Metallactus madefactus Sassi 2019, sp. nov.
Creators: name: Sassi, Davide
Publisher: name: Zenodo
Year: 2019
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Chrysomelidae
Metallactus
Metallactus madefactus

description: Metallactus madefactus sp. nov.
(Figs 11; 28)
Types. HOLOTYPUS: 1♀, glued, abdomen and genitalia glued on a separate card // “ Nova Teutonia S. Catarina Bras F. Plumann [sic] XI.1955 ” [recto, printed] “ 19.11.55 ” [verso, handwritten] [white label] // “ Metallactus madefactus sp. nov. HOLOTYPUS D. Sassi des.” [red label, printed] // (NHMB). PARATYPES: 1♀ // “N. Teutonia, Bras. Sta Catarina Plaumann XI.1955 ” [white label, printed] // “ 10.11.55 ” [white label, handwritten] // (DSPC); 1♀ // “ Brasilien; Nova Teutonia, 27°11 B. 52°23 L., 300-500 m Fritz Plaumann ” [white label, printed] // (NHMB). Both paratypes are labelled: // “ Metallactus madefactus sp. nov. PARATYPUS D. Sassi des.” [red label, printed] //.
Etymology. Latin past participe “madefactus” means “soaked”, “steeped”.
Type locality. Seara (formerly Nova Teutônia) (Santa Catarina, Brazil).
Distribution. Brazil.
Diagnosis. A Metallactus of small size belonging to a subgroup of species characterized by a V-shaped yellow spot on rear portion of pronotum, just in front of scutellum. Occasionally such spot is expanded, taking an elliptical shape. The subgroup also comprises M. abditus, M. octoguttatus, M. albopictus. However, in M. madefactus, like in M. albopictus, the pronotal lateral yellow stripe is not so salient along the posterior margin as it can be seen in M. abditus and in M. octoguttatus, so that it recalls an upside-down L rather than a C as in the two latter species. M. albopictus can be distinguished by the stronger dorsal punctation and the vaguely fishhook-like apical yellow spot. Conversely, this spot is splitted in two wavy patches in M. madefactus. Besides, in M. albopictus the lateral margins of pronotum are narrower, in particular along their posterior half, and more regularly arcued.
Description of female (male unknown). Habitus in Fig. 11 a–b (PT). BL = 4.6–4.9 mm, BW = 2.6–2.8 mm, PL = 1.4 mm, PW = 2.2–2.4 mm. Interocular distance 13.0–14.3% of BL.
Head black with a trilobate yellow patch in middle, shaped as follows: two upper lobes, symmetrical, sickle shaped, extending along upper part of inner ocular rim, third one, dumbbell-shaped, extended across frontoclypeal area. Labrum yellow to brownish. Vertex quite dull, bare, with few, scattered punctures. Frontoclypeal area with sparse, pale setae and irregularly distributed punctures. Mid-cranial suture almost obliterated so that surrounding surface flat. Antennae black with antennomeres 1-5 slightly paler, sublucid, the subsequent ones dull and more diffusedly setose.
Pronotum black with lateral margin and outer part of anterior margin covered with a single upside down Lshaped yellow spot; a median bilobed yellow spot close to posterior margin just in front to scutellum; a further narrowly ellyptical median one, yellow as well, extended from anterior part to just beyond middle of disc. Pronotal shape elliptical with lateral margins thin, barely visible from above, regularly curved with maximum width roughly just behind half length. Posterior angle of pronotum sharp and slightly but perceptibly sticking out. Posterolateral impressions shallow, but perceivable, so that posterior margin perceptibly thickened behind it. Surface moderately lustrous with scattered, fairly impressed punctation, slightly sparser and shallower on disc.
Scutellum black, dull, moderately raised, apex truncated in a straight line, basically impunctate.
Elytron black with yellow pattern consisting of one small spot, briefly elliptical, just beside scutellum; a second one, transverse, at middle of disc; a third winding spot on apical clivus, concave toward median line, not reaching suture nor lateral margin: a fourth one, sickle shaped, on apex. A further marginal C-shaped yellow patch along anterior third of lateral margin, extended over outer part of anterior margin and epipleuron, its posterior end bent towards median discal spot. Elytral outline parallel-sided and very weakly flattened on disc. Postscutellar area very weakly raised. Humeral callus prominent, impunctate. Surface moderately shiny with rather coarse punctures rather irregularly arranged across inner part of disc, almost regular rows clearly visible only on posterior half. Intervals slightly raised here and there.
Pygidium yellow with apex and a bilobed patch along the basal margin black, smooth, covered with sparse shallow punctures and whitish setae.
Inferior parts of thorax black, with quite shallow punctation and sparse setae above all on metathorax. Prosternal process coarsely punctured with long setae.Abdominal ventrites black with yellow sides, shallowly and sparsely punctured, with sparse setae. Legs yellow to brownish, often with tibial apex and tarsi infuscate.
Fifth abdominal ventrite in females with quite large and rather deep pit, bare, with minute wrinkles on bottom. Vasculum of spermatheca (Fig. 11c) relatively slender, scarcely pigmented with slightly bent proximal branch faintly swollen at base and rather long, curved distal branch regularly tapered in pointed apex. Ampulla not pigmented, slightly shifted on dorsal side of vasculum. Duct and sperm gland insertions barely distinct. Duct uniform in size, slender, coiled, coils rather thick, regularly arranged. Distal not coiled portion of duct not detectable in the single anatomized female. Insertion on bursa copulatrix slightly twisted and moderately swollen, clearly pigmented.
description: Published as part of Sassi, Davide, 2019, Revision of the Metallactus hamifer species-group (Coleoptera: Chrysomelidae: Cryptocephalinae), pp. 201-245 in Zootaxa 4657 (2) on pages 228-230, DOI: 10.11646/zootaxa.4657.2.1, http://zenodo.org/record/3763876