Thrips (Masumoto & Okajima, 2019)

Masumoto, Masami, Tsutsumi, Tadaaki & Okajima, Shûji, 2023, Two new species of the genus Thrips Linnaeus (Thysanoptera, Thripidae) in Japan with a revised key to Japanese species of Thrips, Zootaxa 5239 (3), pp. 358-372 : 360-363

Key to Japanese species of Thrips

(*: male unknown; male of T. minutissimus not known from Japan)

1. Female............................................................................................. 2

-. Male.............................................................................................. 40

2. Abdominal sternites with at least 1 pair of discal setae........................................................ 3

-. Abdominal sternites without discal setae.................................................................. 20

3. Abdominal sternite VII with discal setae................................................................... 4

-. Abdominal sternite VII without discal setae............................................................... 17

4. Pleurotergites with discal setae........................................................................... 5

-. Pleurotergites without discal setae........................................................................ 8

5. Fore wing first vein without long gap of setal row, 6–9 distal setae; abdominal tergite VIII with posteromarginal comb complete, microtrichia developed....................................................................... minutissimus

-. Fore wing first vein with long gap of setal row, 3 distal setae; abdominal tergite VIII without posteromarginal comb medially, or no developed microtrichia............................................................................ 6

6. Body uniformly dark; antennae 8-segmented; abdominal sternites III–VI with 6 posteromarginal setae; metascutum sculptured longitudinally and without CPS............................................................. alliorum (in part)

-. Body uniformly pale; antennae 7-segmented; abdominal sternites III–VI with 10–15 posteromarginal setae; metascutum reticulate longitudinally at middle and with CPS............................................................. 7

7. Pronotum with 2 pairs of posteroangular setae...................................................... subnudula

-. Pronotum with no long setae....................................................................... aspinus

8. Antennae 8-segmented; fore wing first vein often with more than 3 setae on distal half; abdominal tergite VIII with posteromarginal comb rarely lacking at middle.............................................................. 9

-. Antennae 7-segmented; fore wing first vein with 3 setae on distal half; abdominal tergite VIII with posteromarginal comb complete........................................................................................... 12

9. Metascutum sculptured with longitudinal striae medially, median pair of setae arising from anterior margin; ocellar setae pair III lateral to fore ocellus............................................................................... 10

-. Metascutum reticulate, no longitudinal striae medially, median pair of setae arising behind anterior margin; ocellar setae pair III posterolateral to fore ocellus......................................................................... 11

10. Abdominal tergite VIII with posteromarginal comb complete, but microtrichia short and slightly irregular; fore wing first vein always with 3 distal setae............................................................... hawaiiensis (in part)

-. Abdominal tergite VIII without posteromarginal comb medially; fore wing first vein often with more than 3 distal setae................................................................................................. vitticornis

11. Fore wing first vein with 6–9 distal setae; metascutum with reticulations having internal wrinkles, CPS absent; pleurotergites with ciliate microtrichia........................................................................... simplex

-. Fore wing first vein with 3 distal setae; metascutum with ill-formed reticulations having no internal wrinkles, CPS present; pleurotergites without ciliate microtrichia............................................................... pini

12. Pronotum with 1 pair of posteroangular setae; body uniformly yellow..................................... unisetifer

-. Pronotum with 2 pairs of posteroangular setae; body not uniformly yellow....................................... 13

13. Metascutum with CPS; ocellar setae pair III lateral to fore ocellus; abdominal tergite II with 4 lateral marginal setae arranged in a line; fore wing not uniformly dark, more or less pale at base............................................... 14

-. Metascutum without CPS; ocellar setae pair III posterolateral to fore ocellus; abdominal tergite II with 3 lateral marginal setae, and a small seta on pleurotergite anterolaterally; fore wing uniformly dark....................................... 16

14. Metascutum with median pair of setae at anterior margin...................................... hawaiiensis (in part)

-. Metascutum with median pair of setae behind anterior margin................................................. 15

