Symmela brasiliensis Moser, 1919

Pacheco, Thaynara L., Wipfler, Benedict, Monné, Marcela L. & Ahrens, Dirk, 2022, The genus Symmela Erichson, 1835 (Coleoptera, Scarabaeidae, Sericini): taxonomy and phylogenetic analysis, Journal of Natural History 56 (9 - 12), pp. 607-705 : 619-621

Symmela brasiliensis Moser, 1919

( Figures 2 , 29 (a), 30(b))

Symmela brasiliensis Moser, 1919: 8 (original description); Frey 1973: 323 (key); Evans 2003: 47; Evans and Smith 2005: 30, 2007: 30, 2009: 30 (checklist)

Type material examined

Holotype. ♂ ‘Brasilia Diamantina/ Symmela brasiliensis Type Mos./ Typus/ brasiliensis Mos’. ( ZMHB).

Additional material examined

1 ♂ ‘ Brasilien Amazonasgeb . Rolle V.’ ( ZMHB), 1 ♂ ‘ Brasilien Obidos 18.1 .04 Rolle V’. ( ZMHB), 13 ♂♂, 5 ♀♀ ‘ Braz . Mato Grosso Barra do Tapirape 26 XII-62 B . Malkin/ CASENT/30 Neotropical Sericini spec.’ ( CAS), 5 ♂♂ ‘ Braz . Mato Grosso Barra do Tapirape I-10-68 B . Malkin/ CASENT/ 30 Neotropical Sericini spec.’ ( CAS), 9 ♂♂ ‘ Braz . Mato Grosso Barra do Tapirape 1-2-63 B . Malkin’ ( CAS), 1 ♂ ‘ Braz . Mato Grosso Barra do Tapirape 18-XII -62 B . Malkin’ ( CAS), 1 ♀ ‘ Braz . Mato Grosso Barra do Tapirape I-10-63 B . Malkin’ ( CAS), 1 ♀ ‘ Braz . Mato Grosso Barra do Tapirape XII-30-62 B . Malkin’ ( CAS).

Redescription

Length: 6 mm. Elytral length: 3.7 mm. Width: 3.1 mm. Head blackish brown, shiny, with erect, sparse setae. Labroclypeus as wide as frons, subtrapezoidal; surface convex; plain, without an anterior concavity on each side; anterior margin weakly emarginated medially, not elevated, with a rim of dense, short setae behind anterior margin; lateral margin not incised anteriorly; punctation of surface posteriorly dense; suture between labrum and clypeus invisible. Smooth area in front of eye distinctly separated from frons by a suture. Frons anteriorly flat, punctation even, dense. Ocular canthus with terminal setae, ratio of length of ocular canthus/eye diameter: 1/3. Eyes evenly spherical, ratio of diameter/ interocular width: 0.48. Antenna with eight antennomeres. Antennal club with three antennomeres, blackish, straight; width of antennal lamella equal to width of antennomeres of funiculus; apical lamella subequal to basal and median ones; length ratio of antennal club vs remaining antennomeres combined: 1/1.1; length ratio of third vs fourth antennomere: 1/3; fourth antennomere without lateral projection; length ratio of fifth vs fourth antennomere: 1/3. Labrum anteriorly bluntly angled on each side, concave at middle. Setae on mentum moderately dense.

Head and pronotum without copper iridescent shine. Pronotum unicoloured, dull but iridescent, brownish orange; widest at base, width subequal to width of elytral base at humerus; anterior marginal line not interrupted medially, posterior marginal line absent; lateral margin not serrated, generally weakly convex, behind anterior angles convex, posteriorly weakly convex; setae of lateral margin sparse; basal margin evenly curved; transverse impression beside basal margin absent; anterior angles produced, sharply pointed; antero-lateral and postero-lateral angles not flattened dorso-ventrally; posterior angles blunt; surface without median longitudinal impression, transversal furrows or setae; punctation on disc moderately dense, simple and fine, without well-defined impunctate areas. Scutellum without punctures.

Elytra bicoloured, yellowish brown in major part, margins blackish; surface iridescent, without setae and microsculpture; striae and intervals distinct; punctation between striae sparse, diameter of punctures compared to those of striae smaller; intervals flat; posterior edge convex; apical margin chitinous, without microtrichomes.

Abdomen: sternites flat in sagittal plane; lateral carina absent; first visible ventrite with row of setae on posterior edge; second visible ventrite with row of setae in medial region; basal ventrites medially of same length as laterally; ultimate and penultimate apical ventrites simple and flat; apical ventrite short (as long as preceding ventrite); penultimate apical ventrite with row of setae like preceding one; beside the robust row of setae, almost glabrous. Pygidium strongly convex.

Legs yellow. Ratio of length of metepisternum/metacoxa: 1/1.26. Metacoxa entirely plain, without elevated lateral longitudinal carina; without longer lateral bristles, with setae on basal surface, posterior margin glabrous. Metafemur with posterior margin straight. Metatibia widest at apex; ratio of width/length: 1/3.06; dorsal margin not carinated, smooth; interior surface more or less glabrous; median longitudinal punctation present on interior surface; interior margin of apex sharply and deeply truncate towards ventral margin; punctation on entire lateral face present; beside dorsal margin without a row of robust setae along entire length; basal group of spines reduced to a single robust spine; distal groups of spines disposed at two-thirds of metatibia length; ventral margin not serrated. Dorsal surface of tarsi glabrous, with dense punctures. Length ratio of dorsal tibial spur/first metatarsomere: 1/1.5. Metatarsi at apex weakly widened; first tarsomere straight, its length subequal to second and third tarsomeres combined; laterally not carinate; ventral margin serrated; ventral margin glabrous; medial face glabrous. Protibia with two distinct teeth; spur straight. First protarsomere curved, its length subequal to second and third combined; width ratio of first protarsomere vs second protarsomere: 1.5/1; second protarsomere narrow, but bent; third and fourth protarsomere elongate and narrow (distinctly longer than wide); fifth protarsomere circular in cross section, a little shorter than third and fourth protarsomere combined. Protarsal claws asymmetrical, shape of inner protarsal claw bifid, apex of basal tooth of inner protarsal claw convex.

Aedeagus: Figure 2 (d,e).

Remarks

The original description was based on a single specimen from Diamantina ( Moser 1919, p. 9) , considered the holotype.

Figures

Figure 2. Symmela brasiliensis Moser, 1919, holotype ♂. (a) Habitus, dorsal view; (b) habitus, lateral view; (c) labels; (d) parameres, dorsal view; (e) aedeagus, lateral view. Scale bars: a, b = 1 mm; d, e = 0.5 mm.

Figure 29. Distribution map of the Symmela species.