Vietothrips bicolor, Okajima & Masumoto, 2025

Okajima, Shûji & Masumoto, Masami, 2025, Some Poaceae-inhabiting Phlaeothripinae (Thysanoptera, Phlaeothripidae) in East Asia, with descriptions of six new genera and 18 new species, Zootaxa 5726 (1), pp. 1-68 : 61

Vietothrips bicolor sp. nov.

( Figs 231–240 )

Female (macroptera). Distended body length: 1.5–1.8mm. Body sharply bicolored brown and yellow ( Fig. 231 ); head, thorax, abdominal segments VIII –IX and tube brown; abdominal segments I– VII yellow. Legs yellow, but fore and mid coxae brown. Antennal segments I and II brown, the remaining segments yellow, segment VIII very weakly shaded with brown. Fore wings weakly shaded with brown, somewhat paler sub-basally. Postocular and prothoracic prominent setae a little shaded, the remaining setae almost hyaline. Head about 2.0 times as long as wide ( Fig. 232 ), widest across eyes; dorsal surface weakly sculptured with transverse reticles. Cheeks straight , with no remarkable setae. Postocular setae shorter than eyes, weakly expanded. Eyes shorter than 0.4 times as long as head, large colored ommatidia on ventro-lateral surface larger than posterior ocelli. Posterior ocelli 15µm in diameter, about 10µm apart from each other, 12–13µm apart from anterior one in holotype. Antennae ( Fig. 239 ) about 1.1 times as long as head; segment VIII weakly constricted at base. Maxillary stylets about half of head width apart, maxillary bridge 43µm width in holotype. Pronotum short ( Fig. 232 ), 0.41 times as long as head and 1.47 times as wide as long in holotype, sculptured laterally and posteriorly; aa, ml, pa and epim expanded; aa and ml subequal in length, shorter than postocular setae; pa and epim subequal in length, almost as long as postocular setae; cox long and sharply pointed. Mesonotum distinctly sculptured, with two pairs of campaniform sensilla. Metanotal median pair of setae minute. Three sub-basal setae of fore wing well developed and expanded. Pelta triangular ( Fig. 236 ), very weakly sculptured, with a pair of campaniform sensilla. Abdominal sternites III – VII with transverse row of 7–10 setae. Tergites II – VIII S2 setae: II reduced, III expanded, IV – VIII long and sharply pointed. Tergite IX S1 setae much shorter than tube, expanded, S2 a little shorter than tube, sharply pointed. Tube shorter than 0.6 times as long as head, 2.4–2.5 times as long as width. Terminal setae almost as long as tube or a little longer .

Measurements ( holotype female in μm). Body length about 1700 (distended). Head length 225, from anterior margin of eyes 202, width across cheeks 105, across eyes 110; eyes length 74–75, width 40–41; postocular setae 50–52. Antenna total length 250, segments I–VIII length (width) as follows: 27 (27), 40 (25), 35 (21), 33 (25), 35 (22), 31 (21), 32 (18), 25 (12). Pronotum length 92, width 135. Setae on prothorax: aa 35–40, ml 35–40, pa 50–55, epim 50, cox 70–80. Fore wing length 670. Sub-basal wing setae: S1 30 –35, S2 25 –30, S3 47 –50. Tergite IX setae: S1 55 –60, S2 115. Tube length 123, maximum width 50; terminal setae 130.

Male (macroptera). Distended body length: 1.2–1.4mm. Color and structure very similar to female. Antennae about 1.2 times as long as head. Fore tarsal inner hamus very small or absent. S2 setae on abdominal tergite III expanded; tergite IX S2 setae much shorter than S1. Tube 0.50–0.55 as long as head, about 2.7 times as long as wide.

Measurements ( paratype male in μm). Body length about 1400 (distended). Head length 203, from anterior margin of eyes 185, width across cheeks 99, across eyes 103; eyes length 70, width 38–40; postocular setae 35–37. Antenna total length 250, segments I–VIII length (width) as follows: 25 (25), 35 (25), 30 (20), 28 (22), 35 (20), 35 (20), 32 (18), 25 (12). Pronotum length 90, width 123. Setae on prothorax: aa less than 20, ml less than 20, pa about 40, epim about 40, cox 45–55. Fore wing length 600. Sub-basal wing setae: S1 20 –25, S2 25 –28, S3 40 –43. Tergite IX setae: S1 40, S2 about 20. Tube length 108, maximum width 40; terminal setae 115.

Type material. Holotype: macropterous female, Vietnam, Lam Dong Province, Bao Loc, Dam Bri , on bamboo, 26.xii.2001, SO . Paratypes: Vietnam, 5 females , collected with holotype; data very similar to holotype , 9 females and 2 males, 27.xii.2001, 23 females and 13 males, 28.xii.2001.

Comments. This species is described from Vietnam based on a good number of females and males collected from bamboo together with Namothrips bambusae described above. It is interesting that both of them have bicolored bodies, but their color patterns are somewhat different. Unfortunately, no biological information about them is known so far.

Figures

FIGURES 231–240. Vietothrips bicolor gen. et sp. nov., female. (231) whole body; (232) head and prothorax; (233) compound eyes, ventral surface; (234) prosternum and mesopresternum; (235) metanotum; (236) pelta; (237) fore wing; (238) sub-basal wing setae; (239) antennal segments III–VIII; (240); fore tarsus.