Symmela martinezi 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 : 659-662

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

( Figures 17 , 29 (c), 31(a))

Type material examined

Holotype. ♂ ‘ Argentina Misiones P ° Iguazú Duret legit. Coll. Martinez Sept. 947/ H. & A. Howden Collection ex. A. Martinez coll./ 27 Neotropical Sericini spec.’ ( CMNC) . Paratypes: Argentina: 1 ♀ ‘ Argentina Misiones P° Iguazú Duret legit . Coll . Martinez Sept. 947/ H. & A. Howden Collection ex. A. Martinez coll ./ 27 Neotropical Sericini spec.’ ( CMNC) , 1 ♀ ‘ARG: Missiones, 200 m Iguazu Nat . Park 23 .XII.90–6.I.91 forest gen. colln. S & J Peck , 90–128’ ( CMNC) . Brazil: 1 ♂ ‘ Rio de Janeiro John Gray’ ( MNHN), 4 ♂♂ ‘ Brasilia Nova Friburgo / Symela instabilis Er ./ 56 Neotropical Sericini spec.’ ( ZMHB, ZFMK) , 1 ♂ ‘Brasilia coll . Moser / Symela instabilis Er. ’ ( ZMHB) , 1 ♂ ‘ Brasil / Symela instabilis Er. ’ ( ZMHB) , 4 ♀♀ ‘ Brasilia Nova Friburgo b . Beske’ ( ZMHB) .

Description

Length: 6.8 mm. Elytral length: 4 mm. Width: 3.6 mm. Head black, shiny and iridescent, with erect, sparse setae. Labroclypeus as wide as frons, subtrapezoidal; surface convex; plain, without an anterior concavity on each side; anterior margin straight, 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 irregular, moderately 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, yellowish, 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 with copper iridescent shine. Pronotum unicoloured, iridescent, black; widest at middle, width distinctly narrower compared to width of elytral base at humerus; anterior marginal line not interrupted medially, posterior marginal line absent; lateral margin serrated, generally bent at middle, otherwise straight, behind anterior angles straight, posteriorly weakly convex; setae of lateral margin dense; basal margin evenly curved; transverse impression beside basal margin absent; anterior angles produced, rectangular; antero-lateral and postero-lateral angles not flattened dorso-ventrally; posterior angles blunt; surface with median longitudinal impression present over entire length of pronotum and two longitudinal furrows on each side, punctation on disc moderately dense, simple and fine, without well-defined impunctate areas. Scutellum without punctures.

Elytra bicoloured, yellowish brown in major part, dark spot on disc; surface opaque and iridescent, without setae and microsculpture; striae and intervals distinct; punctation between striae sparse, diameter of punctures compared to those of striae equal; 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 weakly convex.

Legs yellow. Ratio of length of metepisternum/metacoxa: 1/1.33. Metacoxa entirely plain, without elevated lateral longitudinal carina; with longer lateral bristles, without setae on basal surface, posterior margin glabrous. Metafemur with posterior margin straight. Metatibia widest at apex; ratio of width/length: 1/3.65; 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: 1/2.5. 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 setose, ventral setae standing in a narrow line, robust and sparse (mainly in apical half of tarsomeres); medial face glabrous. Protibia with three indistinct, equidistant teeth; third basal tooth smaller than medium tooth; 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 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 17 (c,d).

Variation

Length: 6.8–7.5 mm. Elytral length: 4–4.4 mm. Width: 3.6–3.9 mm. Elytra from entirely dark brown to yellow with reduced central dark spot. Female: protarsi fine and narrow; protarsal claws symmetric, the basal tooth of interior claw sharply pointed at apex; antennal club short than in male, length ratio of antennal club vs remaining antennomeres combined: 1/1.5.

Diagnosis

Symmela martinezi sp. nov. is in external appearance and the shape of the aedeagus similar to S. elegans Erichson, 1835 . Symmela martinezi sp. nov. differs externally by the straight interior terminal protibial spine, which is in S. elegans curved interiorly, and, of course, in the shape of the aedeagus, parameres and subparameres and the strongly sclerotised endophallus. The latter is externally well visible. The parameres are in S. martinezi narrower and distinctly curved, the aedeagus generally less robust (more narrow); the subparameres are in S. martinezi mesally contiguous in the basal half, while in S. elegans they are divergent from the base onward.

Etymology

This species is named after A. Martínez , an Argentine entomologist who has made numerous contributions to our knowledge of South American scarabs and one of the collectors of the type specimens (noun in genitive case) .

Figures

Figure 17. Symmela martinezi sp.nov., holotype ♂. (a) Habitus, dorsal view; (b) habitus,lateral view;(c) parameres (including extracted endophallus), dorsal view; (d) aedeagus, lateral view. Scale bars: a, b = 1 mm; c, d = 0.5 mm.

Figure 29. Distribution map of the Symmela species.