Polytrichothrips malayanus, Okajima & Masumoto, 2023

Okajima, Shûji & Masumoto, Masami, 2023, Six genera of the subtribe Macrothripina from Southeast Asia to Taiwan (Thysanoptera, Phlaeothripidae, Idolothripinae), Zootaxa 5291 (1), pp. 1-74 : 68-72

Polytrichothrips malayanus sp. n.

( Figs 203–210 , 246 )

Female (aptera). Distended body length: 2.8–2.9mm. Colour brown to dark brown; head and thorax brown, abdomen brown to dark brown, darkened toward posteriorly, tube blackish brown with apical 1/4 paler. Antennal segment I brownish yellow, in contrast with brown head; segment II yellowish brown, a little darker than segment I; segment III pale brown with basal 1/2 yellowish; segments IV and V brown with basal 1/3 yellowish; segments VI–VIII brown, base of segment VI slightly paler. Legs brown, femora yellowish distally; tarsi yellowish brown. Prominent setae brownish. Head ( Fig. 205 ) square (if not pressed by coverslip), about 1.1 times as long as wide, dorsal surface almost smooth, but with indistinct transverse furrows on vertex; cheeks subparallel, with 2–5 stout setae, 2–3 in holotype female, 5– 5 in paratype female; a pair of lateral ommatidium-like structure situated near base ( Fig. 204 ), about 40µm apart from base of head. Postocular setae long, postocellar setae less than 1/3 as long as postoculars; vertexal setae almost as long as postocellars. Eyes small, wider than long, slightly prolonged posteriorly on ventral surface; ocelli small. Antennae ( Fig. 206 ) about twice as long as head; segments III and IV with two and four sense-cones, respectively. Mouth cone rounded at apex; maxillary stylets 12–15µm broad, reaching eyes, close together medially. Pronotum ( Fig. 205 ) much wider than long, about 0.6 times as long as head, almost smooth. Four pairs of pronotal setae well developed and nearly pointed; am setae the shortest, but more than 50μm; epim much longer than pa. Notopleural sutures incomplete. Prosternal basantra slender, ferna pointed medially. Fore tarsal tooth ( Fig. 203 ) small and forwardly directed. Mesopresternum ( Fig. 207 ) slender; metathoracic sternopleural suture absent. Mesonotum ( Fig. 208 ) weakly sculptured with weak transverse reticulation on anterior 1/2; metanotum transverse, surface smooth, median pair of setae slender, about 190µm apart from each other in holotype. Pelta ( Fig. 208 ) broadly hat-shaped, weakly sculptured anteriorly, posterior margin eroded at middle. Each side of abdominal tergites with three setae near posterior margin, S1, S2 and S3 (= posteroangulars); tergites II–VII with short S1, tergite VIII with longer S1, but shorter than tergite, tergite IX with the longest S1, almost as long as tube; tergites II, VI–VII and IX with long S2, longer than tergite, tergites III–V and VIII with short S2; tergites II–V with short S3, shorter than tergite, tergites VI–IX with long S3, longer than tergite. Tube ( Fig. 209 ) tapering, straight sided, 0.83 times as long as head in holotype. Terminal setae much shorter than tube.

Measurements (holotype female in μm). Body length 2850 (distended). Head length 320, width 290; eyes length 40, width 70; postocular setae 125–130; postocellar setae 35–40. Antenna total length 660, segments I–VIII length (width) as follows: 74 (50), 85 (46), 100 (45), 98 (50), 102 (48), 90 (45), 73 (40), 70 (30). Pronotum length 185, width 407. Setae on prothorax: am 65–66, aa 75–80, ml 90–115, pa 115, epim 160–170, cox 65–70. Setae on tergites. II: S1 30, S2 135, S3 20. III: S1 30, S2 50, S3 38. IV: S1 38, S2 60, S3?. V: S1 30, S2 62, S3 100. VI: S1 40, S2 160, S3 230. VII: S1 40, S2 225, S3 300. VIII: S1 140, S2 50, S3 200. IX: S1 260, S2 200, S3 210. Tube length 265, maximum width 145; terminal setae about 200.

Type series. Holotype apterous female, Peninsular Malaysia, Cameron Highlands, nr. Brinchang, on dead leaves and branches, 25.viii.1990, TN & SO . Paratype: Peninsular Malaysia, Cameron Highlands, foot of Gnung Jasar, 1 apterous female, on dead leaves and branches, 29.viii.1990, TN & SO .

Remarks. Two species, P. laticeps (Bagnall) from Sarawak and P. geoffri Mound from Eastern Australia, have previously been known in the genus. However, Eow et al. (2011) indicated that there is a further unnamed species in New Caledonia. P. malayanus is presumably more closely related to geoffri than laticeps , because it has short postocellar and mid-vertex setae on the head. It is interesting that the type-localities of malayanus and geoffri are farther apart than those of malayanus and laticeps .

Figures

FIGURES 203–210. Polytrichothrips malayanus sp. n., female. (203) Fore tarsus; (204) ommatidium-like structure; (205) head & prothorax; (206) antenna; (207) prosternum & mesopresternum; (208) mesonotum to pelta; (209) abdominal segment IX & tube; (210) abdominal tergites III–IV.

FIGURES 235–246. Macrothripina genera and species. Ethirothrips species 235–243: (235) E. stenomelas, male; (236) E. (?) stenomelas, female from Mindanao; (237) E. tenuis sp. n., female; (238) E. terminalis sp. n., female; (239) E. thai sp. n., female; (240) E. tibialis, female; (241) E. tibialis, micropterous male; (242) E. tibialis, macropterous male; (243) E. virgulae, female. (244) Fernothrips femoralis gen. et sp. n., female. (245) Ischyrothrips crassus, female. (246) Polytrichothrips malayanus sp. n., female.