Tytthus chinensis ( Stal )

Henry, Thomas J., 2012, Revision of the Plant Bug Genus Tytthus (Hemiptera, Heteroptera, Miridae, Phylinae), ZooKeys 220, pp. 1-114 : 17-21

Tytthus chinensis ( Stal) Figs 9, 1055 –62121– 124

Capsus chinensis Stål 1860: 258 (orig. descrip.); Atkinson 1890: 107 (cat.).

Cyrtorhinus chinensis : Reuter 1903: 22 (descrip.); Hsiao 1942: 255 (key).

Cyrtorhinus annulicollis Poppius 1915: 65 (orig. descrip.). Synonymized by Carvalho and Southwood 1955: 20.

Cyrtorhinus elongatus Poppius 1915: 65 (orig. descrip.). Synonymized by Carvalho and Southwood 1955: 20.

Cyrtorhinus riveti Cheesman 1927: 94 (orig. descrip.); Knight 1935: 204 (list); Usinger 1939: 270 (key, host), 1946: 79 (note), 1951: 4 (key). Synonymized by Carvalho and Southwood 1955: 20.

Tytthus chinensis : Carvalho and Southwood 1955: 19 (key, descrip.) Carvalho 1958: 157 (cat.); Tomokuni et al. 1993: 307 (note, photo); Schuh 1995: 248 (cat.); Cassis and Gross 1995: 204 (cat.); Kerzhner and Josifov 1999: 441 (cat.); Yasunaga et al. 2001: 182 (note, photo).

Tytthus koreanus Josifov and Kerzhner 1972: 171 (orig. descrip.); Kerzhner 1988: 840 (key); Schuh 1995: 249 (cat.); Kerzhner and Josifov 1999: 441 (cat.); Kwon et al. 2001: 184 (cat.). syn. n.

Diagnosis.

This species is very similar to Tytthus parviceps in general size and in sharing the dark base of each tibia, dark antennae with the apex and base of segment I pale, and short, erect, brushlike setae on antennal segment II. Tytthus chinensis almost always has a uniformly black pronotum (Figs 9, 10) or the pronotum with only weak indications of yellow around the calli, and the endosoma (Fig. 123) is C-shaped, whereas Tytthus parviceps has the anterior one third to half of the pronotum around the calli almost always extensively pale yellow (Figs 32, 34) and the endosoma appears more distinctly S-shaped (Fig. 170). All known specimens of both species are macropterous.

Three other exclusively New World species, Tytthus entrerianus , Tytthus femoralis , and Tytthus mexicanus , also have fuscous “knees,” a character that distinguishes them from all other species of the genus, except. Tytthus chinensis and Tytthus parviceps as noted above and in the key. All three, however, lack the brushlike setae on antennal segment II and the apical one third to two thirds of the hind femora of these species are infuscated.

Description.

Male (n = 15) (Fig. 9): Length to apex of hemelytron 2.18-2.60 mm, length to base of cuneus 1.65-1.88 mm, width across hemelytra 0.79-0.93 mm. Head: Length 0.27-0.29 mm, width across eyes 0.56-0.58 mm, interocular width 0.29-0.30 mm. Labium: Length 0.72-0.94 mm. Antenna: Segment I length 0.24-0.26 mm, II 0.78-0.82 mm, III 0.43-0.51 mm, IV 0.30-0.32 mm. Pronotum: Length 0.29-0.32 mm, basal width 0.69-0.80 mm.

