Rihirbus trochantericus Stål 1861

Gao, Feng, Zhao, Ping, Webb, Mick & Cai, Wanzhi, 2015, A taxonomic review of the polymorphic assassin bug genus Rihirbus Stål (Hemiptera: Reduviidae: Harpactorinae), Zootaxa 3963 (4), pp. 502-516 : 504-510

Rihirbus trochantericus Stål 1861

( Figs 14–28 )

Rihirbus trochantericus Stål 1861: 132 ; Distant 1904: 378; China 1940: 254; Hoffmann 1944: 68; Maldonado-Capriles 1990: 292; Putshkov & Putshkov 1996: 254; Cai & Yang 2002: 216; Aukema et al. 2013: 142.

Rihirbus dentipes Mayr 1865: 437 ; Stål 1874: 21, synonymized.

Rihirbus trochantericus var. luctuosus Stål 1871: 677 .

Rihirbus trochantericus var. niger Stål 1871: 677 .

Rihirbus trochantericus var. rufipes Stål 1871: 677 .

Rihirbus trochantericus var. rufidorsis Stål 1871: 677 .

Rihirbus trochantericus var. rufipennis Stål 1871: 677 .

Rihirbus trochantericus var. scutellaris Stål 1871: 677 .

Rihirbus trochantericus var. semiflavs Stål 1871: 677 .

Rihirbus trochantericus var. tibialis Stål 1871: 677 .

Euagoras trochantericus: Walker 1873:122 .

Rihirbus trochantericus var. testaceus Reuter 1881: 279 .

Rihirbus trochantericus var. ruficeps Casto de Elera 1895: 440.

Rihirbus malignus Miller 1941: 758 ; Maldonado-Capriles 1990: 292; Cai & Yang 2002: 216, synonymized. Rihirbus famulus Miller 1941: 759 ; Maldonado-Capriles 1990: 292; Cai & Yang 2002: 216, synonymized. Rihirbus barbarus Miller 1941: 760 ; Maldonado-Capriles 1990: 291; Cai & Yang 2002: 217, synonymized. Rihirbus banksi Miller 1941: 761 ; Maldonado-Capriles 1990: 292; Cai & Yang 2002: 217, synonymized.

Rihirbus insulanus Miller 1941: 762 ; Maldonado-Capriles 1990: 292; Cai & Yang 2002: 217, synonymized. Rihirbus discrepans Miller 1941: 763 ; Maldonado-Capriles 1990: 292; Cai & Yang 2002: 217, synonymized.

Redescription. Colouration. Body colour patterns varied greatly. In male, body generally yellow or orange. Substitute scapus and pedicellus black, basi- and distiflagellomere brown to blackish brown; markings on dorsal surface of head, apical part of femur (except subapical spot on fore femur yellowish), tibia (except subbasal markings on fore tibia paler) black; mid and hind femora (except apical part black), ventral surface of abdomen yellowish; membrane light brown to brown, semi-transparent. In female, body colour may change from yellow to reddish brown or even almost completely black, mostly reddish brown with different shapes of black markings.

Structure. Body of medium to large size. Body clothed with erect short yellow setae; head, femur and tibia clothed with fine setae in different lengths; thorax densely covered with short setae; anterior part of meso- and meta-pleura of thorax, anterior margin of each abdominal sternum laterally with white tufted setae; corium sometimes scattered with white tufted setae; anterior margin and basal part of corium with bent yellow short setae; ventral surface of fore trochanter and fore femur, apical part of fore tibia densely clothed with short erect yellow setae. Anteocular part subequal to postocular in length; post-antennal protuberance short spine-shaped; first rostral segment somewhat thickened, distinctly extending beyond posterior margin of eyes; first antennal segment longest, subequal to or longer than head and pronotum together in length. Anterior lateral angle of pronotum short and conical; anterior pronotal lobe slightly shiny and with glabrous impression, medially deeply longitudinally sulcate, subbasal part with a pair of larger protuberances; posterior pronotal lobe bulged, shallowly wrinkled or reticulately rugose, discal part somewhat flat, lateral and posterior pronotal angles round and slightly prominent; postolateral margin slightly concaved and upward; posterior margin of pronotum slightly convex; scutellum with “V”-shaped carinae, apical part round. Fore femur thickened, basal half distinctly incurved; fore wing distinctly extending beyond abdominal tip; connexivum of abdomen moderately dilated in female, especially fourth to sixth abdominal segments.

