Ctenoplus balli, Fuller & Platia, 2006

Fuller, E. & Platia, G., 2006, A revision of the click beetle genus Ctenoplus Candèze, 1863 (Coleoptera: Elateridae, Synaptina), Zootaxa 1217 (1), pp. 1-76 : 62-65

Ctenoplus balli n. sp.

Figures 1, 5, 7, 9, 10 , 53 , 64, 81, 102, 112

Diagnosis

Large­sized, uniformly reddish brown Ctenoplus with relatively short, wide prosternal spine, subquadrate pronotum and indistinct lobe on tarsomere 4. C. balli is similar to C. gigas n. sp., but can be distinguished by body size and male genitalia. C. balli is smaller than C. gigas (10.5 mm vs. 12.5–15 mm), and the apices of the parameres are straight ( Fig. 81 ), whereas C. gigas is larger, and the apices of the parameres are slightly curved laterally ( Fig. 83 ).

Description

Body including antennae and legs uniformly dark reddish­brown, elytra lighter reddish­brown; setae opaque pale yellow. Length: 10.5 mm; width 2.0– 2.5 mm.

Head. Punctures shallow, almost contiguous throughout; setae erect, subequal in length to antennomere 3. Eyes: ocular index, males, 65–67 (c.f., C. gigas ). Antenna: antennomeres 2 and 3 elongate, subcylindrical, antennomeres 4–10 elongate, length slightly more than 2X apical width; cuticle microrugose; antenna extending posterad apex of pronotal hind angles by about length of antennomere 11; anterior margin of antennomeres 4–10 with sparse fringe of erect setae in both sexes.

Prothorax. Pronotum slightly wider than long (length:width ratio 0.91–0.97), hind angles slightly divergent; apex of hind angles bluntly pointed; carina of hind angles slightly less than 1/2 length of pronotum; lateral carina weakly sinuate; punctures as on head, very slightly more widely spaced on disk, size equal throughout; posterior 1/2 glabrous along midline; setae as on head; posterior margin adjacent to scutellum transverse, not sinuate. Hypomeron ( Fig. 9 ) glabrous on posterior 1/4; smooth mesal border ( Fig. 9 , mb) with ca. 5 setae anterad procoxae; mesal smooth border bearing triangular projection at level of procoxa ( Fig. 9 , pr); punctures and setae as on head, but separated by up to 1/2 own diameters; posterolateral angle in ventrolateral aspect set off from margin adjacent to epipleuron, angle obtuse. Prosternum: punctures grading from subequal to hypomeral punctures anteriorly to minute around procoxal cavities; prosternal spine ( Figs. 9 , 53 ): ventrolateral carinae remaining separate until apex, continued anteriorly slightly anterad margin of procoxal cavities ( Fig. 9 ); ventral surface slightly narrower than dorsal surface ( Fig. 9 ), margins subparallel, with median carina posterad procoxae, ventral apex very slightly produced, forming ventral surface of U­shaped ridge around posterior vertical margin, U­shaped ridge accentuating medial ridge on posterior surface.

Mesothorax. Scutellum flat; punctures minute, almost contiguous; anterior margin straight and transverse, posterior margin slightly produced. Mesosternum with posterior margin distinctly raised above mesocoxae, horizontal in lateral aspect, concave in ventral aspect; declivity anterad level of mesocoxae angled at ca. 45°; setae finer than pronotal setae. Mesepisternum with anterior groove bearing setae laterally, elsewhere almost glabrous with less than 6 punctures anterolaterally and 3–4 punctures posteromesally in some specimens. Elytra somewhat attenuated posteriorly (Fig. 64); punctures relatively deep, slightly smaller than pronotal punctures; intervals with relatively dense, minute punctures, punctures separated by slightly more than own diameter; apices of elytra dehiscent, sutural interval with small triangular tooth.

Metathorax. Metasternum densely punctured, punctures separated by less than 1/2 own diameters, punctures subequal in size to median prosternal punctures; setae as on mesosternum; carina posterad mesocoxae up to 2X as long as basal width.

Legs. Profemur without obvious dark microspines. Tarsomere 4 with inconspicuous ventral lobe ( Fig. 7 ); claws robust ( Fig. 5 ).

Abdomen. Terga relatively lightly sclerotized, spiracles partially enclosed on terga 3–6. Ventrite 5 about as long as basal width; punctures as in metasternum except becoming separated by about own diameters along midline; dorsal submarginal carina of ventrite 5 broadly rounded. Ventral setae grading from same as metasternum along midline to same as pronotum laterally. Apex of sternum 9 of male with 2 lateral and 1 medial stout setae. Male genitalia, Fig. 81 ; parameres converging anteriorly, separated by width of ejaculatory duct along midline; ventral surface of median lobe with elliptical sclerite like C. girardianus . Female genitalia, Fig. 102 ; bursal plates subreniform, symmetrical; tubular extension: about 2X length of bursa, with 1 distal coil, expanded distally, bearing reticulate pattern of grooves; spines coarse, with conspicuous bases; proximal spines in single row, distal spines in 2 rows; spermatheca absent.

