Parabaliothrips betulaceae, Masumoto & Okajima, 2020

Masumoto, Masami & Okajima, Shûji, 2020, The genus Parabaliothrips Priesner (Thysanoptera, Thripidae) with three new species from Japan and Taiwan, and two new records of related genera from Japan, Zootaxa 4838 (4), pp. 566-580 : 569-572

Parabaliothrips betulaceae n. sp.

( Figs 4, 5 , 10–25 )

Parabaliothrips sp. Tsutsumi, 1997: 67.

Female macroptera. Distended body length 1.7–1.9 mm. Body uniformly dark brown ( Fig. 4 ); antennal segments I– II dark brown, III–V brownish yellow but base of III and apex of V slightly shaded, IV–VIII brown; fore wings brown but pale near base and apex, clavus brown with apex pale; all femora dark brown, fore tibiae brown with distal third yellowish, mid and hind tibiae dark brown, all tarsi yellow to brownish yellow; prominent body setae dark brown. Head 0.7–0.8 times as long as wide, slightly prolonged anteriorly; cheeks straight ( Fig. 9 ). Ocellar setae I longer than II, III very long, 3.0–3.7 times as long as their interval. Postocular setae 4 pairs, setae II absent, III and V very long, III longer than V. Antennal segment II without microtrichial rows, inner dorsal seta much longer than outer one, III–IV widest near apex and weakly tapering to apex, IV longest, gently rounded at basal half and weakly tapering to apex, IV–V pedicelate, VI gently rounded at basal half and weakly tapering to apex ( Fig. 10 ). Antennal segments I–VIII length/width ratio as follows: 0.9–1.0, 1.4–1.7, 2.8–3.3, 2.2–2.9, 2.0–2.3, 2.1–2.7, 0.9–1.1, 2.0–2.3. Pronotum about 0.6 times as long as wide, almost smooth and without discal setae medially; a pair of anteromarginal setae well developed, 58–67 μm long, 0.4–0.5 times as long as pronotal median length and 1.6–2.0 times as long as anteroangular setae; posteroangular setae I 0.7–0.8 times as long as pronotal median length and usually slightly shorter than setae II; posteromarginal setae I 0.3 times as long as pronotal median length, much longer than remaining setae. Mesonotum without CPS anteromedially. Metascutum with median pair of setae 0.6–0.8 times as long as metascutal median length ( Fig. 10 ). Mesosternal spinula weak, often almost invisible. Clavus with subapical setae longer than apical setae on vein. Fore tibiae with 2 stout ventroapical setae.Abdominal tergites laterally with lines of sculpture, some weak lines across between S1 setae; tergite VIII with posteromarginal comb complete, microtrichia slightly sparse ( Fig. 13 ); tergite IX with posterior pair of CPS only; pleurosternites with broad posteromarginal craspeda having no or indistinct teeth (cf. Fig. 15 ). Ovipositor 2.3–2.6 times as long as pronotal median length.

Measurements (holotype female in microns). Distended body length 1930. Head length 148 (length including anterior prolongation 170), width across cheeks 184; compound eyes dorsal length 80, width 53. Ocellar setae III length 77–78, interval 23. Postocular setae III length 40–41, setae V length 35. Pronotal median length 145, width 235; anteroangular setae length 34–37, anteromarginal setae length 63–65 posteroangular setae I length 98–100, setae II length 103–106, posteromarginal setae I length 39. Metascutal median length 103, median setae length 65–74. Fore wing length 1020, width at middle 70. Antennal segments I to VIII length (wide) as follows: 33 (35), 50 (33), 65 (23), 56 (23), 43 (20), 48 (21), 13 (11), 16 (8).

Male macroptera. Distended body length 1.3–1.5 mm. Body colour similar to female ( Fig. 5 ). Abdominal tergite IX with median pair of setae long and stout ( Fig. 14 ); sternal pore plates usually large and oblong ( Fig. 15 ), 31–78 μm wide, often slightly constricted at middle and rarely reduced to small on VI and VII.

Measurements. (paratype males in microns). Distended body length 1325–1460. Head length 125–127 (length including anterior prolongation 140–147), width across cheeks 144–155; compound eyes dorsal length 73–75, width 40–45. Ocellar setae III length 55–65, interval 13–18. Postocular setae III length 28–45, setae V length 21-25. Pronotal median length 113–123, width 113–123; anteroangular setae length 25–32, anteromarginal length 43–50, posteroangular setae I length 70–83, setae II length 73–79, posteromarginal setae I length 21–31. Metascutal median length 75–95, median setae length 48–70. Fore wing length 745–840, width at middle 55–60. Antennal segments I to VIII length (wide) as follows: 18–23 (30), 30 (23–25), 35 (18), 30 (18), 25–30 (18), 38–40 (15–16), 10–13 (8–9), 15 (5).