15. Body bicoloured, yellow with abdominal segments IX–X and median third of tergites II–VIII dark; abdominal sternite VII with S1 setae distinctly in front of posterior margin; fore wing shaded with base slightly pale...................... coloratus

-. Body uniformly dark; abdominal sternite VII with S1 setae at or slightly anterior to posterior margin; fore wing dark with base distinctly pale............................................................................. ogasawarensis

16. Abdominal tergite X less than 65 μm long (usually 58 μm); X1+2X2+X3 (X1=pronotal posteroangular setae I length, X2=S3 setae length on tergite IX, X3=tergite X length) usually 303–353 (range 286–390)............................. griseus

-. Abdominal tergite X more than 70 μm long (usually 76 μm); X1+2X2+X3 usually 397–425 (range 385–438)...... trehernei

17. Pleurotergites with discal setae; fore wing banded, with two dark bands at median fourth and distal fourth, first vein with long gap of setal row, 3 distal setae; metascutum irregularly reticulate; abdominal tergite VIII with posteromarginal comb complete........................................................................................... 18

-. Pleurotergites without discal setae; fore wing not banded, uniformly dark at distal four-thirds, first vein rarely without long gap of setal row; metascutum polygonally reticulate; abdominal tergite VIII without posteromarginal comb medially......... 19

18. Metascutum with CPS; antennal segments almost uniformly dark, VI with 9 setae............................ syringae

-. Metascutum without CPS; antennal segments III–IV pale with apex shaded, VI with 10 setae................... nonakai

19. Fore wing uniformly dark, first vein without long gap in setal row, setal row almost complete........... orientalis (in part)

-. Fore wing pale at base, first vein with long gap of setal row, 3 distal setae........................ extensicornis (in part)

20. Pleurotergites with discal setae.......................................................................... 21

-. Pleurotergites without discal setae....................................................................... 24

21. Body uniformly pale, with no brown markings; abdominal tergite II with 4 lateral marginal setae arranged in a line.................................................................................................... brevicornis

-. Body brown; abdominal tergite II with 3 lateral marginal setae, and a small seta on pleurotergite anterolaterally......... 22

22. Fore wing uniformly pale or slightly shaded; all legs yellowish, never dark; abdominal sternite I with 2 microsetae anteromedially.................................................................................. typicus

-. Fore wing dark with base pale; at least mid and hind femora usually dark; abdominal sternite I without microsetae anteromedially...................................................................................... 23

23. Antennal segment VII 2.3–3.0 times as long as wide, segment VI with 12 setae; tibiae pale...................... setosus

-. Antennal segment VII less than 2.0 times as long as wide, segment VI with 10 setae; tibiae dark................ brunneus

24. Metascutum with polygonal reticulations; abdominal tergite VIII without posteromarginal comb medially; fore wing first vein usually without long gap in setal row..................................................................... 25

-. Metascutum with longitudinal sculpture or ill-formed reticulations, no polygonal reticulations; abdominal tergite VIII with posteromarginal comb complete, microtrichia usually developed; fore wing first vein with long gap in setal row, usually 3 rarely more distal setae, rarely micropterous.................................................................... 27

25. Fore wing first vein with 3 distal setae.................................................... extensicornis (in part)

-. Fore wing first vein with almost complete setal row......................................................... 26

26. Fore wing uniformly dark; metascutum without CPS........................................... orientalis (in part)

-. Fore wing pale at base; metascutum usually with CPS................................................... malloti

27. Abdominal tergite II with 3 lateral marginal setae, no small seta on pleurotergite.................................. 28

-. Abdominal tergite II with 4 lateral marginal setae........................................................... 30

28. Fore wing banded, pale with brown bands at median fourth and extreme base including clavus; body uniformly pale; metascutum with paired CPS; abdominal tergite IX with usually 2 pairs of or 3 CPS, often posterior pair of CPS only........... rhamni

