Stenchaetothrips pleioblasti, Masumoto & Okajima, 2013

Masumoto, Masami & Okajima, Shûji, 2013, Review of the genus <i> Thrips </ i> and related genera (Thysanoptera, Thripidae) from Japan, Zootaxa 3678 (1), pp. 1-65 : 17-18

Stenchaetothrips pleioblasti sp. n.

( Figs. 38–46 )

Female macroptera. Distended body length 1.2–1.5 mm. Body pale brown to brown, pterothorax often slightly paler, sometimes bicoloured, when bicoloured body yellow with posterior half of abdominal segments VII to X dark brown but often abdominal segments gradually darker to terminal segment; antennal segments I to II pale brown with II slightly pale at apex, often yellow, III brownish yellow often with apex slightly shaded, IV to VII brown, IV slightly paler than V; fore wings ( Fig. 41 ) usually pale with median fourth to third shaded, often uniformly pale in bicoloured type; all legs yellow; prominent body setae brown to dark brown. Head ( Fig. 38 ) 0.7– 0.9 times as long as wide, slightly; cheeks slightly constricted just behind compound eyes and rounded toward base. Compound eye without pigmented ommatidia ventrally. Ocellar setae III situated outside or on margin of ocellar triangle, in front of hind ocelli. Postocular setae III the longest and much longer than I, II and IV small. Maxillary palpi 3-segmented. Antennal segments ( Fig. 39 ) IV to V slightly pedicelate, VI widest at basal third and gently tapering to apex, usually the longest, often subequal to III, with 9–10 setae. Antennal segments I to VII length/width ratio as follows: 0.8–1.2, 1.2–1.4, 2.5–3.3, 2.3–3.2, 2.1–2.7, 2.8–3.3, 2.3–3.2. Pronotum ( Fig. 38 ) 0.7– 0.8 times as long as wide, sculptured with wide spaced transverse striae, with 23–31 discal setae; anterior margin without long setae; posteroangular setae I 0.4–0.6 times as long as pronotal median length and 0.9–1.2 times as long as setae II; posteromarginal setae three pairs, setae I the longest. Mesonotum ( Fig. 40 ) sculptured with transverse anastomosing striae; CPS present anteromedially. Metascutum with median pair of setae 0.4–0.6 times as long as metascutal median length; CPS absent, but rarely one CPS present. Fore wing first vein with seven basal and three distal setae, costal vein with 20–27 setae; second vein with 9–15 setae. Mesothoracic endofurca with weak spinula. Abdominal tergites ( Figs. 42–43 ) with a few small microtrichia on posterior margin at each side, often with small scallops on posterior margin at middle; tergites III to V or VI with a few weak lines sculpture between S1 setae; tergite VIII with posteromarginal comb complete; tergite IX with two pairs of CPS, S1 , S2 , S3 and MD setae each 1.2–1.6, 1.5–1.7, 1.5–1.8 and 0.6–0.8 times as long as median length of the tergite; tergite X ( Fig. 13C ) with S1 and S2 setae each 1.6–1.9 and 1.5–1.9 times as long as median length of the tergite; sternite I with two or three microsetae anteromedially. Ovipositor 1.6–2.0 times as long as pronotal median length .

Measurements of holotype female. Distended body length 1470. Head length 99 (109 including anterior projection), width across cheeks 135; compound eye dorsal length 59, width 38. Pronotal median length 123, width 168; posteromarginal setae I length 51–58, setae II length 55–56. Metascutal median length 66, median setae length 35. Fore wing length 750, width at middle 50. Abdominal tergite IX median length 77, S1 setae length 96–99, S2 setae length 112–117, S3 setae length 121–?, MD setae length 50; tergite X length 65, S1 setae length 102, S2 setae length 100–102. Ovipositor length 230. Antennal segments I to VII length (width) as follows: 25 (29), 33 (25), 50 (16), 45 (18), 38 (16), 50 (16), 19 (8).

Male macroptera. Distended body length 0.9–1.0 mm. Body colour generally brownish yellow, head shaded between compound eyes, abdominal tergites VI to VIII with brown markings medially, segments IX to X brown; antennal I to III yellow, III slightly shaded distally, IV to V yellow with distal half brown, VI to VII brown; fore wings uniformly pale; prominent body setae pale to shaded. Abdominal tergites ( Fig. 44 ) with irregular small teeth along posterior margin; tergite VIII ( Figs. 44–45 ) with posteromarginal comb short and irregular spaced; tergite IX with S1 setae at or slightly ahead of level of S2 setae, subequal in length to or slightly shorter than S2 setae, their bases equidistant; sternal pore plates oblong, 40–55microns width ( Fig. 46 ).

Measurements of paratype males. Distended body length 850–1040. Head length 85–93 (89–100 including anterior projection), width across cheeks 110–113; compound eye dorsal length 50–58, width 35–40. Pronotal median length 88–108, width 133–140; posteromarginal setae I length 20, setae II length 51. Metascutal median length 45–53, median setae length 25–33. Fore wing length 520–600, width at middle 35–45. Antennal segments I to VIII length (width) as follows: 20–25 (23–25), 28–30 (20–23), 38–45 (13–15), 37–38 (14–15), 30–33 (15), 40– 45 (15–16), 14–16 (6–8).

Type series. Holotype female, JAPAN, Honshu, Kanagawa Pref., Yokosuka City, Kannonzaki, on leaves of Pleioblastus chino [ Poaceae ], 15.vi.2002, M. Masumoto.

