Thrips rhamni, Masumoto & Okajima, 2019

Masumoto, Masami & Okajima, Shûji, 2019, Three new species of the genus Thrips (Thysanoptera, Thripidae) in Japan, Zootaxa 4614 (3), pp. 575-584 : 578

Thrips rhamni sp. n.

( Figs 1, 2, 6 , 9, 12, 15, 18, 21 , 24, 26 )

Female macroptera . Distended body length about 1.4 mm. Body uniformly yellow ( Fig. 1 ); antennal segment I yellow, II brown, III–V brown with basal half yellow, VI–VII brown; fore wings pale with extreme base including clavus and median fourth pale brown ( Fig. 12 ); all legs yellow; major setae pale brown. Head 0.8–0.9 times as long as width, sculptured with transverse anastomosing striae dorsally, rounded at cheeks ( Fig. 6 ). Ocellar setae III situated lateral to fore ocellus and slightly longer than diameter of ocellus. Postocular setae arranged in a line, setae I slightly shorter than ocellar setae III, setae II and IV much shorter than setae I and II. Antennae 7-segmented, segment II with microtrichia, III and IV with short apical neck, V pedicelate, VI longest and often subequal in length to III, gradually rounded at each side of basal four-fifth and not pedicelate ( Fig. 9 ). Ratio length/width of segments I–VII as follows: 0.8–0.9, 1.4–1.5, 2.3–2.4, 2.3–2.6, 1.9–2.1, 2.7–2.9, 2.0–2.3. Pronotum 0.8 times as long as wide, sculptured with transverse anastomosing striae, with about 25 discal setae; posteroangular setae 2 pairs, setae I 0.5–0.6 times as long as median pronotal length, slightly shorter than setae II; posteromarginal setae 3 pairs, S1 setae longest. Mesonotum with paired CPS anteromedially. Metascutum longitudinally sculptured with anastomosing striae medially except anteromedially; median pair of setae close to each other and much behind anterior margin, 0.5–0.6 times as long as metascutal median length; usually paired CPS present, rarely CPS absent. Fore wing costal vein with 22–25 setae, first vein with 7 basal and 3 (rarely 2) distal setae, second vein with about 10 setae; clavus with 5 veinal and 1 discal setae. Abdominal tergite II with three lateral marginal setae ( Fig. 15 ); tergites II–VII with a line of sculpture across tergites anterior to S1 setae, but smooth between S1 setae; tergite VIII with posteromarginal comb complete ( Fig. 18 ); tergite IX with 2 pairs of CPS; tergite X with median split almost complete; sternites without discal setae; sternite I without microsetae; sternites III–VII with 3 pairs posteromarginal setae, II with 2 pairs; sternite VII with S1 setae in front of posterior margin ( Fig. 21 ); pleurotergites without discal setae and dentate microtrichia. Ovipositor 1.7–1.9 times as long as pronotal median length.

Measurements of holotype female in microns. Body length 1390. Head length 115, width across cheeks 135; compound eye dorsal length 65, width 43. Pronotal median length 118, width 153; posteroangular setae I (outer setae) length 61–64, setae II length 65–70, posteromarginal setae I length 27–29. Metascutal median length 68; median pair of setae length 33–38. Fore wing length 700, width at middle 45. Abdominal tergite IX length 75, tergite X length 52. Ovipositor length 200. Antennal segments I–VII length (width) as follows: 25 (30), 35 (25), 48 (20), 43 (19), 35 (19), 48 (19), 15 (8).

Male macroptera . Body colour and structure very similar to female but smaller ( Fig. 2 ). Abdominal tergite IX with S1 and S2 setae subequal length, S1 setae slightly close to S2 setae, arranged transversely ( Fig. 24 ); sternites III–VII with transverse pore plates, 40–58 μm width ( Fig. 26 ).

Measurements of paratype male in microns. Body length 1090. Head length 100, width across cheeks 118; compound eye dorsal length 58, width 43. Pronotal median length 100, width 138; posteroangular setae I (outer setae) length 57–59, setae II length 50–53, posteromarginal setae I length 27–29. Metascutal median length 60; median pair of setae length 25–30. Fore wing length 610, width at middle 35. Antennal segments I–VII length (width) as follows: 23 (28), 33 (24), 43 (18), 38 (18), 33 (18), 49 (19), 15 (8).

Type series. Holotype female, JAPAN, Honshu, Yamanashi Pref., Hokuto City, nr. Tokusa-toge (alt. about 1600m), on leaf of Rhamnus japonicus [ Rhamnaceae ], 22.vii.2017, M. Masumoto . Paratypes: 15 females & 3 males collected together with holotype . Same place and plants as holotype: 5 females, 2.vi.2018. 1 female, 4.viii.2018. all M.Masumoto.

Comments. This species is similar to T. palmi by yellow body and position of ocellar setae III, but has three lateral setae on tergite II, as indicated in the above key. It is also similar to the Indian species T. taurus Bhatti by yellow body and fore wing with brown areas medially and also on the clavus, and abdominal tergite II with three lateral marginal setae ( Bhatti, 1980). But in T. taurus the fore wing first vein bears six setae on the distal half.

Etymology. In reference to host plant.

Figures

FIGURES 1–8. Thrips species. T. rhamni sp. n., 1–2. (1) Female; (2) Male. (3) T. shiranensis, sp. n., female. T. unisetifer, sp. n., 4–5. (4) Female; (5) Male. Head to metanotum, 6–8. (6) T. rhamni, female.; (7) T. shiranensis, female; (8) T. unisetifer, female.

FIGURES 9–23. Thrips species, female. Antenna, 9–11. (9) T. rhamni; (10) T. shiranensis; (11) T. unisetifer. Fore wing, 12–14. (12) T. rhamni; (13) T. shiranensis; (14) T. unisetifer. Abdominal tergites, 15–20. (15) T. rhamni, tergite II; (16) T. shiranensis, tergites II–III (ac=accessary seta); (17) T. shiranensis, tergites V–VI; (18) T. rhamni, tergites VIII–X; (19) T. shiranensis, tergites VII–X; (20) T. unisetifer, tergites VII–X. Abdominal sternites, 21–23. (21) T. rhamni, sternite VII; (22) T. shiranensis, sternites VI–VII; (23) T. unisetifer, sternites VI–VII.

FIGURES 24–27. Thrips species, male. Abdominal tergites VIII–IX. (24) T. rhamni; (25) T. unisetifer. Abdominal sternites VI–VII, 26-27. (26) T. rhamni; (27) T. unisetifer.