Thyestetha discolor Eberle & Riedel

Eberle, Jonas, Tänzler, Rene & Riedel, Alexander, 2012, Revision and phylogenetic analysis of the Papuan weevil genus Thyestetha Pascoe (Coleoptera, Curculionidae, Cryptorhynchinae), Zootaxa 3355 (1), pp. 1-28 : 6-7

Thyestetha discolor Eberle & Riedel sp. n.

( Figs. 2 , 11 , 35 , 39–40 , 71 )

Diagnosis. Disc of pronotum smooth, polished, with small punctures in apical 1/4, black. Elytra ferruginous except apical half laterally black ( Fig. 11 ); disc glabrous, striae largely effaced; apex laterally punctate. Rostral canal subglabrous. Aedeagus ( Figs. 39–40 ) apically strongly converging with sinuate sides. Transfer apparatus in dorsal view at middle strongly constricted.

Description. Holotype, male. Length. Pronotum + elytra: 3.7 mm. Color. Antenna and tarsi ferruginous; tip of rostrum ferruginous, remainder black; head, pronotum, pleural sclerites, legs and ventral surface black; elytra ferruginous, apical half laterally black. Habitus subovate, in dorsal view with shallow constriction between pronotum and elytra ( Fig. 2 ); profile dorsally constricted between pronotum and elytron ( Fig. 11 ).

Rostrum 4.7 X as long as wide at base. Head. Vertex sparsely punctate.

Prothorax 1.2 X wider than long; anterior 1/4 of disc punctate with small punctures, remainder subglabrous and with minute punctures (except for row of coarse punctures along base); sides distinctly punctate with small punctures; postocular lobe coarsely punctate; marginal carina externally along edge with few whitish scales near procoxa; inner surface of rostral canal with scattered long setae.

Elytra as long as wide; sides rounded; apex slightly extended, jointly rounded; striae effaced on elytral disc, striae 8 and 9 apically distinct; interstices between punctures of stria 8 varying, interstices between punctures of stria 9 equal to diameter of punctures. Metanepisternum 3.7 X wider than high.

Thoracic venter. Meso- and metaventrite laterally with sparse scales; metaventrite submedially behind mesocoxa with pair of moderate protrusions. Pro- and mesocoxa densely punctate, squamose; metacoxa glabrous; trochanter with sparse, coarse punctures containing small scales. Distance between mesocoxae subequal to width of mesocoxa.

Legs. Femora basally sparsely punctate, apically denser, scales slender; meso- and metafemur dorsally with broader scales; metafemur with denser scaling, dorsal squamose line moderately dense; anteroventral ridges relatively weakly developed; with posteroventral ridge in apical third distinctly protruding.

Abdomen. Ventrite 1 laterally and center of ventrite 2 with few thin scales arising from punctures; remaining ventrites subglabrous except lateral margins slightly squamose.

Terminalia. Aedeagus ( Figs. 39, 40 ). Apex strongly curved ventrad, sides sinuate, converging; lateral orificial sclerites small, outer portion 2– 3 X longer than inner portion; anterior median orificial sclerite with small bulge between 2nd and 3rd fold ( Fig. 35 ). Transfer apparatus in profile shallowly incised at middle, ventral contour angularly projecting; anterior and posterior ends curved ventrad; in dorsal view strongly constricted at middle, anterior portion narrower than posterior portion. Sclerotized part of ventral membrane extending proximad 0.81 X length of aedeagal body from insertion of apodemes.

Intraspecific variation. Length, males 3.7–4.5 mm (n=4, x = 4.2 mm ± 0.4 mm). Color. Elytra ferruginous (as in holotype), or much darker (in two specimens) gradually merging with black apical portion. Tibiae and apical portions of femora black or dark ferruginous (in one specimen).

Etymology. The epithet is based on the Latin discolor (not of the same color) and refers to the coloration of the elytra.

Material examined (10 males). Holotype, ARC1367 (EMBL Accession # HE802615 , HE802631 , HE802638 , HE802646 , HE802654 , HE802663 ): PAPUA NEW GUINEA, Morobe Prov., Huon pen., SW Pindiu , S06°27.437’ E147° 30.512’ to S06°27.435’ E147° 30.310’, 1170–1225m, 14.X.2009 ( SMNK). Paratypes: PAPUA NEW GUINEA: 1 male: Morobe Prov., Huon pen., W Pindiu, 1000–1400m, 23.IV.1998 ( ARC); 6 males: Pindiu, Mongi Gorge, S06° 26.542´E147° 31.970´to S06° 25.579´E147° 31.904´, 480–740m, beaten, 13.X.2009 ( SMNK, ZSM); 1 male: Madang Prov., Wannang vill., 5°08'S 145°46'E, 2007 ( NMNH); 1 male: New Guinea, Coll. Hartmann ( SMTD).

Distribution ( Fig. 71 ). Morobe Prov. (Pindiu), Madang Prov. (Wannang). Elevation: 1170–1225 m.

Figures

FIGURE 71. Distribution of Thyestetha carbonaria, T. discolor sp. n., T. emarginata sp. n., T. nitida, and T. oblita sp. n..

FIGURES 1 – 9. Habitus of Thyestetha spp., dorsal aspect: (1) T. carbonaria, lectotype; (2) T. discolor sp. n., holotype; (3) T. emarginata sp. n., holotype; (4) T. glabra sp. n., holotype; (5) T. lubrica sp. n., holotype; (6) T. nitida; (7) T. oblita sp. n., holotype; (8) T. puncticollis sp. n., holotype; (9) T. splendens sp. n., holotype.

FIGURES 10 – 18. Habitus of Thyestetha spp., lateral aspect: (10) T. carbonaria, lectotype; (11) T. discolor sp. n., holotype; (12) T. emarginata sp. n., holotype; (13) T. glabra sp. n., holotype; (14) T. lubrica sp. n., holotype; (15) T. nitida, lectotype; (16) T. oblita sp. n., holotype; (17) T. puncticollis sp. n., holotype; (18) T. splendens sp. n., holotype.

FIGURES 29 – 36. Male terminalia of Thyestetha spp.: (29 – 31) T. glabra sp. n., holotype: (29) tegmen, (30) tergite VII and (31) segments VIII – IX. (32 – 34) T. nitida: (32) tegmen, (33) tergite VII and (34) tergite VIII with sternite VIII and spiculum gastrale. Ostium, lateral aspect: (35) T. discolor sp. n., arrow and dashed line marking bulge between 2 nd and 3 rd fold (36) T. splendens sp. n..

FIGURES 37 – 54. Aedeagus of Thyestetha spp. in dorsal and lateral aspect: (37, 38) T. carbonaria, lectotype; (39, 40) T. discolor sp. n., holotype; (41, 42) T. glabra sp. n., holotype; (43) T. carbonaria, apex of aedeagus, ventral aspect; (44) T. oblita sp. n., holotype, apex of aedeagus, ventral aspect; (45, 46) T. lubrica sp. n., holotype; (47, 48) T. nitida, lectotype; (49, 50) T. oblita sp. n., holotype; (51, 52) T. puncticollis sp. n., holotype and (53, 54) T. splendens sp. n., holotype.