Ethirothrips oculus, 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 : 38-39

Ethirothrips oculus sp. n.

( Figs 96–103 , 227 )

Female (macroptera). Distended body length: 3.1–4.3mm. Colour dark brown. Antennal segment II yellowish apically; segment III brownish yellow. Fore tibiae and all tarsi yellowish. Fore wings pale, almost colourless. Prominent setae yellowish. Head ( Fig. 96 ) longer than broad, about 1.5 times as long as broad, broadest across eyes; dorsal surface sculptured marginally with transverse row of weak striae or reticulation. Cheeks weakly convex, but very weakly constricted sub-basally; cheek setae minute and slender, shorter than 30μm. Postocular setae situated behind eyes, much longer than eyes, 0.34–0.35 times as long as head in holotype, blunt or nearly pointed; postocellar setae minute, shorter than diameter of a posterior ocellus, situated behind posterior ocelli. Eyes comparatively small, about 1/4 as long as head, each with two or three enlarged ommatidia postero-laterally ( Fig. 97 ); posterior ocelli well developed, close to eyes, about 30μm in diameter, 40μm apart from each other in holotype. Antennae ( Fig. 99 ) about 1.8 times as long as head; segment VIII a little shorter than segment VII, constricted basally; segment III 2.7 times as long as broad in holotype, almost as long as segment IV, or a little shorter; sense-cones short, segment IV with four sense-cones, but sometimes with one (rarely two) small dorsal sense-cone in addition to usual four sense-cone (right segment with this small dorsal sense-cone in holotype). Mouth-cone slightly long and pointed. Maxillary stylets deeply retracted, reaching postocular setae, about 1/2 of head width apart from each other. Pronotum shorter than half the length of head, 0.45 times as long as head in holotype; dorsal surface generally weakly sculptured with reticulation. Prominent setae blunt or nearly pointed, at least not sharply pointed, am and aa well developed, am a little longer than aa; pa elongate, almost as long as epim, or a little longer. Metanotum ( Fig. 102 ) without CPS. Fore femora moderately enlarged, with long setae (50–70μm in holotype) on dorso-externally; fore tarsus ( Fig. 100 ) without tooth. Mesopresternum ( Fig. 98 ) widely boat-shaped. Fore wings each with 30–32 duplicated cilia in holotype; sub-basal setae S1and S2 blunt, S3 sharply pointed. Pelta ( Fig. 102 ) broadly triangular, without distinct lateral wings. Abdominal tergite II scarcely eroded laterally. Posteromarginal setae on abdominal tergite IX sharply pointed, a little shorter than tube, S1 and S2 subequal in length. Tube ( Fig. 103 ) longer than head, almost straight sided, about 3.1 times as long as broad, very weakly constricted at apex.

Measurements (holotype female in μm). Body length about 3850 (distended). Head length 400, from anterior margin of eyes 380, width 270; eyes length 100, width 85; postocular setae 135–140. Antenna total length 720, segments I–VIII length (width) as follows: 80 (53), 75 (37), 120 (45), 123 (48), 113 (37), 84 (33), 70 (28), 62 (22). Pronotum length 174, width 360. Setae on prothorax: am 90, aa 75–80, ml 90, pa 150–162, epim 150, cox 55. Fore wing length 1570. Sub-basal wing setae: S1 60, S2 85–88, S3 175–190. Setae on tergite IX: S1 400, S2 400–410. Tube length 430, maximum width 140; terminal setae about 300.

Male (macroptera). Distended body length: 3.2–3.5mm. Colour and structure very similar to female. Head about 1.42–1.45 times as long as broad. Prothorax and fore legs somewhat stouter in large male, with a stout fore tarsal tooth ( Fig. 101 ); pronotum 0.47–0.54 times as long as head. Tube a little shorter than head, 0.93–0.97 times as long as head, 2.7–2.8 times as long as broad.

Measurements (paratype small–large males in μm). Body length about 3180–3500 (distended). Head length 348–360, from anterior margin of eyes 320–335, width 240–253; eyes length 95–100, width 76–80; postocular setae 130–145. Antenna total length 640–670, segments I–VIII length (width) as follows: 65–80 (48–53), 68–75 (35–40), 105–110 (41–43), 100–110 (42–43), 95–105 (33–37), 78–77 (28–32), 65–62 (25–27), 55–57 (20–20). Pronotum length 165–195, width 326–375. Setae on prothorax: am 70–88, aa 65–90, ml 85–108, pa 120–145, epim 120–150, cox 50–60. Fore wing length 1325–1400. Sub-basal wing setae: S1 57 –62, S2 85–100, S3 160–190. Setae on tergite IX: S1 320–350, S2 330–360. Tube length 325–350, maximum width 115–132; terminal setae 250–350.

Type series. Holotype: macropterous female, Borneo, Sabah, Jl. Kimanis, 15km from Kimanis, 9.ix.1990, TN & SO . Paratypes: Borneo, 8 females and 5 males, collected together with holotype ; 2 females and 2 males, similar data as holotype, but 3.ix.1990 .

Remarks. E. oculus may be nearly allied to E. firmus (Hood) from Brazil in having similar head proportion, elongate anteromarginal pronotal setae and broad pelta. However, E. firmus has the fore tarsal tooth in female, short tube which is much shorter than head and about 2.4 times as long as broad, though E. oculus has no tarsal tooth in female ( Fig. 100 ), long tube which is longer than head in female and only a little shorter than head in male, and 2.7 (male)–3.1 (female) times as long as broad ( Fig. 103 ). According to the original description, however, firmus has stout fore tarsal tooth in female, though a paratype female studied by Mound (1974) had a small tarsal tooth. Moreover, in the key to New World species of Ethirothrips ( Mound & Marullo 1996) , firmus was described as “female without fore tarsal tooth”. E. fijiensis (Moulton) from Fiji may also be similar to this species, but has 7- segmented antennae.

Figures

FIGURES 96–103. Ethirothrips oculus sp. n. (96) Head, female; (97) postero-lateral portion of eye, female, arrow indicates large ommatidia; (98) mesopresternum, female; (99) antennal segments II–VIII, female; (100) fore tarsus, female; (101) fore tarsus, male; (102) metanotum & pelta, female; (103) tube, female.

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.