Liothrips populi sp. n.

(Figs 12, 29, 61, 78, 94, 102)

Female macroptera. Body brown; all femora and tibiae brown, fore tibiae brown, pale at apical half, all tarsi yellow; antennal segments I–II lightly brown, paler than head, III–VIII yellow, VII–VIII light brown (Fig. 29); major setae dark; fore wing hyaline.

Head as long as wide (Fig. 12); postocular setae blunt, shorter than eyes, just reaching to posterior margin of eyes (Fig. 12); eyes dorsally and ventrally equal in length; maxillary stylets about 0.14 of head width apart, retracted to level of eyes; mouth cone bluntly pointed, reaching to level of anterior margin of ferna. Antennal segment III about 3 times as long as apical width (Fig. 29); IV with 3 major sense cones, VIII small, distinct from VII. Pronotum transverse, with 5 pairs of long blunt setae, am and aa subequal in length; surface almost smooth, with weak sculpture near margins. Fore wings with 3 blunt sub-basal setae arising in straight line, almost equal in length, with 11 duplicated cilia. Mesonotum transversely reticulate, lateral setae well-developed, blunt, a pair of setae posteromedially slightly shorter than lateral pair, acute. Metanotum longitudinally reticulate, major setae well-developed, slightly blunt (Fig. 78). Mesopresternum boat-shaped, transverse medially (Fig. 61), metathoracic sternopleural sutures short. Pelta broadly triangular, weakly reticulate, with a pair of CPS; tergite II with a pair of lateral setae; tergite VIII with posterolateral setae well-developed, shorter than posteroangulars; tergite IX setae S1–S3 much shorter than tube, softly pointed; tube shorter than head, anal setae about as long as tube.

Measurements (holotype female in microns). Body length 2510. Head length (maximum width) 265 (265); postocular setae length 30; antennal segments I–VIII length (width): 40 (45), 60 (30), 85 (25), 80 (35), 70 (30), 60 (30), 60 (25), 35 (15); sense cone on III length 25. Pronotum length (width) 155 (335); am 40, aa 40, ml 65, epim 100, pa?. Fore wing length 1000; sub-basal setae S1 65, S2 80, S3 100. Tergite VIII posterolateral setae 80; tergite IX setae S1 110, S2 120, S3 135; tube length 200, basal width 80, apical width 45; anal setae length 195.

Male macroptera. Similar to female in colour and sculpture; mesopresternum eroded medially; abdominal tergite IX setae S2 short and softly acute (Fig. 102); sternite VIII largely occupied by pore plate (Fig. 94).

Measurements (paratype male in microns). Body length 1850. Head length (maximum width) 215 (220); postocular setae length 25. Pronotum length (width) 110 (315); am 25, aa 30, ml 50, epim 75, pa 65. Tergite IX setae S1 100, S2 55, S3 155; tube length 165, basal width 65, apical width 35; anal setae length 145.

Specimens studied. Holotype female, CHINA, Inner Mongolia, on leaves of Populus euphratica, 25.vii. 1991 (NZMC).

Paratypes: 1 female and 3 males with same data as holotype (NZMC & SNUT) .

Etymology. This species name is composed of one Latin word based on the plant name from which the type specimens were collected.

Comments. This new species is similar to some others with a short head. It seems closely related to L. rohdeae (Okajima 2006), but differs as follows: mid and hind tibiae uniformly brown; fore wings pale without brown stripe; postocular setae not exceeding posterior margin of eyes (Fig. 12); sense cones on antennal segments III–IV rather short, shorter than width of this segment (Fig. 29); maxillary stylets rather long, reaching eyes (Fig. 12); pelta hatshape with small lateral lobes (Fig. 78); tergite IX setae S1 much shorter than tube, about half length of tube (Fig. 102); taken on the leaves of Populus euphratica . In contrast, L. rohdeae has mid and hind tibiae dark brown with apical third to fourth yellowish; fore wings with a median longitudinal pale brown stripe; postocular setae exceeding posterior margin of eyes (Fig. 16); sense cones on antennal segments III–IV about half length of this segment (Fig. 33); maxillary stylets reaching postocular setae (Fig. 16); pelta triangular (Fig. 87); tergite IX setae S1 about 1.4 times as long as tube; taken on young leaves of Rohdea japonica .