Metallactus bellatrix, Sassi, 2018

Sassi, Davide, 2018, Revision of the Metallactus kollari species-group with a new diagnosis of the genus (Coleoptera: Chrysomelidae: Cryptocephalinae), Zootaxa 4413 (1), pp. 57-110 : 94

Metallactus bellatrix sp. nov.

( Figs 14 ; 23 )

Etymology. Bellatrix is latin for “female warrior”, stressing the fact that only females were available for the study. The word bellatrix is intended here as a noun in the nominative singular, standing in apposition to the generic name (articles 11.9.1.2 and 31.2.1 of I.C.Z.N., 4th edition).

Type material. HOLOTYPE: ♀, // “ Brasil Santa Catharina Corupá II.1949 col. A. Maller” [white label, handwritten] // “F. Monrós collection 1959” [white label, printed] // “ Metallactus bellatrix sp. nov. HOLOTYPUS D. Sassi des.” [red label, printed] // ( USNMNH). PARATYPES: 1 ♀, same data of the holotype, provided with additional label: // “ Metallactus bellatrix sp. nov. PARATYPUS D. Sassi des.” [red label, printed] // ( USNMNH).

Type locality. Corupá (Santa Catarina, Brazil) .

Distribution. Brazil.

Diagnosis. A Metallactus of medium size, characterized by a fairly reduced black dorsal pattern. At first glance, this species looks very similar to M. languidus , but it can be distinguished by the stronger and closer pronotal and elytral punctation and the lack of impressions on sides of pronotum. Pronotal shape is also very distinctive in having lateral margin distinctly larger than in all the other species of the group, with the exception of M. spilotus which is easily distinguishable by the very different general shape and dorsal colour pattern. Light colored specimens of M. corruptus can have a quite similar look, but they are easily diagnosed by the broadly yellow ventral side. The species looks somehow similar to M. verrinus Suffrian, 1866 which has not been included in M. kollari group because of the very different aedeagal shape. The latter is also different in having a much weaker dorsal puncturation, the pronotum slightly vaulted with narrower margins, lighter ventral coloration.

Description of female (male unknown). Habitus in Fig. 14 a–b (HT). BL = 5.6–5.8 mm, BW = 3.4 mm, PL = 1.7–1.8 mm, PW = 3.0– 3.1 mm. Interocular distance 11.7–13.5% of BL.

Head black with a pair of faint yellow oblique “eyebrows” above the upper rim of eyes. Surface matt with scattered punctures fairly impressed on frons and clypeus, slightly smaller on vertex. Mid-cranial suture extended from mid of frons to mid part of vertex. Setosity sparse, limited to clypeus and labrum and near inner rim of eyes. Proximal antennomeres black. Four apical antennomeres missing in both the studied specimens.

Pronotum yellow with two minute rounded black spots on disc. Pronotal shape trapezoidal, rather transversally arranged. Lateral margins large with maximum width behind half of length. Posterolateral impressions almost obliterated, so that posterior margin barely swollen toward sides. Surface moderately lustrous with scattered, fairly impressed punctation, almost evenly dense on sides and disc.

Scutellum completely black, moderately raised, with truncated apex and surface moderately lustrous, smooth, bald, with only few scattered tiny punctures close to lateral margins.

Elytra yellow with black pattern consisting of three tiny black rounded spots, first one on humerous, second one just behind half, closer to suture than to lateral margin, third one near apex. Suture narrowly black. Surface dull with rather strong and dense punctation in particular in anterior half. Remnants of striae only on sides and apical clivus. Intervals flat.

Pygidium completely yellow with surface smooth, evenly and minutely punctate with sparse pale setae.

Inferior parts black with external part of hypomera very narrowly and lateral sides of abdominal sternites widely yellow. All ventral surface covered by scattered whitish setae, quite regularly distributed, somewhat longer on metathorax. Punctuation evenly arranged, coarser on hypomera and sides of mesothorax, minute on abdominal sternites. Prosternal process longitudinally grooved, with rounded to roughly pointed and slightly raised apex and surface covered with long dense pale setae. Legs totally black, or tibiae partly lighter.

Fifth abdominal ventrite with rather deep, rounded pit. Bottom of pit matt, impunctate but covered by tiny wrinkles. Spermatheca ( Fig. 14h ) with lower branch of vasculum slenderer than the upper one, slightly bent backwards. Upper branch darkened, swollen on its middle part and quite abruptly tapered in a sharp, bent downward tip. Ampulla pigmented, squared, rather small, shifted on dorsal side of vasculum. Duct regularly coiled, uniform in thickness, slender. Coils only slightly loosened in the last section. Insertion on bursa copulatrix almost straight, weakly swollen and weakly pigmented. Rectal apparatus ( Fig. 14 k–m) with dorsal sclerites laterally not projected beyond rectus, abruptly tapered towards median line, with apodemes large, hyaline, bent upwards and leaning against rectum. Ventral sclerite quite deep, almost evenly pigmented. Apodemes of ventral sclerite moderately developed, slightly projecting laterally.

Figures

FIGURES 13–14. M. rileyi (13), M. bellatrix (14). 13a–b: habitus; 13c–e: median lobe of aedeagus in ventral (c), dorsal (d) and lateral (e) view [1.0 mm]; 13f: sclerites II–III–IV of endophallus [0.6 mm]; 13g: sclerite I and dorsal spicule of endophallus [0.9 mm]; 13h: spermatheca [0.8 mm]; 13k–m: rectal apparatus in dorsal (k) and ventral (m) view [0.9 mm]; 13n: antenna [1.5 mm]. 14a–b: habitus; 14h: spermatheca [0.7 mm]; 14k–m: rectal apparatus in dorsal (k) and ventral (m) view [0.9 mm]. 13a–b: holotype; 14a–b: holotype. Square brackets: length of scale segment.

FIGURES 20–28. Distribution maps for Metallactus kollari species-group. M. affinis (20); M. albifrons (21); M. albipes (22); M. bellatrix (23); M. bezoar (24); M. corruptus (25); M. dodecastictus (26); M. guarani (27); M. kollari (28). Grey squares: localities reported in a generic way.