Orius (Dimorphella) tantillus ( Motschulsky, 1863 )

Yamada, Kazutaka, Yasunaga, Tomohide & Artchawakom, Taksin, 2015, The flower bug genus Orius Wolff, 1811 (Hemiptera: Heteroptera: Anthocoridae: Oriini) of Thailand, Journal of Natural History 50, pp. 1103-1157 : 1144-1148

Orius (Dimorphella) tantillus ( Motschulsky, 1863)

( Figures 1D , 4E – H , 5O,P , 7B , 8D – F , 10C , 13B , 18D – F , 20B )

Anthocoris tantillus Motschulsky, 1863: 89 . Neotype ( Ghauri 1972: 414): ♂, Ceylon [= Sri Lanka], Pundalu-oya (BMNH) [examined]; Distant 1904: 222 ( Triphleps , list); Distant 1906: 8 ( Triphleps , redescription, figure); Poppius 1909: 43 ( Triphleps , redescription); Ghauri 1964: 687 ( Orius , diagnosis); Ghauri 1972: 411 ( Orius , redescription, neotype designation, figures); Muraleedharan and Ananthakrishnan 1974: 38 ( Orius , diagnosis, key, figures); Manley 1976: 103 ( Orius , record, biology); Muraleedharan 1977: 234 ( Orius , diagnosis, key); Zheng 1982: 193 ( Orius , record, figure); Zhang and Lin 1985: 195 ( Orius , diagnosis, note, figure); Kerzhner and Jansson 1985: 38 (note on type specimens); Woodward and Postle 1986: 247 ( Orius , redescription, key, figures); Zheng and Bu 1990: 26 ( Orius , list); Yasunaga 1993: 231 ( Orius (Paraorius) , figures); Cassis and Gross 1995: 34 ( Orius , catalogue); Péricart 1996: 127 ( Orius (Paraorius) , catalogue); Yasunaga 1997c: 387 ( Orius (Paraorius) , record, diagnosis, key, figures); Hernández and Stonedahl 1999: 559 ( Orius (Dimorphella) , redescription, key, figures); Postle et al. 2001: 232 ( Orius , key, figures); Bu and Zheng 2001: 207 ( Orius , redescription, key, figures); Yasunaga 2001: 291 ( Orius (Dimorphella) , note, key, figures); Ghahari et al. 2009: 50 ( Orius (Dimorphella) , record, note); Aukema et al. 2013: 92 ( Orius (Paraorius) , note).

Triphleps australis China, 1926: 361 (syn. Woodward and Postle 1986: 247). Syntypes: ♀, Australia, Queensland (BMNH) [examined]; Gross 1954: 136 ( Orius , diagnosis).

Orius niobe Herring, 1967: 399 (syn. Ghauri 1972: 411). Holotype: ♂, Guam Is., Yona ( U. S. National Museum of Natural History, Smithsonian Institution) [examined].

Specimens examined

Thailand: Nakhon Ratchasima: three ♂ (one in Figure 1D ) four ♀, Sakaerat Silvicultural Research Station , 14°27 ′ 59.12 ″ N, 101°54 ′ 11.70 ″ E, 404 m alt ., 24 March 2014, K. Yamada.

Saraburi: one ♂ ( Figures 5O , 10C ) one ♀, Kyusei Nature Farming Center, Champakpaew, Kaengkoi, 14°32 ʹ 75.8 ʺ N, 101°04 ʹ 71.5 ʺ E, 60 m alt ., 20 January 2009, K. Yamada ; seven ♂ (one in Figure 4E, F ) 15 ♀ (one in Figure 20B ), same locality, 22 January 2009, K . Yamada . Nakhon Nayok: four ♀, Sarika, 14°17 ʹ 20.8 ʺ – 21 ′ 16.9 ″ N, 101°16 ′ 22.41 ″ – 18 ʹ 07.7 ʺ E, 25 – 96 m alt ., 15 – 17 June 2009, T. Yasunaga ; four ♀, same locality, 16 – 17 June 2009, K . Yamada ; six ♂, 20 ♀ (one in Figures 4G, H , 5P ), same locality, 21 – 23 March 2010, K . Yamada ; two ♂, three ♀, same locality, 6 March 2009, T . Yasunaga ; one ♀, same locality, 20 March 2014, T . Yasunaga and K . Yamada . Suphan Buri: three ♂, two ♀, Sri Prachan, 14°41 ʹ 18.3 ʺ N, 100° 08 ʹ 25.8 ʺ E, 10 m alt ., 21 October 2008, K. Yamada ; two ♂ (one in Figures 7B , 8D – F , 13B , 18D – F ), same locality, 25 October 2008, K . Yamada . Kanchanaburi: five ♂, four ♀, 7 February 2009, T . Yasunaga . All in TKPM .