-. Fore wing never banded, rarely with a shaded marking medially, almost uniformly pale or slightly shaded, often micropterous; body not uniformly pale, usually with brown or pale brown markings; metascutum without CPS; abdominal tergite IX with 1 pair of CPS......................................................................................... 29

29. Always macropterous, fore wing first vein with 4–6 distal setae; pleurotergites with numerous ciliate microtrichia; abdominal tergites smooth medially; compound eyes without pigmented facets ventrally.................................. tabaci

-. Macropterous to micropterous, when macropterous fore wing first vein with 3 distal setae; pleurotergites without ciliate microtrichia; abdominal tergites sculptured medially; compound eyes with 5 pigmented facets ventrally........ nigropilosus

30. Abdominal tergite II with 4 lateral marginal setae arranged not in a line, accessary setae mesad of setal row; head prolonged anteriorly; metascutal sculpture not longitudinal at middle; abdominal tergites sculptured throughout, tergites II–VIII with S1 setae subequal to S2 setae; tergite VIII with complete but short irregular posteromarginal comb [body uniformly pale, antennae 7-segmented]............................................................................... shiranensis *

-. Abdominal tergite II with 4 lateral marginal setae arranged in a line ( Fig. 15 ); head not prolonged anteriorly; metascutal sculpture longitudinal at middle; abdominal tergites smooth medially, with S1 setae shorter than S2 setae; tergite VIII with long regular posteromarginal comb.......................................................................... 31

31. Fore wing dark except base; body uniformly dark; antennae 7-segmented........................................ 32

-. Fore wing uniformly pale ( Figs 7–10 ) or shaded; body pale, rarely with pale brown markings; antennae rarely 8-segmented 33

32. Abdominal sternite VII usually with 2 pairs of posteromarginal setae; metascutum with reticulations medially. shiranesanus *

-. Abdominal sternite VII with 3 pairs of posteromarginal setae; metascutum closely sculptured longitudinally at middle floreus

33. Ocellar setae pair III within ocellar triangle, just behind fore ocellus; antennae 7- or 8-segmented.................. flavus

-. Ocellar setae pair III outside or at anterior margin of ocellar triangle ( Fig. 11 ); antennae 7-segmented.................. 34

34. Abdominal tergite IX with 1 pair of CPS.................................................................. 35

-. Abdominal tergite IX with 2 pairs of, or 3 CPS ( Fig. 24 )..................................................... 36

35. Body usually with pale brown markings; pronotum with a pair of setae longer than remaining discal setae near anterior margin; antennal segment VI pale at base; metascutum with CPS................................................. urticae

-. Body uniformly pale; pronotum without such setae near anterior margin ( Fig. 20 ); antennal segment VI uniformly dark; metascutum with or without CPS................................................... spiranthicola sp. n. (in part)

36. Mouth-cone long and pointed at apex, reaching to mesothorax; antennal segment VI dark with base pale............. sukki

-. Mouth-cone not pointed, not reaching to mesothorax; antennal segment VI uniformly dark.......................... 37

37. Hind coxa with distinct large microtrichia on inner dorsal surface ( Fig. 14 ).............................. coxalis sp. n.

-. Hind coxa without microtrichia or with minute indistinct microtrichia on inner dorsal surface ( Figs 23 , 32, 33 ).......... 38

38. Abdominal tergite VIII with S1 setae usually subequal in length to S2 setae, tergites II–V with S2 setae distinctly paler than lateral marginal setae; fore wing usually brown ( Fig. 7 ); hind coxa often usually with a few minute indistinct microtrichia on inner dorsal surface ( Fig. 32 ).......................................................................... alni

-. Abdominal tergite VIII with S1 setae usually distinctly shorter than S2 setae, tergites II–V with S2 setae almost as dark as lateral marginal setae; fore wing pale ( Fig. 10 ), at most slightly shaded; hind coxa without microtrichia on inner dorsal surface ( Fig. 33 )................................................................................................ 39

