Neoserica (s. str.) pachecoae, Ahrens, 2021

Ahrens, Dirk, 2021, Two new species of the Neoserica (sensu stricto) group from China (Coleoptera: Scarabaeidae: Melolonthinae: Sericini), Journal of Natural History 54 (45 - 46), pp. 2927-2936 : 2931-2935

Neoserica (s. str.) pachecoae sp. nov.

( Figures 1 (e–h), 2)

Type material examined

Holotype: ♂ ‘ China: Guangdong prov. Nanling National Nature Reserve Dadongshan, 18.- 21.iv.2013 (border of mixed forest, at light) 24°56.0 ʹ N, 112°42.9 ʹ E, 690 m J. Hájek & J. Růžička /1080 Sericini Asia spec.’ ( NMPC).

Description of the holotype

Length: 7.1 mm, length of elytra: 5.0 mm, width: 4.1 mm. Body oval, black, dorsal surface with iridescent shine, with dense, fine, yellowish, adpressed setae, mixed with dense erect black setae, which on head and pronotum are directed anteriad.

Labroclypeus subrectangular, widest shortly before base, lateral margins weakly convex and with moderately convergent to broadly rounded anterior angles, lateral border and ocular canthus producing a distinct obtuse angle, anterior margin weakly concave, moderately reflexed; surface flat and shiny, coarsely and sparsely punctate, with dense, long, erect setae; frontoclypeal suture indistinctly impressed and moderately curved, smooth area anterior to eye nearly twice as wide as long; ocular canthus moderately short and robust, finely and densely punctate, with several short setae. Frons finely and densely punctate, with dense, adpressed, short yellow setae, interspersed with coarse punctures bearing erect black setae. Eyes small, ratio of diameter/interocular width 0.49. Antenna with 10 antennomeres; club with four antennomeres, 1.2 times as long as remaining antennomeres combined, all joints of club subequal in length. Mentum elevated and flattened anteriorly.

Pronotum moderately wide, widest at base, lateral margins in basal half slightly concave but weakly convergent, strongly curved and convergent in anterior half, anterior angles not produced and strongly rounded, nearly obsolete, posterior angles slightly acute, anterior margin straight, with distinct and fine marginal line, basal margin without marginal line; surface with large and dense punctures each bearing a yellowish, adpressed seta interspersed with coarser punctures bearing each an erect blackish seta; anterior and lateral borders moderately setose; hypomeron carinate, basal margin of hypomeron moderately produced ventrally. Scutellum subtriangular, apex moderately rounded, with fine and dense punctures and moderately adpressed setae.

Elytra short, widest at middle, striae finely impressed, with fine and dense punctures, intervals weakly convex, with fine, dense punctures concentrated along striae and fine, adpressed setae, each interval with numerous larger single punctures each bearing an erect, long, blackish seta; epipleural edge moderately strong, ending at strongly rounded external apical angle of elytra, epipleura densely setose, apical border chitinous, without short microtrichomes.

Ventral surface dull, including metacoxa with large, dense punctures and dense, short, lightly adpressed setae, metacoxa with some robust setae laterally, abdominal sternites finely and densely punctate and setose, each sternite with an indistinct transverse row of coarse punctures each bearing a short, robust seta. Mesosternum between mesocoxae slightly wider than mesofemur, with numerous strong setae on an indistinct semicircular carina. Ratio of length of metepisternum/metacoxa 1/1.52. Pygidium moderately convex at apex, with fine, dense punctures and fine setae, with numerous robust setae in coarse punctures on apical half, without smooth midline.

Legs moderately slender, femora with fine and dense punctures, densely setose; anterior edge of metafemur acute, lacking an adjacent serrated line,posterior margin weakly convex, with a few fine setae medially,weakly widened in apical half ventrally but not serrate, serrate dorsally. Metatibia rather long, moderately widened at middle, width/length ratio 1/3.4, dorsally sharply carinate, with only one group of spines at three-quarters of metatibial length, with a few single robust spines in punctures along entire length of metatibia, beside dorsal margin with a blunt carina from base to apex, which is indistinctly and discontinuously serrate only in the basal half; lateral face longitudinally convex, finely and densely punctate and setose, ventral edge serrate, with four equidistant robust spines; medial face very sparsely punctate and with a few fine setae, apex interiorly near tarsal articulation deeply and sharply truncate. Tarsomeres glabrous and impunctate dorsally, with sparse, short setae ventrally; metatarsomeres missing in holotype. Protibia short, bidentate, anterior claws symmetrical, with a sharply pointed basal tooth.

Aedeagus: Figure 1 (e–g).

Diagnosis

Neoserica pachecoae sp. nov. is in colour and external shape rather similar to N. kalliesi and N. hongheana sp. nov. It shares with both the lateral lamina at the right ventral phallobase. Neoserica pachecoae sp. nov. differs from both by the simple left and right paramere, these not being divided into a ventral and a dorsal lobe.

Etymology

The new species is named after Thaynara Lara Pacheco (Museum Nacional, Rio de Janeiro, Brazil), a member of our ZFMK beetle lab and a student of South American Sericini.

Key to Neoserica (s. str.) species (♂♂)

1 Phallobase at right side with a short but sharply pointed lateral process.......................... .......................................................................................... N. mengsongensis Liu and Ahrens, 2015

1 Phallobase at right side without lateral process. ...................................................................... 2

2 Serrated carina of metatibia nearly continuous from base to preapical portion......... 5

2 Serrated carina of metatibia widely interrupted or ending at middle............................. 3

3 Body reddish brown.............................................................................................................................. 4

3 ʹ Body black......................................................................................................... N. pachecoae sp. nov.

