Trichromothrips fragilis, Masumoto, Masami & Okajima, Shûji, 2005

Masumoto, Masami & Okajima, Shûji, 2005, Taiwan, with descriptions of four new species and a review of the Trichromothrips group of genera, Zootaxa 1082, pp. 1-27 : 17-21

Trichromothrips fragilis sp. nov.

( Figs. 15–21 )

Trichromothrips sp. 3: Okajima, 2000: 103.

Female. Distended body length 1.2–1.4 mm. Body uniformly yellowish white, except head brown; antennal segments I to II dark brown, III to VI yellowish white with distal half slightly shaded, V yellowish white with distal half brown, VI brown, VII to VIII pale brown; all legs yellowish white; fore wing dark brown; prominent body setae pale or slightly shaded, brown on fore wing.

Head 0.7–0.9 times as long as wide, distinctly sculptured with widely spaced transverse anastomosing striae behind compound eyes, slightly constricted behind compound eyes with cheeks rounded ( Fig. 15 ). Compound eyes longer than cheek length, without pigmented ommatidia. Ocellar setae II slightly more than half length of setae III, setae III situated near anterior inner angles of hind ocelli and 2.2–3.8 times as long as distance between their bases ( Fig. 15 ). Antennal segment IV usually the longest, often subequal to VI; sense­cone of segments III and IV each 0.6–0.8 times and 0.7–0.8 times as long as their segments ( Fig. 16 ). Antennal segments I to VIII length/width: 0.9–1.3, 1.1– 1.4, 2.7–3.3, 3.1–4.2, 2.4–3.6, 3.4–5.1, 1.3–2.0, 3.5–4.0.

Pronotum 1.2–1.7 times as wide as long, almost smooth, with 11–24 discal setae, with five to six anteromarginal setae; posteroangular setae I 1.0–1.6 times as long as setae II and 0.4–0.6 times as long as pronotal median length ( Fig. 15 ). Mesonotum indistinctly sculptured; median pair of setae situated near posterior margin; anteromedian campaniform sensilla absent ( Fig. 17 ). Metascutum weakly sculptured with widely spaced transverse striae; median pair of setae situated near anterior margin and 0.3–0.5 times as long as metascutal median length; campaniform sensilla absent ( Fig. 17 ). Metaepimeron with two setae. Fore wing with 24–31 setae on costal vein (28 in holotype), usually with 6 (rarely 5 or 7) basal setae on first vein, with 13–18 setae on second vein (16 in holotype).

Abdominal terga weakly sculptured with a few transverse lines laterally ( Fig. 18 ); terga VII to VIII with B4 setae minute ( Fig. 19 ): tergum IX without campaniform sensillum, SB2 setae present ( Fig. 19 ); sternum II with two pairs of posteromarginal setae; sternum VII with all setae arising at posterior margin. Ovipositor 2.4–2.9 times as long as pronotal median length.

Measurements of female holotype (in m). Body length 1405. Head dorsal length 108, across cheeks 123, width behind compound eyes 120; compound eye dorsal length (width) 80 (43); ocellar setae III length (interval) 38 (10). Pronotum median length (width) 105 (163); posteroangular setae I length 57, setae II length 49. Metascutum median length 68; median setae length 33. Fore wing length 800. Abdominal tergum IX median length 93; tergum X median length 63. Ovipositor length 250. Antenna length 310; segments I–VIII length (width): 28 (25), 30 (28), 55 (18), 60 (16), 44 (16), 61 (15), 13 (8), 20 (5); segments III and IV sense­cone length 40 and 43.

Male. Macropterous. Distended body length 1.0– 1.2 mm. General structure and colour very similar to female. Abdominal tergum IX with pair of drepanae on posterior margin ( Fig. 20 ); sterna III to VII each with 5 glandular areas (paired circles laterally and 1 oblong medially) ( Fig. 21 ).

Measurements of male paratype (in m). Body length 1025–1160. Head dorsal length 83–93, across cheeks 80–103, width behind compound eyes 75–100; compound eye dorsal length (width) 58–63 (30–38); ocellar setae III length (interval) 19 (5–8). Pronotum median length (width) 75–83 (130–140); posteroangular setae I length 45–55, setae II length 39–41. Metascutum median length 55–60; median setae length 25–30. Fore wing length 525–655. Antenna length 260–265; segments I–VIII length (width): 23 (23), 30 (23), 45 (15–18), 50 (13–15), 38 (13–15), 48–50 (13), 10–13 (8), 18 (5); segments III and IV sense­cone length 25–28 and 33.