39. Mesonotum sculptured around anteromedian CPS, at least between both CPS ( Fig. 31 ); metascutum with paired CPS, longitudinal striae curve to middle near posterior margin at middle.......................................... palmi

-. Mesonotum smooth around anteromedian CPS ( Fig. 22 ); metascutum with paired or single or no CPS, longitudinal striae usually not curve to middle near posterior margin at middle.............................. spiranthicola sp. n. (in part)

40. Abdominal sternites with at least 1 pair of discal setae....................................................... 41

- Abdominal sternites without discal setae ( Fig. 19 ).......................................................... 56

41. Abdominal sternite VIII with discal setae; metascutum sculptured with longitudinal striae or reticulations, or irregular reticulations medially, never polygonally reticulate; pleuroterigites with or without discal setae....................... 42

-. Abdominal sternite VIII without discal setae; metascutum reticulate polygonally; pleuroterigites without discal setae..... 55

42. Pleurotergites with discal setae.......................................................................... 43

-. Pleurotergites without discal setae....................................................................... 46

43. Fore wing first vein without long gap of setal row, 6-9 distal setae..................................... minutissimus

-. Fore wing first vein with long gap of setal row, 3 distal setae or micropterous..................................... 44

44. Body dark and micropterous; antennae 8-segmented; abdominal sternites III–VI with 6 posteromarginal setae; metascutum sculptured with longitudinal narrow spaced anastomosing striae and without CPS..................... alliorum (in part)

-. Body pale and always macropterous; antennae 7-segmented; abdominal sternites III–VI with 10–15 posteromarginal setae; metascutum reticulate longitudinally at middle and with CPS................................................. 45

45. Pronotum with 2 pairs of posteroangular setae...................................................... subnudula

-. Pronotum with no long setae....................................................................... aspinus

46. Pronotum with 1 pair of posteroangular setae........................................................ unisetifer

-. Pronotum with 2 pairs of posteroangular setae............................................................. 47

47. Abdominal sternites III–V or VI with oval pore plates; head bicoloured, dark but pale posteriorly [antennae 8-segmented].................................................................................................... pini

-. Abdominal sternites III–VII with pore plates; head uniformly dark or pale....................................... 48

48. Ocellar setae pair III lateral to fore ocellus; metascutum with CPS.............................................. 49

-. Ocellar setae pair III posterior to, or posterolateral to fore ocellus; metascutum without CPS......................... 52

49. Metascutum with median pair of setae at anterior margin; antennae 7 or 8-segmented.............................. 50

-. Metascutum with median pair of setae behind anterior margin; antennae 7-segmented.............................. 51

50. Body uniformly pale; fore wing uniformly pale, first vein with 3 distal setae; abdominal sternites with narrow oblong pore plats; antennae 7 or 8-segmented..................................................................... hawaiiensis

-. Body uniformly dark; fore wing dark with base pale, first vein with 3 or more distal setae; abdominal sternites with broad oblong pore plats; antennae 8-segmented............................................................ vitticornis

51. Body and fore wing uniformly pale................................................................ coloratus

-. Body uniformly dark, fore wing dark with base pale............................................... ogasawarensis

52. Antennae 8-segmented; ocellar setae pair III within ocellar triangle; metascutum with median pair of setae much behind anterior margin; abdominal tergite IX with median pair of setae anterior to submedian pair, both pairs arranged not in a line...... 53

-. Antennae 7-segmented; ocellar setae pair III on anterior margin of ocellar triangle; metascutum with median pair of setae near anterior margin; abdominal tergite IX with median pair of setae lateral to submedian pair, both pairs arranged in a line.... 54

53. Macropterous, fore wing first vein with 6–9 distal setae; metascutum with longitudinal reticulations and internal wrinkles................................................................................................. simplex

-. Micropterous; metascutum with longitudinal anastomosing striae.................................. alliorum (in part)

