Symmela mutabilis Erichson, 1835

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 : 662-665

Symmela mutabilis Erichson, 1835

( Figures 18 , 29 (c), 31(b), 32(f))

Symmela mutabilis Erichson, 1835: 263 (original description); Blanchard 1850: 85 (catalogue); Burmeister 1855: 133 (revision); Harold 1869: 1127 (checklist); Frey 1973: 323 (key); Evans 2003: 48; Evans and Smith 2005: 31, 2007: 31, 2009: 31 (checklist)

Type material examined

Lectotype (here designated). ♂ ‘24973/ mutabilis Brasil. Setl./ Typus’ ( ZMHB) . Paralectotypes: 2 ♂♂ ‘ Brasil Sello Nr . 24973/ Typus / Symela [sic!] mutabilis Er. ’ ( ZMHB) , 1 ♂ ‘ Brasil Sello Nr . 24973/ Typus/ mutabilis coll . Mos .’ ( CF / NHMB), 1 ♂ ‘24974/ Var ./ Brasil Sello / Typus / Symela [sic!] mutabilis Er. ’ ( ZMHB) , 3 ♀♀ ‘ Brasil Sello Nr . 24974/ Typus / Symela [sic!] mutabilis Er. ’ ( ZMHB) , 1 ♂ ‘ Brasil Sello Nr . 24974/ Typus / Symela [sic!] mutabilis Er. ’ ( ZMHB) , 1 ♂ ‘ Brasil Sello Nr . 24973/ Typus/ Symela [sic!] mutabilis Er. ’ ( ZMHB).

Additional material examined

1 ♀ ‘ Brasilia Sao Paulo / Berlin / mutabilis Er . [handwritten Frey]’ ( ZMHB), 1 ♀ ‘ Brasilia / Berlin / mutabilis coll . Moser [handwritten Frey]’ ( ZMHB), 1 ♀ ‘S . Paulo Brasil./ ♀ mutabilis coll . Moser [handwritten Frey]’ ( ZMHB), 1 ♀ ‘S . Paulo Brasil./ Berlin / Symela [sic!] mutabilis Er. ’ ( ZMHB) , 1 ♀ ‘ Brasilia Sao Paulo / Berlin / Symela [sic!] mutabilis Er. ’ ( ZMHB) , 1 ♂ ‘24976/ Brasil Virm. ’ ( ZMHB) , 1 ♂ ‘ Brasil Virm . Nr. 24976’ ( ZMHB), 1 ♂ ‘24975/ Brasil Virm’. ( ZMHB) , 1 ♂ ‘ Brasil Virm . Nr. 24975’ ( ZMHB), 1 ♂ ‘ Brasilia St . Catharina’ ( ZMHB), 1 ♂ ‘ Curitiba Parana II .1939 1668/ Brasil Halik 1966 Collection’ ( USNM), 1 ♀ ‘ Curitiba Parana II .1939 Halik 1661/ Symmela mutabilis Erich / Halik det. 1958./ Brasil Halik 1966 Collection’ ( USNM), 1 ♂ ‘ Curitiba Parana II .1939 1540/ Brasil Halik 1966 Collection’ ( USNM), 7 ♂♂ ‘ Curitiba Parana II .1939/ Brasil Halik 1966 Collection’ ( USNM, ZFMK), 2 ♂♂ ‘ Curitiba Paraná 3 . 939/ Coll . J . Guerlin S . Paulo Brasil 0485’ ( NHMB), 1 ♂ ‘ clypeata Erichson planifrons Dej . Brésil 1/ 2’ ( MNHN) .

Redescription

Length: 6.2 mm. Elytral length: 3.9 mm. Width: 3.5 mm. Head black, dull and iridescent, with erect, sparse setae. Labroclypeus as wide as frons, subtrapezoidal; surface flat; plain, without an anterior concavity on each side; anterior margin straight, weakly 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: 0.55. 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: 1/5. 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, 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 not serrated, generally weakly convex, behind anterior angles straight, 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, black in major part, posterior half dark; surface opaque, 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 weakly convex.

Legs blackish and yellow. Ratio of length of metepisternum/metacoxa: 1/1.25. Metacoxa entirely plain, without elevated lateral longitudinal carina. Metacoxa with longer lateral bristles. Metacoxa, setae on basal surface present, posterior margin densely setose. Metafemur with posterior margin straight. Metatibia widest at apex; ratio of width/ length: 1/2.85; 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 twothirds of metatibia length; ventral margin not serrated. Dorsal surface of tarsi glabrous, with dense punctures. Length ratio of dorsal tibial spur/first metatarsomere: 1/3. 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 two distinct teeth; spur curved interiorly. First protarsomere straight, as long as second; width ratio of first protarsomere vs second protarsomere: ca. 1/2; second protarsomere enlarged; third and fourth protarsomere elongate and narrow (distinctly longer than wide); fifth protarsomere circular in cross section, as long as 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 18 (d–f).

Figures

Figure 18. Symmela mutabilis Erichson, 1835, lectotype ♂. (a) Habitus, dorsal view; (b) habitus, lateral view; (c) labels; (d) parameres dorsal view; (e) aedeagus, dorsal view; (f) aedeagus, lateral view. Scale bars: a, b = 1 mm; d–f = 0.5 mm.

Figure 29. Distribution map of the Symmela species.