Maladera Mulsant & Rey, 1871

Fabrizi, Silvia, Liu, Wan-Gang, Bai, Ming, Yang, Xing-Ke & Ahrens, Dirk, 2021, A monograph of the genus Maladera Mulsant & Rey, 1871 of China (Coleoptera: Scarabaeidae: Melolonthinae: Sericini), Zootaxa 4922 (1), pp. 1-400 : 11-14

Maladera Mulsant & Rey, 1871

Maladera Mulsant & Rey, 1871: 596 , 599 (Type species by monotypy: Melolontha holosericea Scopoli, 1772 ).

Aserica Lewis, 1895: 394 (Type species by original designation: Serica japonica Lewis, 1895 (nec Motschulsky, 1860) = Autoserica secreta Brenske, 1897 ; Arrow 1946a).

Autoserica auctorum (nec Brenske, 1897).

Key to subgenera and species groups of Maladera in framework of the trilamellate genera of Sericini occurring in Mainland China (³³):

1 Base of pronotum with marginal line. Hypomeron not carinate.................................... Archaehomaloplia

1’ Base of pronotum without marginal line.................................................................... 2

2 Protibia with three teeth................................................................................ 3

2’ Protibia with two teeth................................................................................. 4

3 Body unicoloured: blackish, brown or reddish brown........................................ Maladera sinica group

3’ Body bicoloured. Antennal club in male composed of four antennomeres.................................. Trioserica

4 Hypomeron carinate................................................................................... 8

4’ Hypomeron not carinate................................................................................ 5

5 Antennal club in male composed of three antennomeres....................................................... 6

5 Antennal club in male composed of four antennomeres............................................... Tetraserica

6 Body elongate, dark or light brown, mostly dull. Antennal club in male long. Apex of metatibia shallowly or sharply truncate. ................................................................................................... 7

6’ Body short, yellowish brown, shiny....................................................... Maladera haba group

7 Aedeagus asymmetrical.............................................................. Serica (subgen. Serica )

7’ Aedeagus symmetrical...................................................................... Nipponoserica

8 Antennal club in male composed of three antennomeres....................................................... 9

8’ Antennal club in male composed of more than three antennomeres...................... other genera (not included here)

9 Legs narrow and long (ratio width/length: 1/3.7–4.6)........................................................ 10

9’ Legs not narrow and moderatey long (ratio width/length: 1/2.5–3).............................................. 11

10 Parameres asymmetrical. Metacoxae glabrous except lateral or microscopic setae..................... Serica (sensu lato)

10’ Parameres symmetrical. Metacoxae evenly covered with adjacent fine setae............................... Xenoserica

11 Metafemur with a serrated line adjacent to the anterior margin................................................. 13

11’ Metafemur without serrated line adjacent to the anterior margin............................................... 12

12 Mesostermum not produced anteriorly between mesocoxae................................................... 24

12’ Mesostermum produced anteriorly between mesocoxae, protuding.................................. Hoplomaladera

13 Serrate line adjacent to the anterior margin continuous....................................................... 14

13’ Serrate line adjacent to the anterior margin interrupted multiple times.... Maladera panyuensis Ahrens, Fabrizi & Liu , sp. n.

14 Pronotum and elytra glabrous........................................................................... 15

14’ Pronotum and elytra more or less densely setose......................................... Amiserica insperata group

15 Posterior longitudinal row of setae on metafemur absent.................................. Maladera servitrita group

15’ Posterior longitudinal row of setae on metafemur present..................................................... 16

16 Parameres completely separated......................................................................... 17

16’ Parameres completely fused medially..................................................................... 22

17 Phallobase without dorsal apophysis. Body generally dull.................................................... 18

17’ Phallobase with a dorsal apophysis. Each paramere at apex with a membraneous sac......................... Amiserica

18 Body generally smaller (<7 mm)..................................................... Maladera teinzoana group

18’ Body generally larger (> 8 mm)......................................................................... 19

19 Parameres and phallobase strongly asymmetric. Metatarsomeres ventrally setose.................................. 20

19’ Apical phallobase, at least their distal part, subsymmetric..................................................... 21

20 Apex of phallobase strongly asymmetric. Metatibia short and wide. Body surface coarsely, densely punctate.......................................................................................... Maladera (subg. Eumaladera )

20’ Apex of phallobase weakly asymmetric. Metatibia long and narrow. Body surface finely and moderately densely punctate................................................................... Maladera jatuai Ahrens, Fabrizi & Liu , sp. n.

