Dematochroma culminicola ( Heller, 1916 )

Gómez-Zurita, Jesús, 2011, Revision of New Caledonian species of Eumolpinae described by K. M. Heller (Coleoptera: Chrysomelidae), Zootaxa 3060, pp. 31-46 : 32-36

Dematochroma culminicola ( Heller, 1916)

( Figs 6 , 10–12 , 22 )

Thasycles culminicola Heller, 1916:304 .

Dematochroma culminicola: Jolivet et al., 2007a:39 .

Type material. Province Sud: Holotype, 1Ƥ ( Fig. 6 ): Mt. Humboldt, 1100 m., 17 September 1911, F. Sarasin & J. Roux leg. [pale blue label], 1914/6 [pale blue label], culminicola Typus [red label], Staatl. Museum für Tierkunde, Dresden [white label], Dematochroma culminicola Heller [white label] (MfT).

Other material examined. Province Nord: 23, 6Ƥ: Bourail, Col des Roussettes, 26–27 January 1977, J. Balogh leg. ( HNHM). Province Sud: 23, 2Ƥ: Col d’Amieu, 21º34.922’S 165º46.324’E 630m, 8 August–18 October 2006, S.R.f.P. staff leg. (IBE-JGZ); 33, 3Ƥ: Col d’Amieu, 21º34.922’S 165º46.324’E 630m, 24 August–20 September 2007, S.R.f.P. staff leg. (IBE-JGZ); 43: Col d’Amieu, 21º34.922’S 165º46.324’E 630m, 23 November– 11 January 2008, S.R.f.P. staff leg. (IBE-JGZ); 63, 1Ƥ: ca. Farino, 21.61288ºS 165.70209ºE 384m, 11 April 2008, J. Gómez-Zurita, J.A. Jurado-Rivera & A. Cardoso leg. (IBE-JGZ); 23: Col d’Amieu, 19 January 1977, J. Balogh leg. ( HNHM); 1Ƥ: New-Caledonie, 1977, J. Balogh leg. ( HNHM).

Heller (1916) did not indicate how many specimens were available to him for the description of this species. His collection at Dresden (MfT) currently holds a single female specimen with locality data matching the original description, except for an obvious typographical error in the collection date (37 September 1911[sic] in original). This specimen is regarded here as the holotype, by monotypy. As in other species descriptions by Heller (1916), the diagnosis of D. culminicola is detailed and unambiguous, and is supplemented here with the description of the male as well as genitalia of both the sexes for the first time.

Male: Length: 5.5–7.0 mm, width: 3.4–4.2 mm. Body elongated oval. Head, pronotum, mandibles and base of femora dark brown with bronzy reflections; labrum, scutellum, elytra, epipleura and ventral surfaces dark reddish brown with slighter bronzy reflections; antennae, apex of femora, tibiae, tarsi and external margins of abdominal ventrites reddish brown; palpi yellowish. Teneral specimens paler, with feebly developed bronzy reflections.

Head deeply inserted into pronotum; frons flat, laterally and anteriorly delimited by supraocular furrows and transversal, nearly continuous posterior suture of weakly raised, triangular antennal calli; frons very finely microreticulated, densely covered by fine punctures, with median longitudinal furrow; antennal calli finely alutaceous, almost unpunctured except near eyes; head mostly glabrous, with single erect whitish seta apically on eye, in supraocular furrow, and short, very fine whitish setae on short genae and area below antennal insertions, near clypeal suture. Clypeus transversely rugose, densely punctured, bell-shaped, expanded apically to 2.0x width between antennae; apex deeply depressed, with two anteriorly protruding denticles flanking median concave emargination; anterior margin with short, very fine translucent setae appressed against labrum and mandibles. Labrum subrectangular, feebly emarginated anteriorly. Eyes large, moderately convex, elongated dorso-ventrally, with emargination at inner border; dorsal lobe wider than ventral lobe. Palpi elongated, with feebly enlarged apical palpomere, reaching maximal width at apical 1/3. Male antennae thicker than female antennae and slightly longer, reaching half of elytra, with segments feebly flattened dorsally (evenly curved transversally in females); first antennomere large, weakly elbowed, concave and flattened ventrally, convex dorsally; second as short club, 1.7x longer than wide subapically; third 1.3x longer than second, weakly expanded towards apex; fourth subequal to third, less conspicuously expanded towards apex; fifth 1.8x longer than second, subcylindrical, with feebly callous distal end; sixth 0.9x as long as fifth; seventh subequal to fifth, and 8–10 subequal to sixth; last antennomere longer, pointed apically; three basal antennomeres sparsely covered by short pubescence, antenommeres 4–7 with denser, longer semierect hairs, and 8–11 with shorter, recumbent pubescence.

