Mycterothrips, Trybom, 1910

Masumoto, Masami & Okajima, Shûji, 2024, Further study of the genus Mycterothrips Trybom (Thysanoptera: Thripidae) in Japan, with description of a new species and a new record, Zootaxa 5489 (1), pp. 107-124 : 109-110

Key to Japanese species of Mycterothrips

(*: unknown in Japan, based on Li & Zhang 2022)

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

-. Male.............................................................................................. 12

2. Abdominal sternites III–VI or VII with a pair of, or one or three, discal setae near posterior margin ( Figs 40, 41 ) [abdominal tergites laterally with ciliate regular microtrichia ( Fig. 39 )]............................................... auratus

-. Abdominal sternites without discal setae................................................................... 3

3. Abdominal tergites II–VIII laterally with ciliate regular microtrichia ( Figs 20, 22 ).................................. 4

-. Abdominal tergites without ciliate regular microtrichia, microtrichia, if present, small and irregular or present on posterior tergites only......................................................................................... 6

4. Abdominal tergite II with 3 lateral marginal setae; antennae usually 7-segmented.............................. shihoae

-. Abdominal tergite II with 4 lateral marginal setae; antennae always 8-segmented................................... 5

5. Antennal segments II–VIII almost uniformly brown although III often slightly paler, I at least shaded, never yellow ( Fig. 18 ); pronotum with more than 50 discal setae ( Fig. 16 )................................................. albiziae sp. n.

-. Antennal segments III yellowish at base, paler than II and IV, I pale, not shaded ( Fig. 21 ); pronotum with about 40 or less discal setae......................................................................................... glycines

6. Fore wing banded, with dark bands at middle and apex; mesonotum sculptured with narrow-spaced transverse anastomosing striae......................................................................................... fasciatus

-. Fore wing not banded, uniformly dark, pale, or pale at base; mesonotum sculptured with wide-spaced transverse anastomosing striae............................................................................................... 7

7. Body largely brown to dark brown, abdomen uniformly dark................................................... 8

-. Body white or yellow to brownish yellow, often with brown markings, abdomen never uniformly dark................. 10

8. Fore wing dark with basal fourth pale; antennal segments III and IV yellowish; pronotum with about 20 discal setae, a pair of anteromarginal setae much longer than discal setae; mesonotum with anteromedian CPS...................... japonicus

-. Fore wing uniformly dark; all antennal segments brown; pronotum with more than 30 discal setae, no long anteromarginal setae; mesonotum without anteromedian CPS............................................................... 9

9. Abdominal tergite IX with both anterior and posterior pairs of CPS; head uniformly dark; pronotum with discal setae slightly short, usually not reaching to next setae........................................................... consociatus

-. Abdominal tergite IX with posterior pair of CPS only; head paler at anteriorly than posteriorly; pronotum with discal setae longer, reaching to next setae....................................................................... egonoki

10. Body yellow with brown markings on abdominal tergites; tergites V–VIII with irregular microtrichia........... yamagishii

-. Body uniformly yellow or white, with no brown markings; abdominal tergites without microtrichia................... 11

11. Ocellar setae pair I absent; antennal segment II without MD seta below CPS; pronotum with a pair of anteromarginal setae much longer than discal setae; abdominal tergite IX with posterior pair of CPS only........................... grandis

-. Ocellar setae pair I present; antennal segment II with a MD seta below CPS; pronotum without long anteromarginal setae; abdominal tergite IX without CPS..................................................................... ricini

12. Antennal segment VI more than 1.1 times as long as combined length of segments I–V, and with numerous long setae and no microtrichia ( Fig. 38 )................................................................................. 13

-. Antennal segment VI less than 0.6 times as long as combined length of segments I–V ( Figs 24a, 25, 28 ); other character states variable............................................................................................ 16

13. Body bicoloured, head and thorax brown, intermediate abdominal segments pale; abdominal sternites without discal setae................................................................................................ grandis *