21 Posterior margin of metafemur with a blunt tooth apically. Without additional sclerites between parameres............................................................................................... Maladera (subg. Aserica )

21 Posterior margin of metafemur convexly rounded apically.................................................... 23

22 Anterior margin of labroclypeus bidentate viewed from posterior. Metatibia narrower,..ratio width/ length: 1/3.5. Phallobase with a dorsal apical apophysis. Body iridescent or dull...................................... Maladera egregia group

22’ Anterior margin of labroclypeus tridentate viewed from posterior. Metatibia wider, ratio width/ length: 1/2.2. Phallobase with a lateral preapical apophysis. Body generally larger and dull.......................... Maladera rotunda (Arrow, 1946)

23 Area between parameres with triangular and sharply pointed additional sclerites. Dorsal surface dark and dull......................................................................................... Maladera (subgen. Maladera )

23’ Area between parameres lacking triangular and sharply pointed additional sclerites. Dorsal surface reddish brown and shiny............................................................................. Maladera nitens group (part 1)

24 Apex of metatibia sharply truncate at interior apex near tarsal articulation........ Maladera (subg. Hemiserica ) (part, India)

24’ Apex of metatibia bluntly truncate or concavely emarginate at interior apex near tarsal articulation.................... 25

25 Dorsal posterior margin of metafemur serrate. Legs generally slender........................................... 26

25’ Dorsal posterior margin of metafemur smooth.............................................................. 37

26 Parameres narrow and symmetric....................................................................... 27

26’ Parameres asymmetric................................................................................ 28

27 Body reddish brown and shiny. Metatarsi not carinate laterally. Carina of hypomeron not ventrally produced........................................................................................... Maladera brunnescens group

27’ Body dark brown, dull. Metatarsi carinate laterally. Carina of hypomeron ventrally produced........ Gastromaladera ( Japan)

28 Anterior angles of pronotum not produced, obsolete. Dorsal surface with dense pilosity, often composed by white scale-like setae...................................................................................... Pachyserica

28’ Anterior angles of pronotum produced, blunt to sharp........................................................ 29

29 Hypomeron weakly carinate........................................................ Serica (subgen. Serica ) part

29’ Hypomeron distinctly carinate.......................................................................... 30

30 Mentum convexly elevated anteriorly..................................................................... 31

30’ Mentum flat, with a semi-circular ridge anteriorly................................................ Trichomaladera

31 Dorsal and ventral surface densely setose. Antennal club twice as long as remaining antennomeres combined.... Paraserica

31’ Dorsal and ventral surface sparsely setose. Antennal club generally shorter....................................... 32

32 Base of clypeus shiny. Metafemur with anterior row of setae. Body more elongate................................. 33

32’ Base of clypeus dull. Anterior row of setae of metafemur nearly entirely absent. Body oval....... Maladera liwenzhui group

33 Ventral posterior margin of metafemur serrate in apical half only. Metatibia without serrate line beside dorsal margin......................................................................... Maladera uncipenis group, Paramaladera

33’ Ventral posterior margin of metafemur completely serrate. Metatibia with a serrate line beside dorsal margin, which is interrupted at middle..................................................................................... 34

34 Phallobase without lateral apophysis..................................................................... 36

34’ Phallobase with long lateral apophysis.................................................................... 35

35 Right paramere simple, not bifid. Insertion of parameres at nearly same level of longitude..................................................................................... Maladera jingangshanica Ahrens, Fabrizi & Liu , sp. n.

35 Right paramere bifid. Insertion of parameres strongly asymmetric...... Maladera baishaoensis Ahrens, Fabrizi & Liu , sp. n.

36 Insertion of parameres lateroapical on phallobase. Phallobase dorsoapically deeply and widely emarginate at middle.................................................................................... Maladera crenolatipes group

36’ Insertion of parameres dorsoapical on phallobase. Phallobase dorsoapically narrowly and shallowly emarginate at middle.............................................................. Maladera trifidiforceps Ahrens, Fabrizi & Liu , sp. n.

