Dematochroma terastiomerus ( 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 : 43-44

Dematochroma terastiomerus ( Heller, 1916)

( Figs 4–5 , 21 , 31–33 )

Thasycles terastiomerus Heller, 1916:303 .

Dematochroma terastiomerus: Jolivet et al., 2007a:39 . Dematochroma difficilis: Jolivet et al., 2007a:39 .

Type material. Province Sud: Lectotype (here designated), 13 ( Fig. 4 ): Ciu, 300m., 2 January 1912, F. Sarasin & J. Roux leg. [pale blue label], 1915/18 [pale blue label], Iphimoderus terastiomerus Typus [red label], Staatl. Museum für Tierkunde, Dresden [white label], Dematochroma terastiomerus Hell (…) [white label] (MfT). Paralectotype, 13: Ciu, 300m., 2 January 1912, F. Sarasin & J. Roux leg. [pale blue label], Cotypus [red label], Iphimoderus terastiomerus sp. n. Determ. K. M. Heller [white label] ( NMB). Province Nord: Paralectotype, 1Ƥ ( Fig. 5 ): Oubatche, 25 March 1911, F. Sarasin & J. Roux leg. [pale blue label], Ƥ [white label], 1915/18 [pale blue label], Cotypus [red label], Staatl. Museum für Tierkunde, Dresden [white label] (MfT).

Other material examined. Province Nord: 23, 4Ƥ: Baie Ugué, 21.15543ºS 165.54190ºE 8m, 30 March 2008, J. Gómez-Zurita & J.A. Jurado-Rivera leg. (IBE-JGZ); 43, 3Ƥ: ca. Pouebo, 20.42968ºS 164.65064ºE 0m, 8 April 2008, J. Gómez-Zurita & J.A. Jurado-Rivera leg. (IBE-JGZ); 33: Ponérihouen, 10–12 October 1969, J. Balogh leg. ( HNHM). Province Sud: 13, 1Ƥ: Thio, hour sign 21º35’284S 166º09’078E 26m, 29 March 2008, A. Cardoso & J.A. Jurado-Rivera leg. (IBE-JGZ); 33, 5Ƥ: Sarraméa, 21.67005ºS 165.80852ºE 37m, 13 March 2008, J. Gómez-Zurita, J.A. Jurado-Rivera & A. Cardoso leg. (IBE-JGZ); 23, 3Ƥ: Thio, Ourué, 21.58892ºS 166.19388ºE 10m, 9 March 2008, J. Gómez-Zurita, J.A. Jurado-Rivera & A. Cardoso leg. (IBE-JGZ); 13, 1Ƥ: Poya, 21.42392ºS 165.14715ºE 26m, 1 April 2008, J. Gómez-Zurita & A. Cardoso leg. (IBE-JGZ); 3Ƥ: Poya, 21.47487ºS 165.19103ºE, 16m, 1 April 2008, J. Gómez-Zurita & A. Cardoso leg. (IBE-JGZ); 53, 5Ƥ: ca. Bourail, Baie des Tortues, 21.60550ºS 165.45398ºE, 11m, 27 March 2008, J. Gómez-Zurita, J.A. Jurado-Rivera & A. Cardoso leg. (IBE-JGZ); 13: ca. Table Unio, 21.59633ºS 165.65570ºE 47m, 14 March 2008, J. Gómez-Zurita, J.A. Jurado- Rivera & A. Cardoso leg. (IBE-JGZ); 2Ƥ: Farino (refuge), 21.64877ºS 165.78077ºE 261m, 27–28 March 2008, J. Gómez-Zurita, J.A. Jurado-Rivera & A. Cardoso leg. (IBE-JGZ); 13: Farino, Barbou L., 21.63308ºS 161.71309ºE 183m, 4 November 2004, S. Cazères leg. ( SRFP); 13: Col d’Amieu, 19 January 1977, J. Balogh leg. ( HNHM); 13: Ile des Pins, 23–27 February 1977, J. Balogh leg. ( HNHM).

In the Heller material there are three specimens under this name, including both sexes: one male and one female at MfT, and one male at NMB. The description does not indicate how many specimens were used, but mentions characters for both genders, thus in order to stabilize the taxonomy of this group, the male from Ciu (Province Sud) at MfT, in best preservation and labeled by K. Heller as “ Typus ” is designated here as the lectotype. The two remaining specimens, including the female with missing antennae and collected in Oubatche (Province Nord), are designated as paralectotypes. The original description also mentions one specimen collected in Canala, 30.X.1911, but this was not found among syntypes.

The eumolpine fauna of New Caledonia includes several species externally very similar to D. terastiomerus (see discussion for D. difficilis above). Hence it was possible that Heller’s specimens, collected in remote parts of the island separated by a distance of more than 170km along the eastern coast of Grande Terre, were not conspecific. In a 2008 expedition to New Caledonia, several pairs of D. terastiomerus were collected in copula. Comparison of these females with Heller’s female confirms that it is indeed conspecific with the unmistakable male lectotype. The species is profusely described in Heller (1916) and the description is complemented here with highly diagnostic characters from both male and female genitalia.

Genitalia: Penis ( Figs 31–33 ) of characteristic shape, broadly curved at right angle at basal third; median tubular part of penis narrow, subcylindrical, but gradually expanded laterally beyond middle to nearly 2.0x width at base, tapering towards apex as elongated ellipse; sides of expanded apical third sinuate in profile; apex neatly trifid, with lateral lobes membranous internally and apically, and middle lobe chitinous, with sides concave towards narrow blunt ended apex, reaching slightly beyond edge of ellipse defined by lateral lobes. Ostium large, apically as a semicircle delimited by lateral curvature of penis and basal concavity of median apical lobe, but ill defined basally. Ventrally flat in enlarged preapical area, without apparent features, except median apical lobe and membranous connections with lateral lobes. Spermatheca ( Fig. 21 ) thick, U-shaped; receptacle with slightly irregular profile, particularly at insertions of spermathecal gland and duct, longer and wider than pump, evenly rounded at apex; duct very fine, joined slightly above basal end of receptacle.

Distribution. This species appears widely distributed in the Grande Terre and reaches Île des Pins (Kunyié), an island about 15km diameter and some 50km southeast of the main land. It is always found at relatively low altitudes (at most 261m in Farino), and is sympatric and often syntopic in several places across the island with D. difficilis (Heller) .

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 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.

FIGURES 25 – 36. Dorsal, ventral and lateral views of penis of: 25 – 27, Dematochroma lepros (Heller); 28 – 30, D. maculifrons (Heller); 31 – 33, D. terastiomerus; and 34 – 36, D. humboldtiana (Heller). Scale bars represent 0.2 mm ..