Coloration: Uniformly fuscous to black, with a large, yellow, interocular spot touching inner margin of each eye, spots nearly contiguous in some individuals; eyes fuscous to dark reddish brown. Labium: Uniformly pale yellow, except of brown apical half of segment IV. Antenna: Segment I black, with base and apex narrowly pale yellow; segments II–IV uniformly fuscous to black. Pronotum: Usually uniformly black, anterior third around calli frequently weakly tinged with yellow, and less often entire anterior third yellow; posterior half uniformly fuscous to black. Mesoscutum: Uniformly yellowish brown to fuscous. Scutellum: Uniformly fuscous to black. Hemelytron: Uniformly translucent yellow to whitish. Ostiolar evaporative area: Yellowish, with central area of auricle invaded with fuscous, sometimes entirely fuscous. Ventral surface: Anterior half of proacetabula often yellow, propleura, pro- and mesosterna, and metapleura fuscous; abdomen varying from largely yellowish, with only genital capsule fuscous or black to largely fuscous with only ventral area pale. Legs: Uniformly generally yellow; procoxae uniformly yellow, meso-and metacoxae dark brown at bases, yellow beyond; femora yellow, often tinged with orange; tibiae yellow, bases broadly fuscous; tarsi and claws yellowish.

Structure, texture, and vestiture: Head: Weakly shiny, impunctate; buccula slender, extending posteriorly, ending near level with hind margin of eye; thickly set with short to relatively long semierect setae, especially on frons. Labium: Extending to apices of meso- or bases of metacoxae; segment I extending beyond base of head to xyphyus just before procoxae. Antenna: Segment I set with short, recumbent setae and two, long, subapical, bristlelike setae; segment II thickly set with short, recumbent setae, intermixed with row of longer, erect setae (Fig. 59) along ventral surface. Pronotum: Anterior angles rounded; lateral margins weakly concave, gradually widening to rounded posterior angles; posterior margin weakly sinuate. Mesoscutum: Weakly shiny, impunctate; set with a few scattered, semierect setae. Scutellum: Weakly shiny, impunctate; equilateral; set with a few scattered recumbent and semierect setae. Hemelytron: Macropterous, cuneus and membrane fully developed, extending posteriorly well beyond apex of abdomen; evenly set with relatively long, recumbent setae.

Male genitalia: Left paramere (Fig. 121): Mitt-shaped; right arm long, brown; left arm short, spinelike. Right paramere (Fig. 122): Oval. Endosoma (Fig. 123): C-shaped, apex blunt. Phallotheca (Fig. 124): Relatively slender, strongly bent (C-shaped), apically acute.

Female (n = 15) (Fig. 10): Length to apex of hemelytron 2.50-2.78 mm, length to base of cuneus 1.86-2.00 mm, width across hemelytra 0.90-0.96 mm. Head: Length 0.29-0.30 mm, width across eyes 0.60-0.62 mm, interocular width 0.30-0.32 mm. Labium: Length 0.90-0.94 mm. Antenna: Segment I length 0.26-0.27 mm, II 0.45-0.46 mm, III 0.26-0.27 mm, IV 0.29-0.30 mm. Pronotum: Length 0.29-0.30 mm, basal width 0.80-0.85 mm.

Hosts.

Usinger (1939) reported Tytthus chinensis (as Cyrtorhinus riveti ) feeding on the eggs of Sogata ochrias (Kirkaldy) [ Delphacidae ] on Sporobolus virginicus (L.) Kunth [ Poaceae ] and Nilaparvata lugens ( Stål) [ Delphacidae ] on rice ( Oryza sp.) in Guam. He also recorded this species from Bermudagrass, Cynodon dactylon (L.) Pers., in Samoa, and Tradescantia sp. [ Commelinaceae ] in Tahiti.

Distribution.

This species has been reported from central and southeastern China, Japan, Taiwan, and Australia, India, and the Indo-Pacific Region (Caroline Islands, Childers Island, Cook Islands, Fiji, Gilbert Island, Indonesia, Mariana Islands, Marshall Islands, New Caledonia, New Hebrides, Papua New Guinea, Philippine Islands, Pitcairn Island, Rapa Island, Ryuku Islands, Samoa, Society Islands, Solomon Islands, South Korea, Swain Islands, and Tonga Islands) ( Schuh 1984, 1995; Kerzhner and Josifov 1995; Cassis and Gross 1995). Based on specimens in the USNM, most or all records reported by Schuh (1984) from India and Sri Lanka should be applied to Tytthus parviceps ; Schuh’s (1984) record from Hawaii is based on two specimens intercepted on international commerce at Honolulu (without origin indi cated).

