Rubiothrips galii, Masumoto, Masami & Okajima, Shûji, 2017

Masumoto, Masami & Okajima, Shûji, 2017, Anaphothrips genus-group: key to world genera, with two new species and three new records from Japan (Thysanoptera, Thripidae), Zootaxa 4272 (2), pp. 201-220 : 216-218

Rubiothrips galii sp. n.

( Figs 5 , 39–45 )

Anaphothrips silvarum ; Tsutsumi, 1995: 18 [misidentification].

Female macroptera ( Fig. 5 ). Distended body length 1.3–1.4 mm. Body uniformly dark brown; antennal segment I– II brown to dark brown, but II slightly pale at apex, III yellowish brown, IV pale brown, V–VIII brown; fore wings shaded with two longitudinal veins darker; all femora dark brown, fore tibiae yellowish brown to brown, mid and hind tibiae brown with apex pale, all tarsi yellow. Prominent body setae brown. Head about 0.7 times as long as wide, with anastomosing striae dorsally, cheeks rounded. Ocellar setae III between hind ocelli ( Fig. 39 ). Antennal segment II without microtrichia, III and IV each with sense cone forked, III longest or subequal to VI, almost straight at sides, with weak apical neck, IV to VI pedicelate, gently rounded at each side, VI gently tapering in distal fourth and with inner sensorium about 27 microns ( Fig. 40 ). Antennal segments I–VII length/width ratio as follows: 0.8–0.9, 1.2–1.3, 2.4–3.0, 2.0–2.2, 1.6–1.7, 2.2–2.4, 1.0–1.3, 3.3–3.7. Pronotum 0.6–0.7 times as long as wide, with distinctly transverse anastomosing striae, and about 23 discal setae medially. Mesonotum with anastomosing striae throughout; paired CPS present anteromedially. Metascutum with median pair of setae 0.2–0.3 times as long as metascutal median length; paired CPS present ( Fig. 41 ). Fore wing costal vein with about 30 setae, first vein with 6–8 basal and 3 distal setae, second vein with 7–10 setae. Abdominal tergites with anastomosing striae throughout, no microtrichia, sometime with only a few small microtrichia scattered on the striae ( Figs 42, 43 ); tergites II–VII with small microtrichia at each side on posterior margin, microtrichia larger on anterior segments; tergites III–VIII with S1 setae 10–18 microns behind subbasal line; tergites VI–VIII with S4 setae reduced to minute; tergite IX without a minor setae (ms2) at outside of S2 setae, with both anterior and posterior pairs of CPS; sternite VII with S1 and S2 setae in front of posterior margin ( Fig. 44 ); pleurotergites with a few microtrichia ( Fig. 45 ). Ovipositor 1.7–1.9 times as long as pronotal median length.

Measurements (holotype female in microns). Distended body length 1320. Head length 93, width across cheeks 131; compound dorsal length 53, width 31. Pronotal median length 113, width 174. Metascutal median length 61, median setae length 13–15. Fore wing length 730. Abdominal tergite IX median length 56; MD setae length 38–39; tergite X length 67. Ovipositor length 210. Antennal segments I to VIII length (width) as follows: 20 (24), 30 (25), 41 (18), 38 (19), 30 (19), 41 (19), 6 (6), 13 (4).

Male. Unknown.

Type series. Holotype female, Japan, Honshu, Nagano Pref., Sugadaira , on Galium verum var. asiaticum f. nikkoense [ Rubiaceae ], 6.vii.1995, T. Tsutsumi.

Paratypes: 12 females, same data as the holotype . The holotype and most paratypes are deposited in FU.

Comments. The specimens from Japan seem to be similar to the European species, R. silvarum and the Iranian species R. tongi by having S1 setae close to and only about 10 microns behind the sub-basal line on abdominal tergites (zur Strassen 2003; Mirab-balou & Chen 2013). However, this new species can be distinguished from the other species by having abdominal sternite VII with S2 setae in front of the posterior margin, in contrast to the latter two species in which the S2 setae are at the posterior margin. Moreover, in R. silvarum antennal segment III is dark, the intermediate abdominal tergites have a median pair of CPS at middle to two-thirds from the posterior margin of each sclerite and no posteromarginal teeth, and tergite IX without ms1 and ms2 setae. In contrast, this new species has antennal segment III yellowish, the intermediate tergites have median CPS at one-sixth and small posteromarginal teeth on each side, and tergite IX has a minor seta (ms1) between S1 and S2 setae. According to zur Strassen (2003), R. silvarum has the metanotum with no CPS, but a single CPS is present on a female studied here. According to the original description of R. tongi , antennal segment I is white and irregular microtrichia are present on the sculpture lines of abdominal tergites, whereas in R. galii antennal segment I is dark and microtrichia are absent or only a few microtrichia present on the sculpture lines of abdominal tergites.

In contrast, S1 setae on the abdominal tergites are usually far behind (20–28 microns) sub-basal line in R. ferrugineus (zur Strassen 2003), but in one of two females studied these setae are similar in position to R. galii and both species are very similar to each other in antennal colour and length of inner sensorium on antennal segment VI. However, R. ferrugineus has antennal segment VI distinctly pedicelate with a basal ring , abdominal sternite VII with S2 setae at posterior margin, and abdominal tergites laterally with no posteromarginal microtrichia. In this new species, the base of antennal segment VI is distinctly pedicelate but is small and not ring like, S2 setae on sternite VII are in front of the posterior margin. and posteromarginal microtrichia are present laterally on the intermediate tergites. Moreover, R. pillichi is also similar to R. galii , although S1 setae on the tergites are far behind the sub-basal line as in R. ferrugineus , by having intermediate tergites laterally with posteromarginal microtrichia and sternite VII with S2 setae in front of posterior margin. R. pillichi can be distinguished from the new species by the following character states: in pillichi antennal segments almost uniformly dark, segment VI with inner sensorium longer than 40 microns, and ocellar setae pair III on tangent line of anterior margin of hind ocelli, whereas in the new species antennal segments III and IV are distinctly paler than remaining segments, segment VI with inner sensorium shorter than 30 microns and ocellar setae pair III between hind ocelli.

Etymology. In reference to the host plants of this species.

Figures

FIGURES 1 – 5. Adult. (1) Anaphothrips swezeyi, female. (2) Caprithrips melanophthalmus, female. Oxythrips japonicus sp. n., 3 – 4: (3) Female; (4) Male. (5) Rubiothrips galii sp. n., female.

FIGURES 39 – 45. Rubiothrips galii sp. n., female. (39) Head & pronotum; (40) Antenna; (41) Metascutum; (42) Tergite V; (43) Tergites VIII – X; (44) Sternite VII, sculpture omitted; (45) Pleurotergite V, right.