Ethirothrips colossus Okajima & Masumoto 2023, sp. n.
Creators: name: Okajima, Shûji
name: Masumoto, Masami
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Thysanoptera
Phlaeothripidae
Ethirothrips
Ethirothrips colossus

description: Ethirothrips colossus sp. n.
(Figs 36–42, 217)
Female (macroptera). Distended body length: 5.9–7.2mm. Colour uniformly dark brown. Antennal segment III yellow with apical 1/5 brown. Tarsi brown to dark brown. Fore wings weakly shaded with brown, with a dark brown streak in basal half. Prominent setae yellow to brownish yellow. Head (Fig. 36) elongate, about 2.0 times as long as broad, broadest across eyes, projected shortly in front of eyes; dorsal surface sculptured with fine transverse row of striae or reticulation, but almost smooth before postocellar setae, but the sculpture indistinct along median longitudinal area. Cheeks sub-parallel, but weakly convex and shortly swollen just behind eyes; each with a series of stout setae, most of which are longer than diameter of a posterior ocellus. Postocular setae much longer than eyes, 0.45 times as long as head in holotype, sharply pointed; a pair of mid-vertex setae well developed, 100–120μm in holotype; postocellar setae long and sharply pointed, usually longer than 1/2 as long as postoculars; situated behind posterior ocelli. Eyes bulged, but small, about 0.2 times as long as head; posterior ocelli slightly apart from eyes, 38–40μm in diameter, 68μm apart from each other in holotype. Antennae (Fig. 37) unusually slender in the genus, about 1.5 times as long as head; segment VIII slender, almost as long as segment VII, constricted basally; segment III unusually slender, 4.6 times as long as broad in holotype, much longer than segment IV; segments VI and VII each with a ventral apical small prolongation; sense-cones short, segment IV with four sense-cones. Maxillary stylets deeply retracted, reaching near postocular setae, closer than postocular setae, subparallel. Pronotum (Fig. 36) stout, shorter than half the length of head, 0.42 times as long as head in holotype; dorsal surface with some deep wrinkles on anterior and lateral margins, sculptured with fine transverse reticulation posteriorly. Prominent setae nearly pointed, am and aa subequal in length. Mesopresternum (Fig. 39) distinct, posterior margin and lateral margins forming obtuse angles, lateral margins longer than 1/2 as long as posterior margin. Metanotum (Fig. 38) without CPS. Fore femora moderately enlarged; fore tarsus (Fig. 41) with a wide-based short tooth that has two angles. Fore wings each with 52–54 duplicated cilia in holotype; sub-basal setae S1 and S2 blunt or nearly pointed, S3 sharply pointed. Pelta (Fig. 38) broadly triangular, without distinct lateral wings, generally distinctly sculptured with polygonal reticulation. Posteromarginal setae on abdominal tergite IX sharply pointed, shorter than tube, S1 shorter than S2. Tube (Fig. 40) almost as long as head or a little longer, 4.0 times as long as broad, sides almost straight, but very weakly constricted apically.
Measurements (holotype female in μm). Body length about 7000 (distended). Head length 780, from anterior margin of eyes 700, width across eyes 400; eyes length 160, width 120; postocular setae about 290; postocellar setae length about 170. Antenna total length 1160, segments I–VIII length (width) as follows: 120 (83), 123 (57), 276 (60), 210 (62), 185 (55), 120 (45), 82 (37), 80 (23). Pronotum length 325, width 650. Setae on prothorax: am 85–90, aa 80–100, ml 60–80, pa 200–210, epim 200–225, cox about 100. Fore wing length 2650. Sub-basal wing setae: S1 100, S2 130, S3 225. Setae on tergite IX: S1 550–580, S2 620–650. Tube length 800, maximum width 200; terminal setae 320–370.
Male (macroptera). Distended body length: 5.8–6.8mm. Colour very similar to female. Pronotal am and ml shorter than aa. Fore tarsus (Fig. 42) with a wide-based normal tooth. S1 setae on abdominal tergite IX shorter than S2. Tube a little shorter than head, 4.0–4.1 times as long as broad, weakly swollen at base.
Measurements (paratype male in μm). Body length about 6080 (distended). Head length 720, from anterior margin of eyes 650, width across eyes 350; eyes length 160, width 105–110; postocular setae 200–210.Antenna total length 1100, segments I–VIII length (width) as follows: 100 (77), 105 (52), 258 (52), 190 (55), 180 (50), 112 (45), 80 (33), 80 (22). Pronotum length 320, width 600. Setae on prothorax: am shorter than 20, aa 80, ml shorter than 20, pa 190, epim?, cox 90–100. Fore wing length 2450. Sub-basal wing setae: S1 70–80, S2 105–110, S3 175–200. Setae on tergite IX: S1 430–450, S2 480–510. Tube length 690, maximum width 170; terminal setae 380–390.
Type series. Holotype: macropterous female, Thailand, nr. Chiang Mai, foot of Doi Pui, on dead leaves and branches, 1.ix.1991, TN & SO. Paratypes: Thailand, 15 females and 7 males, collected together with holotype; Doi Suthep, 1100m alt., 3 females and 1 male, 13.viii.1976, SO.
Non-paratypic specimens: Taiwan, 3 females and 3 males, Nantou Hsien, Nanshanchi, on dead leaves, 30.iv.1983, H. Yamazaki; 4 females and 5 males, Nantou Hsien, Rushan, on dead leaves and branches, v.1983, M. Hasegawa. Laos, 2 females, Houa Phan Prov., Xam Neua, Ban Saleui, Mt. Phu Pan, on dead leaves, 23.v.2004, T. Mizusawa et T. Tsuru.
Remarks. Because of the large body, weakly forwardly projected head (Fig. 36), slender antennae with segment VIII pedicellate (Fig. 37), and the relatively close and subparallel maxillary stylets, E. colossus could probably be considered as an unusual member of the genus Ethirothrips. However, each of these character states is not peculiar among the genus: the large body size and elongate antennae are also found in E. (?) stenomelas from Mindanao and East Java (Fig. 150), the pedicellate antennal segment VIII is found in E. malaya sp. n. and E. oculus sp. n. (Figs 85 & 99), and the close and subparallel maxillary stylets are found in E. malaya and E. tibialis. Furthermore, the heads of E. agasthya (Ramakrishna) from India and E. antennalis (Bagnall) from Japan are slightly produced anteriorly. A series of females and males listed in the non-paratypic specimens from Taiwan and Laos are probably same species, but have somewhat paler antennal segments IV and V. Their pedicels are more or less yellowish, though these segments of the type series are uniformly dark brown. Moreover, two females from Laos have somewhat broader head proportion, which is about 1.8 times as long as broad.
description: Published as part of Okajima, Shûji & Masumoto, Masami, 2023, Six genera of the subtribe Macrothripina from Southeast Asia to Taiwan (Thysanoptera, Phlaeothripidae, Idolothripinae), pp. 1-74 in Zootaxa 5291 (1) on pages 21-23, DOI: 10.11646/zootaxa.5291.1.1, http://zenodo.org/record/7959311