37 Parameres symmetric................................................................................. 38

37’ Parameres asymmetric................................................................................ 44

38 Protarsal claws often asymmetrical (if symmetrical, parameres with basal lobe)................................... 43

38’ Protarsal claws symmetrical. Parameres without distinct basal lobe............................................. 39

39 Body dorsally more or less glabrous. Antennal club short and straight........................................... 41

39’ Body dorsally densely setose. Antennal club long and reflexed................................................. 40

40 Body dorsally shiny........................................... Maladera nabanensis Ahrens, Fabrizi & Liu , sp. n.

40’ Body dorsally dull.......................................... Maladera luoxiangensis Ahrens, Fabrizi & Liu , sp. n.

41 Body generally bicoloured, yellowish brown and dark brown to blackish. Body smaller (<6 mm). Antenna with 9 antennomeres........................................................................... Maladara assamica group

41’ Body unicoloured, reddish to dark brown. Body larger (> 7.5 mm). Antenna with 10 antennomeres.................... 42

42 Frons on disc glabrous. Phallobase at apex not narrowed (dorsal view)................. Maladera tibialis ( Brenske, 1898)

42’ Frons on disc sparsely covered with long setae. Phallobase at apex strongly narrowed (dorsal view)............................................................................... Maladera nanlingensis Ahrens, Fabrizi & Liu , sp. n.

43 Parameres with distinct basal lobe. Unicoloured species...................................... Maladera indica group

43’ Parameres without basal lobe. Bicoloured species................................. Maladera sikkimensis group (part1)

44 Parameres setose (apically or basally). Parameres often reduced in length, very narrow and hook-like. Median phallobase produced distally producing a sclerotised tube............................................. Maladera marginella group

44’ Parameres glabrous. Median phallobase not produced distally producing a sclerotised tube........................... 45

45 Basal apodeme of phallobase shortened, corresponding about 1/5 of phallobasal length. Phallobase tube-like extended............................................................................. Maladera (subg. Omaladera ) part 1

45’ Basal apodeme of phallobase not shortened, corresponding about half of phallobasal length. Phallobase not tube-like extend- ed................................................................................................ 46

46 Eyes very small, ratio diameter/ interocular width: 0.29–0.41. Body larger (> 8 mm). Wings often reduced........................................................................................... Maladera erlangshanica group

46’ Eyes small to moderately large, ratio diameter/ interocular width:>0.5. Wings always fully developed................. 47

47 Parameres with basal appendages....................................................................... 48

47’ Parameres without basal appendages..................................................................... 58

48 Basal appendages more or less wide, not filiform........................................................... 49

48’ Basal appendages very long and filiform, partly longer than phallobase. Body larger (> 7 mm). Parameres distinctly asymmetrical................................................................................................ 54

49 Body size small (4.5–5.5 mm)........................................................................... 52

49’ Body size larger 9 mm ................................................................................ 50

50 Phallobase at apex strongly but evenly narrowed (dorsal view). Intervals flat, striae indistinct..................................................................................... Maladera hutiaoensis Ahrens, Fabrizi & Liu , sp. n.

50’ Phallobase at apex not narrowed (dorsal view). Intervals weakly convex, striae distinct............................. 51

51 Frons anteriorly narrowly shiny. Legs long and narrow, ratio width/length: 1/3.3–4.0........... Maladera shenglongi group

51’ Frons completely dull. Legs short and wide, ratio width/ length: 1/ 2.5.. Maladera wulaoshanica Ahrens, Fabrizi & Liu , sp. n.

52 Distal portion of parameres nearly symmetrical. Dorsal body surface dull............. Maladera sikkimensis group (part 2)

52’ Parameres strongly asymmetrical. Dorsal body surface shiny.................................................. 53

53 Phallobase with a long lateral apophysis on left side................................ Maladera punctulata (Frey, 1972)

53’ Phallobase with a long dorsal apophysis........................................... Maladera parva ( Moser, 1908)

54 Epipleural edge ending behind the anterior third of elytra..................................................... 55

54’ Epipleural edge ending at the external apical angle of elytra. Dorsal surface of body glabrous........................ 56

55 Apex of phallobase dorsomedially deeply emarginate. Dorsal surface of body yellow and shiny, glabrous................................................................................. Maladera lukjanovitschi ( Medvedev, 1966)