4 Phallobase produced dorsally to a dorsolateral apophysis (at left side).............................. .................................................................................. N. pseudosangangana Liu and Ahrens, 2015

4 ʹ Phallobase not produced dorsally....................... N. yongkangensis Liu and Ahrens, 2015

5 Eyes large, ratio of diameter/interocular distance~ 0.78. ...................................................... 6

5 ʹ Eyes smaller, ratio of diameter/interocular distance~ 0.6...................................................... 8

6 Antennal club twice as long as remaining antennomeres combined................................... ...................................................... N. flexiclava Ahrens, 2003 , N.schoolmeestersi Ahrens, 2019

6 ʹ Antennal club 1.5 times as long as remaining antennomeres combined. ..................... 7

7 Anterior margin of labroclypeus straight, not emarginate. Metatibia on external face smooth along the middle....................................................... N. semipubescens Ahrens, 2003

7 ʹ Anterior margin of labroclypeus slightly emarginate medially. Metatibia on external face densely punctate also along the middle....................... N. phuruaensis Ahrens, 2003

8 Epipleural edge of elytra ends immediately behind the humerus; only odd elytral intervals with robust setae.................................................................................................................. 9

8 ʹ Epipleural edge of elytra ends at the external apical rounding of the elytra; all elytral intervals with robust setae. .............................................................................................................. 11

9 Metatibia shorter, metatibial width/length ratio 1/2.95–3.1. ............................................. 10

9 ʹ Metatibia longer, metatibial width/length ratio 1/3.78. N. grossepunctata Ahrens, 2003

10 Body wider. Metacoxa very long (metepisternum/metacoxa length ratio 1/2.43)............ ...................................................................................................................... N. lucidifrons Ahrens, 2003

10 ʹ Body narrower. Metacoxa shorter (metepisternum/metacoxa length ratio 1/1.82)......... .............................................................................................................. N. phuphanensis Ahrens, 2003 11 Serrated line on dorsolateral margin of metatibia shortly interrupted by a group of spines......................................................................................................................................................... 12

11 ʹ Serrated line on dorsolateral margin of metatibia complete, not interrupted. .......... 15

12 Dorsal face black, long setae on elytra and pronotum robust. Metatibia short, metatibial width/length ratio 1/3.0–3.1............................................................................................................

... N. nigrosetosa Moser, 1908 , N. fanjingshanica Ahrens, 2003 , N. tamdaoensis Ahrens,

2003

12 ʹ Dorsal face brown, long setae on elytra and pronotum fine. ............................................ 13

13 Left paramere simple........................................................................................................................... 14

13 ʹ Left paramere bifid............................................................. N. taibaiensis Liu and Ahrens, 2015

14 Labroclypeus distinctly wider than long..................... .................... N. unicolour (Frey, 1972)

14 ʹ Labroclypeus little wider than long, anterior angles strongly rounded................................ ........................................................................................................................... N. fukiensis (Frey, 1972)

15 Dorsal face entirely black or reddish brown. ............................................................................. 16

15 ʹ Dorsal face always simply brown................................................................................................... 20

16 First antennomere of antennal club only half as long as club. Dorsal surface black or reddish brown. ....................................................................................................................................... 17

16 ʹ All antennomeres of antennal club subequal in length. Dorsal surface always black. 19

17 Anterior angles of pronotum strongly rounded....................................................................... 18

17 ʹ Anterior angles of pronotum blunt..................... .................... N. sangangana Ahrens, 2003

18 Phallobase without dorsoapical lamina. Right paramere wider and shorter. Left paramere with a ventral and a dorsal lobe........................ ....................... N. kalliesi Ahrens, 2003

18 ʹ Phallobase with a large dorsoapical lamina. Right paramere slender and long. Left paramere without dorsal lobe................................ ............................... N. hongheana sp. nov.

19 Lateral margins of pronotum concavely emarginate in basal half. Metatibia shorter, metatibial width/length ratio 1/3.0–3.1............. ............ N. jinggangshanica Ahrens, 2003

19 ʹ Lateral margins of pronotum subparallel and straight in basal half. Metatibia longer, metatibial width/length ratio 1/3.44....................................... N. shibingensis Ahrens, 2003

20 Metatibia relatively short, medially strongly extended (metatibial width/length ratio 1/3.0–3.2).................................................................................................................................................. 21

20 ʹ Metatibia relatively long, medially almost not extended (metatibial width/length ratio> 1/3.3)...................................................................................................................................................... 22

21 Antennal club slightly longer than remaining antennomeres combined. Eyes small, diameter/interocular width ratio 0.6........................... .......................... N. strbai Ahrens, 2003 21 ʹ Antennal club 1.5 times as long as remaining antennomeres combined. Eyes large, diameter/interocular width ratio 0.79..................................... N. bannapensis Ahrens, 2003

22 Body slightly more flattened, elongate. Right paramere ventroapically with a blunt tooth. N. parursina Ahrens, 2003 , N. kuaichangensis Ahrens, 2003 , N. ursina ( Brenske, 1894)

22 ʹ Body high and oval. ............................................................................................................................ 23

23 Larger species, elytral length along suture ~ 6.6 mm ................................................................... ............................................................. N. vulpina Moser, 1908 , N. pseudovulpina Ahrens, 2003

23 ʹ Smaller species, elytral length along suture <5.6 mm .......... N. hirokazui Ahrens, 2003

Figures

Figure 1. (a–d) Neoserica hongheana sp. nov. (holotype); (e–h) N. pachecoae sp. nov. (holotype). (a, e) Aedeagus, lateral view of left side; (c, g) aedeagus, lateral view of right side; (b, f) parameres, dorsal view; (d, h) habitus. Scale bars: 0.5 mm.