Based on specimens examined, I now also have records of this species from Cambodia, Guadalcanal, Guam, Saipan, and Tinian Island.

Discussion.

Carvalho and Southwood (1955), after consulting with D. R. Malaise at the Swedish Museum of Natural History in Stockholm, reported that the type of Capsus chinensis Stål (1859) must be considered lost. Based on Stål’s original description and study of other types, they concluded that Cyrtorhinus elongatus Poppius and Capsus annulicornis Poppius (both in Deutsches Entomologisches Institut) and Capsus riveti Cheesman (BMNH) are junior synonyms. They characterized Tytthus chinensis as "the smallest species of Tytthus and is distinguished by its black pronotum and scutellum, the dark bases of the tibia and the small size." I have studied the type of Tytthus riveti and agree that it follows the concept of Tytthus chinensis outlined by Carvalho and Southwood (1955) and Carvalho (1956), including a uniformly dark pronotum.

In addition, Kerzhner and Josifov (1995) suggested that Tytthus koreanus Josifov and Kerzhner (1972) could be a junior synonym of Tytthus chinensis . Although I have not examined type material of Tytthus koreanus , the description and figures presented in the original description indicate that this species is based on pale specimens having the calli or anterior third of the pronotum yellow to brownish yellow. Josifov and Kerzhner (1972) did not indicate if they observed specimens with entirely dark pronota. I also have studied a male and two females from South Korea, lent by Dr. Seunghwan Lee (SNU), that agree with the pale color form of Tytthus chinensis having only the calli and mesoscutum tinged with dull brownish yellow. As a consequence, I consider T. koreanus and the material from Dr. Lee conspecific with that of Tytthus chinensis .

Although most material of what I consider to be Tytthus chinensis has a uniformly fuscous to black pronotum, varying degrees of yellow are present on the calli and anterior third of the pronotum on some specimens from eastern Asia, throughout the Indo-Pacific, and Australia, which may cause confusion with Tytthus parviceps that also has yellow on the anterior area of the pronotum. Nevertheless, I consider all material from eastern Asia (including Korea and Japan), Indonesia, Malaysia, Australia, New Guinea, and the South Pacific Islands Tytthus chinensis based on the dark pronotum in most specimens and C-shaped endosoma. However, because of the strong morphological similarity between T. “chinensis” and T. “parviceps,” an effort will be made to accumulate fresh material worldwide for conducting a phylogeographic analysis of species limits within this complex using mitochondrial cytochrome oxidase 1 (COI) sequence data in cooperation with colleagues S. Scheffer and M. Lewis (Systematic Entomology Laboratory, ARS, USDA, Beltsville, Maryland, USA).

For the time being, I am restricting the distribution of Tytthus parviceps that has the anterior third of the pronotum broadly yellow (but certain specimens within populations can have a uniformly dark pronotum) to southern Asia (India, Srilanka, Pakistan, Vietnam, Thailand), the Middle East, Afrotropical and Neotropical regions, and subtropical United States. A few specimens from the Indo-Pacific (e.g., Guam), Australia, Cambodia, and other eastern Asian countries are externally indistinguishable from typical specimens of Tytthus parviceps from Africa and the New World. As noted above, the endosoma of typical Tytthus chinensis is C-shaped, whereas this very simple structure in African and New World specimens of Tytthus parviceps is usually S-shaped. Until additional collections can be made and additional DNA sequencing can be conducted on these populations, the strongly yellow phenotypes within populations of Tytthus chinensis must regarded convergent color forms.

Type material examined.

To ensure nomenclatural stability, I designate the following female as the lectotype of Cyrtorhinus riveti : Label 1 (circular label with orange ring) “Type”; label 2, "Tahiti: Nr. Papeete[,] Mar.-Apr.[,] Miss Cheesman"; label 3 (handwritten), " Cyrtorhinus riveti Cheesman"; label 4, "St. George Exp.[,] BM 1925- 235"; label 5 (00085518 (BMNH)."

