Stenchaetothrips dentatus, Masumoto & Okajima, 2013

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 : 11-13

Stenchaetothrips dentatus sp. n.

( Figs. 18–22 )

Female macroptera. Distended body length 1.3–1.5 mm. Body almost uniformly brown, pterothorax sometime slightly paler; antennal segments I to II brown, III yellow, IV yellow with basal half to third shaded, V brown with basal half to third pale, VI brown often with basal third barely pale, VII brown; fore wings brown with base including clavus pale; fore femora yellowish or pale brown, mid and hind femora brown, all tibiae and tarsi yellow; prominent body setae pale brown to brown. Head ( Fig. 18 ) about 0.8 times as long as wide, weakly prolonged in front of eyes, sculptured with transverse anastomosing striae basal third dorsally, weakly sculptured anteriorly, slightly constricted just behind compound eyes, cheeks rounded. Compound eye without pigmented ommatidia ventrally. Ocellar setae III at outside or on margin of ocellar triangle, in front of hind ocelli. Postocular setae III distinctly longer than I, the longest, II and IV small. Maxillary palpi 3-segmented. Antennal segment ( Fig. 19 ) III straight at each side slightly tapering at apex, usually the longest or often subequal to VI, IV gently rounded at each side, without apical neck, IV to V pedicelate, VI almost straight at each side of basal half and gently tapering to apex. Antennal segments I to VII length/width ratio as follows: 0.9–1.0, 1.4–1.6, 3.1–3.7, 2.6–3.2, 2.1–2.4, 2.9–3.4, 2.5–3.4. Pronotum ( Fig. 18 ) 0.7–0.8 times as long as wide, almost smooth, with 18–25 discal setae; posteroangular setae I 0.4–0.6 times as long as pronotal median length and almost as long as or longer than setae II; posteromarginal setae three pairs, setae I slightly longer than remaining setae. Mesonotum sculptured with transverse anastomosing striae except anteromedially; CPS present or absent anteromedially. Metascutum with median pair of setae 0.4–0.6 times as long as metascutal median length; paired CPS present, often absent or one CPS present. Fore wing first vein with seven basal and three distal setae, costal vein with 22–28 setae; second vein with 11–16 setae. Mesothoracic endofurca with very weak spinula. Abdominal tergites ( Figs. 21–22 ) with five or more teeth-like microtrichia on posterior margin at each side and scallops or small microtrichia medially; tergites II to VII with a few lines of sculpture extending to mesad of S1 setae; tergite VIII with posteromarginal comb complete; tergite IX with both anterior and posterior pairs of CPS, S1, S2, S3 and MD setae each 1.1–1.5, 1.5–1.8, 1.4–1.8 and 0.7–0.8 times as long as median length of the tergite; tergite X with S1 and S2 setae each 1.7–2.0 and 1.6–1.9 times as long as median length of the tergite; sternites without discal setae; sternite I with three microsetae anteromedially. Ovipositor 1.7–1.9 times as long as pronotal median length.

Measurements of holotype female. Distended body length 1440. Head length 110 (120 including anterior projection), width across cheeks 143; compound eye dorsal length 68, width 43. Pronotal median length 130, width 173; posteroangular setae I length 65–70, setae II length 64–65, posteromarginal setae I length 25. Metascutal median length 70, median setae length 28–38. Fore wing length 750, width at middle 45. Abdominal tergite IX median length 85, S1 setae length 93–?, S2 setae length 125–128, S3 setae length 115–123, MD setae length 58– 60; tergite X length 65, S1 setae length 118–?, S2 setae length 110–113. Ovipositor length 230. Antennal segments I to VII length (width) as follows: 25 (29), 38 (25), 55 (16), 48 (18), 40 (18), 54 (18), 20 (8).

Male. Unknown.

Type series. Holotype female, JAPAN, Honshu, Nagano Pref., Sugadaira, Karasawa-taki Falls , on bamboos, 30.vi.1995, T. Tsutsumi.

Paratypes. Honshu: 2 females same data as holotype. Nagano Pref., Sugadaira, University of Tsukuba, Mountain Research Center: 18 females on Salicaceae , 19.v.1995, T. Tsutsumi; 3 females on bamboos, 19.v.1995, T. Tsutsumi; 2 females on bamboos, 20.vi.1995, T. Tsutsumi; 2 females on flowers of Pinus densiflora [ Pinaceae ], 18.v.1995, T. Tsutsumi; 1 female on dead tree, 10.v.1995, T. Tsutsumi. Nagano Pref. Sugadaira, Michinuma: 3 females on bamboos, 22.vi.1995, T. Tsutsumi; 4 females on bamboos, 30.vi.1995, T. Tsutsumi; 3 females on bamboos, 4.x.1995, T. Tsutsumi. Nagano Pref., Sugadaira, Higashigumi, 5 females on bamboos, 10.vii.1995, T. Tsutsumi. Nagano Pref., Sugadaira, Nishigumi, 1 female on bamboos, 11.vii.1995, T. Tsutsumi. Nagano Pref., Mt. Azumaya-san, 1 female on bamboos, 7-vii-1995, T. Tsutsumi. The holotype and most paratypes are deposited in FU.

Comments. This species runs to near S. bambusae in the key by Bhatti ( Bhatti, 1982), by coloration of fore wings and antennal segment VI, having postocular setae III much longer than setae I, and metanotum with or without campaniform sensilla. However, it differs from that species in Bhatti’s sense by having more slender antennal segment III as follows: in this species, 50–58 microns long (mean 53) and 3.1–3.7 times as long as width (mean 3.2), whereas 44–50 microns long and about 2.8 times in Bhatti’s sense. Moreover, according to the original description ( Shumsher, 1946), “Tergite 9 with four long setae at hind borders and two short ones anteriorly near the middle; the postero-median setae about 80 microns long, the short anterior setae about 40 microns long. The lateral setae on the 9th segment about 100 microns long. The dorso-median setae on the 10th segment are 90 microns long, the lateral ones about 80 microns long.”. However, this new species has tergite IX with S1 setae (the posteromedian setae) 90–115 microns long (mean 100), S2 setae (the lateral setae) 115–135 microns long (mean 126) and MD setae (the short anterior setae) 53–68 microns long (mean 59) and has tergite X with S1 setae (the dorsomedian setae) 105–130 microns long (mean 121) and S2 setae (the lateral ones) 105–125 microns long (mean 115).

Etymology. In reference to teeth-like microtrichia at each side of posterior margin of abdominal tergites.

Figures

FIGURES 18–26. Stenchaetothrips species. S. dentatus sp. n., female 18–22: (18) Head & pronotum; (19) Antenna, right; (20) Tergite II, left side; (21) Tergite V, left side; (22) Tergite VIII, sculpture omitted at left side. S. langkawiensis, female 23– 26: (23) Head & pronotum; (24) Antenna, right; (25) Tergite VI, left side; (26) Tergites VIII–X.