Scirtothrips katsura, Masumoto, Masami & Okajima, Shûji, 2007

Masumoto, Masami & Okajima, Shûji, 2007, The genus Scirtothrips Shull (Insecta, Thysanoptera, Thripidae) and three related genera in Japan, Zootaxa 1552, pp. 1-33 : 28-30

Scirtothrips katsura n. sp.

( Figs. 10 B, 12B, 13A, 14B, 16A, 17D & 18C)

Female. Distended body length 1.1–1.4 mm. Body uniformly brownish yellow, head shaded around hind ocelli and apex of frons, pronotum with some brown patches at posterior half, abdominal segments VIII to X slightly brownish, terga III to VII with antecostal ridges dark at median third, sterna III to VII with antecostal ridges dark; antennal segment I pale, II brown, III to V brown with extreme base slightly pale, VI to VIII brown; fore wings uniformly strongly shaded; all femora and tarsi yellow, all tibiae yellow with outer margin shaded; prominent body setae slightly shaded.

Head 1.6–1.9 times as wide as long. Ocellar setae III situated at or slightly anterior to tangent of anterior margin of hind ocelli ( Fig. 10 B). Two pairs postocular setae mesad of compound eyes almost as long as ocellar setae III, minute setae usually present between these setae. Compound eyes without pigmented ommatidia. Antennae 8-segmented, segment II without mid-dorsal seta below CPS, III the longest, widest near apex and rapidly tapering forward to apex, IV and V slightly pedicelate ( Fig. 12 B). Antennal segments I to VIII length/ width ratio as follows: 0.8–1.4, 1.1–1.4, 2.1–2.6, 2.3–2.9, 1.9–2.3, 2.4–2.8, 0.9–1.0, 2.0–2.5.

Pronotum 1.5–1.8 times as wide as long, space between lines of sculpture narrower than diameter of socket of discal setae, with 14–16 discal setae (including anteromarginals and lateralmarginals) (16 in the holotype); posteromarginal setae four pairs, B2 setae 0.2–0.3 times as long as pronotal median length and 1.6– 2.6 times as long as B1 setae ( Fig. 10 B). Mesonotum without CPS anteromedially. Metascutum sculptured with transverse reticulations anteriorly and longitudinal oblong reticulations medially, reticulations with weak internal dots; median pair of setae situated behind anterior margin ( Fig. 13 A). Fore wings with 27–31 setae on costal vein (27 on left, 29 on right, in the holotype), with four basal and three to four distal setae on first vein (four and three in the holotype), with three setae on second vein; clavus with four veinal and one discal setae; antero- and posteromarginal fringe hairs wavy.

Abdominal terga with B1 setae closer together than their length, especially on II to VI, lateral microtrichial fields each with three discal setae ( Fig. 14 B); terga II to VII with posteromarginal microtrichia at out side of B2 setae; tergum VIII with microtrichia anteromedially ( Fig. 16 A); tergum IX without microtrichia ( Fig. 16 A), B1 setae, B2 setae and B3 setae each 0.6–0.8, 0.8–0.9 and 0.7–0.8 times as long as median length of the tergum; tergum X without microtrichia ( Fig. 16 A), B1 setae and B2 setae each 1.2 and 1.0–1.1 times as long as median length of the tergum; sterna with discal microtrichial rows at out side of B1 setae ( Fig. 17 D); sternum VII with B1 setae slightly in front of posterior margin. Ovipositor 2.6–3.0 times as long as pronotal median length.

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Measurements of holotype female in microns. Distended body length 1280. Head length 81, width across cheeks 145; compound dorsal length 63, width 45. Pronotal median length 108, width 175; posteromarginal setae I length 19–20, setae II length 37–45. Metascutal median length 85, median setae length 25. Fore wings length 830, width at middle 40. Abdominal tergum IX median length 105; B1 setae length 73–75, B2 setae length 82–90, B3 setae length 75, mid-dorsal setae length 61–63; tergum X median length 58, B1 setae I length 73–75, B2 setae length 55–63. Ovipositor length 295. Antennal segments I to VIII length (width) as follows: 38 (28), 40 (30), 53 (21), 48 (19), 43 (20), 48 (18), 8 (9), 13 (6).

