Ethirothrips thai, 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 : 59-61

Ethirothrips thai sp. n.

( Fig. 169–175 , 239 )

Female (macroptera). Distended body length: 2.5–3.3mm. Colour dark brown. Antennal segments III and IV yellowish, but IV a little darker than III; segment II with apex paler; segment V–VIII brown to dark brown, V often with basal half somewhat paler. Fore tibiae and all tarsi brown. Fore wings very weakly shaded with brown medially. Prominent setae yellowish. Head ( Fig. 169 ) elongate, about 1.5 times as long as broad, broadest across eyes; dorsal surface sculptured marginally with transverse row of weak striae or reticulation. Cheeks almost straight, evenly narrowed to base; each with a few minute setae. Postocular setae situated behind eyes, much longer than eyes, 0.37–0.40 times as long as head in holotype, nearly pointed, but not sharply pointed; postocellar setae situated between posterior ocelli, variable in length, but mostly much longer than diameter of a posterior ocellus, about 50μm in holotype. Eyes 0.24 times as long as head; posterior ocelli close to eyes, 18–20μm in diameter, 68μm apart from each other in holotype. Antennae ( Fig. 170 ) about 1.7 times as long as head; segment VIII much shorter than segment VII, not strongly constricted basally and widely fused to VII; segment III 3.0 times as long as broad in holotype, longer than segment IV; sense-cones short, segment IV with four sense-cones. Maxillary stylets deeply retracted, reaching postocular setae, more than 1/3 of head width apart from each other. Pronotum ( Fig. 169 ) shorter than half the length of head, 0.41 times as long as head in holotype, almost smooth, but weakly sculptured marginally; prominent setae nearly pointed, am and ml setae shorter than 40μm. Mesopresternum ( Fig. 171 ) widely boat-shaped. Metanotum ( Fig. 173 ) without CPS. Fore femora somewhat enlarged, without long setae; fore tarsus ( Fig. 174 ) with a wide-based stout tooth. Fore wings with 15–17 duplicated cilia in holotype; three sub-basal setae S1 and S2 blunt, S3 sharply pointed. Pelta ( Fig. 173 ) trilobed, with lateral wings which are broadly fused to median lobe. Abdominal tergite II weakly eroded laterally at anterior 2/3. Posteromarginal setae on abdominal tergite IX sharply pointed, longer than tube, S1 shorter than S2. Tube ( Fig. 172 ) shorter than head, about 0.9 times as long as head, about 2.7 times as long as broad, almost straight sided, but very weakly constricted at apex.

Measurements (holotype female in μm). Body length about 2750 (distended). Head length 340, from anterior margin of eyes 320, width 228; eyes length 82, width 60; postocular setae 125–135; postocellars about 50. Antenna total length 570, segments I–VIII length (width) as follows: 63 (45), 62 (32), 105 (35), 95 (38), 82 (35), 72 (32), 50 (25), 35 (17). Pronotum length 140, width 290. Setae on prothorax: am 30–35, aa 40, ml 35–38, pa 70, epim 107–110, cox about 40. Fore wing length 1050. Setae on tergite IX: S1 320, S2 340. Tube length 300, maximum width 110; terminal setae 180–200.

Male (macroptera). Distended body length: 2.5–2.9mm. Colour very similar to female. Head about 1.6 times as long as broad. Prothorax and fore legs stouter, pronotum about 0.58 times as long as head, fore femora enlarged, fore tarsal tooth stout ( Fig. 175 ). Tube 0.84 times as long as head, about 3.2 times as long as broad, bulged at base, weakly constricted sub-basally and apically.

Measurements (paratype large male in μm). Body length about 2900 (distended). Head length 363, from anterior margin of eyes 340, width 225; eyes length 85, width 65; postocular setae 130–150. Antenna total length 580, segments I–VIII length (width) as follows: 68 (50), 68 (37), 102 (38), 98 (40), 88 (35), 75 (33), 50 (28), 35 (17). Pronotum length 210, width 365. Setae on prothorax: am 30–37, aa about 40, ml 70, pa 127–150, epim 138–140, cox 45. Fore wing length 1125. Sub-basal wing setae: S1 40 –45, S2 45 –55, S3 120–125. Setae on tergite IX: S1 330, S2 345. Tube length 305, maximum width 110; terminal setae 235–240.

Type series. Holotype: macropterous female, Thailand, Phuket Is., 17.viii.1976, SO . Paratypes: Thailand, Phuket Is., 1 female and 1 male, collected together with holotype; nr. Tonesai water fall, 1 male, on bamboo, 23.viii.1991, TN & SO; Rang Hill , 9 females and 1 male, on dead leaves and branches, 14.ix.1992, SO .

Remarks. E. thai is presumably related to E. yangi Wang described from Lyudao (= Green Island), Taiwan in having the postocellar setae situated between the posterior ocelli ( Figs 169 & 186 ). Although Wang wrote “one pair of interocellar setae between posterior ocelli” in the original description, these setae are undoubtedly homologous with the postocellar setae of other congeners. However, thai can be distinguished from yangi by the following features: tube shorter than head; antennal segment III short; antennal segment IV uniformly dark brown ( Fig. 170 ); lateral wings of pelta broadly fused to median lobe ( Fig. 173 ); tarsal tooth stout in both sexes ( Figs 174 & 175 ).

Figures

FIGURES 169–175. Ethirothrips thai sp. n. (169) Head & prothorax, female; (170) antenna, female; (171) mesopresternum, female; (172) tube, female; (173) metanotum & pelta, female; (174) fore tarsus, female; (175) fore tarsus, male.

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.

FIGURES 182–189. Ethirothrips species.E. virgulae, female 182–185: (182) Head; (183) antenna; (184) tube; (185) metanotum & pelta. E. yangi, paratype male 186–189 (these images are provided by Dr. C. L. Wang): (186) Head; (187) antennae; (188) pelta; (189) abdomen.