Calambus taiwanensis Arimoto, 2020

Arimoto, Kôichi, 2020, First record and new species of the genus Calambus Thomson (Coleoptera Elateridae, Dendrometrinae) from Taiwan, Zootaxa 4853 (1), pp. 42-50 : 44-47

Calambus taiwanensis Arimoto , sp. n.

( Figures 1–4 )

Etymology. Specific epithet derived from Taiwan, the type locality.

Type material. Holotype. Male , Sung Kang, Nantou County, Taiwan, 4 IV 1971, Kiyoshi Matsuda leg. [CTA001] . Paratypes (2 males, 5 females). 1 female, same data as the holotype [CTA002] ; 1 female, same place as the holotype, S. Takeda leg. [CTA003]; 1 female, Nanshanchi , Nantou County, Taiwan, 12 IV 1972, Kiyoshi Matsuda leg. [CTA004] ; 1 male, same place as the former, 7 IV 1973, Y. Kiyoyama leg. [CTA005]; 1 female, same place as the former, 17 IV 1987, C. Lo leg. [CTA006]; 1 male, Mt. Kuan-tou Shan , Nantou County, Taiwan, 25 IV 1985 (the collector is not stated) [CTA007] ; 1 female, near Puli , Nantou County, Taiwan, 11 VII 2005, F. Y. Huang leg. [CTA008] .

Diagnosis. Body surface generally shining; interspaces between fine punctures distinctly larger than puncture diameter. Body generally black, but elytra dark brown, with outer margin paler. Body covered with yellow white setae. Antennae extending beyond apex of pronotal hind angles by two apical antennomeres in male, but not reaching pronotum posterior lateral apices by apical antennomere in female; antennomere III obconical, slightly longer than II; IV shorter than II–III combined, slightly longer than V. Hind angles of prothorax short, narrow, with apex rounded. Scutellar shield widest at anterior margin; anterior margin slightly rounded; side emarginate anteriorly; posterior margin broadly rounded. Parameres of aedeagus without lateral subapical barb. Female genitalia with robust baculum; vagina with coiled sac; bursa copulatrix without sclerotized piece.

Measurements. Male (n=3, holotype in parentheses). BL: 5.02–5.51 (5.51), BW: 1.54–1.69 (1.69), MBE: 0.58–0.63 (0.63), MAE: 0.84–0.94 (0.94), OI: 143–152 (149), PL: 1.29–1.41 (1.34), PML: 1.14–1.23 (1.16), PW: 1.29–1.40 (1.40), PI: 95.5–100 (95.5), EL: 3.40–3.86 (3.86), EW: 1.54–1.69 (1.69), EI: 221–229 (229), BI: 258–289 (289). Female (n=5). BL: 5.45–6.38, BW: 1.64–1.96, MBE: 0.61–0.71, MAE: 0.85–1.00, OI: 138–144, PL: 1.38– 1.65, PML: 1.21–1.42, PW: 1.41–1.69, PI: 95.7–108, EL: 3.72–4.41, EW: 1.64–1.96, EI: 213–226, BI: 235–279.

Description. Body surface generally smooth and shining, but elytra weakly rough; interspaces between fine punctures distinctly larger than puncture diameter, but larger punctures of anterior edge of pronotum partly overlapping ( Fig. 1A ); large coarse punctures spread all over surface of anterior lobe of prosternum ( Fig. 2F ); punctures of hypomeron near pronotosternal suture large and their interspaces smaller than puncture diameter ( Fig. 2F ). Color. Body generally black, but elytra dark brown, with outer margin paler. ( Fig. 1A, B, C ). Labrum black ( Fig. 2A ). Antennae and mouth parts generally dark brown; mandible black, with apical and internal parts orange ( Fig. 2A ). Legs dark brown, becoming paler apically ( Fig. 1B ). Tergites and sternites VIII‒X yellow brown, but median basal area of tergite VIII and posterior area of sternite VIII translucent ( Fig. 3A, B ). Aedeagus yellow brown ( Fig. 3E, F ). Hairs. Body covered with yellow-white setae ( Fig. 1A, B ). Antennae and mouth parts except for labrum with yellow to brown setae. Setae of legs yellow white becoming yellow apically.

Head. Frons without depression. Supra-antennal carina incomplete medially ( Fig. 2A ); frontclypeal region gradually sloping to base of labrum ( Fig. 2A, B ). Antennomeres I, III, IV and IX–XI longer than wide ( Fig. 2B, C ); II globular, shortest, as long as wide; III obconical, slightly longer than II; IV–X serrate; IV shorter than II–III combined, slightly longer than V. Male. Antennae extending beyond apex of pronotal hind angles by two apical antennomeres ( Fig. 1A ); antennomere IV 1.16–1.35 x as long as wide, 1.74–2.00 x as long as III; V–VIII longer than wide; XI 2.40–2.78 x as long as wide. Female. Antennae not reaching pronotum posterior lateral apices by apical antennomere ( Fig. 1C ); antennomere IV 1.18–1.45 x as long as wide, 1.53–1.68 x as long as III; V–VIII almost as long as wide; XI 1.82–2.14 x as long as wide. Mandible bidentate.