Pygophore round, median pygophore process short; paramere clavate, apical part with few hairs ( Figs 21, 22 ); basal plate of phallobase slightly shorter than and thicker than plate bridge, pedicel short and wide ( Fig. 23 ); phallosome elliptic; dorsal phallothecal sclerite sclerotized, apical part gradually widened and widely concave in apex ( Figs 24–26 ); struts shown as Fig. 24 .

Measurements [♂ (n= 7) /♀ (n= 9), in mm]. Body length 18.26–22.00 / 19.33–23.99; maximum abdomen width 3.47–4.34 / 5.34–9.33. Head length (including neck) 3.00–3.74 / 3.34–4.34; anteocular part length 1.07–1.20 / 1.13–1.47; postocular part length 1.20–1.53 / 1.53–1.87; synthlipsis length 0.67–0.87 / 0.80–1.00; interocellar space 0.60 / 0.60–0.67; visible antennal segments length I–IV= 8.14–10.26 / 8.67–11.33, 2.78–3.60 / 2.87–3.87, 6.00–7.20 / 6.47–7.60, 3.00–4.10 / 4.87; labial segments length I–III= 2.13–2.67 / 2.47–3.13, 1.00–1.27 / 1.13– 1.33, 0.51–0.53 / 0.60–0.73. Anterior pronotal lobe length 1.53–1.67 / 1.33–2.00; posterior pronotal lobe length 2.00–2.67 / 2.73–3.47; maximum thorax width 4.00–5.54 / 5.13–6.91; scutellum length 0.73–0.87 / 1.27–2.00; hemelytron length 12.01–14.40 / 14.01–19.60.

Type materials. Type specimen of Rihirbus trochantericus Stål : ST, ♀, India; in Naturhistoriska Riksmuseet, Stockholm, not examined.

Type specimen of Rihirbus dentipes Mayr : ST, Sri Lanka; in Naturhistorisches Museum Wien, not examined. Type specimen of Rihirbus malignus Miller : Holotype: ♂; “ type ” [white, rounded with red circle, pr.]; “B. N.

Borneo, Mt. Kinabalu, Kenokok, 3800 ft, 26. Apr. 1929 ” [dark pink, rectangular, pr, with two hw numbers]; “Brit. Mus. 1947-269” [white, rectangular, pr]; “ Rihirbus malignus sp. n., det. N. C. E. Miller 1939 ” [white, rectangular, Miller’s hw, with “det. N. C. E. Miller 193 ” pr.] ( BMNH). The specimen is nearly in good condition, antennae just with right basal one segment left, left hind tibia and tarsus, and right hind tarsus missing; male genitalia is glued on a rectangular card.

In Miller’s (1941) original description and Aukema et al. (2013) the sex of this unique type is wrongly stated as female.

Type specimen of Rihirbus famulus Miller : Holotype: ♀; “ type ” [white with red circle, rounded, pr.]; “ Sarawak: C. J. Brooks. B. M. 1928-193” [white, rectangular, pr.]; “ Rihirbus famulus sp. n., det. N. C. E. Miller 1939” [white, rectangular, Miller’s hr., with “det. N. C. E. Miller 193” pr.] ( BMNH). The specimen is not in good condition, antennae, left fore leg, left hind tibia and all tarsi missing.

The type depository of this specimen in the catalogue of Aukema et al. (2013) is correct.

Type specimen of Rihirbus barbarus Miller : Holotype: ♀; “ type ” [white with red circle, rounded, pr.]; “Gunung Keledang Perak 2646, Nov. 1916 ” [white, rectangular, pr.]; “Brit. Mus. 1947-269” [white, rectangular, pr.]; “ Rihirbus barbarus sp. n., det. N. C. E. Miller 1939” [white, rectangular, Miller’s hw., with “det. N. C. E. Miller 193” pr.] ( BMNH). The specimen is in poor condition, antennae with right scapus only, mid legs and left hind tarsus missing.

Type specimen of Rihirbus banksi Miller : Holotype: ♀; “ type ” [white with red circle, rounded, pr.]; “Trusan, Aug. 100” [white, rectangular, Aug. and a number 189 pr., but 189 is crossed]; “Brit. Mus. 1947-269” [white, rectangular, pr.]; “ Rihirbus banksi sp. n., det. N. C. E. Miller 1939” [white, rectangular, Miller’s hw., with “det. N. C. E. Miller 193” pr.] ( BMNH). The specimen is in poor condition, antennae with right scapus only, right mid leg and left hind leg, all tarsi except left fore tarsus missing.

