Taeniothrips changbaiensis, Cui & Lee & Wang, 2019

Cui, Yanze, Lee, Gwan-Seok & Wang, Jun, 2019, Taeniothrips changbaiensis sp. n. (Thysanoptera, Thripidae) living on the leaves of a Poaceae species in China, Zootaxa 4559 (2), pp. 314-320 : 315-319

Taeniothrips changbaiensis sp. n.

( Figs 4–16 )

Female macroptera. With the structural characters of the genus. Body brown ( Fig. 4 ); all femora brown, tibiae light brown, tarsi yellowish; antennal segments I brown, II brown with yellowish apex, III yellow, IV yellow but brownish distally, V–VIII brown but the base of V paler ( Fig. 6 ). Fore wing mostly pale, with one dark band in basal second quarter, apex usually darker ( Fig. 11 ).

Head length about 0.9 times basal width, with weak transverse sculpture in posterior part, usually with 1 to 3 tubercles in front of anterior ocellus. Ocellar setae III about 1.6 times as long as distance between posterior ocelli, and arising between posterior ocelli; postocular setae I–III rather apart from compound eyes ( Fig. 7 ). Forked sense cone on segment III and IV usually not extending beyond basal third of next segment, segment VII basally wider, and usually shorter than VIII ( Fig. 6 ).

Pronotum almost smooth, with two pairs of posteroangular setae, inner usually longer ( Fig. 8 ). Metanotum striated laterally, anterior margin irregularly reticulate, posterior half nearly smooth; median setae close to anterior margin and close to each other, paired campaniform sensilla arising medially ( Fig. 9 ). Fore wing first vein with 2 to 7 setae on basal half, 2 setae distally, usually without a median seta.

Abdominal tergites with irregular sculpture laterally but smooth between setae S2; tergites III–VII with lateral setae S4 shorter than S2 ( Fig. 10 ); tergite VIII postero-marginal comb irregularly incomplete ( Figs 12, 13 b-f). Sternite VII with setae S1 and S2 arising far ahead of posterior margin.

Measurements (Holotype in microns). Body length 1717. Head, length 163; width behind eyes 164, width at base 182; eyes length 73; diameter of ocelli 10–13; shortest distance between posterior ocelli 40; ocellar setae II, III 32, 56; postocular setae I–III: 26, 25, 24. Pronotum, median length 149, width 239; posteroangular setae: outer 58, inner 73. Mesonotum median setae 24; posteromarginal setae 20. Metanotum anteromarginal setae 25, median setae 38, distance from base of median setae 10. Fore wing length 735. Abdominal tergite IX median setae 57, posteromarginal setae SI 138, S2 152, S3 155; tergite X setae S1 145, S2 143. Antennae, total length 298; segments I–VIII length (width): 33(35), 43(32), 55(23), 55(23), 39(23), 53(24), 16(9), 19(7), terminal setae 31.

Male macroptera. Similar to female but smaller ( Fig. 5 ); abdominal sternites III–VII with narrowly elongated pore plates ( Fig. 15 ) (on VII rarely reduced to small spots) ( Fig. 14 ); tergites IX–X as Fig. 16 .

Measurements (in microns). Body length 1471. Head, length 153; width: behind eyes 133, width at base 153; eyes length 77; diameter of ocelli 11–14; shortest distance between posterior ocelli 33; ocellar setae II, III 25, 58; postocular setae I–III: 17, 16, 34. Pronotum, median length 149, width 199; posteroangular setae: outer 55, inner 69. Mesonotum median setae 19, posteromarginal setae 24. Metanotum anteromarginal setae 28, median setae 36, distance from base of median setae 5. Fore wing length 727. Abdominal sternites III–VII width: 157, 177, 189, 195, 170; pore plates on sternites III–VII width: 75, 62, 58, 56, 36. Antennae, total length 278; segments I–VIII length (width): 30(33), 31(29), 49(22), 56(23), 36(23), 48(23), 19(11), 21(7), terminal setae 30.

