Symmela unidentata Pacheco, Wipfler, Monné and Ahrens, 2022

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 : 691-696

Symmela unidentata Pacheco, Wipfler, Monné and Ahrens sp. nov.

( Figures 28 , 31 (l))

Type material examined

Holotype. ♂ ‘Chapada Brazil Acc. No. 2966/ L.W. Saylor Collection / Det. L.W. Saylor / CASENT 8438110/ 149 Neotropical Sericini spec.’ ( CAS) . Paratype: 1 ♂ ‘ Chapada Brazil Acc . No. 2966/ L.W. Saylor Collection/ Det . L .W. Saylor/ CASENT 8438109’ ( ZFMK).

Description

Length: 5.9 mm. Elytral length: 3.2 mm. Width: 3 mm. Head black, shiny, with erect, sparse setae. Labroclypeus as wide as frons, subtrapezoidal; surface convex; plain, without an anterior concavity on each side; anterior margin straight, strongly reflexed, 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: 0.47. 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: 1/1.5; 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 bicoloured, shiny, black; widest at middle, width subequal to width of elytral base at humerus; anterior marginal line not interrupted medially, posterior marginal line absent; lateral margin not serrated, generally bent at middle, otherwise straight, behind anterior angles straight, posteriorly straight; 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 dense, simple and fine, without well-defined impunctate areas. Scutellum without punctures.

Elytra unicoloured, blackish brown; surface shiny, 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 blackish and yellow. Ratio of length of metepisternum/metacoxa: 1/1.39. 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: 1/2.68; 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 comprising at least two robust spines at same level of metatibial length; 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: 1/2. 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 one tooth. External teeth of protibia indistinct; spur straight. First protarsomere straight, its length subequal to second and third combined; width ratio of first protarsomere vs second protarsomere: ca. 2/1; second protarsomere enlarged; 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 28 (c–e).

Female unknown.

Variation

Length: 5.5–5.9 mm. Elytral length: 3.1–3.2 mm. Width: 2.8–3 mm. Paratype unicoloured, dark reddish brown.

Diagnosis

Symmela unidentata sp. nov. is similar to Symmela terezae sp. nov. and shares with this species the unidentate protibia. Symmela unidentata differs by the metatibia which is widest at the apex rather than having subparallel dorsal and ventral margins in the apical half, and the paramere having in S. unidentata no lateral tooth (tooth present in S. terezae ).

Etymology

This species is named after the presence of only one tooth in the protibia (adjective in nominative case).

Figures

Figure 28. Symmela unidentata sp. nov., holotype ♂. (a) Habitus, dorsal view; (b) habitus, lateral view; (c) parameres, dorsal view; (d) aedeagus, dorsal view; (e) aedeagus, lateral view. Scale bars: a, b = 1 mm; c–e = 0.5 mm.

Figure 31. Heads of Symmela species. (a) S. martinezi sp. nov.; (b) S. mutabilis; (c) S. nitida; (d) S. nitidicollis; (e) S. nunesorum sp. nov.; (f) S. opaca; (g) S. paschoali sp. nov.; (h) S. pseudopaca sp. nov.; (i) S. reischei sp. nov.; (j) S. tarsalis; (k) S. terezae sp. nov.; (l) S. unidentata sp. nov. Scale bars: 0.5 mm.