Ethirothrips terminalis, 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 : 57-59

Ethirothrips terminalis sp. n.

( Figs 162–168 , 238 )

Female (macroptera). Distended body length: 2.9–3.4mm. Colour dark brown. Antennal segment II paler distally; segments III and IV yellowish, but IV a little darker than III; segment V-VIII dark brown, extreme base of V somewhat paler. Fore tibiae yellowish brown, mid and hind tibiae dark brown with extreme bases a little paler, all tarsi brownish yellow. Fore wings very weakly shaded, without distinct streak. Prominent setae yellowish. Head ( Fig. 162 ) longer, about 1.36 times as long as broad in holotype, broadest across cheeks just behind eyes; dorsal surface sculptured laterally with transverse row of weak reticulation, with fine reticulation basally. Cheeks narrowed to base, weakly convex in anterior 1/2, scarcely emarginate sub-basally; each with a few short but stout setae. Postocular setae situated behind eyes, much longer than eyes, 0.42–0.47 times as long as head in holotype, blunt or nearly pointed; postocellar setae minute, shorter than diameter of a posterior ocellus, situated behind eyes. Eyes directed forwards, about 1/4 of head length, 0.26 times as long as head in holotype; posterior ocelli close to eyes, 23–27μm in diameter, 70μm apart from each other in holotype. Antennae ( Fig. 163 ) about 1.7 times as long as head; segment VIII slender, not constricted basally; segment III 2.8 times as long as broad in holotype, a little longer than segment IV; sense-cones short, segment IV with four sense-cones. Maxillary stylets deeply retracted, reaching postocular setae, narrowly V-shaped, about 1/3 of head width apart from each other. Pronotum ( Fig. 162 ) a little shorter than half the length of head, 0.47 times as long as head in holotype, almost smooth, but weakly sculptured laterally and posteriorly; prominent setae blunt, aa longer than am, pa and epim elongate, almost as long as median length of pronotum in holotype. Mesopresternum ( Fig. 164 ) widely boat-shaped. Metanotum ( Fig. 165 ) without CPS. Fore femora somewhat enlarged, without long setae; fore tarsus ( Fig. 167 ) with a wide-based stout tooth. Fore wings each with 17 duplicated cilia in holotype; three sub-basal setae blunt. Pelta ( Fig. 165 ) trilobed, with narrow lateral wings. Abdominal tergite II weakly eroded laterally at anterior 2/3. Posteromarginal setae on abdominal tergite IX sharply pointed, longer than tube, S1 usually shorter than S2. Tube ( Fig. 166 ) a little shorter than head, 0.96 times as long as head in holotype, about 2.5 times as long as broad, sides weakly convex; terminal setae almost as long as tube or a little longer.

Measurements (holotype female in μm). Body length about 3400 (distended). Head length 360, from anterior margin of eyes 340, maximum width across cheeks 265, minimum width near base 215; eyes length 95, width 70; postocular setae 150–170.Antenna total length 610, segments I–VIII length (width) as follows: 70 (55), 75 (38), 105 (38), 100 (41), 86 (37), 78 (30), 54 (26), 45 (15). Pronotum length 170, width 357. Setae on prothorax: am 45–50, aa 65–70, ml 90–95, pa 170–172, epim 165–170. Fore wing length?. Sub-basal wing setae: S1 70, S2 70–90, S3 105–125. Setae on tergite IX: S1 430–450, S2 430–500. Tube length 345, maximum width 138, width at apex 55; terminal setae 350–360.

Male (macroptera). Distended body length: 2.5–2.6mm. Colour very similar to female. Head widest across eyes. Prothorax and fore legs stouter, pronotum about 1/2 the length of head, fore femora enlarged, fore tarsal tooth longer ( Fig. 168 ). Tube about 0.9 times as long as head.

Measurements (paratype male in μm). Body length about 2600 (distended). Head length 310, from anterior margin of eyes 290, width across eyes 230, maximum width across cheeks 225, minimum width near base 186; eyes length 85, width 60; postocular setae 130–132. Antenna total length 550, segments I–VIII length (width) as follows: 65 (45), 67 (34), 93 (33), 85 (35), 78 (33), 65 (30), 50 (25), 40 (13). Pronotum length 160, width 307. Setae on prothorax: am 43–45, aa 55–60, ml 75–78, pa 130–135, epim 132–135. Fore wing length 1130. Sub-basal wing setae: S1 50 –52, S2 60, S3 83–87. Setae on tergite IX: S1 360–370, S2 400–410. Tube length 270, maximum width 109; terminal setae 300–320.

Type series. Holotype: macropterous female, Thailand, nr. Chiang Mai, Doi Inthanon , on dead leaves and branches, 29.viii.1992, TN & SO . Paratypes: Thailand, 2 females and 2 males, collected together with holotype .

Remarks. E. terminalis is probably related to E. saigon sp. n. described above in having the head moderately elongate with long maxillary stylets which are retracted to postocular setae or longer, antennal segments III and IV yellowish, and the body setae longer including terminal ones. Especially, the long terminal setae of these two species are peculiar at least in the Asian species of the genus, whereas these setae are also longer in some Australian species, such as E. barretti (Mound) and E. distasmus (Mound) . Although, saigon has the maxillary stylets nearly allied and sub-parallel, and the compound eyes smaller and about one-fifth as long as head, terminalis has wider apart V-shaped stylets ( Fig. 162 ) and comparatively larger eyes which are about one-fourth as long as head. E. barretti is also similar to terminalis in the head proportion and longer body setae. However, E. barretti has antennal segments III and IV bicoloured, and shorter tube which is distinctly shorter than head (0.77–0.78 times as long as head in males, 0.82 times in female), whereas terminalis has antennal segments III and IV yellowish ( Fig. 163 ), and the tube longer and 0.9 times as long as head in male, 0.9–1.0 times in female.

Figures

FIGURES 162–168. Ethirothrips terminalis sp. n. (162) Head & prothorax, female; (163) antennal segments II–VIII, female; (164) prosternum & mesopresternum, female; (165) metanotum & pelta, female; (166) tube, female; (167) fore tarsus, female; (168) 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.