Metallactus pollens Suffrian 1866
Creators: name: Sassi, Davide
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Chrysomelidae
Metallactus
Metallactus pollens

description: Metallactus pollens Suffrian, 1866
(Figs 12; 33)
Metallactus pollens Suffrian, 1866: 356; Clavareau, 1913: 93; Blackwelder, 1946: 641.
Type material. Three syntypes were available for this study: a female in MNHUB, a male and a specimen of undetermined gender in BNHM. The typification has been made as follows. LECTOTYPE: ♂, glued, abdomen glued on the same label bearing the specimen, aedeagus and part of two legs glued on a separate label, // [unreadable initials, small white label, handwritten] // “Baly coll.” [white label, printed] // “Type Suffr Coll Baly” [white label, handwritten] // “ Metallactus pollens Suffr Brazil ” [recto], “Type Suffr” [verso] [white label, handwritten] // “ Syntype ”[white label with blue border, printed] // “ Metallactus pollens Suffrian, 1866 LECTOTYPUS D. Sassi des.” [red label, printed] // (BNHM). PARALECTOTYPES: 1 ex. gender undetermined, pinned, heavily damaged: abdomen, left elytron, antennae and most part of legs missing // “E Coll Laferté” [white label, printed] // “67.56” [white label, printed] // “Corrientes” [white label, handwritten] // “ Metallactus pollens ” [white label, handwritten] // “ Syntypus ”[white with blue border, printed] // (BMNH); 1♀, // “23981” [white label, printed] // “ pollens Suffr. * Brasil. Sellow” [blue label, handwritten] //The label information match the registration data from the old catalogue of the MNHUB (“23981 Metallactus pollens Suffr. * 1. Brasil., Sello”). (MNHUB). Both paralectotypes bearing: // “ Metallactus pollens Suffrian, 1866 PARALECTOTYPUS D. Sassi des.”[red label, printed] //.
Type locality. Brazil.
Further material examined. BRAZIL: São Paulo Campinas (1, MNHUB); Rio Negro (1, DSPC); Rio Grande do Sul Puerto Alegre Hensel (3, MNHUB); Santa Catarina Florianopolis 6.V.1981 ex Baccharis spicata C. Garcia (6, BMNH); Vacaria, Rio Grande do Sul 12.I.1974 McFayden (1, USNMNH); Rio Grande do Sul Pelotus [Pelotas] C. Biezanko (1, MNHUB); “ Brasil ” (1, NHMP). ARGENTINA: Buenos Aires 2.I.1982 & 16.III.1982 L. Peña (29, FSCA); Buenos Aires Ezeiza XII.1986 L. Peña (6, FSCA); Buenos Aires 3 km N Laguna del Monte 31.I.1989 C. W. & L. W. O'Brien & G. J. Wibmer (1, BYU); Chaco de Santa-Fé Las Garzas Bords du Rio Las Garzas 25 kil. a l'O d'Ocampo E.R. Wagner 1903 (1, MNHN); Gran Chaco Rio Tapenago [Tapenagà] (2, NHMP); Corrientes Alvear I.1991 (2, DSPC); Entre Rios Liebig XI.1987 & XI.1990 (8, DSPC); Entre Rios XII.1993 Peña (3, MSNM); Chubut Pt Piramide 15.I.1994 on Baccharis divaricata D. Gandolfo (2, TAMU); Santiago del Estero Rio Salado (3, NHMP); Santiago del Estero Rio Salado Averias E.R. Wagner 1909 Avril & Décembre (11, MNHN); Santiago del Estero E.R. Wagner 1936 (1, MNHN); Santiago del Estero Rio Dulce (1, NHMP); Cordoba (1, MNHUB); La Pampa, Conhello I.1943 Hepper (5, USNMNH). URUGUAY: Dept. Canelones Progreso 2-3.I.2010 S. Krejĉik (2, JPPC); Canelones, 19 Km NE Canelones R 63 7.II.1989 C. W. & L. O'Brien & G. J. Wibmer (4, BYU); Colonia San Pedro Ruta 21 ca Km 186.5 10.II.2014 G. J. Wibmer (7, BYU); Montevideo Sivori (18, MSNG); Montevideo 18.II.1942 H. L. Parker (4, USNMNH); Montevideo on Baccharis spicata Parker (1, USNMNH); Maldonado R 13 22 km NE Aiguá 5.II.1989 C. W. & L. W. O'Brien (2, BYU); Maldonado 28 km NE San Carlos 4.II.1989 C. W. & L. W. O'Brien & G. J. Wibmer (9, BYU); Maldonado 1 km E San Carlos 7.II.1989 C. & L. O'Brien & G. Wibmer (1, BYU); Rocha 10 km SW Aguas Dulces R 10 4.II.1989 C. W. & L. W. O'Brien (8, BYU); Rocha 3 km N La Coronilla 6.II.1989 C. W. & L. W. O'Brien & G. J. Wibmer (1, BYU); Rocha Laguna Negra 6.II.1989 C. W. & L. W. O'Brien & G. J. Wibmer (4, BYU).
Distribution. Argentina, Brazil, Uruguay. New to Uruguay.
