Orius (Orius) sakaerat Yamada and Yasunaga, sp. nov. (Figures 1A,B, 2A – D, 5A,B, 6A, 9A, 11A, 14A – C, 19A)

Type materials

Holotype. ♂ (Figures 2A, B, 5A, 6A, 9A, 11A, 14A – C), THAILAND, Nakhon Ratchasima, Sakaerat Environmental Research Station, N 14°29ʹ24.4ʺ – 30ʹ37.5ʺ, E101°54ʹ37.8ʺ – 55ʹ49.7ʺ, 372 – 601 m alt., 23 – 25 January 2009, T. Yasunaga leg ’ (DOA) . Paratypes. Two ♀ (one in Figures 2C, D, 5B, the other in Figure 19A), same locality as holotype, 14°30ʹ26.7ʺN, 101° 55ʹ39.2ʺE, 407 m alt ., light trap, 11 – 14 June 2009, K. Yamada (one ♀ in TKPM, one ♀ in DOA) . Nakhon Nayok: two ♀, Sarika, 14°18′45.37″ – 14°21′16.9″N, 101°16′22.41″ – 101°18′ 03.83″E, 40 – 96 m alt ., 19 March 2014, K. Yamada (TKPM); one ♂, four ♀ (one in Figure 1A, one in Figure 1B), same locality, 20 March 2014, T . Yasunaga and K . Yamada (one ♀ in BMNH, one ♀ in TYCN, others in TKPM) .

Diagnosis

Recognised by the following characters: body generally blackish brown to pitch black (Figures 1A, B, 2A – D); femora blackish brown to black excepting pale yellow apex (Figure 2B, D); cone very thin, gradually acute apicad; denticule slender and straight; flagellum gently curved, slightly exceeding the tip of cone (Figures 14A – C); copulatory tube very small, consisting of short, rounded membranous apex and slightly curved, tubular basal section (Figure 19A).

Description

Colouration. Body generally blackish brown to pitch black (Figures 1A, B, 2A – D). Head and pronotum uniformly blackish brown, tylus with pale tinge; eyes reddish brown, area surrounding ocellus reddish brown (Figure 5A, B). Antennae yellowish brown, with segments I, III and IV faintly darkened (Figure 5A, B). Labium dark brown, with apical half of segment III and basal half of IV yellowish brown (Figure 2B, D). Scutellum and hemelytra overall blackish brown to pitch black, with cuneus more darkened; membrane uniformly greyish brown (Figure 2A, C). Coxae, trochanters and femora blackish brown to black, with apex of femora pale yellow; tibiae uniformly pale yellow, but male metatibiae somewhat darkened except for pale yellow base; tarsi pale yellow, with darkened apex. Venter of thorax and abdomen blackish brown to black (Figure 2B, D).

Structure. Body oblong oval, somewhat parallel sided (Figure 2A, C). Head smooth, shiny, about 0.6 times as long as width across eyes, sparsely covered with short decumbent setae, and with a longer erect seta on each side of clypeus, near anteromedial margin of each eye, and between eye and ocellus; ante-ocular portion 0.6 – 0.7 times as long as length of eye in dorsal view; vertex about 2.2 times as wide as eye in dorsal view; eye oblong, about 1.5 times as long as eye width in dorsal view; postocular portion constricted; neck shortened (Figure 9A). Antennal segment I stout, slightly exceeding apex of head, sparsely covered with short suberect setae; segment II 0.55 times as long as head width across eyes in male, 0.5 times in female, densely covered with suberect setae which are shorter than width of the segment; segments III and IV slightly narrower than maximum width of segment II, covered with long erect setae intermixed with short decumbent setae, longest seta about as long as width of respective segment; segment III equal length to segment IV (Figures 5A, B, 9A). Labium extending to about middle of mesosternum, sparsely covered with short suberect setae. Pronotum smooth, shiny, sparsely covered with long decumbent setae; anterior margin nearly straight, width about 1.2 times as wide as mesal length; lateral margin nearly straight, curved at anterior corner in female; lateral carinae weakly expanded anteriorly; posterior margin shallowly concave, width about 2.4 times as wide as anterior pronotal width; collar narrow, with transverse weak groove and suberect setae, demarcated by shallow impression from callus; callus strongly convex, impunctate, with scattered long setae, demarcated posteriorly by deep transverse impression (Figures 5A, B, 9A). Scutellum nearly equilateral, shorter than basal width, depressed through middle, uniformly covered with long decumbent setae. Hemelytra impunctate, overall densely covered with short decumbent setae; maximum width of endocorium about twice as wide as embolium; cuneal margin about 0.7 times as long as embolial margin in male, 0.55 times in female; membrane with single visible vein located near costal margin (Figure 2A, C). Anterior area to median furrow in ostiolar peritreme smooth, about as wide as maximum width of posterior area to median furrow; posterior area weakly squamous entirely; supracoxal area smooth, without rugosity (Figure 6A). Legs densely covered with decumbent setae; male protibiae with a row of fuscous small teeth on ventral side.

