-4 narrow, of equal length, each with one row of deep squamiferous punctures. Ventrite 5 densely punctate, narrow interspaces between punctures microreticulate, at middle with deep concavity, laterally with sparse erect scales; apex simple, not crenulate.

Terminalia. Sternite VIII ( Figs. 41–42 ) subtrapezoid, sides converging to subtruncate apex, at base 1.7 X wider than long; well sclerotized; apex setose. Sternite IX ( Fig. 42 ) straight, apical arms forming “V”, half covered by sternite VIII. Tegmen ( Fig. 45 ) with complete, slender ring, apodeme relatively long, parameroid lobes vestigial. Aedeagus ( Figs. 39–40, 43–44 ); body with sides subparallel; when viewed vertically apex rounded, medially extended into short acute tip; dorsal surface glabrous, apex sparsely setose; membrane of ostium angulately folded; with various endophallic sclerites contained in aedeagal body; apodemes ca. 2.8 X as long as aedeagal body; transfer apparatus flagelliform, subequal to length of aedeagus, its apex somewhat spatulate; ductus ejaculatorius ca. 1.5 X as long as aedeagus, basally near insertion with transfer apparatus relatively thin, internally strongly sclerotized, more apically slightly swollen (“bulbus ejaculatorius”).

Material examined. Type specimens. Male, lectotype by present designation: INDONESIA, Sulawesi tenggara, Kendari; labels ( Fig. 37 ): 1) [blue, ovate] “Celebes, Kandari [hand-written]” 2) [rectangular, white] “ Eurysia fulvicornis Pasc. , Type [hand-written]” 3) [rectangular, white with black margin] “ Eurysia fulvicornis Pasc. [handwritten]” 4) [rectangular, white] “Pascoe Coll. B.M.1893-60 [printed]” 5) [round, white with red margin] “HOLO- TYPE [printed]” 6) [rectangular, red] “ LECTOTYPE, Eurysia fulvicornis Pascoe , det A.Riedel 2009 [printed]”; condition: specimen originally card-mounted, remounted on point; right antennal funicle and right protarsus broken and missing; left hindleg loose from metacoxa and glued separately to card; genitalia in glycerol in microtube ( BMNH).

Distribution. INDONESIA, Sulawesi tenggara (Kendari).

Notes. Pascoe (1885) did not designate a holotype in the original description nor specify the number of specimens examined. The round label stating “ Holotype ” has subsequently been added by the staff of the BMNH. Other specimens may exist in addition to the specimen stored at the BMNH, which is considered a syntype and is here designated lectotype to ensure stability of nomenclature in case additional syntypes are discovered that belong to different species.

Figures

FIGURES 33 – 38. Trigonopterus fulvicornis, lectotype: (33) dorsal aspect; (34) frontal aspect; (35) lateral aspect; (36) ventral aspect; (37) labels; (38) thanatosis position, lateral aspect.

FIGURES 39 – 45. Male terminalia of Trigonopterus fulvicornis, lectotype: (39, 43) aedeagus, lateral aspect; (40, 44) aedeagus, dorsal aspect; (41 – 42) sternite VIII – IX; (45) tegmen.