Other specimens examined.

AUSTRALIA: New South Wales: Deewhy Beach dunes, 28 Jan 1957, W. W. Wirth, 1 ♂ (00162347), 1 ♀ (00167399) (USNM). Narrabri, 25 Jan 1960, M. Nikitin, by light, 1 ♀ (BMNH). Northern Territory: Katherina River, 14.5°S, 132.25°E, 12 Nov 1979, Zaytsev, 1 ♂ (00235059) (ZISP). Katherine, 14.467°S, 132.267°E, 17 Nov 1990, W. F. Chamberlain, Light Trap, 1 ♂ (00167391) (USNM). Queensland:Cape York Islands Co.: Banaga, N. Cape York, gum forest, Jan 1958, P.F. Darlington, 1 ♂ (00409566) (KU). Gracemere, 05 Nov 1990, W. F. Chamberlain, Light Trap, 1 ♂ (00167392), 1 ♀ (00167398) (USNM). Mossman, 16.47°S, 145.37172°E, 36 m, 11 Nov 1990, W. F. Chamberlain, 1♀ (00167400), Light Trap, 2 ♂♂ (00167389, 00167393) (USNM). Mt. Berryman Rd., Laidley, 05 Dec 1990, W. F. Chamberlain, Light Trap, 2 ♂♂ (00167395, 00167396) (USNM); 06 Dec 1990, W. F. Chamberlain, Light Trap, 1 ♂ (00167397) (USNM); 07 Dec 1990, W. F. Chamberlain, Light Trap, 1 ♂ (00167394) (USNM). Mt. Isa, 15 Nov 1990, W. F. Chamberlain, Light Trap, 1 ♂ (00167390), 1 ♀ (00167402) (USNM). Tozer Range, Cape York Peninsula, 12.7833°S, 143.2167°E, 122 m, 01 Jul 1948 - 05 Jul 1948, G. M. Tate, 1♀ (00167403) (USNM). BISMARCK ARCHIPELIGO: New Britain, Keravat, 17 Nov 1957, J. Smart, 1 ♂ (BMNH). CAMBODIA: Kampong Seila Dist. National Road, Pk 135, Boeung Trach Village, Picnic Resort, 11-12 Nov 2010, L. T. & R. K. Duval, S. H. Lee, W. Lee, & S. Kim, 1 ♂, 1 ♀ (SNU). FIJI:Viti Levu: Suva, 02 Mar 1985, Koebele Collection, 1 ♂ (00162346) (USNM). none, 13 Apr 1959, Haw, 2 ♀♀ (00162356, 00162357) (USNM). GUAM:Mariana Is.: Agana, port, 15 Aug 1945, H. S. Dybas, 1 ♀ (00162351) (USNM). Asan Village, Asan River at Rt. 1, 13.47278°N, 144.7135°E, 08 Jun 2008, R. S. Zack, 1 ♂ (00410393) (WSU). Asan Village, Rt. 1, Asan River outlet at Nino Perdito church, 13.47286°N, 144.71655°E, 13 Mar 2011, R. S. Zack, 38 ♂♂ (00410329 - 00410366), 26 ♀♀ (00410367 - 00410392) (WSU). Mangilao Village, University of Guam campus, Marine Biology Lab area, 13.42856°N, 144.79855°E, 03 Aug 2005, R. S. Zack, 1 ♂ (00410396) (WSU). Mangilao Village, University of Guam campus near Marine Lab dormitory field, 13.42888°N, 144.80083°E, 30 May 2008, R. S. Zack, 1 ♂ (00410395) (WSU). Mongmong-Toto-Maite Village, Pipeline Rd. off of Rt. 33, 13.45678°N, 