Trichromothrips elegans, 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 : 7-11

Trichromothrips elegans sp. nov.

( Figs. 1–5 )

Trichromothrips sp. 2: Okajima, 2000: 103.

Female. Distended body length 1.5–1.8 mm. Body bicoloured, with internal red pigment in abdomen. Head dark brown, often with small median area slightly paler along posterior margin dorsally. Segments I and II dark brown, III to IV yellowish white with distal third brown, V yellowish white with distal half brown, VI brown with basal third yellowish white, VII to VIII brown. Pronotum with dark brown lateral stripes, median large triangular area yellowish white ( Fig. 1 ); pterothorax yellowish white; fore wing uniformly dark brown with a small pale spot near base; all legs yellowish white. Abdominal segments brown to dark brown, darker toward posterior segments, VI, VII or VIII to IX dark brown; terga of anterior segments often slightly pale at middle, tergum X pale brown with base dark. Prominent body setae shaded on dark areas.

Head 1.1–1.0 times as long as wide, distinctly sculptured with transverse anastomosing striae at basal third of dorsal surface, strongly produced in front of fore ocellus, strongly constricted behind compound eyes with cheeks rounded ( Fig. 1 ). Compound eyes almost as long as cheeks, without pigmented ommatidia. Ocellar setae II about half length of setae III, setae III situated near anterior margin of hind ocelli and 2.8– 5.7 times as long as distance between their bases ( Fig. 1 ). Antennal segment IV usually the longest, often subequal to segment VI; sense­cone of segments III and IV each 0.5–0.7 times and 0.5–0.6 times as long as their segments ( Fig. 2 ). Antennal segments I to VIII length/width: 0.8–1.2, 1.3–1.6, 2.9–3.7, 3.6–4.8, 2.6–3.7, 3.9–5.6, 1.3–1.7, 3.5–6.0.

Pronotum 1.5–1.7 times as wide as long, almost smooth, with 9–14 discal setae, one pair of setae near anterior margin slightly longer; posteroangular setae I (=inner pair) 1.1– 2.0 times as long as setae II (outer pair) and 0.5–0.8 times as long as pronotal median length ( Fig. 1 ). Mesonotum almost smooth; median pair of setae situated in front of submedian pairs; anteromedian campaniform sensilla absent. Metascutum smooth medially; median pair of setae situated at anterior margin and 0.2–0.3 times as long as metascutal median length, slightly shorter than submedian pairs; campaniform sensilla absent ( Fig. 3 ). Metaepisternum with 0–1 setae, often on only one side. Fore wing costal vein with 20–30 setae (27 in holotype), first vein with 5 (rarely 4 or 6) basal setae, second vein with 9–17 setae (left 12, right 13 in holotype).

Abdominal terga IV or V to VIII with B4 setae minute ( Fig. 4 ); tergum VIII usually with two small setae in front of posteroangular setae (B3 setae) on each (often one) side ( Fig. 4 ); tergum IX without campaniform sensilla, SB2 setae present ( Fig.5 ); sterna without discal setae; sternum II with three pairs of posteromarginal setae; sternum VII with all setae in front of posterior margin. Ovipositor 2.4­2.8 times as long as pronotal median length.

Measurements of female holotype (in m). Body length 1685. Head, dorsal length 138, across cheeks 130, width behind compound eyes 118; compound eye dorsal length (width) 75 (43); ocellar setae III length (interval) 30 (10). Pronotum median length (width) 120 (185); posteroangular setae I length 63, setae II length 57. Metascutum median length 80; median setae length 23. Fore wing length 875. Abdominal tergum IX median length 108; tergum X median length 75. Ovipositor length 300. Antenna length 373; segments I­VIII length (width): 30 (33), 40 (28), 65 (20), 75 (18), 50 (18), 75 (15), 13 (8), 25 (5); segments III and IV sense­cone length 38 and 43.

Male. unknown.

Type series. Holotype (female): Japan, Tokyo, The Imperial Palace Grounds, Fukiage­gyoen, on leaves of Aucuba japonica [ Cornaceae ], 26­v­1999, S. Okajima. Paratypes Japan: 91 females collected together with the holotype. 79 females, collected at same place and plants with the holotype, 7­v­1997, S. Okajima. 249 females, collected at same place with the holotype, host unknown, 12­vi­1996, S. Okajima. 24 females, Kanagawa Pref., Yokosuka City, Kannonzaki, on leaves of Aucuba japonica , 28­v­2005, M. Masumoto. 1 female, Kanagawa Pref., Yokosuka City, Kannonzaki, on leaves of Neolitsea serica [ Lauraceae ], 28­v­2005, M. Masumoto. 4 females, Kanagawa Pref., Yokosuka City, on leaves of Lithocarpus edulis [ Fagaceae ], 5­vi­2005, M. Masumoto. 8 females, Kanagawa Pref., Yokosuka City, Kannonzaki, on leaves of Aucuba japonica , 5­ vi­2005, M. Masumoto. 1 female, Kanagawa Pref., Yokosuka City, Kannonzaki, on leaves of Machilus thunbergii [ Lauraceae ], 5­vi­2005, M. Masumoto. The holotype and most paratypes are deposited in Laboratory of Insect Resources, Faculty of Agriculture, Tokyo University of Agriculture, Atsugi, Kanagawa Pref., Japan.

Comments. The colour of this species is beautiful when alive due to the internal red pigments in the abdomen. This colour distinguishes the species from other members of Trichromothrips , although the structure is similar to that of T. alis . However, T. alis has the abdomen strongly bicoloured in contrast to this new species. Moreover, in this new species the chaetotaxy is characteristic on abdominal tergum VIII with two small setae (B4 and accessory setae?) present in front of B3 setae, whereas only the B4 setae are present in other species.

This new species is included with T. alis in the bellus section of Trichromothrips ( Bhatti, 2000) , although it often has one seta on each metaepimeron (often only on one side).

Etymology. In reference to the beautiful body colour of this species when alive.

Figures

FIGURES 1 – 3. Trichromothrips elegans n. sp. (female): (1) Head with antennal segment I & pronotum (median pale area on pronotum indicated by dotted lines); (2) Antennal segments II – VIII (right); (3) Mesonotum & metascutum (sculpture line on mesonotum omitted.). Scale bar = 0.04 mm.

FIGURES 4 – 5. Trichromothrips elegans n. sp. (female). Abdominal segments: (4) Terga VII – VIII & laterotergite VII (right side); (5) Terga IX – X (left­dorsal aspect). MD = mid­dorsal seta; sp = spiracle. Scale bar = 0.04 mm.