Ethirothrips quadratus, 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 : 43-45

Ethirothrips quadratus sp. n.

( Figs 115–120 , 230 )

Female (macroptera). Distended body length: 3.6mm. Colour uniformly dark brown. Antennal segment III yellowish at base. Tarsi brown. Fore wings weakly shaded with brown, shaded darker at base. Prominent setae brownish yellow. Head ( Fig. 115 ) a little longer than broad, about 1.1 times as long as broad in holotype; anterior costa vertical; dorsal surface weakly sculptured with transverse row of striae, but with weak transverse reticulation at base. Cheeks weakly convex, more or less constricted at base, with some minute setae, but postocular cheek setae a little stouter. Postocular setae well developed, but shorter than 1/2 of head length, sharply pointed; ocellar setae minute, postocellar setae shorter than diameter of a posterior ocellus, situated behind posterior ocelli. Eyes comparatively small, about 1/4 as long as head, with at least two enlarged ommatidia postero-laterally ( Fig. 115a ); ocelli comparatively small, posterior ocelli 24–25μm in diameter, about 90μm apart from each other in holotype. Antennae ( Fig. 117 ) about 1.9 times as long as head; segment VIII short, but slightly constricted at base and well separated from VII; segment III longer than IV, about 2.6 times as long as broad; sense-cones short, segment IV with four sense-cones. Maxillary stylets wide apart, V-shaped. Pronotum ( Fig. 115 ) longer than half the length of head, 0.59 times as long as head in holotype, almost smooth, but very weakly sculptured posteromarginally; prominent setae pointed or nearly pointed, am setae developed, but shorter than aa. Mesopresternum boat-shaped ( Fig. 116 ). Metanotum ( Fig. 119 ) without CPS. Fore femora somewhat enlarged, fore tarsus ( Fig. 118 ) with a wide-based tooth. Fore wings each with 25–27 duplicated cilia in holotype; three sub-basal setae sharply pointed. Pelta ( Fig. 119 ) broadly triangular, without distinct lateral wings. Abdominal tergite II strongly eroded laterally at anterior 2/3. Posteromarginal setae on abdominal tergite IX sharply pointed, shorter than tube, S1 longer than S2. Tube ( Fig. 120 ) almost as long as head, about 2.5 times as long as broad, sides weakly convex, weakly constricted at apex.

Measurements (holotype female in μm). Body length 3550 (distended). Head length 350, from anterior margin of eyes 335, width 310; eyes length 90, width 85; postocular setae 140–145.Antenna total length about 670, segments I–VIII length (width) as follows: 82 (60), 75 (45), 120 (46), 110 (50), 100 (45), 76 (40), 60 (33), 38 (18). Pronotum length 206, width 438. Setae on prothorax: am 45–50, aa 60–63, ml 80–85, pa 98–105, epim 180–190, cox 50–56. Fore wing length 1380. Sub-basal wing setae: S1 60 –62, S2 140–142, S3 180–186. Setae on tergite IX: S1 about 300, S2 210–270. Tube length 345, maximum width 140; terminal setae 240.

Male (macroptera). Distended body length: 3.0mm. Colour very similar to female. Head about 1.2 times as long as broad. Prothorax and fore legs somewhat stouter, pronotum about 0.7 times as long as head, fore femora enlarged, fore tarsal tooth stout. Tube shorter than head, about 2.3 times as long as broad, bulged at base, weakly constricted sub-basally and apically.

Measurements (paratype male in μm). Body length 2950 (distended). Head length 325, from anterior margin of eyes 305, width 270; eyes length 85, width 80; postocular setae about 120. Antenna total length about 600, segments I–VIII length (width) as follows: 75 (52), 75 (40), 110 (41), 100 (44), 90 (40), 72 (36), 57 (30), 38 (18). Pronotum length 225, width 395. Setae on prothorax: am 30–35, aa?, ml 40–50, pa 110–140, epim 150–180, cox about 50. Fore wing length 1250. Sub-basal wing setae: S1 62–68, S2 130–142, S3 170–172. Setae on tergite IX: S1 240–250, S2 about 180. Tube length 280, maximum width 120; terminal setae 200–220.

Type series. Holotype: macropterous female, Taiwan, Taoyuan Hsien, nr. Su-Lin , on dead leaves, 4.v.1988, M. Hasegawa . Paratype: Taiwan, Taipei Hsien, Mt. Tatung shan, 1 male, on dead leaves, 4.iv.1988, SO .

Remarks. E. quadratus is somewhat similar to an Australian species, E. australiensis (Moulton) in appearance. Both of them have particularly short head, dark antennal segment III with yellowish extreme base, broad triangular pelta, and short tube which is almost as long as head. However, this species has short antennal segment VIII which is shorter than 2/3 as long as segment VII ( Fig. 117 ), and wide-based fore tarsal tooth ( Fig. 118 ), whereas australiensis has antennal segment VIII long and almost as long as segment VII, and slender fore tarsal tooth. Moreover, S2 setae on the abdominal tergite IX are shorter than both tube and S1 setae in quadratus , while those of australiensis are longer than S1 setae and almost as long as tube.

Figures

FIGURES 115–120. Ethirothrips quadratus sp. n., female. (115) Head & prothorax; (115a) large ommatidia; (116) mesopresternum; (117) antennal segments III–VIII; (118) fore tarsus; (119) metanotum & pelta; (120) tube.

FIGURES 223–234. Ethirothrips species, female. (223) E. longiceps sp. n.; (224) E. longisetis; (225) E. malaya sp. n.; (226) E. obscurus; (227) E. oculus sp. n.; (228) E. ommatus sp. n.; (229) E. puiensis sp. n.; (230) E. quadratus sp. n.; (231) E. rubeus, paratype; (232) E. rubeus from Thailand; (233) E. saigon sp. n.; (234) E. setosus sp. n.