Parabaliothrips Priesner, 1935

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 : 567-569

Parabaliothrips Priesner

Parabaliothrips Priesner, 1935: 125 . Type species: Parabaliothrips takahashii, Priesner , by original designation.

Female. Wings fully developed. Head with interantennal projection often relatively wide ( Fig. 9 ); maxillary palpi 3-segmented. Compound eyes without pigmented ommatidia ventrally. Ocellar setae I present, III situated posterior to mid-point between hind ocelli, usually at or slightly behind tangent line of posterior margin of hind ocelli. Postocular setae 4–5 pairs. Antennae 8-segmented, segment I without median dorsal apical setae, II with inner dorsal apical setae much longer than outer one, III and IV with forked sense-cones ( Fig. 10 ). Pronotum with 2 pairs of posteroangular setae, posteromarginal setae 2–4 pairs but number often different at each side. Mesonotum weakly sculptured, almost smooth medially; median pair of setae near posterior margin. Metascutum almost smooth or very weakly reticulate medially; median pair of setae at anterior margin; CPS absent. Spinula present or absent on mesosternum, absent on metasternum. Fore wing first and second veins each with no long gap in setal rows, setae arranged almost evenly or irregularly spaced; clavus with 5 veinal and 1 discal setae; posteromarginal fringe cilia wavy. Tarsi 2-segmented. Abdominal tergites without posteromarginal craspeda, with S1 setae very small; tergites VI–VIII with paired regular ctenidia, ctenidia anterolateral to spiracles on tergite VIII and ending anterior to lateral median setae (S5) on VI–VII ( Figs 12, 13 ); tergites V–VII with posteromarginal setae (S3) far mesad of posterior angle; S2 setae and S4 setae reduced to minute on tergites V–VIII and VI–VIII, respectively ( Fig. 39 ); sternites without posteromarginal craspeda or discal setae; sternites III–VII with 3 pairs of posteromarginal setae, but II with 2 pairs; pleurotergites without discal setae. Ovipositor well-developed.

Male. General structure same as female. Abdominal tergite IX with median pair of setae short and thorn-like ( Figs 14 , 42 ); sternites III–VII each with a large pore plate ( Fig. 15 ).

Comments. Previously six species are known in this genus, three from Nepal and Taiwan, and three from Australia (one introduced to New Zealand) ( Gillespie et al. 2002). Wang et al. (2019) suggested that Parabaliothrips was not monophyletic and the Asian species might be sister group to Sitothrips . The Asian species have mesosternum with no or weak spinula, abdominal tergite VIII with posteromarginal comb medially, intermediate abdominal tergites without posteromarginal teeth lateral to S3 setae, and 4 pairs of postocular setae (setae II absent). In contrast, the Australian species have the mesosternum with a distinct spinula, abdominal tergite VIII without a posteromarginal comb medially, the intermediate abdominal tergites with posteromarginal teeth lateral to S3 setae in P. newmani and P. setifer , and 5 pairs of postocular setae (setae II present). The members seem to be leaf-feeders ( Gillespie et al. 2002) but P. brevisetosus described below is probably flower-living.

Key to known species of Parabaliothrips

(modified from Gillespie et al. 2002: * based on literature)

1. Abdominal tergite VIII with posteromarginal comb present medially even if irregular in length ( Figs 13 , 30 ); ocellar setae III arising on tangent line to posterior margin of hind ocelli ( Fig. 9 ); pronotal anteromarginal setae usually longer than anteocellar setae ( Fig. 26 ); abdominal tergites V–VII without posteromarginal teeth lateral to S3 setae ( Fig. 12 ); mesosternal spinula weak or absent [Southeast Asia to Japan]....................................................................... 2

-. Abdominal tergite VIII without posteromarginal comb medially, at most a few small dentate microtrichia present laterally; ocellar setae III arising anterior to tangent line to posterior margin of hind ocelli; pronotal anteromarginal setae not elongate, subequal in length to or much shorter than anteocellar setae; abdominal tergites V–VII usually with posteromarginal teeth lateral to S3 setae; mesosternal spinula present [ Australia, New Zealand]........................................... 7

2. Pronotum with a pair of anteromarginal setae much shorter than anteocellar setae ( Fig. 26 ); postocular setae all subequal in length, at most 20 microns long; abdominal tergite IX with both anterior and posterior pairs of CPS ( Fig. 30 ).................................................................................................. brevisetosus n. sp.

