Hoplandrothrips basantratus sp. n., 2024

Okajima, Shûji & Masumoto, Masami, 2024, The genus Hoplandrothrips and its relatives (Thysanoptera: Phlaeothripidae) from Southeast Asia and Taiwan, Zootaxa 5489 (1), pp. 22-91 : 41-43

Hoplandrothrips basantratus sp. n.

( Figs 26–27 , 161–169 )

Female (macroptera). Distended body length: about 2.7–3.0mm. Body bicolourous yellow and brown. Head yellow, weakly shaded with brown, slightly darker behind eyes; prothorax and abdominal segments I–VII yellow, pterothorax yellowish brown, abdominal segments VIII–IX and tube brown. Antennal segments I–II brown, segment III yellow, segments IV–VIII pale brown, segments IV–VI with basal 1/4 yellowish. Legs yellow, fore femora scarcely shaded with brown. Fore wings almost clear. All prominent setae pale. Head ( Fig. 161 ) elongate, 1.38 times as long as wide in holotype, dorsal surface almost smooth, very weakly sculptured postero-laterally, with irregular reticles just behind eyes. Cheeks weakly rounded, incised just behind eyes, weakly serrated, without stout setae. Postocular setae shorter than eyes, expanded. Eyes well-developed, 0.32 times as long as head in holotype; distance between posterior ocelli slightly longer than diameter of an ocellus, 25μm apart from one another in holotype. Antennae ( Fig. 162 ) about 1.9 times as long as head; segment VIII long and distinctly constricted at base, pedicellate; segment III 1.9 times as long as wide, with three sense cones. Mouth cone short; maxillary stylets retracted to basal 1/3 of head, not reaching postocular setae, 15μm apart from each other in holotype. Pronotum ( Fig. 161 ) almost smooth; am reduced, remaining four pairs of prominent setae expanded, ml longer than pa. Prosternal basantra ( Fig. 167 ) present, but weak. Mesopresternum ( Fig. 167 ) divided into two lateral large triangles. Metanotum ( Fig. 165 ) very weakly sculptured or almost smooth, median pair of setae about 60μm apart from anterior margin, about 100μm apart from one another in holotype. Fore tarsal tooth ( Fig. 163 ) well-developed, directed laterally. Fore wings each with 7 duplicated cilia in holotype; three sub-basal setae ( Fig. 168 ) expanded, S2 the longest. Pelta ( Fig. 166 ) weak, hat-shaped. Tergite IX setae S1 and S2 shorter than tube, blunt, at least not sharply pointed, S2 a little longer than S1. Tube ( Fig. 169 ) 0.56 times as long as head, about 1.9 times as long as wide. Terminal setae longer than tube.

Measurements (holotype female in μm). Body length about 2960 (distended). Head length 276, from anterior margin of eyes 242, width across eyes 184, maximum width across cheeks 200; eyes length 87, width 55; diameter of posterior ocelli 23–24; postocular setae 65. Antenna total length 530, segments I–VIII length (width) as follows: 50 (50), 55 (38), 80 (43), 76 (43), 75 (30), 63 (25), 60 (22), 55 (15). Pronotum length 212, width 293. Setae on prothorax: am less than 15, aa 50–53, ml 75–80, pa 55–65, epim 75, cox 50–55. Fore wing length 1020. Sub-basal wing setae: S1 50, S2 75, S3 70. Tergite IX setae: S1 112, S2 117–125. Tube length 155, maximum width 82; terminal setae 225.

Male (macroptera). Distended body length: 2.2–2.6mm. Colour similar to female. Prothorax and fore legs stout at least in large male; pronotal aa more or less elongate, pa shorter than that of female; fore coxa with some stout setae on posterior margin, fore femur ( Fig. 164 ) with a ventro-apical tubercle, fore tibia with a sub-basal inner tubercle, fore tarsal tooth stout. Fore wings with 4–6 duplicated cilia; sub-basal setae S3 much shorter than S2, nearly pointed, at least not expanded. Abdominal sternite VIII without pore plate; tergite IX S2 setae a little longer than 1/2 length of S1, intermediate setae shorter than S2.