Pronotum transverse, 1.7x wider at base than longitudinally at middle, convex, strongly sloping ventrally at anterior angles; anterior border weakly biconcave, finely margined, 0.7x narrower than basal border; basal border weakly concave near posterior angles, straight towards widely convex median lobe, medially with fine margin, widened towards angles; sides evenly curved with narrowly explanate margin, obsolete before anterior angle forming small, laterally protruding denticle; setigerous pore of anterior angle [= trichobothrium] at short distance from denticle on anterior border; posterior angles weakly obtuse, bearing minute denticle with setigerous pore at corner; surface smooth, shiny, finely and densely punctured with shallow punctures of heterogeneous size, but always smaller than punctures on vertex, interstrices occupied by numerous minute punctures. Prosternum weakly concave anteriorly, narrowly margined at middle, alutaceous, unpunctured, with short, anteriorly recumbent pale yellowish setae at anterior angles; narrow between anterior border and procoxae; prosternal process broad, slightly narrower than diameter of procoxae, completely margined and around anterior procoxal margin, sides concave with short lateral denticles medially and gradually expanding towards round posterior angles and feebly convex apical border; apex of prosternal process fused laterally to base of hypomera, enclosing procoxae completely. Procoxae moderately protruding, with tuft of sparse long golden setae internally. Hypomeral suture impressed anteriorly; hypomera alutaceous, unpunctured.

Scutellum broader than long, subpentagonal, with maximum width behind middle. Elytra 1.2x longer than wide; humeral angle broadly round; sides weakly curved, reaching maximum width at middle, slightly emarginated preapically seen in lateral view, and broadly curved at apex; apex of each elytron with weakly concave emargination before sutural angle, with short fine pale yellowish setae; elytra with narrowly explanate margin entirely visible from above, except briefly at apex due to elytral lateral convexity; surface smooth, shiny, densely punctured with small, shallow punctures, larger than pronotal punctures, with interstices generally 2– 3 x wider than puncture diameter and densely covered by minute punctures, as on pronotum; humeri unpunctured; primary punctures forming longitudinal arrangements, more apparent on disc and along suture; scutellar row of 11–12 punctures present. Epipleura very broad, broader than tibiae basally, quickly tapering to pointed apex beyond penultimate abdominal ventrite; concave, hardly visible from side, except at lateral preapical emargination; surface alutaceous, with sparse short and fine whitish setae. Hind wings fully developed.

