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.

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.’

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.

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).

Brazil (Amazonas and Pará), Fench Guiana.

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).

Brazil (Amazonas, Amapá and Goiás).

This species can be distinguished from all other of virens group by the internal sac of male genitalia that has a pair of subtriangular sclerites with denticulate margins (Ribeiro-Costa 1998: 632. Fig. 9) (Amblycerus virens, Amblycerus viridis and Amblycerus viridans, have a pair of sclerites with small rounded protuberances) (Fig. 5; Ribeiro-Costa 1998: 634, 636. Figs 14, 19); Amblycerus medialis Ribeiro-Costa, Vieira & Manfio, sp. n. absent (Fig. 11)).

Amblycerus virescens and Amblycerus viridans have no salient eyes (Ribeiro-Costa 1998: 631. Fig. 1), postocular lobe long, and metaventrite not protuberant (Ribeiro-Costa 1998: 631. Fig. 4). However, comparisons of male genitalia indicate that Amblycerus virescens is similar to Amblycerus virens because they both have a wishbone sclerite that is longer than the blades (Fig. 5; Ribeiro-Costa 1998: 632. Fig. 9).

Brazil (Mato Grosso).

Amblycerus viridans differs from all other species in the group by the structure of the internal sac of male genitalia, which includes a pair of sclerites formed by dense denticles (Ribeiro-Costa 1998: 634, Fig. 14: EPL) (character absent in Amblycerus virescens, Amblycerus viridis, Amblycerus virens andAmblycerus medialis). This species is similar to Amblycerus viridis because they both have a wishbone sclerite that is shorter than the blades; in addition both species also share the presence of a pair of slender denticulate sclerites on median region (Ribeiro-Costa 1998: 634, Fig. 14: EPC). Additional information on external morphological similarities is also presented in the section dedicated to Amblycerus virescens.

Brazil (Mato Grosso).

Amblycerus viridis differs from the other species in the group by its shorter hind femur, which is 2.32 times longer than its width (in others species the ratio is superior to 2.5 times). Additional information on external and internal similarities is also presented in the sections dedicated to Amblycerus virens and Amblycerus viridans.

BL: 6.3 mm; BW: 3.78 mm

Integument color (Figs 7–10). Body black except mouth parts brownish; apical spurs of hind tibiae brownish to black.

Vestiture (Figs 7–10). Pronotum with a predominantly green vestiture but also with yellowish setae on the anterior margin, lateral areas and median line; elytra with a predominantly green vestiture but also with yellowish setae on 1 interstria; thorax and abdomen covered with pale yellowish setae.

Head (Fig. 9) covered with fine and dense punctures. Frons without frontal carina. Eyes moderately faceted, strongly prominent laterally. Ocular index: 2.23; ocular sinus: 0.78; postocular lobe 0.34 the eye length. Antennae not reaching anterior margin of hind coxa (Fig. 8); serrated from 4 to 10 antennomeres; from 3 to 11 antennomeres 1.94 longer than wider; 11 antennomere with truncate apex (Fig. 8). Frontoclypeal suture indistinct. Clypeus covered with fine and dense punctures except on a narrow band on apical portion. Labrum with few fine punctures on basal margin.

Prothorax (Fig. 7). Pronotum semicircular; covered with fine and dense punctures, moderately coarse punctures intermixed all over pronotum. Lateral carina complete, almost reaching the anterior margin of pronotum. Cervical sulcus absent. Prosternal process longer than anterior coxae, gently arched between coxae and slightly constricted between coxae.

Mesothorax and Metathorax. Scutellum longer than wide with tridentate apex. Elytron with striae moderately impressed, not fused apically. Interstriae with moderately coarse and dense punctures (Fig. 7). Metaventrite slightly protuberant with moderately coarse and sparse punctures; median sulcus one-half as long as metaventrite. Metepisternum without punctures; metepisternal sulcus forming straight angle, with transverse axis straight and reaching lateral margin of metepisternum. Mid coxae lower than anterior coxae, in lateral view (Fig. 8). Surface of hind coxae without punctures. Hind femur 3 times longer than wide. Hind tibia lateral spur about 1.5 times the length of median spur, and 1-tarsomere about 1.5 the length of lateral spur and 2.5 times the median spur.

Abdomen (Fig. 10). Ventrites finely punctulate, the last about 2 times wider than the 4-ventrite; pygidium one-half covered by the elytra, with apical margin rounded, with fine punctures.

Male genitalia (Figs 11–12). Median lobe (Fig. 11) about 5.43 times its widest at apical region; ventral valve with lateral margins concave, dorsal valve with lateral margins straight. Internal sac (Fig. 11) in the apical region without sclerites. Median region with a pair of straight blade sclerites, one side denticulate; wishbone sclerite as long as blade sclerites, curved at apex and stems moderately separated. Basal region with a sclerite with long stems gradually approximated. Apical and median regions with several spines and denticles. Tegmen (Fig. 12) deeply emarginated, about 0.35 times the length of the expanded lateral lobes.

Holotype deposited in FSCA, male, with labels: ‘BRAZIL: Rondônia 62/ km SW Ariquemes, nr/ Fzda. Rancho Grande/ 8-20-XI-1994 JE Eger/ MV & Black Lights’[white, printed in black]; ‘FSCA’ [green, printed in black]; ‘HOLOTYPE/ Amblycerus medialis/ Ribeiro-Costa, Vieira & Manfio, / [white with red margin, printed in black] (FSCA). 1 paratype deposited in CNCI, female, with labels: ‘BRAZIL, Pará ♀/ Faz. Taperinha/ XI-19-22-1969/ JM & BA Campbell’ [white, printed in black]; ‘CNC’ [white with green line in the middle, printed in black]; ‘PARATYPE/ Amblycerus medialis/ Ribeiro-Costa, Vieira & Manfio/ [white with yellow margin, printed in black] (CNCI).

Brazil (Pará and Rondônia).

Amblycerus medialis can be easily separated from others species in the group by the presence of yellow pubescent stripes on the pronotum and elytra (Fig. 7) (others species are exclusively with a green vestiture); antennomeres about 2 times as long as wide (Figs 7–8) (others wider than long).

Additional information on external and internal similarities is also presented in the sections dedicated to Amblycerus virens and Amblycerus viridans.

The specific name refers to the median line on dorsum.