Dicronocephalus diminuata Young

Young, Ronald M., 2012, A Diminutive New Speciesof DicronocephalusHope (Coleoptera: Scarabaeidae: Cetoniinae) from Xizang Zizhiqu (Tibet Autonomous Region), China, with a Distributional Analysis of the Genus, The Coleopterists Bulletin 66 (3), pp. 203-208 : 203-207

Dicronocephalus diminuata Young , new species ( Figs. 2–4 , Table 1)

Type Series. Holotype male, allotype female, six male and four female paratypes labelled “ XIZANG ZIZHIQU (Tibet Autonomous Region): Lingze Co: Lingze 29.51N 96.10E, Famudi,VII-l/ 19-2007, S.Yuntai & A. Dehong, collectors” . Holotype, allotype, and two male paratypes deposited in the Bishop Museum, Honolulu, Hawaii. Four male and four female paratypes retained in the author’ s collection .

Description. Holotype ( Figs. 2–4 ). Length excluding clypeal extensions 19.5 mm, length including clypeal extensions 25.0 mm, width at anterior humeri 9.0 mm. Head: Frons black in center, tan bordering eyes; clypeus modified into pair of forward directed projections (termed “antlers” in the Asian literature), projection: head ratio 2.5:1; projections with an outwardly directed tooth just past midlength, distal tip bifid. Between projections, front of clypeus modified into an oval, vertical plate covering mouthparts. Pronotum: Widest at midlength, narrowing anteriorly and posteriorly, with tan tomentum; 2 shining black lines directed from front to beyond midlength; raised borders laterally and ventrally. Scutellum: Tan, long, recumbent hairs cover 2/3 of surface. Elytra: Covered with same tan tomentum as pronotum; humeral umbone forms a black, distinctive Y-shaped ridge, posterior umbones shiny black ridges elongated anteriorly. Legs: Femora brown on inner surfaces, meso- and metafemora with tan scales and short, thick hairs on outer surface; protibiae weakly tridentate, black dorsally, brown ventrally; tarsal segments yellow with black distal tips; ratio of protibial length to protarsal length 1.2:1; claws equal in size. Sternites: Abdominal sternites brown, thoracic sternites with tan tomentum as on dorsum, (color partially damaged with what appears to be white glue), long, recumbent hairs on all 3 segments. Parameres: As in Fig. 2 .

Allotype female ( Fig. 3a ). Length 19.0 mm, width at anterior humeri 10.0 mm. Characters like that of male except: Clypeus: Forward directed projections and vertical oval structure covering mouthparts absent, concave front and sharply curved lateral sides form 2 anterolateral points, inner surface covered with coarse, dense punctures. Elytra: Tomentum thinning on disc, suggesting band between humeri on each elytron; underlying color of elytra tan. Legs: Protibia sharply tridentate. Pygidium: Much less bulbous than male, tomentose in anterolateral corners, disc with long, erect hairs. Sternites: Without tomentum, reddish brown except thoracic segments which are black.

Paratypes. Length 16–21 mm, width at anterior humeri 8–11 mm. Suite of characters and their variations as in the holotype and allotype.

Etymology. The name of this species refers to its small size compared to some of its continental congeners ( Fig. 3 ).

Diagnosis. Dicronocephalus diminuata is distinguished from all other Dicronocephalus species by the combined characters listed in Table 1 and its occurrence in eastern Tibet, with which it occurs sympatrically with Dicronocephalus dabryi (Auzoux) . These two species may be separated by the character states compared in Table 1 and especially by their dissimilar metasternal processes ( Fig. 4 ) and parameres ( Fig. 2 ). Dicronocephalus dabryi is distinguished from all other Dicronocephalus species by the distinct black spot at midlength on the elytra.

