Metallactus luniger Suffrian, 1866

Sassi, Davide, 2019, Revision of the Metallactus hamifer species-group (Coleoptera: Chrysomelidae: Cryptocephalinae), Zootaxa 4657 (2), pp. 201-245 : 226-228

Metallactus luniger Suffrian, 1866

( Figs 10 ; 27 )

Metallactus luniger Suffrian, 1866: 327 ; Clavareau, 1913: 93 (catalogue); Blackwelder, 1946: 641 (catalogue); Agrain et al., 2017: 59 (annotated checklist).

Types. Suffrian did not mention the number of specimens under study but he reported several original type depositories (“Hamburg, Thorey, Dohrn, MNHUB, Riehl, Baly, Clark, Saunders”). Afterwards, most of those collections were incorporated in MNHUB and BMNH. At present, six syntypes are housed in MNHUB, it is very likely that they all belong to the same series, even though only one specimen is labelled. The number of specimens and the label information match the registration data from the old catalogue of the MNHUB (“23964 luniger Suffr. 6 [specs.], Brasil, Sello."). One syntype was traced in MLUH. Three syntypes are stored in BMNH. The type designation was made as follows, in order to stabilize the epithet. LECTOTYPE (by present designation): ♂, glued, aedeagus glued on the same card bearing the specimen, abdomen glued on a separate card // “pictus N. Bras. C. Sell. [blue label, handwritten] // “ luniger Suffr. *” [white label, handwritten] // “23964” [white label, printed] // “ Metallactus luniger Suffrian, 1866 LECTOTYPUS D. Sassi des.” [red label, printed] // (MNHUB). PARALECTOTYPES: 2♂ 3♀ [none of them bear any label, but they certainly belong to the same series of the lectotype] (MNHUB); 1 spec., undetermined sex // “luniger m. Montevideo.” [blue label, handwritten] // “20361” [white label, handwritten] // “MLU Halle WB Zoologie S.-Nr. 7/1/6” [white label, printed, partly handwritten] // (MLUH); 1♂ // “ ♂ ” [white label, handwritten] // “Type Suffrian Coll. Baly” [white label, handwritten] // “Baly Coll.” [white label, printed] // “ Metallactus luniger Suffr Brazil ” [recto], “Suff types ♂ ♀ ” [verso] [white label, handwritten] // (BMNH); 1♀ // [blank pale blue label] // “ ♀ ” [white label, handwritten] // “Type Suffr Coll. Baly” [white label, handwritten] // “Baly Coll.” [white label, printed] // (BMNH); 1♂ // “E. Coll. Chevt “ [white label, printed] // “a D. Suffrian determinat.” [white label, printed] // [unreadable phrase, white label, handwritten] // “ albopictus Buquet ” [white label, handwritten] // “67.56” [white label, printed] // (BMNH). All paratypes labelled: “ Metallactus luniger Suffrian, 1866 PARALECTOTYPUS D. Sassi des.” [red label, printed].

Type locality. Brazil .