Measurements (paratype male in μm). Body length about 2580 (distended). Head length 270, from anterior margin of eyes 235, width across eyes 170, maximum width across cheeks 188; eyes length 80, width 53; postocular setae 65. Antenna total length 500, segments I–VIII length (width) as follows: 43 (46), 45 (32), 72 (39), 73 (39), 70 (27), 58 (24), 53 (20), 50 (14). Pronotum length 220, width 288. Setae on prothorax: am less than 10, aa 75–80, ml 85–90, pa about 30, epim 75, cox 60. Fore wing length 910. Sub-basal wing setae: S1 50 –56, S2 65–75, S3 35 –40. Tergite IX setae: S1 100, S2 55 –60. Tube length 122, maximum width 75; terminal setae 200.

Type series. Holotype: macropterous female, Thailand, Saraburi, Farm of Kasetsart University , on grass, 20.viii.1990, TN & SO . Paratypes: Thailand, 1 female and 1 male, collected together with holotype .

Non-paratypic specimens. Taiwan, Kuantzulin , 7 females and 2 males, on grass, 22.viii.1993, TN & SO .

Remarks. H. basantratus is a grass-inhabiting species collected from Thailand and Taiwan, and may well be included in the nobilis -group. It may be related to H. samirseni comb. n. from India and Southeast Asia in having the head elongate with a constriction just behind compound eyes and the maxillary stylets rather short and not reaching middle of head capsule, also the prosternal basantra weakly developed. However, they are clearly different in body colour from each other as in the key above. According to the literature ( Ananthakrishnan 1956, 1964; Priesner 1939), a grass-inhibiting species recorded from Africa, India and China ( Tong & Zhang 1989), H. nobilis Priesner (= H. graminis Ananthakrishnan , H. indicus Ananthakrishnan and H. priesneri Ananthakrishnan ), may be more closely related to this species, but it can be distinguished from basantratus by having the head and prothorax darker (largely yellow, but head often shaded partly with brown in basantratus ), the postocular setae almost as long as eyes or a little longer (much shorter than eyes in basantratus ), the fore tarsal tooth very small in female, and abdominal segments VII–X dark brown (VIII–X dark brown, but VII yellow in basantratus ). In addition, Ananthakrishnan (1956) mentioned that the anterior abdominal segments of priesneri have dark brown longitudinal streaks at sides, but Ananthakrishnan (1964) did not mention these streaks in the description of the female of graminis . There is a possibility that those lateral dark streaks of priesneri are the Malpighian tubes, not the colour pattern of the cuticle. Moreover, in the same publication, four sense cones on the antennal segment III were drawn incorrectly for H. graminis female (see Fig. 3B in Ananthakrishnan 1964) although the sense cone formula was not mentioned in the descriptions of both priesneri and graminis , whereas the original description of nobilis stated three sense cones on that segment. However, when graminis was recognised as a junior synonym for nobilis , zur Strassen (1992) confirmed that graminis was completely consistent with the original description of nobilis . It is currently unknown whether nobilis has prosternal basantra or not. Six females and two males from Taiwan listed above in the non-paratypic specimens could not be distinguished from the type series, but their mounting condition is not sufficiently good to designate them as paratypes.

Within the genus Hoplandrothrips the maxillary stylets of these grass-living species are unusually short, but H. elongatus , also grass-living species from the mainland of Japan, has the maxillary stylets somewhat intermediate in length.

Figures

FIGURES 15–28. Ecacanthothrips and Hoplandrothrips species. E. tenuicornis 15–16: (15) female; (16) large male. E. tibialis 17–18: (17) female; (18) large male. H. adraneoides sp. n. 19–20: (19) female; (20) large male. H. aseanae sp. n. 21–23: (21) female; (22) small male; (23) large male. H. asianus sp. n. 24–25: (24) female; (25) male. H. basantratus sp. n. 26–27: (26) female; (27) large male. H. flavicornis sp. n.: (28) female.

FIGURES 161–169. Hoplandrothrips basantratus sp. n. (161) Head and prothorax, female; (162) antenna, female; (163) fore leg, female; (164) fore leg, large male; (165) metanotum, female; (166) pelta, female; (167) prosternum and mesopresternum, female; (168) sub-basal wing setae, female; (169) tube, female.

FIGURES 1–14. Ecacanthothrips species. E. andrei 1–2: (1) female; (2) large male. E. brevicornis sp. n. 3–4: (3) female; (4) male. E. claricornis 5–6: (5) female; (6) large male. E. coniger 7–8: (7) female; (8) large male. E. leai 9–11: (9) female; (10) large male; (11) small male. E. moundi 12–13: (12) fmale; (13) large male. E. nigellus: (14) female.