Prothorax sub-trapezoidal, slightly shorter than wide or as long as wide, widest at hind angles; side distinctly rounded, weakly narrowed anterior to hind angles ( Fig. 2D, E ); anterior angles acute; lateral carina extending just behind anterior angles ( Fig. 2B : arrow) to hind angles; hind angles divergent, short, narrow, straight, incurved in some specimens ( Fig. 2D, E ), with apex rounded. Pronotum without median longitudinal depression; median basal tubercle indistinct; median basal furrow poorly developed; sublateral incision near hind angles weak; hind angles without carina. Hypomeron; mesial edge weakly rounded, with impunctate ridge next to pronotosternal suture, carinate anterolaterally ( Fig. 2F : black arrow); posterior margin sinuate, with large emargination near hind angles ( Fig. 2F, G ). Prosternum in profile slightly concave anterior to mesocoxal cavity ( Fig. 2H : arrow); anterior lobe broadly rounded, exceeding anterior angles of prothorax ( Fig. 1B ), in profile strongly inclined (at 39–54 degrees against prosternal horizontal line, Fig. 2H : red line) and in some specimens concave just behind anterior lobe. Prosternal spine in profile strongly inclined (at 24–36 degrees against prosternal horizontal line, Fig. 2H ), incurved, without subapical tooth; sides in ventral view straight ( Fig. 2G ); ventral margin of dorsal lobe in profile slightly sinuate ( Fig. 2H : yellow line); apex in ventral view rather rounded ( Fig. 2G ), in profile rounded ( Fig. 2H ). Pronotosternal sutures not grooved, moderately opened ( Fig. 2F : white arrow). Scutellar shield ( Fig. 2I ) 1.11–1.49 x as long as wide, widest at anterior margin, strongly inclined anterior-downwards; anterior margin slightly rounded, with transversely micro-striated ridge, laterally bent downwards; side emarginate anteriorly and then convex posteriorly; posterior margin broadly rounded. Borders of mesosternal cavity horizontal anteriorly and strongly declivous posteriorly ( Fig. 2H : green line); posterior margin of mesosternite between mesocoxae wider than half width of mesocoxa ( Fig. 2G ). Mesepisternum reaching mesocoxal cavity ( Fig. 2F : triangle). Metasternum sulcate medially and behind mesocoxae ( Fig. 1B ). Elytra convex; outmost interval narrowly extending sideways, forming flat plate, with a lateral carina; striae I–V grooved, but V partly reduced; remaining striae ungrooved and defined only by rows of punctures; apices rounded. Hind wings complete. Legs simple; tarsomeres I–IV becoming shorter apically; V longest.

Abdomen. Ventrite V 0.59–0.67 x as long as wide. Male. Tergite VIII ( Fig.3A ) ca. 0.70 x as long as wide; apical margin strongly prominent and broadly rounded. Sternite ( Fig. 3B ) VIII without median notch; posterior angles slightly prominent and rounded. Tergite IX ( Fig.3C ) longer than wide, ca. 1.4 x length of tergite X; median notch rounded. Tergite X ( Fig.3C ) ca. 1.5 x as long as wide; posterior margin rounded. Sternite IX ( Fig.3D ) ca. 2.9 x as long as wide, rounded apically, concave laterally. Female. Tergite VIII ca. 0.95 x as long as wide ( Fig. 4B ). Sternite VIII with side almost parallel on basal half ( Fig. 4C ); spiculum ventrale robust, ca. 2.0 x as long as sternite VIII ( Fig. 4A ).

Genitalia. Male ( Fig. 3E, F ). Basal piece ca. 0.25 x total length of aedeagus. Median lobe exceeding apices of parameres; basal struts ca. 0.20 x total length of median lobe. Parameres separated ventrally, without lateral subapical barb, not expanded apically; apex with several setae dorsally ( Fig. 3G ), with one seta ventrally ( Fig. 3H ), with two setae apically ( Fig. 3G, H ). Female. Baculum robust, ca. 2.4 x as long as coxites ( Fig. 4D ); coxites not segmented ( Fig. 4E, F ), with some setae at each side; stylus with a seta near apex. Vagina with coiled sac extending from ventral side ( Fig. 4D : arrow); bursa copulatrix globular, without sclerotized structures.

Distribution. Taiwan: Nantou County.

Figures

FIGURE 1. Calambus taiwanensis Arimoto sp. n. A–B: male, holotype [CTA001]; C: female, paratype [CTA002]. A, C: habitus, dorsal; B: habitus, ventral.

FIGURE 2. Calambus taiwanensis Arimoto sp. n. A–D, F–I: male, holotype [CTA001]; E: female, paratype [CTA004]. A: head, anterior view; B: head and pronotum in laterodorsal view and basal five antennomeres of right antenna (arrow: lateral carina of prothorax extending just behind anterior angles); C: apical four antennomeres of right antenna; D, E: left side of pronotum; F: anterior half of habitus, lateroventral view (black arrow: mesial edge of hypomeron carinate anterolaterally; white arrow: pronotosternal sutures moderately opened; white triangle: mesepisternum reaching mesocoxal cavity); G: posterior half of prothorax and mesothorax, ventral view; H: anterior half of habitus, lateral view (arrow: prosternum slightly concave anterior to mesocoxal cavity; red line: anterior lobe of prosternum strongly inclined; yellow line: dorsal lobe of prosternal spine with ventral margin slightly sinuate; green line: borders of mesosternal cavity horizontal followed by strongly declivous); I: scutellar shield.

FIGURE 3. Calambus taiwanensis Arimoto sp. n., male, holotype [CTA001]. A: tergite VIII; B: sternite VIII; C: tergites IX–X; D: sternite IX; E: aedeagus, dorsal view; F: aedeagus, ventral view; G: apical part of left paramere, dorsal view; H: apical part of left paramere, ventral view.

FIGURE 4. Calambus taiwanensis Arimoto sp. n., female, paratype.A–C: [CTA004]; D–F: [CTA008]. A: tergite VIII and sternite VIII, dorsal view; B: tergite VIII; C: sternite VIII; D: genitalia, dorsal view (arrow: vagina with coiled sac extending from ventral side); E: apical part of ovipositor, dorsal side; F: ditto, ventral side.