Megalothrips sulawesicus, Okajima & Masumoto, 2025

Okajima, Shûji & Masumoto, Masami, 2025, Two idolothripine genera, Bactrothrips and Megalothrips (Thysanoptera, Phlaeothripidae), from Asia between India and Taiwan, with descriptions of two new species, Zootaxa 5696 (4), pp. 491-516 : 512-513

Megalothrips sulawesicus sp. nov.

( Figs 92–101 )

Female (macroptera). Distended body length: 5.6–7.5mm. Body dark brown including legs and antennae; antennal segment III with extreme base yellowish ( Fig. 95 ), often scarcely paled sub-apically at exterior side. Wings weakly shaded with brown, with a distinct longitudinal brown line on basal three-fifths. Prominent body setae yellowish, but weakly shaded. Head elongate ( Fig. 94 ), typical of the genus, longer than 2.2 times as long as broad, about 2.4 times as long as broad in holotype; cheeks each with about 10 setae, blunt at apices; postocular cheek setae about 70µm in holotype. Postocular setae pair II located before the middle of head, 200–210µm apart from posterior ocelli, 105µm apart from each other in holotype, long and blunt, at least not sharply pointed; a pair of interocellar setae situated at lateral sides of ocellar triangle, much shorter than half length of postocular pair II, blunt at apices; other cephalic setae on dorsum including postocular pair I short. Eyes smaller in ventral surface, but sometimes not smaller in small female. Posterior ocelli about 35µm in diameter, about 77µm apart from each other in holotype. Antennae ( Fig. 95 ) about 1.3 times as long as head in holotype; segment III about 3.6 times as long as broad. Pronotum about one-fourth as long as head, anterior margin eroded and more or less indistinct; prominent setae blunt, am usually much longer than aa, epim shorter than median length of pronotum; fore coxa with three setae. Prothoracic notopleural suture distinct, but incomplete, noto-episternal suture complete, but half to two-thirds of noto-epimeral suture reduced ( Fig. 97 ). Metanotal median pair of setae blunt, 160µm apart from each other, 70–80µm apart from anterior margin in holotype. Fore wing with 46–50 duplicated cilia in holotype, 33–36 in small female; three sub-basal setae blunt or very weakly expanded, S2 almost as long as S1, or a little shorter than S1. Median lobe of pelta very narrowly or scarcely fused to lateral wings ( Fig. 98 ). Posteromarginal setae on abdominal tergite IX pointed, S1 about half as long as tube, S2 a little shorter than S1. Tube with short setae sparsely ( Fig. 101 ), about 1.1–1.2 times as long as head, about 4.8 times as long as broad in holotype.

Measurements ( paratype small female– holotype large female in µm).Body length about 5600–7500 (distended). Head length 690–880, from anterior margin of eyes 660–840, maximum width across cheeks 312–368, across eyes 300–351; eyes length 140–160, width 95–106; postocular setae pair II 250–310. Antenna total length 980–1140, segments I–VIII length (width) as follows: 110–110 (66–76), 95–100 (53–60), 200–240 (55–66), 157–192 (60–65), 148–180 (55–62), 135–141 (50–53), 75–75 (40–43), 75–90 (28–30). Pronotum median length 170–225, width 470– 560. Setae on prothorax: am 100–120, aa less than 50–less than 30, ml less than 40–about 30, pa 105–170, epim 140–200, cox 70–85. Metanotal median setae 140–150. Sub-basal wing setae: S1 80–82, S2 65–80, S3 110–170. Tergite IX setae: S1 420–500, S2 400–430. Tube length 830–980, maximum width 170–203; terminal setae 280– 280.

Male (macroptera). Distended body length: 4.4–5.3mm. Color very similar to female. Prominent body setae almost pointed and longer than those of female. Fore wing with 44–46 duplicated cilia in large male, 34–36 in small male. Lateral tubercles on abdominal tergite VI almost straight ( Fig. 100 ), slightly paler than tergites. Posteromarginal median setae (S1) on tergite IX variable in length, 0.57–0.70 times as long as tube, S2 setae short, about one-fourth as long as S1 or shorter. Tube bulged sub-basally, shorter than 0.9 times as long as head, about 4.0 times as long as broad; terminal setae shorter than half of tube.

Measurements (small–large paratype males in µm). Body length about 4400–5250 (distended). Head length 580–700, from anterior margin of eyes 550–650, width across cheeks 288–340, across eyes 270–310; eyes length 115–125, width 80–90; postocular setae pair II 160–260. Antenna total length 780–910, segments I–VIII length (width) as follows: 92–105 (60–72), 80–90 (50–55), 150–180 (50–55), 118–140 (53–55), 110–128 (51–52), 102– 120 (50–51), 62–70 (40–40), 71–70 (23–25). Pronotum length 160–200, width 444–508. Setae on prothorax: am 140–105, aa 40–less than 30, ml 30–less than 30, pa 140–220, epim 170–280, cox 70–80. Metanotal median setae 120–180. Sub-basal wing setae: S1 115–140, S2 100–165, S3 210–240. Tergite IX setae: S1 300–330, S2 75–85. Tube length 530–540, maximum width 130–152; terminal setae 220–260.

Type material. Holotype: female, Indonesia, C. Sulawesi, near Rantepao , Pedamaran , alt. about 1000m, on dead leaves and branches, 13.viii.1984. SO . Paratypes: Indonesia, C. Sulawesi, 4 females and 4 males, collected with holotype; data similar to holotype , 4 females and 1 male, 8.viii.1984 , 3 females, 9.viii.1984, 5 females and 2 males, 10.viii.1984, 2 females, 12.viii.1984, 3 females, 14.viii.1984, SO.

Remarks. M. sulawesicus belongs to a group with complete noto-episternal sutures on the prothorax and is easily distinguished from M. rotundus by having antennal segment III darker, the postocular and interocellar setae shorter, and the prothoracic noto-epimeral sutures one-third to half. One of the North American species, M. spinosus Hood , also has dark antennal segment III and well-developed prothoracic noto-episternal sutures ( Hood 1908; Stannard 1968). However, it can probably be distinguished from sulawesicus by the elongate interocellar setae that are almost as long as the postocular setae (these setae are undetermined whether pair I or pair II), and absence of the prothoracic noto-epimeral suture.

Figures

FIGURES 92–93. Megalothrips sulawesicus sp. nov.: (92) female; (93) male.

FIGURES 94–102. Megalothrips species. M. sulawesicus sp. nov. 94–101: (94) head and prothorax, female; (95) antenna, female; (96) prosternum, female; (97) prothorax, female; (98) pelta, female; (99) tergites III–IV, female; (100) abdominal segment VI and VII, male; (101) tube, female. M. curvidens, female: (102) prothorax, female.