-. Body not bicoloured, uniformly brown or pale; abdominal sternites IV or V or VI or VII–VIII with discal setae ( Fig. 27 ).. 14

14. Antennal segment IV more than 0.80 times as long as segment III length; sense-cones on antennal segment III elongate and reaching to middle of the next segment............................................................... egonoki

-. Antennal segment IV less than 0.71 times as long as segment III length; sense-cone on III not reaching to middle of the next segment............................................................................................ 15

15. Pronotum with more than 30 discal setae ( Fig. 36 )...................................................... auratus

-. Pronotum with about 20 discal setae............................................................. consociatus

16. Fore wings banded, dark at middle and apex; antennal segment VI not elongate, 0.2 times as long as combined length of segments I–V, chaetotaxy same as in female, with microtrichia on both dorsal and ventral surfaces............... fasciatus

-. Fore wings not banded; antennal segment VI more or elongate, 0.4–0.6 times as long as combined length of segments I–V, with many more setae than in female, usually without microtrichia on dorsal surface................................... 17

17. Abdominal sternites with discal setae.................................................................... 18

-. Abdominal sternites without discal setae.................................................................. 19

18. Body almost uniformly shaded ( Fig. 6 ); antennal segments almost uniformly brown, segment VI with a few microtrichia near base at least ventrally and more than 85 microns long, more than 0.54 times as long as combined length of antennal segments I–V ( Table 2 ; Figs 24b, 25 )................................................................... albiziae sp. n.

-. Body pale ( Fig. 9 ); antennal segments I–II and base of III yellow, segment VI without microtrichia and less than 80 microns long, less than 0.46 times as long as combined length of antennal segments I–V ( Fig. 28 )...................... glycines

19. Abdominal tergite II with 3 lateral marginal setae; antennae 7-segmented.................................... shihoae

-. Abdominal tergite II with 4 lateral marginal setae; antennae 8-segmented........................................ 20

20. Pronotum with a pair of anteromarginal setae much longer than discal setae; antennal segment VI 0.4 times as long as combined length of segments I–V, with microtrichia on ventral surface; body brown.................................. japonicus

-. Pronotum without long anteromarginal setae; antennal segment VI 0.5–0.6 times as long as combined length of segments I–V, without microtrichia; body white...................................................................... ricini

Figures

FIGURES 39–42. Mycterothrips auratus, abdominal segments, female, 39–41: (39) Tergites VII–X; (40) Sternites V–VII; (41) Sternites IV–VI. (42) Abdominal tergite IX and apex of hypomere, male. hy=hypomere. (39 & 40, paratype; others, Okinawa)

FIGURES 16–22. Mycterothrips species, female. M. albiziae sp. n., 16–20: (16) Head and pronotum; (17) Antenna; (18) Antenna, slide-mounted specimen; (19) Mesonotum and metascutum: (20) Abdominal segments V and VI, lateral aspect, right. M. glycines, 21–22: (21) Antenna, slide-mounted specimen; (22) Abdominal tergites and pleurotergites, V and VI, sculptures on pleurotergites omitted.

FIGURES 35–38. Mycterothrips auratus. Head, 35–36: (35) Female; (36) Male. Antenna, 37–38; (37) Female; (38) Male.

FIGURES 23–28. Mycterothrips species, male. M. albiziae sp. n., 23–27: (23) Head and pronotum; (24a) Antenna; (24b) Base of antennal segment VI, ventral aspect; (25)Antenna, slide-mounted specimen; (26) Abdominal tergite IX and apex of hypomere; (27) Abdominal segments VI–X, lateral aspect, right. (28) M. glycines, antenna, slide-mounted specimen. hy=hypomere.

FIGURES 5–15. Mycterothrips species, slide-mounted specimens. Adult 5–11. M. albiziae sp. n.: (5) Female; (6) Male. M. auratus: (7) Female; (8) Male. M. glycines: (9) Female; (10) Female, dark type; (11) Male. Second instar larvae, 12–15: (12) M. albiziae, sp. n.; (13) M. fasciatus; (14) M. glycines; (15) M. japonicus.