Ethirothrips ommatus, 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 : 40

Ethirothrips ommatus sp. n.

( Figs 104–109 , 228 )

Female (macroptera). Distended body length: 2.7–3.6mm. Colour uniformly dark brown. Antennal segment III scarcely paler than segment IV, with base yellowish. Tarsi brown to dark brown. Fore wings weakly shaded with brown, with a brown median long streak. Prominent setae brownish yellow. Head ( Fig. 104 ) elongate, broadest across eyes, 1.59 times as long as broad in holotype; dorsal surface sculptured laterally with transverse row of reticulation or striae, but with indistinct spaced wrinkles medially. Cheeks sinuate, very weakly constricted behind eyes, distinctly narrowed sub-basally, with a pair of small ommatidium-like structures at basal 1/3 ( Fig. 104b ), with some minute setae, postocular cheek setae 25–30μm in holotype. Postocular setae comparatively short, shorter than 1/3 of head length, sharply pointed, situated behind eyes; postocellar setae elongate, but variable in length, usually longer than 2/3 of postoculars, situated behind posterior ocelli.A pair of mid-vertex setae 33–37μm in holotype. Eyes comparatively small; ocelli well developed, anterior one directed forward, posterior ocelli close to eyes, 25–30μm in diameter, about 70μm apart from each other in holotype. Antennae ( Fig. 105 ) 1.9–2.0 times as long as head; segment VIII long and scarcely constricted at base; segment III longer than IV, about 3.3 times as long as broad; sense-cones short, segment IV with four sense-cones. Mouth-cone more or less pointed; maxillary stylets wide apart, retracted to postocular setae. Pronotum much shorter than half the length of head, 0.37 times as long as head in holotype; dorsal surface almost smooth, weakly sculptured with reticulation laterally and posteriorly. Prominent setae pointed, am well developed, usually longer than aa, pa a little shorter than median length of pronotum, but variable length in paratypes, 70–150μm. Mesopresternum ( Fig. 109 ) boat-shaped. Metanotum ( Fig. 107 ) without CPS. Fore femora not enlarged, each with about 10 setae on dorso-external surface, the longest seta situated at middle (90–100μm in holotype); fore tarsus ( Fig. 108 ) with a wide-based tooth. Fore wings each with 17–19 duplicated cilia in holotype; three sub-basal setae pointed or nearly pointed. Pelta ( Fig. 107 ) broadly triangular, with indistinct lateral wings, with weak reticulation. Posteromarginal setae on abdominal tergite IX sharply pointed, shorter than tube, S1 and S2 subequal in length. Tube ( Fig. 106 ) a little longer than head, almost straight sided, but weakly swollen at base and weakly constricted at apex, 3.9 times as long as broad.

Measurements (holotype female in μm). Body length about 3530 (distended). Head length 435, from anterior margin of eyes 405, width 274; eyes length 100, width 76; postocular setae 120–130; postocellars 97–103. Antenna total length 850, segments I–VIII length (width) as follows: 75 (58), 72 (40), 163 (50), 137 (53), 118 (46), 100 (40), 94 (30), 70 (25). Pronotum length 160, width 325. Setae on prothorax: am 75, aa 50–60, ml 85–95, pa 142–150, epim 125–135, cox 55–60. Fore wing length 1400. Sub-basal wing setae: S1 50 –55, S2 78–80, S3 155–165. Setae on tergite IX: S1 380–400, S2 400–410. Tube length 450, maximum width 115; terminal setae 230.

Male. Unknown.

Type series. Holotype: macropterous female, Vietnam, Lam Dong Prov., Bao Loc, Dam Bri , on dead leaves, 28.xii.2001, SO . Paratypes: Vietnam, Tuyen Quang Prov., Ham Yen Distr., Tan Lap, Lam Truong , 1 female, on dead leaves and branches, 19.viii.2000, SO; Ha Tay Prov. , Mt. Ba Vi , 1 female, on dead leaves and branches, 8.iii.2000, SO; Nghe Chuong Prov. , Thanh Chuong Distr. , Thanh An , Cau Cau , ca 40m alt., 2 females, 9.viii.2007, SO ; Quang Binh Prov., Bo Trach Distr., Son Trach, nr. Phong Nha , ca 20m alt., 2 females, 14.viii.2007, SO .

Remarks. A small ommatidium-like structure is present in E. ommatus at behind the middle of cheeks (Fig, 104b), which may be unique in the genus Ethirothrips . Certain species of the genus, such as E. stenomelas , also have similar ommatidium-like structure, but usually situated immediately behind compound eyes. The genera Polytrichothrips and Tarassothrips have similar ommatidium-like structures which are situated at the middle or near base of cheeks, but these genera have different shape of maxillary stylets which are very long and close together medially.

Figures

FIGURES 104–109. Ethirothrips ommatus sp. n., female. (104) Head & prothorax; (104a) large ommatidia; (104b) ommatidium-like structure; (105) antennal segments II–VIII; (106) tube; (107) metanotum & pelta; (108) fore tarsus; (109) ferna and mesopresternum.

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.