Thyestetha splendens 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 : 23-24

Thyestetha splendens Eberle & Riedel sp. n.

( Figs. 9 , 18 , 36 , 53–54 , 72 )

Diagnosis. Prothorax with bluish purple lustre, elytra with coppery purple lustre ( Figs. 9 , 18 ). Pronotum and elytra largely glabrous. Rostral canal glabrous. Aedeagus ( Figs. 53–54 ) with apex rounded; transfer apparatus in dorsal view Y-shaped.

Description. Holotype, male. Length. Pronotum + elytra: 2.8 mm. Color. Antenna and tarsi ferruginous; remainder black; prothorax with bluish purple lustre, elytra with coppery purple lustre. Habitus subglobose, in dorsal view constricted between pronotum and elytra ( Fig. 9 ); profile dorsally constricted between pronotum and elytron ( Fig. 18 ).

Rostrum 5.3 X as long as wide at base. Head. Vertex slightly punctate, with distinct pit between eyes.

Prothorax 1.4 X wider than long; disc in anterior 1/4 densely punctate with very small punctures, remainder subglabrous with minute punctures (except for row of coarse punctures along base); sides smooth except few indistinct punctures ventrally; postocular lobe weakly developed; inner surface of rostral canal with scattered long setae; marginal carina externally along edge with sparse slender scales.

Elytra 0.8 X longer than wide; sides rounded; apex slightly extended, jointly rounded; striae mostly effaced, striae 7, 8 and 9 apically weakly impressed; elytral apex obscurely punctate. Metanepisternum 2.7 X wider than high.

Thoracic venter. Meso- and metaventrite subglabrous; ventral rim of mesothoracic receptacle with sparse thin scales; Metaventrite submedially flat. Procoxa densely punctate, with long slender scales; mesocoxa sparsely squamose; metacoxa glabrous; trochanter with sparse, coarse punctures containing slender scales. Distance between mesocoxae about 1.5 X width of mesocoxa.

Legs. Femora sparsely punctate, apically slightly denser, scales slender; meso- and metafemur dorsally with slightly broader scales, dorsal squamose line of metafemur moderately dense; anteroventral ridges relatively weak. Metafemur in apical third with slightly protruding posteroventral ridge.

Abdomen. Ventrites glabrous except ventrite 1 laterally with few thin scales.

Terminalia. Aedeagus ( Figs. 53, 54 ). Apex rounded, moderately curved ventrad; lateral orificial sclerites medium-sized, outer portion ca. as long as inner portion; anterior median orificial sclerite simple between 2nd and 3rd fold ( Fig. 36 ). Anterior end of transfer apparatus curved dorsad; in dorsal view Y-shaped. Sclerotized part of ventral membrane extending proximad 1.56 X length of aedeagal body from insertion of apodemes.

Allotype, female. Same as holotype except: Rostrum 6.29 X longer than wide. Prothorax 1.21 X longer than wide. Elytra 0.92 X longer than wide. Terminalia. Hemisternites of ovipositor 6.36 X longer than wide. Tergite VII 1.88 X longer than wide. Tergite VIII 2.22 X longer than wide. Bursal sclerite at insertion of spermathecal duct distinctly sclerotized.

Intraspecific variation. Length, males 2.8–3.7 mm (n=2, x = 3.3 mm), females 3.1–4.3 mm (n=2, x = 3.7 mm). Lustre of prontum and elytra weak in some specimens. Scales at rostral base smaller or larger, punctures on apical margin of prothorax more distinct in holotype than in other specimens.

Etymology. The epithet is based on the participle of the Latin verb splendere (shine) and refers to the bright coloration.

Material examined (2 males, 2 females). Male, holotype: PAPUA NEW GUINEA, Morobe Prov., ca. 10 km S Garaina , Saureri , 1400–1700m, 22.III.1998 ( SMNK) . Paratypes: PAPUA NEW GUINEA, Morobe Prov., ca. 10 km S Garaina, Saurei: 1 male: 1600–1800m, 24.III.1998 ( ARC); 1 female (allotype), 1600–1800m, 24–25.III.1998 ( SMNK); 1 male: 1550–1700m, 27.III.1998 ( ARC).

Distribution ( Fig. 72 ). Morobe Prov. (Garaina). Elevation: ca. 1600 m.

Figures

FIGURE 72. Distribution of Thyestetha glabra sp. n., T. lubrica sp. n., T. puncticollis sp. n., and T. splendens 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.