Type specimen of Rihirbus insulanus Miller : Holotype: ♀; “ type ” [white with red circle, rounded, pr.]; “Malay Penin: West Cost. Langkawi Is. April 17th, 1928,” [white, rectangular, pr. with April 17th in hw.]; “Brit. Mus. 1947-269”[white, rectangular, pr.]; “ Rihirbus insulanus sp. n., det. N. C. E. Miller 1939” [white, rectangular, Miller’s hw, with “det. N. C. E. Miller 193” pr.] ( BMNH). The specimen is in poor condition: antennae, right fore, right mid and hind legs, all tarsi except left mid tarsus, and apex of abdomen missing.

Type specimen of Rihirbus discrepans Miller : Holotype: ♀; “ type ” [white with red circle, rounded, pr.]; “Malay Penin: Selangor. Bukit Kutu, 3500 ft, 10.3.1931. H. M. Pendlebury” [white, rectangular, pr. with three hw. numbers]; “Brit. Mus. 1947-269”[white, rectangular, pr]; “ Rihirbus discrepans sp. n., det. N. C. E. Miller 1939” [white, rectangular, Miller’s hw., with “det. N. C. E. Miller 193” pr.] ( BMNH). The specimen is in poor condition: antennae, right fore and mid legs missing.

Other materials examined: 1♂, 2♀, “ China, Guangxi, Dayao Mountain, Jinxiu, Hekou, 24-VII- 2005, 700 m, Huang Xia & Zhao Ping leg.” ( CAU); 1♀, “ China, Yunnan, Jinghong, 19-IV-1984 ” ( CAU); 2♂, “ China, Guangxi, Dayao Mountain, 10-IX-2006, Huang Xia leg.” ( CAU); 1♂, “ China, Guangdong, Shaoguan, Xiaokeng National Forest Park, I– X-2013 ” ( CAU); 1♀, “ China, Guangxi, Longzhou, Nonggang, 18-VIII-2014 ” ( CAU). 4♀, “ Cambodia, Siem, Reap Province, Angkor Thom, IX-2005, VI-2005, Daniel R. Jump leg.” ( ISNB). 1♀, “ Ceylon, Maha Illupalama, VII-1912, J. C. F. Fryer, Reg. 28-xi-1912 ” [this individual totally black except most of seventh connexival segment and eighth connexival segment] ( BMNH). 1♀, “ Ceylon, Maha Illupalama, VII-1912, J. C. F. Fryer” ( BMNH). 1♀, “ Ceylon, Maha Illupalama, VI-(19)12”; “Brit. Mus., 1909-80 ” ( BMNH). 1♀, “ Ceylon, Maha Illupalama, VII-1912, J. C. F. Fryer, Reg. 28,xi,1912” ( BMNH). 1♀, 1 ♂, “ Ceylon, Maha Illupalama, VI-1912, J. C. F. Fryer, Reg. 28,xi,1912”; “no 142”; female with “ Rihirbus trochantericus Stål, M. L. Cook det. 1974” ( BMNH). 1 ♂, “ Ceylon, Maha Illupalama, VI-(19)12” ( BMNH). 1 ♂, “ Ceylon (green)”; “Distant Coll. 1911-383” ( BMNH). 1♀, “ Birmania [= Myanmar, Burma], Teinzo, Fea, Naggio 1886”; “Distant Coll. 1911-383” ( BMNH). 1♀, “Phil Isl/ 42, 22” ( BMNH). 1♀, “ Nepal, Terai, Dhakna Bogh, 23–24.IV.07 ”; “Distant Coll. 1911-383” ( BMNH). 1♀, “Assam, W. F. Badgley, 1906-185” ( BMNH). 1♀, “Assam, Shillong, 4900 ft, 23.VI. (19)06(?), Boy Coll.”; “ Rihirbus trochantericus Stal, Det. D. Ambrose ( BMNH). 1 ♂, “ Laos, Luang Prabang, Sept. 1917, R. V. de Salvaza”; “1918-1” ( BMNH). 1♀, “ Laos, Pak Hang, Nam. Khane R. 28. XI.1918; R. V. de Salvaza” ( BMNH). 1♀, “Haut Mekong, Vien Poukha, 3.V.1918, R. V. de Salvaza” ( BMNH). 1♀, “Nam Ngun [= Nam Ngum, Laos], Haut Mekong, 12.V.1918, R. V. de Salvaza”; “1918-1” ( BMNH). 1♀, “N. Luzon 2000’, Mt. Banahao [= Mt. Banahaw, the Philippines], leg. G. Böttcher”; “Taeuber Coll., B. M. 1949-474” ( BMNH). 1♀, “N. Mindano, Kolambugan, leg. G. Böttcher”; “Taeuber Coll., B. M. 1949-474/ 30.1.(19)15”; “ Rihirbus trochantericus var. rufidorsis Stål, M.

