Symmela reischei 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 : 682-685

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

( Figures 25 , 31 (i))

Type material examined

Holotype. ♂ ‘ Symmela nitidula Brésil Reische 2/2/152 Neotropical Sericini spec.’ ( MNHN) . Paratype: 1 ♂ ‘Brasilia/ Symela longula, Er. / 79 Neotropical Sericini spec.’ ( ZMHB).

Description

Elytral length: 4 mm. Width: 3.3 mm. Scutellum without punctures. Elytra bicoloured, yellowish brown in major part, margins blackish; 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 with half length as laterally; ultimate and penultimate apical ventrites simple and flat; apical ventrite very short (half 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: 1/1.03. 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: 1/3.14; dorsal margin 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 two distinct teeth; spur straight. First protarsomere straight, its length subequal to second and third combined; width ratio of first protarsomere vs second protarsomere: 1.5/1; second protarsomere narrow and straight; 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 25 (c–e).

Female unknown.

Variation

Length: 7.1 mm. Elytral length: 4–4.2 mm. Width: 3.3–3.8 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 straight, weakly reflexed, with a rim of sparse 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 irregular, dense. Ocular canthus with terminal setae, ratio of length of ocular canthus/eye diameter: 1/3. Eyes evenly spherical. 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: 1/2; fourth antennomere without lateral projection; length ratio of fifth vs fourth antennomere: 1/3. Labrum anteriorly without blunt processes. Setae on mentum moderately dense.

Head and pronotum without copper iridescent shine. Pronotum bicoloured, shiny, blackish brown; 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 bent at middle, otherwise straight, behind anterior angles convex, 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 moderately dense, simple and fine, without well-defined impunctate areas.

Diagnosis

Symmela reischei sp. nov. is in external appearance similar to Symmela longula Erichson, 1835 , but the body of this new species is significantly larger, and the parameres are stout and have a complicated shape, which differentiates them from all other Symmela species: at the apex they have a sharp dorsal process which is reflexed interiorly.

Etymology

The new species is named after Reische, collector of the holotype specimen (noun in genitive case).

Remarks

Pronotum and head of the holotype are missing. The parameres are broken in the paratype; however, based on the shape of the phallobase and the rest of the external morphology, this specimen can be clearly assigned to S. reischei .

Figures

Figure 25. Symmela reischei sp. nov., (a, b) paratype ♂, (c–e) holotype ♂. (a) Habitus, dorsal view; (b) habitus, lateral view; (c) aedeagus, lateral view; (d) aedeagus, dorsal view; (e) parameres, dorsal 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.