First instar larva. Body yellowish white ( Fig. 16 ) with pale internal reddish pink pigments before KOH treatment, head with grey markings along internal margin of antennal socket, anterior margin and laterally anterior to eyes ( Fig. 17 ), abdominal tergite VIII with narrow grey band along posterior margin ( Fig. 22 ), tergite X grey at posterior half; antennal segment I grey internal half dorsally, II grey with distal third pale, III-VII pale grey. Head smooth, with 4 pairs of dorsal setae, D1 setae minute D2 longer than D3, D4 much longer than remaining setae and almost as long as interval D4. Antennae 7-segmented, setae much elongate, setae on segments II and III longer than each segment, III without microtrichia, IV with microtrichia, V and VI not united ( Fig. 18 ). Pronotum smooth and with 6 pairs setae D1 and D2 setae subequal in length and slightly shorter than D7, D3 minute, D4 much shorter than D2, D5 much longer than remaining setae and more than twice as long as D1; meso and metanota with small scattered granules, each with 5 pairs and 4 pairs of setae ( Fig. 19 ). Abdominal tergites I–VIII with a few rows of scattered granules, dorsal setae longer than half of tergal length ( Figs 21–23 ); tergite IX with no posteromarginal teeth, about 3 rows of granules along posterior margin, median CPS apart from each other about 1.7 times as wide as interval of D1 setae, D2 setae much elongate and about 3 times as long as D1 setae; tergite X with grey area reach as CPS; sternites with scattered granules as tergites ( Figs 24, 25 ). Spiracle on mesonotum relatively large and circular ( Fig. 20 ), but small on tergites II ( Fig. 21 ) and VIII.

Type series. Holotype female, JAPAN, Honshu, Yamanashi-ken, Sutama-cho (now Hokuto-shi), Tokusa-toge (alt. about 1600m), on leaf of Alnus hirsuta [Betulaceae], 14.vii.2006, M. Masumoto. Paratypes: Honshu: 26 females & 1 male collected together with holotype. Same place and date as holotype: 3 females on leaf of Betula sp. [Betulaceae]; all M. Masumoto. Same place as holotype: 1 male on flower of Scilla scilloides [ Liliaceae ], 22.viii.2006; 1 male on flower of Senecio cannabifolius [ Asteraceae ], 1.ix.2006; 17 females & 1 male on leaf of Alnus hirsuta , 3.ix.2002; 3 females & 1 male on leaf of Alnus hirsuta , 28.viii.2014; 7 females & 3 males on leaf of Alnus hirsuta , 21.viii.2015; 8 females & 1 male on leaf of Alnus hirsuta , 22.vii.2017; 1 female on fern, 4.viii.2018; 6 females on Alnus hirsta , 4.viii.2018; all M. Masumoto. Yamanashi-ken, Kanayama: 1 female on leaf of Quercus crispula [ Fagaceae ], 30.vi.1990, T. Nonaka & S. Okajima. 3 females & 1 males, host unknown, 2.viii.2006, S. Okajima; 2 females on Alnus hirsuta , 28.viii.2014, M. Masumoto. Yamanashi-ken, Fujiyoshida-shi, Fuji-rindou, nr. Mt. Fuji (alt. about 1100m): 1 female & 1 male on leaf of Alnus hirsuta , 24.vii.2001; 32 females on leaf of Alnus hirsuta , 18.ix.2001; 4 females & 1male on leaf of Polygonum cuspidatum , 18.ix.2001; all M. Masumoto. Nagano-ken, Sugadaira: 1 female & 1 males on Quercus acutissima [ Fagaceae ], 30.vi.1973; all K. Haga. Nagano-ken, Yamanouchi-machi (alt. 1700m), 2 females on leaf of Alnus hirsuta , 12.viii.2016, M. Masumoto. Nagano-ken, Kamikochi, 1 male on flower of Labiatae, 31.viii.2013, T. Tsutsumi. Tokyo, Setagaya-ku, Okamoto-cho, 1 female on leaf of Viburnum awabuki [ Caprifoliaceae ], 18.vi.1987, S. Okajima. The holotype and most paratypes are deposited in TUA.

Non-paratypic specimens: Nagano-ken, Yamanouchi-machi (alt. 1700m), 7 first instar larvae on leaf of Alnus hirsuta , 12.viii.2016. Yamanashi-ken, Hokuto-shi, Tokusa-toge (alt. about 1600m), 4 first instar larvae on leaf of Alnus hirsuta , 22.vii.2017; all M. Masumoto. All are deposited in TUA.

Comments. This new species was recorded as an unidentified species from Nagano Prefecture, Japan by Tsutsumi (1997) and referred to as undescribed species by Gillespie et al. (2002). It is very similar to P. coluckus described from Quercus [ Fagaceae ] of Nepal, Taiwan and Malaya, also P. robustus described below, in having long pronotal anteromarginal setae and postocular setae. However, these species are distinguished in the key above. First instar larvae of P. betulaceae are often collected together with adults but second instar larva have not been collected so far.

Etymology. In reference to their host plant.

Figures

FIGURES 1–8. Frankliniella genus-group. (1) Firmothrips firmus. Iridothrips mariae 2–3: (2) Female; (3) Male. Parabaliothrips betulaceae n. sp. 4–5: (4) Female; (5) Male. (6) P. brevisetosus n. sp. P. robustus n. sp. 7–8: (7) Female; (8) Male.

FIGURES 9–15. Parabaliothrips betulaceae n. sp. Female, 9–13: (9) Head & pronotum; (10) Antenna; (11) Posterior margin of mesonotum & metascutum. Abdominal segments 12–13: (12) Tergites VI–VII, sculpture omitted; (13) Tergite VIII. Male abdominal segments, 14–15: (14) Tergite IX, sculpture omitted; (15) Sternite VI & left pleurosternite, sculpture omitted.

FIGURES 16–25. Parabaliothrips betulaceae n. sp., first instar larva. (16) Dorsal aspect; (17) Head & pronotum; (18) Antenna; (19) Meso & metanota; (20) Spiracle of mesonotum. Abdominal segments 21–25: (21) Tergite II; (22) Tergites VIII–XI; (23) Middle of tergite VIII; (24) Sternites V–VII; (25) Sternites IX–X.