L. Cook det. 1974” ( BMNH). 1♀, “Surigao Mindanao”; “13516”; “Taeuber Coll., B. M. 1949-474”; “ Rihirbus trochantericus var. rufidorsis Stål ” ( BMNH). 1♀, “Surigao Mindanao”; “13515”; “Taeuber Coll., B. M. 1949- 474”; “ Rihirbus trochantericus var. ruficeps Stål ” ( BMNH). 1♀, “Luzon, Laguna, Paete, coll. W. Schultze”; “35172”; “Taeuber Coll., B. M. 1949-474”; “ Rihirbus trochantericus var. ruficeps Stål, M. L. Cook det. 1974” ( BMNH). 1 ♂, “Luzon, Isabela, San Mariano, coll. W. Schultze”; “36722”; “Taeuber Coll., B. M. 1949-474”; “ Rihirbus trochantericus var.” [with the left fore leg glued on the label]?“ Rihirbus trochantericus var. semiflavus Stål, M. L. Cook det. 1974” ( BMNH). 1 ♂, “N. Luzon, 2000’, Mt. Banahao, leg. G. Böttcher”; “Taeuber Coll., B. M. 1949-474/ 27.IV. (19)14”; “ Rihirbus trochantericus Stål v. semiflavus Stål ” ( BMNH). 1 ♂, “Nord Mindanao, Surigao, leg. G. Böttcher/ 18. V. (19)15’; “Taeuber Coll., B. M. 1949-474”; “ Rihirbus trochantericus var.”; “ Rihirbus trochantericus var. semiflavus Stål, M. L. Cook det. 1974” ( BMNH). 1 ♂, “Nord Mindanao, Momungan, leg. G. Böttcher/ 22.II. (19)15”; “Taeuber Coll., B. M. 1949-474”; “ Rihirbus trochantericus Stål var. tibialis Stål ” ( BMNH). 1 ♂, “Br. Sikhim, Tista Valley, Gielle Khola, August. 19, 600 ft, H. Stevens” ( BMNH). 1♀, “ Sarawak, Sg. Tongab Rd., 12-X- (19)62, coll. S. Kuzh”; “Pool of Entomologists Collection. Per C. R. Wallace”; “ Rihirbus sp. M. S. K. Ghauri det. 1963” ( BMNH). 1♀, “Nord-Luzon, Bangui, leg. G. Böttcher” “Taeuber Coll., B. M. 1949- 474”; “ Rihirbus trochantericus var. ruficeps Stål, M. L. Cook det. 1974” ( BMNH). 1♀, “Nord-Mindanao, Momugan, leg. G. Böttcher/ 18.II. (19)15”; “Taeuber Coll., B. M. 1949-474”; “ Rihirbus trochantericus var. ruficeps Stål, M. L. Cook det. 1974” ( BMNH). 1♀, “Nord-Mindanao, Surigao, leg. G. Böttcher/ 13.XI. (19)15”; “Taeuber Coll., B. M. 1949-474”; “ Rihirbus trochantericus var. ruficeps Stål, M. L. Cook det. 1974” ( BMNH). 1♀, Luzon, Prov. Batan, leg. G. Böttcher/ 15.7.(19)14”; “Taeuber Coll., B. M. 1949-474”; “ Rihirbus trochantericus var.”; “ Rihirbus trochantericus var. ruficeps Stål, M. L. Cook det. 1974” ( BMNH). 1 ♂, “N. Palawan, Binaluan, Nov.- Dec.1913, leg. G. Boettcher”; “Taeuber Coll., B. M. 1949-474”; “ Rihirbus trochantericus var.” ( BMNH). 1♂, “N. Palawan, Binaluan, Nov.-Dec.1913, leg. G. Boettcher”; “8229”; “Taeuber Coll., B. M. 1949-474”; “ Rihirbus trochantericus Stål ”; “ Rihirbus famulus Miller, M. L. Cook det. 1974” ( BMNH). 1♀, “S. India, Malabar, Nadungayam, 200’, 16-22-IX-38 / B. M.-C. M. Expdn. to S. India, Sept.–Oct., 1938”; “Brit. Mus. 1939-205” ( BMNH). 1♀, “Himalaya”; “Sharp Coll., 1905-313 [the specimen without abdomen]”; “ Rihirbus sp., M. L. Cook det. 1974” ( BMNH). 1♀, “P. I., Maar Ney, O., 24-VII-1902, Phil. Mus. Coll., Banks”; “ Philippines, C. S. Banks, 1908-228” ( BMNH). 1♀, “ April 1914, F. Hamington, coorg” ( BMNH). 1 ♂, “ Tonkin, Hagiang [= Ha Giang, Vietnam], May 1914, R. V. de Salvaza” ( BMNH). 1♀, “Darjeeling, Nurbong, Bw., 2050 ft, -14, H. Stevens/ 31.8.(19)14”; “?, W. R. webb” ( BMNH). 1♀, “S. India, Kodai Kanal, T. V. Campbell”; “33, 12, Brit. Mus. 1926- 171” ( BMNH). 1 ♂, “Ghal-Malabar, Kavkuv, iii.(19)10, 2000 ft. M. L. Andrewes”; “1910-290”; “ Rihirbus sp., M. L. Cook det. 1974” ( BMNH). 1 ♂, “Upper Burma (?), 6–29 (?)”; “Distant Coll. 1911-383”; “ Rihirbus trochantericus var. testaceus Stål, M. L. Cook det. 1974” ( BMNH). 1 ♂, “Palon (Pegu) [= Hanthawaddy, Myanmar], L. Fea, VIII.IX.(18)87”; “Distant Coll. 1911-383”; “ trochantericus var. Stål”; “ Rihirbus trochantericus var. testaceus Stål, M. L. Cook det. 1974” ( BMNH). 1♀, “Palon (Pegu), L. Fea, VIII.IX.(18)87”; “Distant Coll. 1911-383”; “ Rihirbus trochantericus var. testaceus Stål, M. L. Cook det. 1974” ( BMNH). 1♀, “Saunders, 65 13”; “ Siam ” [= Thailand], ( BMNH). 1♀, “N. Indo China, Muong Bien; 27.IX.1918, R. V. de Salvaza” ( BMNH).

