Ctenoplus alutaceus, 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 : 58-60

Ctenoplus alutaceus n. sp.

Figures 27 , 39 , 44 , 56 , 79 , 101 , 111

Diagnosis

Small, uniformly yellowish­brown Ctenoplus with a broad patch of alutaceous cuticle on the posterolateral margin of the hypomeron ( Fig. 44 ) and with the pronotum broader than long ( Fig. 39 ). C. alutaceus is similar to C. divergens , but the latter species lacks alutaceous cuticle on the hypomeron.

Description

As in C. divergens except as noted below.

Body light yellowish­brown; antennae, legs and palpi light brownish­yellow; setae opaque light yellow. Length: 6.0– 6.5 mm; width 1.0–2.0 mm.

Head. Punctures shallow, almost contiguous throughout; antenna ( Fig. 27 ) extending almost to apex of pronotal hind angles.

Prothorax. Pronotum ( Fig. 39 ): punctures grading from separated by about 1/2 own diameters anteriorly to separated by about own diameters posteriorly, punctures shallow, simple; carina of hind angles slightly less than 1/2 length of pronotum in lateral aspect. Hypomeron: mesal margin bearing linear row of five punctures and with small rounded projection adjacent to procoxa; posterolateral margin with broad band of alutaceous cuticle ( Fig. 44 ), band separated from lateral margin by single row of punctures, band about 1/3 width of hypomeron at level of procoxa. Prosternum: punctures grading from almost contiguous anteriorly to separated by about own diameters around procoxa; prosternal spine ( Fig. 56 ): ventral margin concave in lateral aspect; ventrolateral carinae joining about 2/3 length of spine posterad procoxae.

Mesothorax. Scutellum flat; anterior margin convex; scutellum depressed below level of adjacent elytra anteriorly. Mesosternum moderately raised between mesocoxae, margin convex in lateral aspect, declivous beaded margin angled at ca. 45°; posterior margin of mesosternum slightly concave; posterolateral angle glabrous. Mesepisternum glabrous on posterior 1/2. Elytra not attenuated posteriorly, broadly rounded at apex; apices subtruncate, without sutural teeth; striae shallowly impressed; intervals moderately densely punctured with minute punctures, punctures separated by about 2X own diameters.

Metathorax. Metasternum: carina posterad mesocoxa 3–5X as long as basal width; punctures separated by own diameters along midline.

Legs. Claws with 4 subapical tines, apical tine slightly longer than subapical tines; tarsomere 4 with indistinct lobe.

Abdomen. Terga not heavily sclerotized; spiracles marginal on terga 2–6 and appearing narrowly enclosed in cuticle laterally; dorsal carina of ventrite 5 broadly Ushaped. Male genitalia, Fig. 79 ; parameres not enclosing median lobe ventrally, separated by slightly less than width of median lobe across basal struts; median lobe evenly tapered from basal struts to apex, curved ventrally. Female genitalia, Fig. 101 ; bursal plates subcrescentic, symmetrical; band of bursal spines extending almost completely around bursa anterad base of tubular extension; tubular extension: base very wide, length of base about 1/2 length of bursa; base almost completely covered with pale spines, spines smaller and finer than bursal spines, grading to size of bursal spines, band of pale spines continuous around extension proximally, interrupted distally; distal bulbous spineless section of extension arising laterally on base; spermatheca absent; spermathecal gland tubular, with subreniform reservoir.

Material examined and range

1♂, 2♀. THAILAND: Holotype female, “Thailand, Chiang Dao, 21.v –11.vi. 1995, M Snížek lgt.”/ SRGI [ CRG] . Paratypes: 1♂, 1♀, “THAILAND bor., CHIANG DAO env., 21.5– 4.6.1995, M. Snížek leg.” [ CPG]. This species is known from northern Thailand ( Fig. 111 ) .

Etymology The species epithet refers to the alutaceous cuticle of the hypomeron.

Natural history Adults have been collected between 21 May and 11 June.

Discussion

Female genitalia are similar to those of C. divergens , suggesting a close relationship, but can be distinguished by the bursal plates, and the length and shape of the tubular extension (c.f., Figs 100, 101 ). The bursal plates of C. alutaceus are narrower and less heavily spined than those of C. divergens . The tubular extension of C. alutaceus is shorter (about half the length of the bursa vs. subequal in length to the bursa), and the extension appears to branch laterally from the wide base, rather than being continuous distally as in C. divergens .

Figures

FIGURE 111. Distribution of Ctenoplus species.

FIGURES 15–30. Antenna of Ctenoplus species. 15, C. javanensis Cand.; 16, C. sumatrensis n. sp.; 17, C. sanguinolentus (Cand.); 18, C. sanguinolentoides n. sp.; 19, C. nitidipennis Schwarz; 20, C. indicus n. sp.; 21, C. neosiamensis n. sp.; 22, C. siamensis n. sp.; 23, C. rufoantennatus n. sp.; 24, C. castaneus (Fleut.); 25, C. coomani Fleut.; 26, C. divergens n. sp.; 27, C. alutaceus n. sp.; 28, C. semialutaceus n. sp.; 29, C. cateianus n. sp.; 30, C. dorsalis n. sp. Scale bar = 0.5 mm.

FIGURES 31–43. Pronotal outline of Ctenoplus species, dorsal. 31, C. javanensis Cand.; 32, C. sumatrensis n. sp.; 33, C. sanguinolentoides n. sp.; 34, C. indicus n. sp.; 35, C. rufoantennatus n. sp.; 36, C. castaneus (Fleut.); 37, C. coomani Fleut.; 38, C. divergens n. sp., a: male, b: female; 39, C. alutaceus n. sp.; 40, C. semialutaceus n. sp.; 41, C. gigas n. sp.; 42, C. cateianus n. sp.; 43, C. dorsalis n. sp. Abbreviation: bf, sublateral longitudinal incision. Scale bar = 0.5 mm.

FIGURES 44–46. posterior part of hypomeron of Ctenoplus species. 44, C. alutaceus n. sp.; 45, C. semialutaceus n. sp.; 46, C. girardianus n. sp. 47, prosternum of C. nitidipennis Schwarz, ventral. 48, venter of mesothorax of C. dorsalis n. sp., ventral. 49, tarsus of C. castaneus (Fleut.), lateral. Abbreviations: ac, alutaceous cuticle; ag, anterior groove of mesepisternum; as, anterior articulating surface of mesosternum; c, mesocoxa; d, lateral depression of mesosternum; gr, groove on prosternum; l, lobe of tarsomere 4; lp, anterolateral projection of mesepimeron; mf, mesosternal cavity; pr, projection of mesal border of hypomeron. Scale bar = 44–46, 48, 49: 0.25 mm; 48: 0.5 mm.

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.