Additional specimens examined

Cambodia: Siem Reap: two ♂, two ♀, 31 . i . 2014, T. Yasunaga ( TKPM) .

Diagnosis

Recognised by the following characters: hemelytra semitransparent pale yellow ( Figure 4E, G ); anterior area to median furrow in ostiolar peritreme very wide ( Figure 7B ); male profemora with 2 – 4 small fuscous teeth on ventral side ( Figure 8F ); cone acute at apex ( Figure 18D ); flagellum with three branches ( Figure 18D – F ); copulatory tube consisting of membranous apical section and cylindrical basal section ( Figure 20B ).

Redescription

Colouration. Head black, tinged with orange brown at apex; eyes reddish brown, ocellus and its surrounding area red to reddish brown ( Figure 5O, P ). Antennae pale yellow; segments III and IV with fuscous tinge ( Figure 5O, P ). Labium blackish brown; apex of segment III and base of segment IV yellowish brown ( Figure 4F, H ). Pronotum and scutellum uniformly black ( Figure 4E, G ). Hemelytra semitransparent pale yellow; membrane semitransparent greyish brown ( Figure 4E, G ). Legs uniformly pale yellow; coxae generally blackish brown ( Figure 4F, H ). Venter of head and thorax blackish brown tinged with orange brown distally ( Figure 4F, H ).

Structure. Body small, oblong oval ( Figure 4E, G ). Head about 0.7 – 0.75 times as long as width across eyes, densely punctate with very short setae; ante-ocular portion about 0.7 times as long as length of eye in dorsal view; vertex about 2.2 times as wide as width of eye in dorsal view; eye oblong, about 1.6 times as long as eye width in dorsal view, proximate to anterior margin of pronotum; neck very shortened ( Figure 10C ). Antennal segment I stout, slightly exceeding apex of head, sparsely covered with short suberect setae; segment II thickened, fusiform, 0.8 – 0.85 times as long as head width across eyes, densely covered with suberect setae which are shorter than half width of the segment; segments III and IV narrower than maximum width of segment II, densely covered with suberect setae which are shorter than width of respective segment; segment III 0.8 – 0.9 times as long as segment IV ( Figures 5O, P , 10C ). Labium reaching the procoxae, sparsely covered with short suberect setae. Anterior pronotal margin slightly concave, width about as wide as mesal length; lateral margin nearly straight; lateral carinae expanded at anterior two-thirds; posterior margin shallowly concave, width 2.2 – 2.4 times as wide as anterior pronotal width; callus weakly convex, scattered short setae and deep punctures, density of setae and punctures a little higher than that of O. maxidentex ( Figures 8D, E , 10C ). Maximum width of endocorium about twice as wide as embolium; cuneal margin about 0.57 times as long as embolial margin; membrane with two distinct veins near costal margin and at middle. Ostiolar peritreme wide; anterior area to median furrow in ostiolar peritreme smooth, very wide; posterior area to median furrow strongly squamous entirely, a little narrower than maximum width of anterior area to median furrow; evaporatorium narrow; supracoxal area smooth, without rugosity ( Figure 7B ). Male trochanters with one small fuscous tooth on ventral side; male profemora with 2 – 4 small fuscous teeth on ventral side; male protibiae with a row of 21 – 22 small fuscous teeth on ventral side ( Figure 8F ).

Male genitalia ( Figures 13B , 18D–F ). Pygophore globular shaped but somewhat dorsoventrally depressed, posteroventrally covered with seven long, stout setae which are much shorter than half length of pygophore ( Figure 13B ); mediodorsal surface distributed with short, suberect setae; cone thin, acute at apex in dorsal view ( Figure 18D ); flagellum with three branches: uppermost (outermost) branch slightly thickened apically in dorsal view and weakly sinuate in lateral view; middle branch longest, straight, exceeding the apex of cone; lowermost (innermost) branch slightly curved in lateral view ( Figure 18D – F ).

Female genitalia ( Figure 20B ). Copulatory tube fused on mesal part of intersegmental membrane between sterna VII and VIII, extremely remote from base of ovipositor, consisting of membranous apical section and cylindrical basal section: apical section slender, short, slightly curved; basal section weakly sclerotised, thickened.