54. Body uniformly pale.............................................................................. griseus

-. Body uniformly dark............................................................................ trehernei

55. Body and fore wing uniformly pale; fore wing first vein with 3 distal setae....................... extensicornis (in part)

-. Body and fore wing uniformly dark; fore wing first vein with almost complete setal row............... orientalis (in part)

56. Plesurotergites with discal setae......................................................................... 57

-. Plesurotergites without discal setae...................................................................... 60

57. Antennal segment VII more than 2.3 times as long as broad, segment VI with about 12 setae; body largely pale but shaded between compound eyes........................................................................... setosus

-. Antennal segment VII less than 2.0 times as long as broad, segment VI with about 20 setae; head uniformly pale or dark.. 58

58. Body uniformly dark; abdominal sternite I without microsetae anteromedially.............................. brunneus

-. Body uniformly pale; abdominal sternite I usually with 1–3 microsetae anteromedially............................. 59

59. Abdominal tergite II with 4 lateral marginal setae arranged in a line..................................... brevicornis

-. Abdominal tergite II usually with 3 lateral marginal setae, and a small seta on pleurotergite...................... typicus

60. Metascutum reticulate polygonally...................................................................... 61

-. Metascutum striate longitudinally (cf. Fig. 13 ) or irregularly reticulate at middle, never reticulate polygonally........... 63

61. Fore wing first vein with long gap of setal row, 3 distal setae; body uniformly pale................ extensicornis (in part)

-. Fore wing first vein with almost complete setal row; body uniformly dark....................................... 62

62. Fore wing uniformly dark; legs dark; metascutum without CPS................................... orientalis (in part)

-. Fore wing dark with base pale; legs pale; metascutum with CPS.................................... malloti (in part)

63. Abdominal tergite II with 3 lateral marginal setae, and no small seta on pleurotergite............................... 64

-. Abdominal tergite II with 4 lateral marginal setae arranged in a line (cf. Fig. 15 ).................................. 68

64. Micropterous; abdominal tergites II–VII with S1 setae subequal in length to S2 setae, sculptured with transverse striae between S1 setae; compound eyes with 5 pigmented facets ventrolaterally; body yellow to yellowish brown, usually with brown markings [metascutum irregularly reticulate, without CPS]................................................... nigropilosus

-. Macropterous; abdominal tergites II–VII with S1 setae much shorter than S2 setae, smooth between S1 setae; compound eyes without pigmented facets ventrolaterally; body usually almost pale............................................. 65

65. Fore wing never banded, uniformly slightly shaded, first vein with 4–6 distal setae; all postocular setae subequal in length [abdominal sternites III–V with oblong pore plates]...................................................... tabaci

-. Fore wing banded, not uniformly pale or shaded, first vein with 3 distal setae; postocular setae S1 and S3 longer than S2 and S4................................................................................................ 66

66. Fore wing with brown bands at median forth and extreme base including clavus; abdominal sternites III–VII with oblong pore plates; metascutum sculptured with longitudinal striae, with CPS.......................................... rhamni

-. Fore wing with dark bands at middle fourth and distal fourth; abdominal sternites III–IV (rarely VI) with small circular or oval pore plates; metascutum irregularly reticulate, with or without CPS............................................. 67

67. Metascutum with CPS; antennal segment III and IV uniformly dark....................................... syringae

-. Metascutum without CPS; antennal segment III and IV pale at basal half................................... nonakai

68. Body uniformly dark; antennal segment III yellow, remaining segments dark; abdominal sternal pore plates large, occupying most area of each sternite.......................................................................... floreus

-. Body usually uniformly pale ( Figs 3, 6 ); antennal segment colour different; abdominal sternal pore plates smaller ( Figs 19 , 27 , 38, 39 )............................................................................................. 69

69. Ocellar setae pair III just behind fore ocellus; antennae 7- or 8-segmented.................................... flavus

-. Ocellar setae pair III lateral or posterolateral to fore ocellus; antennae 7-segmented............................... 70

