Amblycerus virens (Jekel, 1855)

Ribeiro-Costa, Cibele Stramare, Vieira, Marcelli Krul, Manfio, Daiara & Kergoat, Gael J., 2014, A remarkable new species group of green seed beetles from genus Amblycerus Thunberg (Coleoptera, Chrysomelidae, Bruchinae), with description of a new Brazilian species, ZooKeys 401, pp. 31-44 : 34-37

Amblycerus virens (Jekel, 1855) Figs 1-6

Spermophagus virens Jekel, 1855: 33 (holotype, type locality: French Guiana; description, distribution); Gemminger and Harold 1873: 3219 (catalog, distribution); Pic 1913: 63. (catalog, distribution).

Amblycerus virens : Blackwelder 1946: 763 (catalog, new combination); Udayagiri and Wadhi 1989: 16 (catalog); Ribeiro-Costa 1998: 633 (citation).

Redescription.

BL: 5.6 mm; BW: 3.84 mm

Integument (Figs 1-4). Body mostly black, mouth parts and antennomeres 1 and 2 brown to yellowish, apical spurs of hind tibiae reddish brown, pygidium and abdomen rufous with golden shine.

Vestiture (Figs 1-4). Pronotum, elytra and thorax covered with greenish setae, abdomen and pygidium with yellowish setae, both not variegated.

Head (Fig. 3). Covered with fine and dense punctures. Frons without frontal carina. Eye finely faceted, moderately prominent laterally. Ocular index: 3.11; ocular sinus: 0.63; postocular lobe 0.33 the eye length. Antenna not reaching anterior margin of hind coxa; moderately serrate from antennomeres 5-10 ( Ribeiro-Costa 1998: 631, Fig. 3); from 5 to11 antennomeres 1.33 wider than long; last antennomere with truncate apex. Frontoclypeal suture indistinct. Clypeus covered with fine and dense punctures except in narrow band on apical portion. Labrum with few fine punctures on basal margin.

Prothorax. Pronotum semicircular; covered with fine and dense punctures, moderately coarse punctures intermixed on lateral areas (Fig. 1). Lateral carina almost reaching the anterior margin of pronotum (Fig. 2). Cervical sulcus absent. Prosternal process not expanded beyond anterior coxae; flat and slightly constricted between coxae.

Mesothorax and metathorax. Scutellum as long as wide; round or unidentate at apex (Fig. 1). Elytron with striae 1 and 10 moderately impressed; 2, 3, 8 and 9 weakly impressed until the third apical region of elytron then only isolated punctures representing striae; 4-7 striae formed only by isolated punctures; 4 and 5 anastomosed before the fusion of 6+7. Interstriae with moderately coarse and sparse punctures. Metaventrite moderately protuberant (Fig. 2) with moderately coarse and sparse punctures; median sulcus one-half as long as metaventrite. Metepisternum with moderately coarse and sparse punctures; metepisternal sulcus forming straight angle, with transverse axis straight and not reaching lateral margin of metepisternum. Mid coxae lower than anterior coxae, in lateral view (Fig. 2). Hind femur about 2.5 times longer than wide. Hind coxae with moderately coarse and sparse punctures. Hind tibia lateral spur about 1.5 times the length of median spur; 1-tarsomere about 1.5 the length of the lateral spur and 2.5 times the median spur.

Abdomen (Fig. 4). Ventrites with moderately coarse and dense punctures; last ventrite as long as 4-ventrite. Pygidium one-third covered by the elytra; apical margin rounded, with moderately coarse and dense punctures.

Male genitalia. Median lobe (Fig. 5) about 4.15 times its widest at apical region; ventral valve with lateral margins straight; dorsal valve with lateral margins concave and acuminate apex. Internal sac (Fig. 5) in the apical region without anterior sclerites; a pair of tuberculate median sclerites; a pair of ovoid and denticulate posterior sclerites. Median region with a pair of sinuous blade sclerites, sinuous at base and denticulate at apex; a long wishbone sclerite, about two times longer than the blade sclerites, curved and denticulate at apex and with stems moderately separated. Basal region of sac without sclerites; apical and median regions with several spines. Tegmen (Fig. 6) slightly emarginated between lateral lobes expanded.

Type material.

Syntype studied by the first author and deposited in BMNH, sex undetermined, labels: 'Type H. T.' [round, white with red margin]; ‘Cayenna’ [white]; 'ex. Mus. W. W. S.' [white]; ‘Type’ [white]; ‘53272’ [white]; 'Fry Coll. 1905. 100' [white]; ' Spermophagus virens Dj. n. sp. Cayen’; 'SYNTYPE/Spermophagus/virens Jekel, 1855/Ribeiro-Costa, C. S.'

Notes.

Jekel (1855) described the material quoted by Dejean (1837) but in his description, he did not specify how many specimens were studied. Therefore the exemplar received from BMNH, from the locality quoted in the original description, is a type specimen and regarded as a syntype.

Additional material.

BRAZIL: Amazonas: 1 male specimen, São Gabriel, Rio Negro, 9.X.1927, J.F. Zikán, (FIOC). Pará: 1 male specimen, Santarém, VII.1919, S. M. Klages(CARN). FRENCH GUIANA: Bélvédère de Saül: 1 male specimen, Mont Itoupé, 30.III.2010, P. H. D. leg. (DZUP).

Distribution.

Brazil (Amazonas and Pará), Fench Guiana.

Comparative notes.

Amblycerus virens differs from the other species of the group by the length of the lateral spur of hind tibia (2.4 times the length of median; Fig. 2) (for other species the length of the lateral spur of hind tibia is less than 1.85 times the length of median); the internal sac of male genitalia has small blade sclerites (Fig. 5) (other species in the group have long blade sclerites).

This species shares with Amblycerus viridis and Amblycerus medialis the prominent eyes (Figs 3, 9), postocular lobe narrower and metaventrite protuberant in lateral view (Figs 2) but the male genitalia do not show closer similarities among these species. Amblycerus virens and Amblycerus virescens share a long wishbone sclerite comparing to the blades in the internal sac of male genitalia (Fig. 5; Ribeiro-Costa 1998: 632. Fig. 9).