Distribution ( Fig. 31 ). Cambodia, China, India, Laos, Malaysia, Myanmar, Nepal, Philippines, Sri Lanka, Thailand, Vietnam.

Remarks. This reduviid exhibits distinct sexual dimorphism in body shape and colour patterns. The males are much smaller and thinner than females. The abdomen of males is not dilated laterally with sides nearly parallel, while in females the abdomen is distinctly laterally dilated. The pronotal humeral angles are slightly variable with those from individuals from China more rounded.

The colour patterns are very polymorphic in this species and some have been given names resulting in the synonyms noted above.

The tips of fore tibia processes may be sharp or rounded. The functional morphology of the modified fore legs of this reduviid and related species are briefly discussed by Cai & Tomokuni (2003), Weirauch et al. (2011), and Zhao et al. (2014), but detailed observations on the feeding behaviour still remains to be done.

Figures

FIGURE 14. Rihirbus trochantericus Stål 1861, ♀, habitus. Scale bar of 14 = 5.11 mm.

FIGURE 15. Rihirbus trochantericus Stål 1861, ♂, habitus. Scale bar of 15 = 4.90 mm.

FIGURES 16 – 26. Rihirbus trochantericus Stål 1861. 16, 17, ♀; 18 – 26, ♂. 16, head, pronotum and scutellum, antennae removed; 17, fore leg; 18, 19, pygophore; 20, apical part of abdomen; 21, 22, paramere; 23, phallobase; 24 – 26, phallosoma. 19, 20, 26, ventral view; 16, 17, 18, 25, lateral view; 24, dorsal view. Scale bar of 16, 17, 20 = 2.74 mm; of 18, 19 = 1.04 mm; of 21, 22 = 0.42 mm; of 23 – 26 = 0.68 mm.

FIGURES 27 – 30. Rihirbus spp. 27, 28, R. trochantericus Stål 1861, ♀; 29, 30. R. sinicus Hsiao & Ren 1981, ♀. 27, 29, 30, photographed by Hu Li; 28, photographed by Ping Zhao.

FIGURE 31. The geographical distribution map of species in genus Rihirbus. The green circle represents R. sinicus Hsiao & Ren and the red circle represents R. trochantericus Stål.