Scolothrips takahashii Priesner

Masumoto, Masami, Ohno, Suguru, Ganaha-Kikumura, Tomoko, Miyagi, Akiko & Okajima, Shûji, 2012, Review of the genus Scolothrips (Insecta, Thysanoptera, Thripidae) from Japan, Zootaxa 3183 (1), pp. 36-48 : 44-47

Scolothrips takahashii Priesner

( Figs. 5 A −D & 6A −F)

Scolothrips takahashii Priesner, 1950: 52 ; Haga, 1983: 3; Wang, 2002: 257; Mound, 2011: 52 . Scolothrips sexmaculatus (Pergande) ; Kurosawa, 1968: 38.

Scolothrips priesneri Sakimura 1954: 357 . [Synonymized by Mound, 2011: 52]

Female macroptera. Distended body length 1.1−1.3 mm. Body almost uniformly white or yellowish white, metascutum shaded; all antennal segments slightly shaded in grey, but I slightly paler; fore wing ( Fig. 6 A) with three hyaline areas, clavus dark brown with distal third hyaline; all legs white; prominent body setae pale or slightly shaded, but darker at fore wing.

Head ( Fig. 5 A) 0.6−0.8 times as long as wide. Ocellar setae III on ocellar hump and in front of hind ocelli.

Antennal segments ( Fig. 6 C) III and IV widest at middle, VI the longest, widest near base and tapering, microtrichial row present on ventral surface of III and both dorsal and ventral surfaces of IV −VI. Antennal segments I to VIII length/width ratio as follows: 0.5−0.8, 1.0−1.3, 1.5−2.0, 1.5−1.9, 1.6−2.0, 2.4−3.1, 1.1−1.7, 1.0−3.0.

Pronotum ( Fig. 5 A) 0.6−0.7 times as long as wide, with indistinct groove-like transverse lines of sculpture, without discal setae; major setae 0.8−1.2 times as long as pronotal median length. Mesonotum ( Fig. 5 B) sculptured with wide spaced transverse anastomosing striae posterior half; CPS present anteromedially. Metascutum ( Fig. 5 B) irregularly reticulate medially; median pair of setae close to lateral setae, 0.5−0.9 times as long as metascutal median length; CPS absent. Prospinasternum narrow ( Fig. 5 C). Fore wing costal vein with 18−22 setae, first vein with 8−11 setae.

Abdominal tergites I −II ( Fig. 5 D) with wide spaced transverse anastomosing lines of sculpture, but smooth at submedian areas, III −VIII ( Fig. 6 D) laterally with similar sculpture not reaching median CPS; tergite IX ( Fig. 6 D) with posterior pair of CPS only, only lateral minor setae (SS3) present and usually very small, 0.3−0.9 times as long as median length of the tergite; sternite VII with S1 setae situated in front of posterior margin. Ovipositor 2.0−2.2 times as long as pronotal median length.

Measurements (female in microns). Holotype in parentheses. Body length 1120−1330 (ca. 1070). Head length 66−88 (ca. 80), length including anterior prolongation 78−95 (ca. 93), width across cheeks 109−154 (154); compound eye dorsal length 45−65 (ca. 65), width 38−43 (−). Ocellar setae III length 78−94 (ca. 83), distance between their bases 23−33 (−). Pronotal median length 105−116 (ca. 108), width 150−180 (−); anteromarginal setae length 108−125 (ca. 108), anteroangular setae length 88−123 (88−ca.103), posteroangular setae I length 91−113 (91−ca.100), setae II length 93−114 (93−ca.98); posteromarginal setae I length 103−118 (106−ca.113), ML setae length 88−113 (88−ca.93). Metascutal median length 63−73 (ca.65); median setae length 38−60 (40−ca.50). Fore wing length 700-810 (810), width at middle 50-70 (70). Abdominal tergite IX median length 68-80 (ca. 80); S1 setae length 68-88 (68- ca. 75), S2 seta length 69-84 (75- ca. 81), S3 setae length 73-93 (81- ca. 90), ML setae length 30-43 (30- ca. 39), SS3 setae length 20-63 (21- ca. 23); tergite X median length 55−70 (ca. 63), S1 setae length 57−79 (70−ca.75), S2 setae 50−71 (52−ca. 61). Ovipositor length 220−240 (235). Antennal segments I −VIII length (width) 15−23 (20)/28−30 (28), 28−35 (30)/25−28 (28), 33−40 (38)/25−28 (21), 30−38 (33)/19−20 (20), 28−33 (33)/15−19 (19), 40−50 (50)/16−18 (16), 9−13 (13)/8−9 (8), 5−16 (16)/5−7 (5).

Male macroptera. Body colour similar to female. Abdominal tergite IX ( Fig. 6 E) with MD setae, S1 setae much ahead of level of S2 setae and lateral to MD setae; sternal pore plates ( Fig. 6 F), 113−135 µm wide.

Measurements (male in microns). Body length 1030. Head length 73 (length including anterior prolongation 76), width across cheeks 113; compound eye dorsal length 52, width 38. Ocellar setae III length 75−78, distance between their bases 25. Pronotal median length 98, width 148; anteromarginal setae length 100, anteroangular setae length 86-101, posteroangular setae I length 83−88, setae II length 89−93; posteromarginal setae I length 99−100, MD setae length 79−86. Metascutal median length 55; median setae length 25−28. Fore wing length 600, width at middle 45. Antennal segments I −VIII length (width) 20 (28), 28 (25), 33 (19), 29 (16), 28 (15), 39 (16), 10 (6), 15 (5).

Specimens examined. Holotype female, TAIWAN, Taihoku, on leaf of Ricinus [ Euphorbiaceae ], 16.i.1938, R. Takahashi (SMF). Other specimens: JAPAN, Honshu: 70 females & 7 males. Shikoku: 59 females & 2 males. Ryukyus: 6 females in Okinawa-hontou Island. TAIWAN, 1 female.

Distribution. Japan: Honshu, Shikoku, Ryukyus (Okinawa-hontou); Taiwan; Hawaii.

Comments. This species is included in longicornis group, together with S. dilongicornis from China and S. longicornis from Europe ( Mound, 2011). They can be distinguished by metascutum colour and length of male fore wing. S. takahashii has shaded metascutum and macropterous male, whereas S. dilongicornis has pale metascutum and micropterous male and S. longicornis has pale metascutum and hemimacropterous male. In Honshu, Japan, this species has been known as “six-spotted thrips ” for a long time but is here newly recorded from Okinawa.

Figures

FIGURE 5. Scolothrips takahashii, female. A, Head and pronotum; B, mesonotum and metascutum; C, prosternal ferna and prospinasternum; D, tergites I – II (right side omitted). Scales: 0.04 mm.

FIGURE 6. Scolothrips takahashii, female (A − D) and male (E − F). A, Fore wing, right (marginal fringe hairs omitted); C, antenna, right; D, tergites VIII – X; E, tergite IX; F, sternite VII (sculpture omitted). Scales: 0.04 mm.