Xyphandrothrips vietnamicus, Okajima & Masumoto, 2025

Xyphandrothrips vietnamicus sp. nov.

( Figs 358 View FIGURES 349–358 , 423–430 View FIGURES 423–430 )

Female (macroptera). Distended body length: 1.4–1.6mm. Body brown ( Fig. 358 View FIGURES 349–358 ). Abdomen somewhat paler than head and thorax, tube with basal one-third yellowish. Fore femora brown, with apical one-third paler, mid and hind femora pale brown, with apices paler; fore tibiae pale brown, mid and hind tibiae largely yellowish, but very weakly shaded; tarsi yellow. Antennal segments I and IV – VIII brown, but IV with extreme base yellowish; segment II pale brown, segment III yellowish. Fore wing scarcely shaded with brown. Major body setae pale. Head ( Fig. 423 View FIGURES 423–430 ) longer than wide, about 1.3 times as long as wide, 1.34 times in holotype; dorsal surface almost smooth at middle. Cheeks very weakly rounded, gradually narrowed to base, anterior end shortly overlapping with eyes, serrated. Eyes about one-third of head length. Ocelli well developed; posterior pair in contact with eyes, 22µm apart from each other in holotype. Postocular setae much shorter than eyes, expanded; 89µm apart from each other, 8µm apart from eyes in holotype. Antennae ( Fig. 430 View FIGURES 423–430 ) short, 1.55 times as long as head in holotype; segment VIII conical, not constricted at base, widely and closely joined to segment VII; segment III almost symmetrical, truncated at apex, shorter than IV, almost as long as VII; segment IV the largest; segments III and IV with three (1+2) and four (2+2 +1) sense cones respectively. Maxillary stylets retracted to eyes, sub-parallel at middle, their distance about one-fifth of head width; maxillary bridge weak. Pronotum ( Fig. 423 View FIGURES 423–430 ) about 0.6 times as long as head, 0.57 times in holotype, about 1.6 times as wide as long; almost smooth; five pairs of prothoracic setae expanded; am and aa subequal in length, pa longer than ml, almost as long as postocular setae, epim a little longer than pa. Prospinasternum ( Fig. 424 View FIGURES 423–430 ) largely developed, about 40µm wide; mesopresternum divided into lateral triangles. Mesonotal lateral setae developed, expanded. Metanotum sculptured with polygonal reticulation; median pair of setae pointed, less than 20µm, distance between both median setae wider than distance between each seta and anterior margin of metanotum, 40µm apart from each other, 29–31µm apart from anterior margin in holotype. Fore tarsal tooth long ( Fig. 427 View FIGURES 423–430 ). Fore wing with 4–5 duplicated cilia; three sub-basal setae relatively short, expanded. Pelta ( Fig. 425 View FIGURES 423–430 ) trapezoid, sculptured weakly, 1.55 times as wide as long in holotype. Tergites III – VIII S2 setae: III – VI expanded, VII pointed, VIII bluntly pointed. Tergite IX S1 setae blunt, shorter than tube, S2 sharply pointed, a little longer than tube; intermediate setae about two-thirds of Sl. Tube ( Fig. 429 View FIGURES 423–430 ) 0.45 times as long as head, 1.84 times as long as wide; terminal setae about 1.4 times as long as tube .

Measurements (holotype female in µm). Body length 1430 (distended). Head length 184, from anterior margin of eyes 169, width across eyes 127, maximum width across cheeks 137, minimum width across base 113; eyes length 61; diameter of posterior ocelli 12–15; postocular setae 30–32. Maxillary bridge width 32. Antenna total length 285, segments III–VIII length (width) as follows: 33 (25), 40 (28), 37 (24), 35 (21), 33 (20), 22 (14). Pronotum length 105, width 168. Setae on prothorax: am 23–24, aa?25, ml?25, pa 30–32, epim 35. Fore wing length 550. Sub-basal wing setae: S1 25 –26, S2 28, S3 28. Pelta length 53, width 82. Tergite IX setae: S1 62–63, S2 90. Tube length 83, maximum width 45; terminal setae 115.

Male. Unknown.

Type material. Holotype: macropterous female, Vietnam, Hoa Binh Province, Mai Chau , on dead leaves and branches, 11.viii.2000, SO . Paratype: Vietnam, 1 female, collected together with holotype .

Doubtful specimens. Vietnam, 1 male, Bac Can Province, Ba Be National Park , on dead branches, 2.viii.2000, SO ; 1 male, Lam Dong Province, Bao Loc, Dam Bri , on bamboo, 26.xii.2001, SO .

Comments. This species may be related to X. pallens sp. nov. described above also from Vietnam. These two species share the terminal two antennal segments closely joined, antennal segments III and IV with three and four major sense cones respectively, and the sub-basal setae S3 expanded. The unique paratype female was collected together with the holotype but is somewhat dissimilar in coloration. The abdomen of the holotype is slightly paler than the thorax, whereas it is darker and almost as dark as thorax in the paratype. However, these two females are indistinguishable in most structures other than body color, and it is presumed that the holotype female is probably a teneral individual. Two males listed under doubtful specimens are very similar to the type series in structure, and may represent vietnamicus , but have the yellowish abdomen .