Further material examined. ARGENTINA: Misiones Iguazu 2-25.I.1988 J. Foerster (28, NHMB) ; Misiones Iguazu 18.II.1988 R. Foerster (4, ZSM) ; Misiones Iguazu II.1986 & 16.XI.1986 leg. R. Foerster (2, MSPC & MNHUB) ; Misiones Iguazu I.1987 Luis Pena coll. (4, FSCA) ; Misiones Puerto Iguazú 24.XI.1989 J. Foerster (8, NHMB) ; Misiones Pto Iguazú II.1988 & XI.1991 (2, DSPC & MSNM) ; Misiones Puerto Iguazú 27.II.1989 (1, HNHMB) ; Misiones El Dorado XI.1986 leg. Peña (1, MNHUB) ; Sta Anna leg. Černovitov (1, NHMP) ; Entre Ríos XII.1998 coll. Liebig (1, MSPC) . BRAZIL: Itapiranga IX 1953 & X.1954 & XII 1954 (35, NHMB) ; Santa Catarina XI.1953 (1, NHMB) ; Santa Catarina 1.I.1990 Rautenstrauch leg. (2, MMPC) ; Santa Catarina Rio Vermelho XI.1948 A. Maller coll. (3, AMNH) ; Santa Catarina Lages Hochland Fruhstorfer (1, NHMB) ; Santa Catarina Hansa Humboldt Reitter (1, USNMNH) ; Santa Catarina Hansa Humboldt Ant. Maller 1933 (1, MNHN) ; Santa Catarina 2 mi. N Sta Cecélia 2.III.1980 D. B. Thomas coll. (1, ERPC) ; N. Teutonia Santa Catarina 23.X.1946 & XII. 1950 & XI.1955 & XII 1955 Plaumann (11, NHMB) ; Nova Teutonia 27°11'S 52°23'W 3-500m Fritz Plaumann (1, NHMB) ; Mafra 800m (5, MNHN) ; Castro , Paranà (1, BMNH) ; Paranà Curitiba 13.I.1969 C. W. & L. B. O’Brien Araucaria Forest (1, BYU) ; “ Brasil ” (2, MNHUB) . PARAGUAY: Paraguay Jacoby 2 nd coll. (1, USNMNH) ; Paraguay leg. C. Fiebrig (1, MNHUB) ; Col. Independencia 11.XI.951 coll. Förster (2, NHMB); Guayra 300m (2, NHMB, ZSM) ; Villarica 13.XI.49 leg. F. Schade (1, ZSM) ; Dpt. Caaguazú Paso Yobul 280m (1, NHMB) ; Itapua Pastoreo 3.I.1972 (1, FSCA) ; Sapucay WT Foster coll. (1, USNMNH); Sapucay W. Foster 1903-138 (2, BMNH) ; San Bernardino K. Fiebrig coll. (7, US- NMNH); Jesús y Tr. Sedý (1, NHMP) ; Asuncion 3.XI.1904 Vezényi (1, HNHMB) ; Asuncion Anisitis (1, HNHMB) ; Asuncion Revoil 1891 (2, MNHN) ; Paraguary Jaguaron Santa Clara Gosset 1900 (1, MNHN) ; Rio Monday G. Boggiani XII. 98 (3, MSNG) .

Distribution. Argentina, Brazil, Paraguay, Uruguay. New to Paraguay.

Diagnosis. A Metallactus of medium-large size. It resembles M. hamifer as regards the pronotal color pattern, but the light parts are more extended. From M. hamifer it is also distinguished by the shape of aedeagal apex, which is blunter. However, the most similar species is M. crassicollis from which it is distinguished by the following characters: larger size, more massive outline, pronotal sides more arcuate with generally wider margin, more rounded periscutellar yellow spots and, above all, for the legs completely black.

Description of male. Habitus in Fig. 10 a–b (PLT). BL = 4.4–5.3 mm, BW = 2.8–3.3 mm, PL = 1.4–1.8 mm, PW = 2.4–2.9 mm. Interocular distance 11.3–11.4% of BL.

Head black with somehow pentagonal, slightly raised yellow spot between upper rim of eyes, extended to lower section of vertex. A second strictly elliptical, longitudinally arranged yellow patch across frontoclypeal area. Labrum brownish. Vertex subopaque, bare with very few, scattered punctures. Frontoclypeal area with shallow but coarse punctation and relatively reduced setosity, concentrated on black sections. Mid-cranial suture long, slender, well impressed. Antennae blackish, only antennomeres 2-5 slightly lighter. First five antennomeres yellowish, sublucid, the subsequent ones totally darkened, dull, more flattened and more diffusedly setose.

Pronotum black with two large C-shaped yellow bands along lateral margins, projecting upwards along the outer third of anterior and posterior margins as well. A broad yellow longitudinal stripe extending in middle of disc from anterior to posterior margin. Pronotal outline elliptical. Lateral margins relatively large, visible from above for almost the whole length, regularly curved with maximum width just behind half length. Posterolateral impressions shallow but generally perceptible so that posterior margin appears slightly thickened and salient just behind them. Surface rather flat, moderately shiny with scattered well impressed punctation.

Scutellum black, moderately shiny, distinctly raised, almost bare and punctuation very fine and scattered. Outline relatively narrow and lengthened, apex truncated in a straight line.

