Thrips fuscicornis Ishida, 1936

Masumoto, Masami & Okajima, Shûji, 2013, Review of the genus <i> Thrips </ i> and related genera (Thysanoptera, Thripidae) from Japan, Zootaxa 3678 (1), pp. 1-65 : 32-34

Thrips fuscicornis Ishida

( Figs. 116–122 )

Male macroptera. Distended body length 1.2 mm. Body including legs uniformly yellow; antennal segments I to II yellow, III yellow with slightly shaded at apex, VI to VII pale brownish yellow; fore wings including clavus uniformly pale; prominent body setae pale or slightly shaded. Head ( Fig. 116 ) 0.7 times as long as wide, sculptured with transverse anastomosing striae, weakly sculptured within ocellar triangle, rounded at cheeks. Ocellar setae III at outside of margin of ocellar triangle, posterolateral to fore ocellus. Postocular setae I the longest, II and IV minute. Antennae ( Fig. 117 ) 7-segmented, segment II with a few microtrichial rows on dorsal surface, III to IV gently rounded at each side and without apical neck, IV to V pedicelate, VI gently rounded at each side, with about 20 setae. Antennal segments I to VII length/width ratio as follows: 0.9, 1.3, 2.5, 2.4, 1.7, 2.6, 2.0. Pronotum ( Fig. 116 ) 0.7 times as long as wide, sculptured with transverse striae, with 25 discal setae; posteroangular setae 2 pairs, setae I 0.5 times as long as pronotal median length and slightly longer than setae II; posteromarginal setae 3 pairs, setae I the longest. Mesonotum sculptured with transverse anastomosing striae; CPS present anteromedially. Metascutum ( Fig. 118 ) sculptured with longitudinal anastomosing striae except anteromedially; median pair of setae behind anterior margin and 0.5 times as long as metascutal median length; CPS present. Fore wing costal vein with 25–26 setae, first vein with long gap of setal row, seven basal and three distal setae, second vein with 10–12 setae. Abdominal tergites II to VII laterally with lines of sculpture not reaching at median CPS; tergite II ( Fig. 129 ) with 3 lateral marginal setae, a small seta present near anterior margin; tergite VIII ( Fig. 120 ) with short posteromarginal comb wide spaced but almost complete; tergite IX with S1 setae almost at level of S2 setae, subequal length to or slightly shorter than S2 setae, their bases equidistance; sternites without discal setae, III to VII ( Fig. 121 ) each with a transverse pore plate, 35–53 microns wide; pleurotergites ( Fig. 122 ) with at least one discal setae.

Measurements of Holotype male. Distended body length 1200. Head length 103 (length including anterior prolongation 107), width across cheeks 140; compound eye dorsal length 58, width 43. Pronotal median length 115, width 175; posteroangular setae I length 70–96, setae II length 88–90; posteromarginal setae I length 35. Metascutal median length 70, median setae length 43–45. Fore wings length 630, width at middle 40?. Antennal segments I to VII length (width) as follows: 28 (30), 35 (26), 48 (19), 45 (19), 31 (19), 53 (20), 15 (8).

Female. Unknown.

Specimens examined. Holotype male, Urup Is., Tokotan, flowers of Saussurea riederi [ Asteraceae ], 3-viii- 1936, Y. Sugihara (IHU).

Distribution. Urup Island.

Biology. This species may be flower-living species.

Comments. This species may be closely related to T. brevicornis and T. typicus described below by having pleurotergites with discal setae, metascutum with longitudinal sculpture, and antennal segment VI with many setae in the male. It cannot be distinguished from these two species satisfactorily although the posteromarginal comb on tergite VIII appears to be distinct in this species. Another related species, T. setosus can be distinguished easily by antennal segment VI with fewer setae in males.

Figures

FIGURES 116–129. Thrips species. T. fuscicornis, holotype male 116–122: (116) Head & pronotum; (117) Antennal segments III–VII, right; (118) Metascutum; (119) Tergite II, left side, sculpture omitted; (120) Tergites VIII–IX, sculpture omitted; (121) Sternite VI, sculpture omitted. (122) Pleurotergite V, right, sculpture omitted. T. griseus, female. 123–127: (123) Head & pronotum; (124) Antenna, right; (125) Metascutum; (126) Tergites VIII–X; (127) Sternite VII. T. griseus, male 128– 129: (128) Tergite IX; (129) Sternites VI–VII, sculpture omitted.