144.76826°E, 06 Jun 2008, R. S. Zack, 1 ♂ (00410394) (WSU). Pt. Oca, 13.503°N, 144.771°E, 23 Jun 1945, G.E. Bohart and J.L. Gressit, 1 ♀ (00162354) (USNM); 16 Jul 1945, G.E. Bohart and J.L. Gressit, 1 ♂ (00162342), 1 ♀ (00162350) (USNM); 20 Dec 1945, J. L. Gressitt, Light Trap, 1 ♂ (00095351) (AMNH), 1 ♂ (00162341), 2 ♀♀ (00162352, 00162353), Light Trap, 1 ♀ (00162355) (USNM), 2 ♂♂ (00410279, 00410280), 2 ♀♀ (00410277, 00410278) (WSU). INDONESIA: Sulawesi: Utara, Dumoga-Bone N. P., 2 ♂♂ (BMNH). MICRONESIA:Ngulu Atoll: Ngulu Island, 03 Oct 1952, N. L. H. Krauss, 2 ♀♀ (00162358, 00162359) (USNM). NEW HEBRIDES: Erromana, Jul 1930, L. E. Cheesman, B. M. 1930-477, 2 ♂♂ (BMNH). Malekula, Malua Bay, May 1929, Miss L. E. Cheesman, B. M. 1929-410, 1 ♀ (BMNH). NORTHERN MARIANA ISLANDS:Rota Island: (Luta), "Josen Cristina Country" Park, 14.11836°N, 145.1857°E, 14 May 2004, R. S. Zack, 2 ♂♂ (00410401, 00410402) (WSU). (Luta), farm plots/stream area, 14.11851°N, 145.17846°E, 14 May 2004, R. S. Zack, 1 ♂ (00410403) (WSU). Saipan: 1 - 2 mi. E. of Tanapag, 10 Jan 1945, H. S. Dybas, 1 ♀ (00162349) (USNM). Saipan: Garapan, sweeping beach, 15.19458°N, 145.71678°E, 20 Jun 2006, R. S. Zack, 3;m (00410398 - 00410400) (WSU). Saipan; Kagman, Kagman Exp. Farm, Northern Marianas College, 15.17503°N, 145.77166°E, 19 Jun 2006, R. S. Zack, 1 ♂ (00410397) (WSU). Tinian: Tinian Island, 15.02333°N, 145.63305°E, 11 Jun 1946, H. K. Townes, 3 ♂♂ (00162343 - 00162345) (USNM). SAMOA:Tutuila Island: Pago Pago, 04 Sep 1923, Swezey and Wilder, 1 ♂ (00162340) (USNM); 20 Sep 1923, Swezey and Wilder, 1 ♀ (00162348) (USNM). Tutuila, 1930, Swezey & Wilder, 1 ♂, 1 ♀ (BMNH). Upolu, Apia, 9 Dec 1923, Swezey & Wilder, on Bermuda grass, 2 ♂♂ (BMNH). SOLOMON ISLANDS:Guadalcanal: Guadalcanal, 29 Mar 1944, L. J. Lipovsky, 1 ♀ (00409562) (KU); 04 Apr 1944, L. J. Lipovsky, 1 ♀ (00409563) (KU); 19 Apr 1944, L. J. Lipovsky, 1 ♂ (00409564) (KU). Ilu, 8 Apr 1963, M. Mquillan, 2 ♂♂ (BMNH). Kukun, 17 Dec 1962, P. Greenslade, 1 ♂ (BMNH). Nr. Honiara, 25027 Jun 1965, Roy. Soc. Exped. B.M. 1966-1, at light and sweeping around pond, 2 ♀♀ (BMNH). SOUTH KOREA: Gyeongsangbuk-do, Is. Ulleung, 30-31 Aug. 2010, L. T. & R. K. Duwal, 1 ♂, 2 ♀♀ (SNU). THAILAND:Bangkok: Bangkapi at light, 15 Dec 1951, M. E. Griffith, 1 ♂ (00409565) (KU).