Mesanepisterna finely alutaceous, unpunctured. Mesoventral process longer than wide; sides subparallel at basal half, 0.7x as broad as diameter of mesocoxae, slightly expanded at apical half, with apical angles amply round and apex with weakly convex median lobe. Metanepisterna finely punctured, with short, posteriorly recumbent pale yellowish setae. Metaventrite short, not much longer medially than mesoventral process, finely alutaceous, with sparse fine punctures and sparse fine pale yellowish pubescence except medially at apex; sides evenly curved; anterior border biconcave accommodating mesocoxae; metaventral process short, broadly angular; posterior border concave at obtuse angle between metacoxae, with short median longitudinal notch. Meso- and metacoxae with internal tuft of pale yellowish setae. Femora long, spindle-shaped, narrower at base, strongly widening towards middle and gradually narrowing towards subcylindrical apical fifth; surface alutaceous, with sparse small punctures, similar to pronotal punctures, becoming coarser and denser on paler apical area and posteriorly on profemora; punctures with short, strong erect and semierect whitish and translucent setae. Protibiae weakly curved at basal third, robust, gradually expanding towards apex; mesotibiae curved at middle, with external subapical broad emargination; metatibiae longer, nearly straight, with weak preapical external emargination; tibial angles with longitudinal keels, sharper in pro- and mesotibiae; longitudinal intervals between keels with rows of long semierect golden setae, densely clothing apex of tibiae internally. All tarsi enlarged in males; first tarsomere elongated, with concave anterior margin, wider than second in pro- and mesotarsi, as broad as second in metatarsi (narrower in all tarsi of females); second triangular, with apical concave emargination; first and second in pro- and mesotarsi densely clothed ventrally with short hairs; third narrower than second, deeply bilobed, densely clothed with long yellowish setae; fifth less than twice as long as third tarsomere, strongly dilated preapically; claws divergent, appendiculate, with ventral lobe at right angle. Anterior border of first abdominal ventrite with broad semicircular process between metacoxae, sides of process obliquely folded as raised moderately thick margin, disappearing at apex, opposite to median apical notch of metaventrite; first abdominal ventrite feebly convex apically, second with weaker convexity, third nearly straight, fourth weakly concave and fifth strongly emarginated at apex; surface of abdominal ventrites with fine sparse punctures and short, posteriorly recumbent pale yellowish setae, longer along median longitudinal stripe; small median depression on disc of fifth ventrite. Pygidium with wide dorsal longitudinal furrow.

Genitalia: Penis ( Figs 10–12 ) regularly curved in lateral view, tapering towards apex; parallel-sided before middle in dorsal view, progressively enlarged as elongated ellipse at apical half, reaching maximum width at middle, 1.4x as wide as basal half of penis; apex broadly round, slightly expanded medially as two small rounded contiguous lobes; ostium large, with V-shaped basal opening and occupying area defined by ellipsoidal apical enlargement of penis; ventral face of penis without features except slight short apical depression between small lobes at apex. Spermatheca ( Fig. 22 ) simple, broadly U-shaped without clearly differentiated pump and receptacle; spermathecal gland and duct connected to basal end of receptacle, after slight prebasal narrowing, at opposite, external and internal sides of receptacle, respectively; spermathecal duct very fine, long, straight, without forming sclerotized coils.

Distribution. Dematochroma culminicola was reported by Jolivet et al. (2007a) from Mandjélia in northeastern Grande Terre, as well as from Farino and Mt. Humboldt in the southern half of the island. Material examined above includes an additional locality in the central chain, more than 40km NW from Farino, in the locality of Col des Roussettes. The specimens studied by Jolivet et al. (2007a) were not examined for this work, but assuming that their identification was correct, it seems that this species is widely distributed in the main island of New Caledonia from mid to high altitudes.

Figures

FIGURES 1 – 9. Type specimens of: 1, Dematochroma lepros (Heller), female holotype; 2, D. humboldtiana (Heller), male lectotype; 3, D. maculifrons (Heller), male holotype; 4, D. terastiomerus (Heller), male lectotype; 5, D. terastiomerus, female paralectotype; 6, D. culminicola (Heller), female holotype; 7, D. difficilis (Heller), male holotype; 8, Taophila subsericea Heller, female lectotype; and 9, Taophila subsericea, male paralectotype. Scale bars represent 2.0 mm.

FIGURES 10 – 19. Dorsal, ventral and lateral views of penis of: 10 – 12, Dematochroma culminicola (Heller); 13 – 15, Taophila subsericea Heller; and 16 – 19, D. difficilis (Heller), arrows indicate different ventral perspectives as shown. Scale bars represent 0.2 mm.

FIGURES 20 – 24. Spermathecae of: 20, Dematochroma lepros (Heller); 21, D. terastiomerus (Heller); 22, D. culminicola (Heller); 23, D. difficilis (Heller); and 24, Taophila subsericea Heller. Arrowheads point at position of insertion of spermathecal gland. All spermathecae shown at the same scale.