70. Abdominal sternites III–V or VI with small oval pore plates ( Fig. 38 ); fore wing usually brown [abdominal tergite VIII with posteromarginal comb not developed, usually no microtrichia medially ( Fig. 36 )]................................ alni

-. Abdominal sternites III–VII with oblong pore plates; fore wing at most shaded................................... 71

71. Mouth-cone long and pointed at apex, reaching to mesothorax [antennal segment VI pale at base].................. sukki

-. Mouth-cone not pointed, not reaching to mesothorax........................................................ 72

72. Pronotum with a pair of setae near anterior margin longer than remaining discal setae; antennal segment VI pale at base................................................................................................... urticae

-. Pronotum without such setae near anterior margin; antennal segment VI uniformly dark............................ 73

73. Hind coxa with distinct large microtrichia on inner dorsal surface; abdominal tergite VIII with posteromarginal comb not complete, weakly developed, but microtrichia often fine and long medially ( Fig. 18 ); sternal pore plates as wide as interval of S1 setae ( Fig. 19 )........................................................................... coxalis sp. n.

-. Hind coxa without microtrichia on inner dorsal surface; abdominal tergite VIII with posteromarginal comb almost complete, microtrichia fine and long ( Figs 26 , 37 ); sternal pore plates much wider than interval of S1 setae..................... 74

74. Abdominal sternal pore plates not reaching to S2 setae ( Fig. 39 ), width of pore plate at most 75 μm ( Table 4 ); metascutum with CPS, longitudinal striae usually curve to middle near posterior margin at middle; antennal segment VI with about 20 setae.................................................................................................. palmi

-. Abdominal sternal pore plates larger, reaching or almost reaching to S2 setae ( Fig. 27 ), width of pore plate at least 78 μm ( Table 4 ), metascutum with or without CPS, variable sculpture, usually longitudinal not curve to middle near posterior margin, or irregular or longitudinal reticulations at middle; antennal segment VI with 14 setae.................. spiranthicola sp. n.

Figures

FIGURES 11–19. Thrips coxalis sp. n. (11) head & pronotum, female. Antenna 12a–b: (12a) segments I–VII, female; (12b) segments VI-VII, male. (13) mesonotum & metascutum, female; (14) hind coxa to femur, female; (15) tergite II, female; (16) tergites VIII–X, female; (17) pleurotergite IV (left), female. Male 18–19: (18) tergites VIII–IX; (19) sternites V–VI.

FIGURES 1–10. Thrips species. (1) T. alni, female. T. coxalis sp. n. 2–3: (2) female; (3) male. (4) T. palmi, female. T. spiranthicola sp. n. 5–6: (5) female; (6) male. Fore wing, female 7–10: (7) T. alni; (8) T. coxalis sp. n.; (9) T. palmi; (10) T. spiranthicola sp. n.

FIGURES 20–27. Thrips spiranthicola sp. n. (20) head & pronotum, female. Antenna 21a–b: (21a) segments I–VII, female; (21b) segments VI-VII, male. (22) mesonotum & metascutum, female; (23) hind coxa to femur, female; (24) tergites VIII–X, female; (25) pleurotergite IV (right), female. Male 26–27: (26) tergites VIII–IX; (27) sternites V–VI.

FIGURES 28–33. Thrips species, female. Head 28– 29: (28) T. alni; (29) T. palmi. Mesonotum & metascutum 30–31: (30) T. alni; (31) T. palmi. Hind coxa to femur 32–33: (32) T. alni; (33) T. palmi.

FIGURES 34–39. Thrips species. Antenna 34–35, a: female; b: male: (34) T. alni; (35) T. palmi. Abdominal tergites VIII–IX, male 36–37: (36a) T. alni; (36b) T. alni, variation of posteromarginal comb on tergite VIII; (37) T. palmi. Abdominal sternites V–VI, male 38–39: (38) T. alni; (39) T. palmi.