Elytron surface black with yellow pattern as follows. A rounded spot just beside scutellum; a large, transversal stripe in middle of disc, reaching lateral margin and extended along its anterior half, epipleuron and outer third of anterior margin; a further large transversal stripe just before apical clivus; a rounded spot on apex. Elytral outline parallel-sided, rather squat, weakly flattened on posterior part of disc. Postscutellar area slightly raised. Humeral callus prominent, impunctate. Surface moderately shiny with rather fine but well impressed punctures arranged in irregular rows. Intervals flat to faintly raised sporadically.

Pygidium black with two vaguely triangular yellow spots on sides, smooth, matt, covered with sparse very shallow punctures and scattered whitish setae.

Inferior parts of thorax totally black. Hypomera and mesoepisterna almost bare with coarse punctation, mesoepimera bare and smooth to mostly rugose. Metaepisterna and metasternum with coarse punctation as well and sparse setae. Prosternal process relatively large, coarsely punctured with long setae and raised, short, blunt triangular apex. Abdominal ventrites black with broad yellow border, shallowly and sparsely punctured, with rather long, recumbent setae. Legs totally black.

Median depression on fifth abdominal ventrite rather deep, large, with semiopaque, impunctate bottom. Posterior margin of fifth abdominal ventrite weakly notched. Median lobe of aedeagus ( Fig. 10 c-e) cylindrical with apex scarcely separated from the rest of aedeagus, short, blunt. In lateral view apex faintly bent ventrally. Hairy dents shallowly impressed, scarcely delimited, bearing rather long, curly setae. Aedeagal ventral surface not swollen in lateral view, devoid of particular structures. Endophallus ( Fig. 10 f–g) with sclerite I rather small with denticle moderately developed, rather pointed, upwardly directed, slightly sticking out laterally. Dorsal spicule moderately developed, thorn-like, distinctly pigmented. Sclerite II long, regularly bent near base, gradually tapered towards apex.Arch of sclerite III low, curved, so poorly projecting upwards. Apex of sclerite III slightly curved upwards and perceptibly expanded on its proximal half, so that the sclerite looks like the head of a grebe. Branches of sclerite IV about as high as to slightly shorther than sclerite III in the folded-up structure, vaguely bent, poorly expanded distally, with rounded, slightly asymmetrical, microdenticulate apex and surface perceptibly sculptured, mainly consisting of tiny wrinkles.

Female. BL = 5.5–6.6 mm, BW = 3.4–4.1 mm, PL = 1.6–2.1 mm, PW = 3.0– 3.7 mm. Interocular distance 12.7–13.6% of BL.

Fifth abdominal ventrite in females with deep, transverse pit whose bottom is bald, matt, impunctate but covered with tiny wrinkles. Vasculum of spermatheca ( Fig. 10h ) relatively slender and quite strongly pigmented with slightly bent proximal branch and quite long distal branch regularly tapered in short pointed apex. Ampulla not pigmented, with only sperm gland insertion slightly shifted on dorsal side of vasculum. Duct insertion and sperm gland insertion clearly distinct. Duct uniform in size, coiled, coils rather loose and rather irregularly arranged. Distal not coiled portion of duct long and straight. Insertion on bursa copulatrix lengthened and slightly swollen, moderately pigmented.

Figures

FIGURES 10–11. M. luniger (10), M. madefactus (11). 10a–b: habitus; 10c–e: median lobe of aedeagus in ventral (c), dorsal (d) and lateral (e) view [0.9 mm]; 10f: sclerite I and dorsal spicule of endophallus [0.6 mm]; 10g: sclerites II–III–IV of endophallus [0.5 mm]; 10h: spermatheca [0.6 mm]; 10k: antenna [2.0 mm]. 11a–b: habitus; 11c: spermatheca [0.4 mm]; 11d: antenna [1.9 mm]. 10a–b: paralectotype (BMNH); 11a–b: paratype (DSPC). scI–IV: sclerites I–IV of endophallus; ds: dorsal spicule. Square brackets: length of scale segment.

FIGURES 27–34. Distribution maps for Metallactus hamifer species-group. M. luniger (27); M. madefactus (28); M. octoguttatus (29); M. pollinctor (30); M. praetorius (31); M. sekerkai (32); M. tarsalis (33); M. viator (34). Grey squares: localities reported in a generic way.