55’ Apex of phallobase dorsomedially not or only shallowly emarginate. Dorsal surface of body dull. Elytra and pronotum with a few long setae on disc.............................................................. Maladera thomsoni group

56 Surface dull. Anterior femur with a single row of setae behind the anterior margin............. Maladera modestula group

56’ Surface mostly shiny. If dull, anterior femur with two rows of setae behind the anterior margin....................... 57

57 Metatibia without serrate line beside dorsal margin. Legs short and wide, ratio of width/length: 1/2.38–2.67. Anterior femur with a single row of setae behind the anterior margin........................................ Maladera detersa group

57’ Metatibia with serrate line beside dorsal margin. Legs moderately long and narrow, ratio of width/length: 1/2.5–3.2. Anterior femur with two rows of setae behind the anterior margin............................... Maladera nitens group (part 2)

58 Phallobase dorsally at apex produced into a shortly lobe-like apophysis between parameres................................................................................................... Maladera (subg. Omaladera ) part 2

58’ Phallobase dorsally at apex concavely emarginate between parameres........................................... 59

58’’ Phallobase at apex with a roof-like, sharply pointed dorsal process that equals the parameres in length................................................................................................. Maladera gansuensis group

59 Base of labroclypeus dull, otherwise moderately shiny.................................. Maladera granuligera group

59’ Complete labroclypeus shiny........................................................................... 60

60 Surface of labroclypeus carinate along middle. Legs short and wide.......................... Maladera drescheri group

60’ Surface of labroclypeus flat or convex. Legs moderately long and wide.......................................... 61

61 Hypomeron carinate, carina not produced ventrally.......................................................... 62

61’ Hypomeron carinate, carina strongly produced ventrally................................. Maladera gibbiventris group

62 Surface of labroclypeus convex........................................ Maladera (subg. Hemiserica ) part 2 ( China)

62’ Surface of labroclypeus flat............................................................................ 63

63 Dorsal apical emargination of phallobase deep and wide, dorsal phallobase not narrowed before insertion of parameres... 64

63’ Dorsal apical emargination of phallobase shallow and narrow, dorsal sclerotized part of phallobase extremely narrowed before insertion of parameres......................................... Maladera wandingana Ahrens, Fabrizi & Liu , sp. n.

64 Body reddish to dark brown........................................................ Maladera ferruginea group

64’ Body yellowish brown......................................................................... Amaladera

Maladera (subgen. Maladera )

Key to species of Maladera (subgen. Maladera ) occurring in China (³³):

1 Robust serrate line beside anterior margin of metafemur present. Dorsal margin of metatibia longitudinally sharply carinate. Triangular and sharply pointed additional sclerites between parameres robust...................................... 2

1’ Serrate line beside anterior margin of metafemur absent or very weak. Dorsal margin of metatibia longitudinally convex. Triangular sclerites between parameres very narrow, sometime not visible. Antennal club long, 1.5–1.7 times as long as remaining antennomeres combined.................................................. Maladera holosericea ( Scopoli, 1772)

2 Antennal club long, 1.5–1.7 times as long as remaining antennomeres combined......... Maladera renardi ( Ballion, 1870)

2’ Antennal club short, as long as or little longer than remaining antennomeres combined.............................. 3

3 Left paramere split one third of its length before apex. Right paramere without blunt preapical lateral tooth.................................................................................... Maladera spissigrada ( Brenske, 1897)

3 Left paramere simple, not split. Right paramere with blunt preapical lateral tooth................................... 4

4 Right paramere at middle weakly bent externally ( Fig. 2B ). Preapical lateral tooth small, near apex.......................................................................................... Maladera motschulskyi ( Brenske, 1897)

4’ Right paramere at middle strongly bent externally ( Fig. 2F ). Preapical latheral tooth larger, well before apical third but behind middle..................................................... Maladera chenzhouana Ahrens, Fabrizi & Liu , sp. n.

Figures

FIGURE 2. A–D: Maladera motschulskyi (Brenske, 1897) (Korea); E–H: M. chenzhouana Ahrens, Fabrizi & Liu, sp. n. (holotype). A, E: aedeagus, left side lateral view; C, G: aedeagus, right side lateral view; B, F: parameres, dorsal view; D, H: habitus. Scale: 0.5 mm. Habitus not to scale.