Stenchaetothrips amamiensis, 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 : 8-10

Stenchaetothrips amamiensis sp. n.

( Figs. 1–7 )

Female macroptera. Distended body length 1.4–1.6 mm. Body brown to dark brown, abdomen darker than head and thorax; antennal segment I brown, II to IV brownish yellow; V brownish yellow with distal half darker, VI brown with basal half yellowish brown, VII brown; fore wings brown with basal fifth including clavus pale; all legs brownish yellow; prominent body setae brown to dark brown. Head ( Fig. 1 ) 0.8–1.0 times as long as wide; 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 I subequal to III, II and IV small, II to IV close to each other. Maxillary palpi 3-segmented. Antennal segment II with microtrichial rows, IV to V slightly pedicelate, VI parallel at each side basal half and tapering to apex, usually the longest, sometimes subequal to III ( Fig. 2 ). Antennal segments I to VIII length/width ratio as follows: 0.8–1.1, 1.3–1.6, 2.8–3.8, 2.6–3.2, 1.8–2.8, 2.9–3.4, 2.7–3.6. Pronotum ( Fig. 1 ) about 0.8 times as long as wide, sculptured with widely spaced transverse striae, with 20–27 discal setae; anterior margin without long setae; posteroangular setae I almost as long as setae II and 0.4–0.6 times as long as pronotal median length; posteromarginal setae three pairs, setae I the longest. Mesonotum sculptured with transverse anastomosing striae; CPS present anteromedially. Metascutum ( Fig. 3 ) with median pair of setae 0.5 times as long as metascutal median length; CPS absent. Fore wing first vein with seven basal and three distal setae, costal vein with 22–28 setae, second vein with 10–16 setae. Mesothoracic endofurca with weak spinula. Abdominal tergites ( Fig. 4 ) with small teeth directed laterally along posterior tergite, teeth weak and scallop-like at middle of anterior tergites; tergites II– VII with a few lines of sculpture between S1 setae; tergite VIII with posteromarginal comb complete; tergite IX with both anterior and posterior pairs of CPS, S1, S2, S3 and MD setae each 1.0–1.5, 1.4–1.9, 1.4–1.7 and 0.6–0.8 times as long as median length of the tergite; tergite X with S1 and S2 setae each 1.5–1.9 and 1.4–1.8 times as long as median length of the tergite; sternites without discal setae, with scallops along posterior margin; sternite I without microsetae anteromedially. Ovipositor 1.5–2.0 times as long as pronotal median length.

Measurements of holotype female. Distended body length 1530. Head length 123 (133 including anterior projection), width across cheeks 135; compound eye dorsal length 73, width 43. Pronotal median length 130, width 163; posteromarginal setae I length 60–61, setae II length 55–62. Metascutal median length 70, median setae length 30–33. Fore wing length 780, width at middle 50. Abdominal tergite IX median length 85; S1 setae length 95–102, S2 setae length 127–128, S3 setae length 128, MD setae length 58–60; tergite X length 70, S1 setae length 106– 108, S2 setae length 105. Ovipositor length 190. Antennal segments I to VII length (width) as follows: 28 (29), 35 (25), 53 (16), 50 (16), 40 (15), 55 (18), 19 (6).

Male macroptera. Distended body length about 1.2 mm. Body colour similar to female, but paler and thorax brownish yellow with pterothorax partly shaded; all antennal segments yellow with segments I and apex of VI to VII barely shaded. Abdominal tergites ( Fig. 5 ) with posteromarginal teeth distinct more than in female; tergite VIII ( Fig. 5 ) with teeth-like posteromarginal comb irregular sized and spaced, directed to middle; tergite IX ( Fig. 6 ) with S1 setae at level of S2 setae, subequal length to S2 setae, their bases equidistant; sternites ( Fig. 7 ) with scallops having small irregular sized teeth; sternal pore plates oval, 33–53 microns width.

Measurements of paratype males. Distended body length 1160–1180. Head length 105–115 (113–123 including anterior projection), width across cheeks 120–123; compound eye dorsal length 65–71, width 43–45. Pronotal median length 110–118, width 145–153; posteromarginal setae I length 55–60, setae II length 50–56. Metascutal median length 63–64, median setae length 25–28. Fore wing length 640–650, width at middle 30–40. Antennal segments I to VIII length (width) as follows: 25 (25), 55 (24), 46 (14), 45 (14), 36 (15), 50 (16), 19 (6).

Type series. Holotype female, Japan, Kagoshima Pref., Amami-ohshima Is., Kinsakubaru , under sheath of Poaceae , 3.vii.2000, M. Masumoto.

Paratypes: 39 females, 9 males, same data as holotype. The holotype and most paratypes are deposited in TUA .

Comments. In females, this species is somewhat similar to the Taiwanese species S. undatus Wang in the wing coloration and postocular setae III subequal in length to setae I, but it can be distinguished from that species as follows: not bicoloured, mesothoracic endofurca with spinula and mesonotum with paired CPS anteromedially. In contrast, S. undatus is bicoloured, the mesothoracic endofurca lacks a spinula, and the mesonotum is without paired CPS anteromedially. Males of the two species are very similar to each other in having large stout teeth along the posterior margin of abdominal tergites. In the new species, however, the body is almost uniformly dark and abdominal tergite IX has S1 and S2 setae longer, whereas in S. undatus the body is largely yellow with darker terminal abdominal segments, and tergite IX has S1 and S2 setae shorter.

Etymology. In reference to locality of the species.

Figures

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.