Material examined and range

3♂, 1♀. THAILAND: Holotype male, “ THAI 24–29.IV.1992, DOI SUTHEP, Pacholatko & Dembicky leg”. [ CPG] . Paratypes: 1♂, “ THAILAND. CHIANG MAI: Doi Inthanon NP, 1300m, UV light 1900–2300h, 1 MAY 1990, EF#90037; E. Fuller ”[ ERFC] ; 1♂, same data except: “ 4 MAY 1990, on plants, EF#90043A” [ ERFC] ; LAOS: 1♀, “ LAOS, 600–700 m, Luang Namtha, 13–24.v.1997, leg Hergovitz” [ CCW]. This species is known from northwestern Thailand and western Laos ( Fig. 112 ), but see Discussion below .

Etymology

The species is named in honour of Dr. George E. Ball, carabidologist, University of Alberta.

Natural history

Specimens have been collected between 24 April and 24 May, and between 600 and 1600m in elevation. At Doi Inthanon, both specimens were collected in predominantly pine forest; one specimen was attracted to UV light, the other hand­picked from roadside vegetation .

Discussion The males and female of the type series were not collected at the same time or place.

Given the presence of externally indistinguishable species pairs in Ctenoplus , the association must be regarded as tentative.

Figures

FIGURE 112. Distribution of Ctenoplus species.

FIGURES 1–10. 1–4, head capsule, lateral. 5–6, tarsal claw. 7–8, tarsus. 9, venter of prothorax. Fig. 10: venter of mesothorax, lateral. 1, 5, 7, 9, 10, Ctenoplus balli n. sp.; 2, Silesis hilaris Cand.; 3, Synaptus filiformis (L.); 4, Glyphonyx sp.; 6, 8, Ctenoplus rufoantennatus n. sp. Abbreviations: a, antennal socket; ag, anterior groove of mesepisternum; as, anterior articulating surface of mesosternum; bm, beaded margin of mesosternal cavity; c, mesocoxa; d, lateral depression of mesosternum; da, dorsal apex of prosternal spine; dp, dorsal periocular pit; g, gena; hc, anteromesal concavity of hypomeron; l, ventral lobe of tarsomere 4; lb, lateral border of prosternum; lp, anterolateral projection of mesepimeron; mb, mesal border of hypomeron; mc, mandibular condyle; mm, mesepimeron; ms, mesepisternum; pr, projection of mesal border of hypomeron; sc, supra­antennal carina; tp, anterior tentorial pit; va, ventral apex of prosternal spine; vp, ventral periocular pit.

FIGURES 50–57. Prosternal spine of Ctenoplus and Silesis species. 50–57, lateral; 58, 59, ventral. 50, C. sanguinolentus (Cand.); 51, C. sanguinolentoides n. sp.; 52a, b, C. coomani Fleut.; 53, C. balli n. sp.; 54, C. gigas n. sp.; 55, C. divergens n. sp.; 56, C. alutaceus n. sp.; 57, C. dorsalis n. sp.; 58, C. brunneus Fleut.; 59, S. fulvus Fleut.; Abbreviations: da, dorsal apex; va, ventral apex. Scale bar = 0.25 mm.

FIGURES 66–85. Male genitalia of Ctenoplus species, dorsal aspect unless otherwise specified. 66, C. javanensis Cand.; 67, C. sumatrensis n. sp.; 68, C. sanguinolentoides n. sp.; 69, C. nitidipennis Schwarz; 70, C. indicus n. sp.; 71, C. collaris Cand., a, dorsal, b, ventral; 72, C. pseudocollaris n. sp.; 73, C. neosiamensis n. sp.; 74, C. siamensis n. sp.; 75, C. rufoantennatus n. sp.; 76, C. castaneus (Fleut.), a, dorsal, b, lateral; 77, C. coomani Fleut.; 78, C. divergens n. sp.; 79, C. alutaceus n. sp., a, dorsal, b, lateral; 80, C. semialutaceus n. sp.; 81, C. balli n. sp.; 82, C. girardianus n. sp.; 83, C. gigas n. sp.; 84, C. cateianus n. sp.; 85, C. deceptus n. sp. Abbreviations: st, median struts; pa, parameres; ph, phallobase. Scale bar = 0.25 mm.

FIGURES 98–106. Female genitalia of Ctenoplus species. 98, C. coomani Fleut.; 99, C. brunneus Fleut.; 100, C. divergens n. sp.; 101, C. alutaceus n. sp.; 102, C. balli n. sp.; 103, C. girardianus n. sp.; 104, C. gigas n. sp.; 105, C. cateianus n. sp.; 106, C. deceptus n. sp. Abbreviations: sd, tubular extension. Scale bar = 0.5 mm.