Male. Distended body length 0.9–1.1 mm. Body colour as in female. Abdominal tergum IX with a pair of lateral drepanae dark ( Fig. 18 C).

Measurements of paratype males in microns. Distended body length 940–1050. Head length 71–83, width across cheeks 128–133; compound dorsal length 58–63, width 38–43. Pronotal median length 88–95, width 140–150; posteromarginal setae I length 13–18, setae II length 28–35. Metascutal median length 63–68, median setae length 18–25. Fore wings length 640–670, width at middle 40–45. Antennal segments I to VIII length (width) as follows: 20–23 (24–25), 33–40 (25–28), 45–48 (18–20), 40–43 (18–19), 35–40 (18), 40–45 (16–18), 8–10 (9), 10 (5).

Type series. Holotype female: Japan, Honshu, Gunma Pref., Nakanojo-machi, side of the river Shimagawa, on leaves of Cercydiphyllum japonicum [ Cercidiphyllaceae ], 13-v-2005, M. Masumoto. Paratypes: 22 females, 21 males collected together with the holotype. 6 females, same host plant and locality as the holotype, 14-v-2005, M. Masumoto. 3 females, 1 male, same host plant and locality as the holotype, 11-v-2006, M. Masumoto. The holotype and most paratypes are deposited in Laboratory of Entomology, TUA, Atsugi, Japan.

Etymology. In reference to Japanese name of the host plants of the species.

Comments. It can be distinguished easily from the other species by the body colour and the metascutal reticulation that has internal dots.

Figures

FIGURE 10. Scirtothrips species, head & pronotum (female). (A) S. flavus n. sp.; (B) S. katsura n. sp.

FIGURE 12. Scirtothrips species (female). A – C, Antenna: (A) S. flavus n. sp.; (B) S. katsura n. sp.; (C) S. machili n. sp., (D) S. albidus n. sp., mesonotum & metascutum. E – F, Metascutum: (E) S. dorsalis; (F) S. flavus n. sp.

FIGURE 13. Scirtothrips species (female). A – B, Metascutum: (A) S. katsura n. sp.; (B) S. machili n. sp. C – E, Abdominal terga: (C) S. albidus n. sp., tergum VI (microtrichial row omitted on left side); (D) S. albidus n. sp., tergum VII (microtrichial row omitted on left side); (E) S. dorsalis, left side of tergum VI (microtrichial row omitted.).

FIGURE 14. Scirtothrips species, abdominal terga (female). (A) S. flavus n. sp., right side of tergum V; (B) S. katsura n. sp., tergum VI (microtrichial row omitted on left side.).

FIGURE 16. Scirtothrips species, terminal abdominal terga (female). (A) S. katsura n. sp., terga VIII – XI; (B) S. machili n. sp., terga VIII – XI (microtrichial row omitted on left side of tergum VIII).

FIGURE 17. Scirtothrips species, abdominal sternum (female). (A) S. albidus n. sp., sternum VII; (B) S. dorsalis, sternum VI (microtrichial row omitted on left side.); (C) S. flavus n. sp., right side of sternum VI; (D) S. katsura n. sp., sternum VI (microtrichial row omitted on left side.); (E) S. machili n. sp. sternum V (microtrichial row omitted on left side.).

FIGURE 18. Scirtothrips species. (A) S. machili n. sp., Female (ventral aspect of thorax). B – D, Male abdominal terga: (B) S. dorsalis, tergum IX; (C) S. katsura n. sp., tergum IX (sculpture omitted.); (D) S. machili n. sp., terga IX – X (sculpture omitted.).