Chrysodema (Gelaeus) walkeri walkeri ( Waterhouse, 1892 )

Frank, David & Sekerka, Lukáš, 2016, Revision of the subgenusGelaeus of Chrysodema (Coleoptera: Buprestidae: Chrysochroinae), Acta Entomologica Musei Nationalis Pragae 56 (2), pp. 671-719 : 705-708

Chrysodema (Gelaeus) walkeri walkeri ( Waterhouse, 1892)

( Figs 24–26 , 62 )

Pseudochrysodema (?) Walkeri Waterhouse, 1892: 411 (original description).

Chrysodema Walkeri: KERREMANS (1903) : 76 (catalogue); KUROSAWA (1982): 190 (noted as type species of Gelaeus ).

Gelaeus Walkeri: WATERHOUSE (1905) : 584 (noted); OBENBERGER (1926): 129 (catalogue); THÉRY (1935): 248 (key, catalogue); VOLKOVITSH (2001): 46 (noted); BELLAMY (2003): 35 (catalogue).

Chrysodema (Gelaeus) Walkeri: KERREMANS (1909) : 509 (key), 510 (redescription, incl. colour Fig. 5 , Pl. 22); HOŁYŃSKI (1994): 71 (noted as type species of Gelaeus in key to subgenera); LANDER (2003): Fig. 152 (colour photograph, not typical C. (G.) walkeri ), BELLAMY (2008): 542 (catalogue).

Type locality. Indonesia, Maluku Province, Damar Island.

Type material examined. LECTOTYPE (present designation): ♀, ‘Damma I. [6.–11. xi.1891, J. J. Walker lgt.] / 92—20. [w, p] / Pseudochrysodema ? / Walkeri / (Type) Waterh. [w, h] / Type [r, p] / 5766 [w, p]’ ( BMNH). The specimen provided with an additional red printed label: ‘ LECTOTYPE ♀ / Chrysodema (Gelaeus) / walkeri walkeri / (WATERHOUSE, 1892) / David Frank & / Lukáš Sekerka des. 2016 [year handwritten]’.

Additional material examined. INDONESIA: MALUKU PROV.: Damar Island, 1 ♀ ( NMPC), 1 ♀ ( MNHN), 9 ♀♀ ( MFNB), 2 ♀♀ ( DFPC), 1 ♀ ( RMNH), 1 ♂ 2 ♀♀ ( RMNH, ex coll ZMAN), 6.–11. xi.1891, 1 ♀, J. J. Walker lgt. ( BMNH).

Redescription of lectotype. Well preserved ♀ specimen missing only left fore ultimate tarsomere with claws. Length 31.75 mm, width 11.75 mm, length/width ratio: 2.70. Body strongly shiny.

Body generally bright green with golden and copper reflections, only tibiae with bluishgreen reflections ( Figs 24–26 ). Elytra deep blue-violet, apex with purple reflections ( Figs 24, 26 ). Tarsi brown with metallic green distal half of last tarsomere and claws.

Pronotum in general coarsely but sparsely punctate, only laterally punctures dense. Medial line well marked and impunctate. Medial impressions very weak, impressed only along medial line, basically present as rows of dense punctures, punctures slightly smaller than remaining ones on disc. Principal impressions present as narrow, moderately deep and sharply bordered line almost connected to basal impressions, with small dense punctures. Lateral impression shallow and punctate. Basal impressions large and triangular.

Elytra without lateral impressions, moderately punctate. Rows visible from base to apex, only apically weakly impressed, generally regularly arranged, and irregularly double in apical half. Punctures in rows V–VIII in middle third of elytra quite regular and sparse, forming distinct rows, not isolated groups; spaces much broader than puncture diameter, flat, not reticulate ( Fig. 26 ). Intervals basally flat, not elevated, broad, approximately 4–6× as wide as rows of punctures, impunctate; apically and laterally somewhat elevated and punctate.

Mid femora in central part strongly shiny, sparsely punctate, punctures large, on sides punctures smaller and densely arranged.

Ventral side of body ( Fig. 25 ) overall coarsely and quite densely punctate, only central parts of thoracic and abdominal ventrites sparsely punctate. Almost whole lateral sides of abdominal ventrite I densely and coarsely punctate, punctures small. Lateral sides of ventrite II mostly similarly punctate to ventrite I only basal line impunctate. Ventrites III–V largely smooth and sparsely punctate, dense punctation present as patch in lateroapical corners.

Variation. Body ♂ (n = 1) length: 31.25 mm, width: 11.00 mm, length/width ratio: 2.84; ♀♀ (n = 18) length: (26.50)29.25–35.00 mm, width: (9.50) 10.50–12.75 mm, length/width ratio: (2.66)2.71–2.85. Medial impressions in some specimens more impressed thus medial line looks elevated. Pronotum a variable tone of green but mostly with more or less distinct bluish tint. Principal impressions variable but always with more or less deeply impressed furrow. Two specimens have tarsi brown except for metallic claws. Remaining 17 studied specimens have last tarsomere metallic green. Aedeagus ( Fig. 62 ) (n = 1) length: 8.11 mm, width 1.63 mm, length/width ratio: 4.97. Apex of parameres rounded. Penis elongate, subparallel-sided.

Differential diagnosis. The nominotypical subspecies can be easily distinguished from others by usually metallic coloured ultimate tarsomere (brown in other subspecies) and has smoothest elytra with sparsest punctation of all the subspecies. For additional characters see Table 1 .

Chrysodema (G.) walkeri can be distinguished from other species of Gelaeus by dichromatic dorsal side of body with green pronotum and blue elytra. Similar colour combination is also present in C. (G.) cyanicollis (differing in uniformly metallic green tarsi) and in C. (G.) sara sp. nov. (differing in smooth surface of elytra without impressed rows or elevated intervals).

