Ethirothrips saigon, 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 : 47-49

Ethirothrips saigon sp. n.

( Figs 127–132 , 233 )

Female (macroptera). Distended body length: 3.0– 3.3mm. Colour uniformly dark brown. Antennal segment II with paler apex; segment III yellow; segment IV yellowish, scarcely darker than segment III. Tarsi brown to dark brown. Fore wings pale almost clear, without dark streak. Prominent setae including cheek setae yellowish. Head ( Fig. 127 ) elongate and weakly swollen dorsally, broadest across cheeks just behind eyes, about 1.5 times as long as broad, 1.47 times in holotype; dorsal surface sculptured laterally and basally with transverse row of weak reticulation. Cheeks swollen behind eyes, distinctly constricted from behind the middle to base; cheek setae minute, but postocular cheek setae more than 30μm. Postocular setae developed, but shorter than 1/2 head length, blunt, at least not sharply pointed, situated behind eyes; postocellar setae minute, shorter than diameter of a posterior ocellus, situated behind posteriorocelli. Eyes directed forwardly, comparatively small, about 1/5 as long as head; ocelli comparatively small, anterior ocellus directed forwards; posterior ocelli 25μm in diameter, about 80μm apart from each other in holotype. Antennae ( Fig. 128 ) 1.55 times as long as head; segment VIII long, slender and weakly constricted at base, about 4/5 as long as VII; segment III longer than IV, 2.9 times as long as broad; sense-cones short, segment IV with four sense-cones. Maxillary stylets retracted to eyes, not wide apart, less than 1/5 of head width apart at the middle of head, and sub-parallel. Pronotum much shorter than half the length of head, 0.36 times as long as head in holotype; dorsal surface almost smooth, weakly sculptured with reticulation marginally. Prominent setae blunt, am longer than 50μm (left am is minute in holotype, but this may be an aberration). Mesopresternum ( Fig. 129 ) distinct, widely boat shaped. Metanotum ( Fig. 131 ) without CPS. Fore femora moderately enlarged, without long setae on dorso-external surface; fore tarsus ( Fig. 130 ) with a wide-based tooth. Fore wings each with 14–17 duplicated cilia in holotype; three sub-basal setae blunt, arising in a triangle, S1 setae situated before S2. Pelta ( Fig. 131 ) with short lateral wings. Posteromarginal setae on abdominal tergite IX sharply pointed, much longer than tube, S1 and S2 subequal in length. Tube ( Fig. 132 ) shorter than head, about 0.9 times as long as head, 2.7–2.8 times as long as broad, very weakly convex, but almost evenly narrowed to apex, weakly constricted at apex.

Measurements (holotype female in μm). Body length about 3300 (distended). Head length 406, from anterior margin of eyes 393, width 277; eyes length 83, width 71; postocular setae 150. Antenna total length 630, segments I–VIII length (width) as follows: 66 (50), 65 (38), 110 (38), 98 (40), 86 (35), 79 (30), 55 (26), 45 (15). Pronotum length 145, width 365. Setae on prothorax: am 55, aa 55–60, ml 80, pa 110–120, epim 150–160, cox 50. Fore wing length 1275. Sub-basal wing setae: S1 57, S2 72–75, S3 120–135. Setae on tergite IX: S1 420–450, S2 470. Tube length 356, maximum width 128; terminal setae 350–355.

Male. Unknown.

Type series. Holotype: macropterous female, Vietnam, Lam Dong Prov., Finom Ward, Don Duong , on dead leaves and branches, 25.xii.2001, SO . Paratypes: Vietnam, 2 females, collected together with holotype .

Remarks. The dorsally swollen head, forwardly directed compound eyes and the long and subparallel maxillary stylets of E. saigon are similar to some species described in the synonymous genus Uredothrips , such as E. tirumalaiensis and E. tibialis . However, saigon can be distinguished from them by the head shape ( Fig. 127 ) which is distinctly constricted behind the middle, longer anteromarginal pronotal setae, longer posteromarginal setae on abdominal tergite IX, and longer tube and terminal setae. According to Priesner (1939) and Faure (1955), E. vitreipennis is somewhat similar to this species in the head shape and number of fore wing duplicated cilia, but saigon has the antennal segments III and IV paler, maxillary stylets longer, and the tube shorter.

Figures

FIGURES 127–132. Ethirothrips saigon sp. n., female. (127) Head; (128) antenna; (129) ferna & mesopresternum; (130) fore tarsus; (131) metanotum & pelta; (132) abdominal segment IX & tube.

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.