Male genitalia (Figures 11A, 14A–C). Pygophore globular shaped but somewhat dorsoventrally depressed, posteroventrally covered with six long, stout setae intermixed with short, erect setae along outer margin, of which the longest setae are shorter than half length of pygophore (Figure 11A); dorsal surface densely distributed with short, suberect setae; cone very thin, gradually acute apicad (Figure 14A); denticule slender and straight, arising from inner side of cone, shorter than half of maximum width of cone (Figure 14A, B); flagellum gently curved, thickened at base, slightly exceeding the tip of cone in dorsal view (Figure 14A – C).

Female genitalia (Figure 19A). Copulatory tube very small, fused on left part of intersegmental membrane between sterna VII and VIII in dorsal view, consisting of short, rounded membranous apex and slightly curved, tubular, basal section; basal section more or less divided into weakly sclerotised apical half and more membranous basal half.

Measurements (mm)

[♂ (n = 1, holotype)/ ♀ (n = 2)]. Body length 1.68/1.65 – 1.70; head length (excluding neck) 0.22/0.22 – 0.23; head width across eyes 0.34/0.34 – 0.35; vertex width 0.18/0.18; width between ocelli 0.14/0.15 – 0.16; lengths of antennal segments I – IV: I – 0.08/0.08, II – 0.19/ 0.17, III – 0.14/0.13 – 0.14, IV – 0.14/0.13 – 0.14; lengths of labial segments II – IV: II – 0.07/0.08, III – 0.21/0.22, IV – 0.16/0.19; anterior pronotal width 0.28/0.29 – 0.30; mesal pronotal length 0.24/ 0.24 – 0.26; basal pronotal width 0.66/0.66 – 0.72; length of embolial margin 0.50/0.51 – 0.54; length of cuneal margin 0.34/0.27 – 0.34; maximum width across hemelytra 0.73/0.72 – 0.78.

Etymology

Named after the type locality, Sakaerat Environmental Research Station in Wang Nam Khieo District, Nakhon Ratchasima Province, northeastern Thailand; a noun in apposition .

Distribution

Northeastern Thailand (Nakhon Ratchasima, Nakhon Nayok) .

Remarks

Orius sakaerat is most similar in external appearance to the darkened variant of O. niger Wolff, 1811 from continental Palearctic Region and India, but is clearly distinguished from it by the blackish brown to black femora excepting pale yellow apex (in niger, entirely black meso- and metafemora), the gradually curved flagellum of paramere slightly exceeding the tip of cone (in niger, straight, much exceeding the tip of cone), and the slightly curved and tubular basal section of copulatory tube. In having the blackish colouration of body, this new species also resembles O. fi liferus described below, but clearly differs from the latter by the colouration of head and legs, the shape of ostiolar peritreme, and the structure of paramere and copulatory tube.

Habitat

Collected on inflorescence of the fabaceous broadleaf trees ( Acacia spp., Leucaena spp.) and the spurge tree Homonoia riparia Lour. (Euphorbiaceae) . A few specimens were captured by light trap.