Distribution. Indonesia: Maluku Prov.: Damar Is.

Remarks. WATERHOUSE (1892) did not state how many specimens he had at his disposal when describing C. (G.) walkeri . We have located two specimens in BMNH with identical locality label ‘Damma I. / 92—20’, however, only one is labelled as type and has the original label handwritten by C. O. Waterhouse. The latter specimen perfectly matches the original description and has identical size to that of mentioned in the original description hence we designate this specimen a lectotype in order to fix identity of this taxon. We do not consider the other specimen as part of the type series as it has larger size than mentioned in the original description and the specimen does not bear any proof that it was studied by Waterhouse when describing C. (G.) walkeri . It is listed among Additional material examined with supplemented data according to the BMNH collection register. The number ‘[18]92—20’ refers to the following entry in the register: ‘458 coleoptera, various localities presented by the Lords of the Admiralty: collected by Mr J. J. Walker during the cruise of HMS ‘Penguin’; [Nos.] 5762–5988 (266 coleoptera) Damma Island Nov[ember] 6–11 [18]91’ (M. Barclay, pers. comm.).

AKIYAMA & OHMOMO (2000: plate 42) illustrated three forms of C. (G.) walkeri , however, they belong to C. (G.) walkeri nigriventris subsp. nov. (Figs 445-1, 445-2) and C. (G.) sara sp. nov. (Fig. 445-3).

Figures

Figs 24–29. 24–26 – Chrysodema (Gelaeus) walkeri walkeri (Waterhouse, 1892) (lectotype ♀, 31.75 mm). 25–29 – C. (G.) walkeri horaki subsp. nov. (holotype ♂, 26.00 mm). 24, 27 – dorsal view; 25 28 – ventral view; 26, 29 – lateral view.

Figs 56–71. Parameres and penis. 56 – Chrysodema (Gelaeus) florensis Lansberge, 1880 (lectotype); 57 – C. (G.) foraminifera Lansberge, 1879 (Timor Is., RMNH); 58 – C. (G.) iris iris (Kerremans, 1898) (lectotype); 59 – C. (G.) iris moluensis Novak, 2010 (topotype); 60 – C. (G.) oborili oborili sp. nov.(holotype); 61 – C. (G.) oborili laratensis subsp. nov. (holotype); 62 – C. (G.) walkeri walkeri (Waterhouse, 1892) (Damar Is.); 63 – C. (G.) walkeri horaki subsp. nov. (holotype); 64 – C. (G.) walkeri rejzeki subsp. nov. (paratype); 65 – C. (G.) walkeri nigriventris subsp. nov.(holotype); 66 – C. (G.) walkeri bilyi subsp.nov.(holotype); 67 – C. (G.) walkeri kubani subsp. nov. (holotype); 68 – C. (G.) sara sp. nov. (holotype); 69 – C. (G.) cupriventris (Kerremans, 1898) (Wetar Is., DFPC); 70 – C. (G.) katka sp. nov. (holotype); 71 – C. (G.) wetteriana (Théry, 1935) (lectotype).

Figs 1–5. Morphological details of the subgenus Gelaeus Waterhouse, 1905. 1–2 – dorsal and lateral aspects of pronotum of Chrysodema (G.) walkeri bilyi subsp. nov. (holotype); a – basal impression, b – principal impression, c – medial impression, d – lateral impression. 3–5 – abdominal ventrites II–III. 3 – C. (G.) cupriventris (Kerremans, 1898), 4 – C. (G.) walkeri nigriventris subsp. nov., 5 – C. (G.) florensis Lansberge, 1880.

Tables

Table 1. Diagnostic characters of subspecies of Chrysodema (Gelaeus) walkeri (Waterhouse, 1892).

	C. (G.) walkeri walkeri	C. (G.) walkeri bilyi	C. (G.) walkeri horaki	C. (G.) walkeri kubani	C. (G.) walkeri nigriventris	C. (G.) walkeri rejzeki
colouration of last tarsomere	usually metallic; rarely brown	brown	brown	brown	brown	brown
colouration of elytra	deep blue- violet, apex with purple reflections	dark blue, apex with purple reflections	uniformly dark blue	dark bluish-black, apex with or without purple reflections	dark viridian with purple reflections on apical half	dark blue including apex, lateral sides and suture greenish
brightness of ventral side of body	strongly shiny	dull	strongly shiny	dull	dull	strongly shiny
lateral impressions of elytra	absent	absent	sometimes slightly indicated	absent	absent	obvious and deep
elytra apically	smooth; sparsely punctate; intervals not elevated	somewhat irregular; moderately densely punctate; intervals elevated	rugose; very densely punctate; intervals elevated	rugose; densely punctate; intervals elevated	somewhat irregular; moderately densely punctate; intervals elevated	somewhat irregular; moderately densely punctate; intervals elevated
punctation in rows V–VIII	regular	regular	irregular	partly irregular	irregular	partly irregular
intervals among rows V–VIII	not elevated, 5–6× as broad as puncture diameter	slightly elevated, 1–2× as broad as puncture diameter	slightly elevated, as wide or narrower than puncture diameter	slightly elevated, 1–2× as broad as puncture diameter	slightly elevated, 2–3× as broad as puncture diameter	slightly elevated, 2–3× as broad as puncture diameter
apices of parameres	obliquely truncate	obliquely truncate	horizontally truncate	obliquely truncate	rounded	horizontally truncate
distribution	Damar Island	Selaru Island	Leti Island	Romang Island	Moa Island	Alor Island