Diagnosis. A Metallactus of large size. The species belongs to the group with subconical pronotal outline and legs partly yellow. This group comprises also M. patagonicus, M. rileyi, M. dodecastictus and M. bezoar. M. pollens differs from the related species in having antennae particularly developed in males (Fig. 12n). That was underlined by Suffrian (1866) himself (“in male antennae as long as the body”). The pronotal black color pattern is also peculiar, being almost constantly arranged in a M-shaped median stripe. In M. ridley the black pattern on pronotum might also be seen as M-shaped, but in this last species the inner part of black patch tends to reach the pronotal anterior margin, so that the outline of the black patch is rather oblique, which does not occur in M. pollens. Besides, in M. pollens the aedeagal tube is stockier than in the other species, with a slightly enlarged apex (in ventral view). Besides, the colour of aedeagus tends to be yellow, while being brownish in the most similar species.
Description of male. Habitus in Fig. 12 a–b (LT). BL = 5.4–6.4 mm, BW = 3.1–3.6 mm, PL = 1.9–2.2 mm, PW = 2.7–3.3 mm. Interocular distance 11.2–13.4% of BL.
Head yellow, vertex and upper part of frons black. Antennal insertion and ocular rim more or less darkened. Mid-cranial suture brownish. Labrum blackish to brownish with lighter lower rim. Surface dull with scattered shallow punctures, denser on clypeus and close to inner ocular rims. Mid-cranial suture apparent. Setosity sparse, often few scattered curly whitish setae more apparent on inner ocular rim, clypeus and labrum. Antennae (Fig. 12n) characteristically lengthened, with first five antennomeres brownish, the subsequent totally darkened, dull and more diffusedly setose.
Pronotum yellow with a transverse black stripe not reaching margins, M-shaped, often abruptly and narrowly constricted on median line. Pronotal surface subconical in shape with lateral margins narrow, almost regularly arcuate and maximum width behind half of length. Posterolateral impressions almost obliterated, so that posterior margin faintly swollen on sides. Surface moderately lustrous with scattered, fairly impressed punctation, sparser on posterior middle part of disc.
Scutellum black, moderately raised, subsquared with truncated apex and surface quite strongly punctured with scattered rather long whitish setae.
Elytra yellow with black pattern consisting of three pairs of roughly rounded spots. Outer spot of anterior pair slightly lengthened, covering humerus and generally reaching anterior margin. Outer spot of median pair slightly transverse, extending to lateral margin. Spots of anterior and median pairs sometimes fused together to form irregular transverse bands. Spots of posterior pair small, rounded, rather constant in size and shape. Posterior half of lateral margin and suture narrowly black. Parallel-sided, base and middle equally wide. Surface dull with shallow punctation quite dense on anterior half. Almost regular striae apparent only on posterior half but almost obliterated on apical clivus. Intervals flat.
Surface of pygidium completely yellow, smooth, covered with sparse moderately impressed punctures and pale setae.
Inferior parts black with external part of hypomera and lateral sides of abdominal sternites yellow. All ventral surface covered by scattered whitish rather long setae, quite regularly distributed. Punctuation regularly arranged and shallow, coarser on hypomera. Prosternal process longitudinally sunken with apex rounded to roughly pointed and surface covered with long dense pale setae. Legs yellow with tarsi, part of fore tibiae and anterior surface of fore femora, apex of mid and hind tibiae black.
Fifth abdominal ventrite with rather shallow, smooth, bald, impunctate median depression and posterior margin fairly notched. Median lobe of aedeagus (Fig. 12 c–e) intensely yellow, cylindrical, stout, with apex triangular, short, rather blunt, weakly bent ventrally. Hairy dents shallow but apparent, quite coarsely punctured, bearing short, scattered whitish setae. Ventral aedeagal profile perceptibly swollen in lateral view.
Endophallus (Fig. 12 f–g) with sclerite I well sclerotized, with denticle well developed, robust, blunt, sometimes slightly bent upwards. Dorsal spicule strongly reduced, barely distinguishable. Sclerite II long, fairly bent near half of length to almost straight. Sclerite III rather oblique, poorly projecting upwards, with arch slender and a long tapered straight apex. Branches of sclerite IV slightly longer than sclerite III in the folded up structure, robust, with rounded, symmetrical apex and surface poorly microsculptured to almost smooth.
Female. BL = 6.9–7.3 mm, BW = 3.8–4.3 mm, PL = 2.1–2.4 mm, PW = 3.3–3.7 mm. Interocular distance 15.3–16.4% of BL. Antennae not particularly lengthened. remarkably shorter than in males in proportion to BL.
Fifth abdominal ventrite in females with rather deep, almost circular pit. Spermatheca (Fig. 12h) with upper and lower branches of vasculum relatively thin. Upper branch fairly thinned toward apex which is sharp and slightly to fairly bent downwards. Duct tightly coiled in proximal and median part, coils gradually loosened in the last section. Insertion on bursa copulatrix lengthened and pear-shaped, fairly twisted. Rectal apparatus (Fig. 12 km) with dorsal sclerites rather slender, moderately tapered towards median line, with large, apparent apodemes, barely pigmented on distal rim, bent upwards and leaning against rectum. Ventral sclerite large, ribbon-like, tapered on sides, almost evenly pigmented, with apodemes rather large, fairly protruding, crenulate on margin.
Available biological data. Biology is unknown, some label data of specimens coming from Chubut (Argentina), Florianopolis (Brazil) and Montevideo (Uruguay) point to Baccharis divaricata Hauman and B. spicata (Lam.) Baill. as host plants.
description: Published as part of Sassi, Davide, 2018, Revision of the Metallactus kollari species-group with a new diagnosis of the genus (Coleoptera: Chrysomelidae: Cryptocephalinae), pp. 57-110 in Zootaxa 4413 (1) on pages 88-91, DOI: 10.11646/zootaxa.4413.1.2, http://zenodo.org/record/3066636