Measurements (mm)

[♂ (n = 10)/ ♀ (n = 10)]. Body length 1.80 – 2.00/1.56 – 2.30; head length (excluding neck) 0.26 – 0.28/0.25 – 0.29; head width across eyes 0.35 – 0.36/0.35 – 0.40; vertex width 0.18 – 0.19/0.18 – 0.22; width between ocelli 0.15 – 0.16/0.16 – 0.18; lengths of antennal segments I – IV: I – 0.09 – 0.10/0.10 – 0.11, II – 0.22 – 0.24/0.19 – 0.23, III – 0.19 – 0.22/0.16 – 0.19, IV – 0.21 – 0.24/0.19 – 0.23; lengths of labial segments II – IV: II – 0.07 – 0.09/0.06 – 0.09, III – 0.24 – 0.26/ 0.25 – 0.28, IV – 0.14 – 0.18/0.14 – 0.17; anterior pronotal width 0.29 – 0.30/0.29 – 0.33; mesal pronotal length 0.28 – 0.29/0.29 – 0.33; basal pronotal width 0.65 – 0.68/0.67 – 0.78; length of embolial margin 0.56 – 0.60/0.58 – 0.69; length of cuneal margin 0.32 – 0.35/0.34 – 0.39; maximum width across hemelytra 0.70 – 0.73/0.73 – 0.81.

Distribution

Thailand (Chiang Mai, Nakhon Ratchasima, Saraburi, Nakhon Nayok, Suphan Buri, Kanchana Buri) ( Yasunaga and Miyamoto 1993; present study); Cambodia (present study; new record); Malaysia ( Manley 1976), India ( Ghauri 1972), Sri Lanka ( Distant 1906), Iran ( Ghahari et al. 2009), China ( Zheng 1982; Bu and Zheng 2001), Taiwan ( Yasunaga 1997c), Japan ( Yasunaga 1997c), Australia ( China 1926; Woodward and Postle 1986), Micronesia ( Herring 1967), Nigeria ( Hernández and Stonedahl 1999), Tanzania ( Hernández and Stonedahl 1999), Kenya ( Hernández and Stonedahl 1999).

Remarks

In general habitus, O. tantillus is similar to O. albidipennis ( Reuter, 1884) mainly known from the Atlantic zone of western Europe, middle East and sub-Saharan Africa, and O. naivashae ( Poppius, 1920) from Kenya, but is distinguished from them by the wider ostiolar peritreme, the uniformly pale yellow femora (in albidipennis , profemora yellow, meso- and metafemora brown or dark brown; in naivashae , each femur dark brown), and the paramere with three-branched flagellum (in albidipennis and naivashae , with roundly curved flagellum and distinct lamelliform process).

Habitat

Abundantly collected on Gramineae and Cyperaceae plants near and in rice paddy fields, grasslands and other cultivated areas.

Figures

Figure 1. Habitus photographs of living individuals. (A, B) O. sakaerat, female; (C) O. filiferus, female; (D) O. tantillus, male; (E) O. dravidiensis, female; (F) same, male.

Figure 4. Habitus.(A,B) O. maxidentex, male,dorsal and lateral views;(C,D) same,female,dorsal and lateral views; (E, F) O. tantillus, male, dorsal and lateral views; (G, H) same, female, dorsal and lateral views; (I, J) O. dravidiensis, male, dorsal and lateral views; (K, L) same, female,dorsal and lateral views. Scale bars: 0.5 mm.

Figure 5. Head and pronotum, dorsal view. (A, B) O. sakaerat; (C, D) O. taksini; (E, F) O. tomokunii; (G, H) O. filiferus; (I, J) O. machaerus; (K), O. inthanonus; (L) O. crassus; (M, N) O. maxidentex; (O, P) O. tantillus; (Q, R) O. dravidiensis.

Figure 7. SEM images of ostiolar peritreme and evaporatorium, left lateroventral view. (A) O. maxidentex, male; (B) O. tantillus, male; (C) O. dravidiensis, female. Abbreviations: eva = evaporatorium; mf = median furrow; op = ostiolar peritreme; sca = supracoxal area.

Figure 8. SEM images of three Dimorphella species, male. (A, B) pronotum of Orius maxidentex; (C) proleg of O. maxidentex; (D, E) pronotum of O. tantillus; (F) proleg of O. tantillus; (G, H) pronotum of O. dravidiensis; (I) proleg of O. dravidiensis. Arrows show small teeth.

Figure 10. Head and pronotum, male, dorsal view. (A) O. crassus, holotype; (B) O. maxidentex; (C) O. tantillus; (D) O. dravidiensis. Scale bars: 0.2 mm.

Figure 13. Pygophore with paramere, dorsal view. (A) O. maxidentex (ejaculatory bulb omitted); (B) O. tantillus; (C) O. dravidiensis. Abbreviations: eb = ejaculatory bulb; prm = paramere; pyg = pygophore. Scale bars: 0.1 mm.

Figure 18. Paramere, three different views. (A–C) O. maxidentex; (D–F) O. tantillus; (G–I) O. dravidiensis. Abbreviations: cn = cone; flg = flagellum; lmp = lamelliform process. Scale bars: 0.05 mm.

Figure 20. Female genitalia, dorsal view. (A) O. maxidentex; (B) O. tantillus; (C) O. dravidiensis. Abbreviations: ism = intersegmental membrane between abdominal sterna VII and VIII; st VII = sternum VII. Scale bars: 0.05 mm.