Type series. Holotype (female): Japan, Tokyo, The Imperial Palace Grounds, Fukiage­gyoen, on leaves of Aucuba japonica [ Cornaceae ], 26­v­1999, S. Okajima. Paratypes Japan: 23 females and 1 male collected together with the holotype. 1 female, The Imperial Palace Grounds, Fukiage­gyoen, on leaves of Cinnamomum camphora [ Lauraceae ], 16­x­1996, S. Okajima. 13 females and 3 males, Kanagawa Pref., Kawasaki City, Tama­ku, Ikuta­ryokuchi, on leaves Cocculus orbiculatus [ Menispermaceae ], 7­ix­ 1994, S. Okajima. 1 female, Kanagawa Pref., Atsugi City, Tokyo University of Agriculture, on leaves of Aucuba japonica , 22­v­2002, M. Masumoto. 1 female, Kanagawa Pref., Yokosuka City, Kannonzaki, on leaves of Aucuba japonica , 29­vi­2002, M. Masumoto. 1 female, Kanagawa Pref., Yokosuka City, Kannonzaki, on leaves of Aucuba japonica , 5­vi­2005, M. Masumoto" before " 1female, Aichi Pref. 1 female, Aichi Pref., Tokoname City, Hibara park, on Magnolia sp. [Mognoliaceae], 19­v­2002, K. Minoura. 26 females and 1 male, Hiroshima Pref., Hiroshima City, Higashi­ku, Ushitayama, on leaves of Machilus thunbergii [ Lauraceae ], 25­x­1994, S. Okajima. 2 females, Nagasaki Pref., Kitamatsuura­gun, Tabira­cho, Motoyama­rindou, on leaves Machilus thunbergii , 28­x­1994, S. Okajima. 1 female, Nagasaki Pref., Kitamatsuura­gun, Tabiracho, Yakiyama, on leaves of Machilus thunbergii , 28­x­1994, S. Okajima. The holotype and almost paratypes are deposited in Laboratory of Insect Resources, Faculty of Agriculture, Tokyo University of Agriculture, Atsugi, Kanagawa Pref., Japan.

Non­paratypic specimens. Japan: 1 female, Ibaraki Pref., northern side of Mt. Tsukuba­san (alt. about 430 m), collected by yellow pan trap, 25­26­ix­1999, Nagashima & Suenaga. 1 female, Fukuoka Pref., Mt. Tachibana, collected by yellow pan trap, 30­ix­ 1978, K. Yamagishi. 3 females and 1 male, Fukuoka Pref., Mt. Tachibana, collected by yellow pan trap, 14­x­1978, K. Yamagishi. 1 female, Fukuoka Pref., Mt. Tachibana, collected by yellow pan trap, 16­iv­1979, K. Yamagishi.

Taiwan: 1 female, Chiai­hsien, Kuantzulin, 1­iv­1993, T. Nonaka & S. Okajima. 3 females, Nantou­hsien, Nanshanchi, on leaves of Liquidambar formosana [ Hamamelidaceae ], 3­iv­1993, T. Nonaka & S. Okajima. 9 females and 7 males, Nantouhsien, Nanshanchi, on leaves of Pssiflora coerulea [ Passifloraceae ], 3­iv­1993, T. Nonaka & S. Okajima. 4 females and 1 male, Nantou­hsien, Nanshanchi, on leaves of Passiflora edulis Sims (passion fruits), 29­viii­1993, T. Nonaka & S. Okajima. 2 females and 6 males, Nantou­hsien, Nanshanchi, on leaves of Liquidambar formosana [ Hamamelidaceae ], 7­ix­1993, T. Nonaka & S. Okajima.

Comments. This species is similar to the Indian species T. nilgiricus (Ramakrishna & Margabandhu) according to Bhatti (2000). However, T. nilgiricus has the following characteristics: ocellar setae length usually about 30 m, fore wing with costal setae about 1.1 times as long as median width of wing. In contrast, T. fragilis has ocellar setae length 38–41 m, and the fore wing with costal setae about 1.2–1.4 times as long as median width of wing. Moreover, in the original description of T. nilgiricus antennal segments III and V are stated to be equal in length (50 m), and segments VII and VIII are also almost equal in length (17 m and 18 m) ( Ramakrishna & Margabandhu, 1928). In contrast, in this new species segment V is usually shorter than segment III, about 0.9 times, and segment VIII is distinctly longer than segment VII, about 1.6 times. This species appears to belong in the hospes section of Trichromothrips ( Bhatti, 2000) . It is also similar to T. xanthius , but in that species antennal segment IV is widest near the middle and strongly tapering forwardly as a neck, and segments III and IV have the forked sense cones slightly stouter than in this species.

Etymology. In reference to the weak body of this species.

Figures

FIGURES 15 – 17. Trichromothrips fragilis n. sp. (female): (15) Head & pronotum; (16) Antennal segments I – VIII (right); (17) Mesonotum & metascutum (sculpture line on mesonotum omitted.). Scale bar = 0.04 mm.

FIGURES 18 – 21. Trichromothrips fragilis n. sp. Abdominal segments. Female 18 – 19: (18) Tergum II (left side); (19) Terga VIII – X (sculpture lines on tergum VIII omitted); male 20 – 21: (20) Tergum IX; (21) Sternum VII. Scale bar = 0.04 mm.