Specimens examined (Slides mounted in Canada balsam unless otherwise noted). Holotype female, China, Jilin Province, Antu County, Erdaobaihe, the North Slope of Changbai Mountain, asl 1500–1800 m (42°3.45′N, 128°3.99′E), 14.vii.2017, from Deyeuxia angustifolia [ Poaceae ] (Yanze Cui).

Paratypes: same data as holotype 16 females, 12 males (more than 200 individuals stored in absolute ethyl alcohol); Jilin Province, Changbai County, the Fifteenth Valley, Wangtian’e Mountain , asl 1700 m (41°45.50′N, 127°56.69′E), 4 females, 14.vii.2017 (Yanze Cui) .

The holotype and paratypes are deposited in the Insect Collection of Jilin University except for 4 paratypes (3 female and 1 male) deposited in the Insect Collection, South China Agricultural University ( SCAU) and 5 paratypes (3 female and 2 male) deposited in Department of Plant Protection , National Institute of Agricultural Sciences, RDA, South Korea .

Etymology. This new species is named after the type locality.

Structural variation. The sex ratio based on all of the collected specimens was female/male: 100/5. Using a sub-sample of 20 females and 12 males, structural variation was studied in the following three characters that are usually considered important for recognising species in the genus Taeniothrips .

Tergite VIII posteromarginal comb. A long and regular comb is a generic character state for Taeniothrips ( Mound et al. 2012) , and its irregularly interrupted condition in the new species is thus of significance. In eight males and eight females the comb is interrupted medially ( Figs 13 a–c); in three males and nine females it is interrupted medially and at one side ( Figs 13 e & f ); in one male and three females it is interrupted medially and at both sides ( Fig. 13 d ).

Fore wing first vein setal row. This setal row is widely interrupted distally in Taeniothrips species, with two setae distally and one medially, and the presence or absence of the median seta has been used to distinguish certain species ( Mound et al. 2012). This median seta is absent in most of the sample of this species, but is present in two males and three females. Moreover, the number of setae on the basal half of this vein varies from two to seven.

Sternal pore plates of males. In 11 of the males these narrow transverse structures are present on sternites III– VII, but in one male the pore plate on VII is reduced to small circles ( Fig. 14 ).

Relationships. T. changbaiensis is very similar to T. coreanus Woo , a species that has been collected recently from a species of Poaceae , Calamagrostis arundinacea , at the type locality, Jiri Mountain, South Korea. Together with T. tigris Bhatti from bamboo leaves at Darjeeling in northern India, these three are the only known Taeniothrips species with the fore wing bearing light and dark bands ( Mound et al. 2012). Moreover, for no species other than coreanus has the comb of microtrichia on the posterior margin of abdominal tergite VIII been reported as interrupted irregularly. Slide mounted specimens of these two species were compared (holotype also 2 females and 2 males coreanus ), and the species are distinguished as follows:

1. Antennal segment IV bicolored, VI brown ( Fig 6 ); abdominal tergites III–VII with lateral seta S4 shorter than S2 ( Fig 10 ); male sternite VII with pore plate present or reduced ( Figs 14–15 )..................................... changbaiensis

-. Antennal segment IV yellow, VI bicolored; abdominal tergites III–VII with lateral seta S4 usually longer than S2; male sternite VII without pore plate............................................................................ coreanus

Figures

FIGURES 4–5. Habitus of T. changbaiensis sp. n. (4) Female, (5) Male.

FIGURES 6–11. T. changbaiensis sp. n. (female): (6) Antenna, (7) Head, (8) Pronotum (9) Meso- and metanotum, (10) Abdominal tergites IV–VII, (11) Fore wing.

FIGURES 12–16. T. changbaiensis sp. n. (12–13 female; 14–16 male) (12) Abdominal tergites VIII–X, (13) Comb of microtrichia on abdominal tergite VIII and varieties, (14) Abdominal sternite VII, (15) Abdominal sternites III–VII, (16) Abdominal tergites IX–X.