-. Pronotum with a pair of anteromarginal setae longer than anteocellar setae ( Fig. 36 ); one pair of postocular setae much longer than remaining setae, at least 40 microns long; abdominal tergite IX with only posterior pair of CPS (not known in grandiceps )............................................................................................... 3

3. Pronotal anteromarginal setae no more than 40 microns long................................................... 4

-. Pronotal anteromarginal setae at least 50 microns long ( Fig. 36 )................................................ 5

4. Longest postocular setae 44 microns long; antennal segment VI yellow, VII–VIII yellow but weakly shaded..... takahashii

-. Longest postocular setae 60 microns long; antennal segment VI brown with basal third paler, VII–VIII dark.... grandiceps *

5. Pronotum with anteroangular setae 0.5–0.6 times as long as anteromarginal setae ( Fig. 9 ); antennal segment V usually shaded at distal third [antennal segment VI shaded]................................................... betulaceae n. sp.

-. Pronotum with anteroangular setae slightly shorter than or subequal in length to anteromarginal setae ( Fig. 36 ); antennal segment V uniformly yellow............................................................................... 6

6. Antennal segment VI shaded; mid- and hind tibiae uniformly dark, apices not yellow ( Fig. 7 ); pronotal anteroangular setae almost same length as anteromarginal setae ( Fig. 36 ).............................................. robustus n. sp.

-. Antennal segment VI yellow; mid- and hind tibiae yellow at apices; pronotal anteroangular setae slightly shorter than anteromarginal setae.................................................................................. coluckus

7. Pronotal inner posteroangular setae much longer than outer setae; metascutum distinctly reticulate medially; antennal segment IV dark; abdominal tergites V–VII without posteromarginal teeth lateral to S3 setae......................... montanus *

-. Pronotal inner posteroangular setae subequal in length to outer setae; metascutum almost smooth medially; antennal segment IV pale; abdominal tergites V–VII with posteromarginal teeth lateral to S3 setae................................... 8

8. Fore wing brown but sharply pale at base, hind vein with about 12 setae evenly spaced; abdominal tergite IX only with posterior pair of CPS; pleurosternites with large teeth-like posteromarginal craspeda; fore tibia without stout seta ventro-apically; male abdominal sternites without pore plate, tergite IX with median pair of setae long and stout........................ setifer

-. Fore wing brown, not sharply pale at base, hind vein with 14–18 setae closely spaced; abdominal tergite IX with both anterior and posterior pairs of CPS; pleurosternites with broad posteromarginal craspeda; fore tibia with a stout seta ventro-apically; male abdominal sternites III–VII each with a U-shaped pore plate, tergite IX with median pair of setae short and thorn-like............................................................................................... newmani

Figures

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 36–43. Parabaliothrips robustus s n. sp., Female, 36–41: (36) Head & pronotum; (37) Antenna; (38) Mesonotum & metascutum. Abdominal segments 39–41: (39) Tergites V–VII; (40) Tergite VIII; (41) Pleurosternite VI. Male abdominal segments, 42–43: (42) Tergite IX, sculpture omitted; (43) Sternite V, sculpture omitted.

FIGURES 26–30. Parabaliothrips brevisetosus n. sp., female. (26) Head & pronotum; (27) Antenna; (28) Mesonotum & metascutum. Abdominal segments 29–30: (29) Tergites V–VI; (30) Tergites VIII–X, sculpture omitted.

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.