Paratypes: Honshu: 12 females, 1 male same data as holotype; 6 females, same locality and plants as holotype, 25.viii.2002, M. Masumoto; 1 female, same locality and plants as holotype, 25.vi.2006, M. Masumoto. Same locality as the holotype: 1 female on leaves of Aucuba japonica [ Cornaceae ], 15.vi.2002, M. Masumoto; 1 female on leaves of Machilus thunbergii [ Lauraceae ], 29.vi.2002, M. Masumoto; 1 female, on leaves of Carex kobomugi [ Cyperaceae ], 30.iii.2003, M. Masumoto; 1 male on flowers of Deutzia crenata [ Saxifragaceae ], 5.vi.2005, M. Masumoto. Kanagawa Pref., Kawasaki City, Mukougaoka: 4 females, sweeping, 28.v.1976, S. Okajima; 1 female on Pueraria [ Fabaceae ], 3.vi.1976, S. Okajima; 16 females, 2 males on leaves Pleioblastus sp. , 15.vii.1989, S. Okajima. Kanagawa Pref., Kawasaki City, Tama-ku, Ikuta-ryokuchi, 2 females, 1 male on leaves of Artemisia princes [ Asteraceae ], 27.v.1993, S. Okajima. Kanagawa Pref., Tsurukawa, 1 female on Pueraria , 17.vi.1976, S. Okajima. Kanagawa Pref., Yokohama City, Kanazawa-shizenkouen Park, 2 females on leaves of Pleioblastus chino , 26.v.2002, M. Masumoto. Ibaraki Pref., Yawara-mura, side of the river Kokai-gawa, 5 females on leaves Pleioblastus sp. , 20.v.1999, M. Masumoto. Ibaraki pref., Tsuchiura City, side of Shishitsuka-ohike: 26 females, 1 male on leaves of Pleioblastus chino , 16.vi.2000, M. Masumoto; 43 females, 1 male on leaves of Pleioblastus chino , 11.vii.2000, M. Masumoto. Miyagi Pref., Mt. Zao, 6 females, sweeping, 12.vi.1976, S. Okajima.

The holotype and most paratypes are deposited in TUA .

Non-paratypic specimens. Following bicoloured specimens were excluded from type series. JAPAN, Honshu: Kanagawa Pref., Zushi City, Mt. Futago-yama, 5 females, on Pleioblastus chino , 25-viii-1996, M. Masumoto. Kanagawa Pref., Kawasaki City, Tama-ku, Ikuta-ryokuchi, 1 female, 1 male on leaves of Pueraria lobata , 7-ix-1994, S. Okajima. Ibaraki Pref., Makabe-cho, middle of the Mt. Tsukuba-san, 8 females on leaves of Pleioblastus chino , 27-v-2000, M. Masumoto. Ibaraki Pref., Tsuchiura City, side of the Shishitsuka-ohike, 1 female on leaves of Pleioblastus chino , 11-vii-2000, M. Masumoto. Ibaraki Pref., Ushiku City, near Ushiku-numa, 1 female on leaves of Pleioblastus chino , 1-x-2000, M. Masumoto. Ibaraki Pref., Yawara-mura, side of the river Kokai-gawa, 1 female on leaves of Miscanthus sinensis [ Poaceae ], 28-vii-2000, M. Masumoto. Fukushima Pref., Fukushima City, Fukushima University, 10 females on Pleioblastus chino , 16-x-2000, M. Masumoto. Ogasawara Islands: 5 females, Chichi-jima Is., Mt. Mikazuki-yama, on Pseudosasa japonica [ Poaceae ], 10-iii-1988, S. Okajima.

Comments. This species is usually brown but there are often bicoloured individuals, and these two colour forms look like distinct species. However, both colour forms are often collected at same time, the degree of abdominal coloration of the bicoloured type is continuous, and there are no morphological differences between them. According to Bhatti (1982), the new species is similar to the Indian species, S. tenebricus (Ananthakrishnan & Jagadish) but it can be distinguished from the latter species as follows: fore wings shaded at middle although often not shaded in bicoloured type and male with pore plate on abdominal sternite VII. In contrast S. tenebricus has the fore wings uniformly greyish-brown beyond basal fourth to third, body not bicoloured, and male without pore plate on sternite VII.

Etymology. In reference to host plants of the species.

Figures

FIGURES 38–50. Stenchaetothrips species. S. pleioblasti sp. n., female 38–43: (38) Head & pronotum; (39) Antenna, right; (40) Mesonotum & metascutum; (41) Fore wing, right; (42) Tergite V & pleurotergite, right side; (43) Tergites VIII–X. S. pleioblastus sp. n., male 44–46: (44) Tergites VII–VIII, sculpture omitted at left side; (45) Posterior margin of tergite VIII with fine microtrichia; (46) Sternites VII–VIII, sculpture omitted. S. undatus. 47–50: (47) Head, female, from Fukushima Pref., Honshu; (48) Head, female, from Ishigaki-jima, Islands; (49) Antenna, female, from Ishigaki-jima Island; (50) Antenna, female, from Fukushima Pref., Honshu.

FIGURES 1–17. Stenchaetothrips species. S. amamiensis sp. n., female 1–4: (1) Head & pronotum; (2) Antenna, right; (3) Metascutum; (4) Tergite VII. S. amamiensis sp. n., male 5–7: (5) Tergites VII–VIII, sculpture omitted; (6) Tergite IX, sculpture omitted; (7) Sternite VII, sculpture omitted. S. biformis, female 8–15: (8) Head & pronotum; (9) Postocular setae, setae I present; (10) Postocular setae, setae I absent; (11) Antenna, right; (12) Metascutum; (13) Tergite VII; (14) Posterior margin of tergite VII with large teeth; (15) Tergites VIII to X. S. biformis, male 16–17: (16) Tergite VII, sculpture omitted; (17) Sternite VII, sculpture omitted.