Ethirothrips tenuis, 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 : 55-57

Ethirothrips tenuis sp. n.

( Figs 156–161 , 237 )

Female (macroptera). Distended body length: 4.1–4.5mm.Colour dark brown.Antennal segment II yellowish distally, segment III yellowish with apical 1/3 or 1/4 brown. Fore tibiae brown, a little paler than head; tarsi yellowish. Fore wings weakly shaded with brown, with a brown streak. Prominent setae yellow to brownish yellow. Head ( Fig. 156 ) elongate, longer than twice as long as broad, 2.25 times as long as broad in holotype, broadest across eyes; dorsal surface smooth anteriorly, sculptured with weak striae or reticulation laterally and posteriorly. Cheeks sub-parallel, almost straight, very weakly narrowed basally; each with a few short and weak setae. Postocular setae much longer than eyes, 0.45 times as long as head in holotype, sharply pointed; a pair of mid-vertex setae 40–45μm in holotype; postocellar setae a little longer than diameter of a posterior ocellus, situated behind posterior ocelli; anteocellar setae shorter. Eyes small, about 0.2 times as long as head; posterior ocelli close to eyes, 27–30μm in diameter, 53μm apart from each other in holotype. Antennae ( Fig. 157 ) short, about 1.4 times as long as head; segment VIII weakly constricted basally; segment III slender, 3.8–3.9 times as long as broad, a little longer than segment IV; sense-cones slender, setiform, but shorter than half the length of the segment III, segment III with three sense-cones (with a small dorsal sense-cone in addition to usual two sense-cones), segment IV with four sense-cones. Mouth cone short and rounded; maxillary stylets deeply retracted, reaching eyes, close together medially. Pronotum ( Fig. 156 ) much shorter than half the length of head, 0.28 times as long as head in holotype; dorsal surface smooth medially, sculptured with weak reticulation laterally. Prominent setae pointed, am shorter than aa, epim the longest. Basantra and ferna ( Fig. 160 ) well developed. Mesopresternum ( Fig. 160 ) broadly boat-shaped. Metanotum without CPS, sculptured with weak longitudinal reticulation posteriorly. Fore femora moderately enlarged; fore tarsus ( Fig. 161 ) with a wide-based short tooth. Fore wings with 21–22 duplicated cilia in holotype; sub-basal setae S1 short, S2 and S3 blunt or nearly pointed. Pelta ( Fig. 159 ) broadly triangular, angular-shaped anteriorly, somewhat similar to that of Aesthesiothrips . Posteromarginal setae on abdominal tergite IX sharply pointed, a little shorter than tube, S1 and S2 subequal in length. Tube ( Fig. 158 ) a little shorter than head, 0.95 times as long as head, 4.1 times as long as broad in holotype, sides almost straight, but swollen at base, constricted at apex. Terminal setae shorter than tube (about 350μm in paratype female).

Measurements (holotype female in μm). Body length about 4450 (distended). Head length 535, from anterior margin of eyes 505, width across eyes 238; eyes length 110, width 70; postocular setae 240. Antenna total length 750, segments I–VIII length (width) as follows: 80 (58), 80 (42), 170 (44), 160 (43), 135 (40), 88 (35), 60 (28), 52 (18). Pronotum length 150, width 340. Setae on prothorax: am 35–40, aa 50–70, ml about 80, pa 105–110, epim 195. Fore wing length 1800. Sub-basal wing setae: S1?, S2 108–110, S3 145–150. Pelta length 160, width 335. Setae on tergite IX: S1 about 500, S2 about 500. Tube length 510, basal width 125, apical width 62; terminal setae?.

Male (macroptera). Distended body length: 3.2–3.7mm. Colour very similar to female. Head 2.1–2.2 times as long as broad. Fore femora largely developed in large male; fore tarsal tooth stouter. Fore wings with 16–20 duplicated cilia. S1 and S2 setae on abdominal tergite IX longer than Tube.

Measurements (paratype small–large males in μm). Body length about 3250–3650 (distended). Head length 415–475, from anterior margin of eyes 395–450, width across eyes 200–215; eyes length 90–100, width 55–60; postocular setae 175–197. Antenna total length 640–720, segments I–VIII length (width) as follows: 70–75 (46– 50), 70–72 (35–37), 115–135 (35–43), 105–125 (37–40), 100–115 (35–36), 74–83 (30–30), 50–55 (25–28), 46–50 (17–20). Pronotum length 130–165, width 280–300. Setae on prothorax: am 25–30, aa?, ml?–90, pa 80–125, epim 145–180. Fore wing length 1300–1550. Sub-basal wing setae: S1 50 –65, S2 85–95, S3 130–142. Setae on tergite IX: S1 430–450, S2 450–480. Tube length 390–440, basal width 100–105, apical width 55–60; terminal setae 280–315.

Type series. Holotype: macropterous female, Indonesia, Bali Is., Tabanan, nr. Wangaya, Pura Jero Sasah , 12.viii.2006, SO . Paratypes: Indonesia, Bali Is., Kuta (sea level), 1 male, on dead leaves and branches, 23.vii.1984, Tabanan, Jatiliwih (Peteli Temple), 1 female and 1 male, on dead branches, 14.iii.2005, SO ; Java, Banyuwangi , Malan Sari, 1 male, on bamboo, 27.viii.2005, SO; Flores Is., Ngada, Bajawa, Wolomeli, 1 female, 28.viii.2006, SO .

Remarks. E. tenuis not only has unusual features in the genus, but also has some intermediate character states between Aesthesiothrips and Ethirothrips . It has the maxillary stylets deeply retracted to eyes and close together in the middle of head ( Fig. 156 ), and has the characteristic pelta which is triangular with recurved lateral wings and recessed into the anterior margin of tergite II ( Fig. 159 ), and it is indistinguishable from those of other Aesthesiothrips species. However, unlike Aesthesiothrips species, the head is not strongly elevated dorsally, antennal segment III is longer than segment IV ( Fig. 157 ) with shorter sense-cones which are about half the length of segment III, and the postocellar setae are short in this species. In consequence, this species is presumably more closely related to Ethirothrips than to Aesthesiothrips .

Figures

FIGURES 156–161. Ethirothrips tenuis sp. n., female. (156) Head & prothorax; (157) antennal segments III–VIII; (158) tube; (159) metanotum & pelta; (160) prosternum & mesopresternum; (161) fore tarsus.

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.