Distribution of Dicronocephalus . The four taxa endemic to Taiwan are Dicronocephalus shimomurai Kurosawa , Dicronocephalus uenoi Kurosawa , Dicronocephalus yui Kurosawa , and Dicronocephalus wallichii bourgoini Pouillaude ( Fig. 5 ). The four other species widely spread across China and southeastern Tibet ( Fig. 1 ) include records from Jilin, Liaoning, Shansi, Gansu, Qinghai, Guangxi, Guangdong, Hong Kong, Hainan, Sichuan (Szechwan), Yunnan, and Xizang (Tibet) (Sakai and Nagai 1998; my collection). The genus extends into the tablelands of southeastern Tibet where it is confirmed at Linzhi at 29.51°N 96.10°E near one of the headwaters of the Brahmaputra River. The western and northern limits of that extension remain unknown, but there are numerous Tibetan localities waiting to be placed on a distribution map by an investigator conversant in the Sino-Tibetan language. Dicronocephalus species occur in the Himalayan Kingdom of Nepal ( Pouillaude 1914b) and in Sikkim, Assam, and the northern Indian District of Darjiling at 27.02°N 88.20°N which joins the state of Sikkim on its southern border ( Arrow 1925). Although there are no records in the literature, Dicronocephalus species surely occur in Bhutan. This absence of records in Bhutan is almost certainly due to a lack of collecting efforts rather than beetles.

There are no records of Dicronocephalus from the lowlands of the Indian subcontinent or Pakistan ( Arrow 1925). There are, however, records from central Laos at Thakek (17.22°N 104.50°E) along the Mekong River forming the Thai/Laotian border (author’ s collection). There are also records from northern montane Thailand (Sakai and Nagai 1998) and northern Vietnam (Dong Van at 23.21°N 105.23°E and Bao Lac at 22.58°N 105.40°E ( Pouillaude 1914a). Krajic (1998) recorded Dicronocephalus wallichii wallichii Hope from Myanmar and Dicronocephalus wallichii bowringi Pascoe from Hainan Island (Hainan) in the Gulf of Tonking ( Tonkin). Both of these records appear to be singletons and are subject to confirmation.

Pouillaude (1914a) recorded Dicronocephalus adamsi Pascoe at Chosun, Korea (40.47°N 124.44°E) and Medvedev (1972) reported the collection of four D. wallichii bowringi in a forest nursery 40 km (direction not given) from Vladivostok in the then-USSR Maritime Territory. This marks the second-most northern record of a Dicronocephalus species (43.09°N) at Vladivostok ( Fig. 1 ); the northern-most record is from Xi-Shan’ (43.54°N), Jilin Province, China ( Fig. 1 ). The eastern-most record I have for the genus is Vladivostok at 131.53°E. The Vladivostok record is the first verified occurrence of a species of Goliathini in Russia.

I hypothesize that the high xerophytic shrub desert of Inner Mongolia effectively limits expan- sion of Dicronocephalus to the north. As this genus is primarily limited to mountainous areas, I also hypothesize it is limited to the south by the dramatic geological/topographical fall away of Southeast Asia from the Himalayan massif to the tropical southern lowlands and, finally, seacoast. This genus, though not particularly speciose, is marked by a broad range. From western Nepal to Vladivostok is about 2,250 km, and from central Laos to Vladivostok is about 1,580 km. In sumary, Dicronocephalus thrives within the latitude/longitude limits noted below and as shown in Fig. 1 .

East: 131.53°E Vladivostok , Russia

West: 80.58°E Silgarhi-Doti , west Nepal

North: 43.54°N China: Jilin Prov: Xi-Shan

South: 17.22°N Thaktek , Laos on the Mekong River border of Laos / Thailand

Distribution Records. Distribution records for each species are detailed below. When known, latitude and longitude values are included. Authorities

Dicronocephalus dabryi Dicronocephalus diminuata

1. Elytral color wine red with 2 black dots near midlength 1. Elytral color tan without black dots near midlength

2. Tarsal segments black 2. Tarsal segments yellow-brown with black apices

3. Broad longitudinal pronotal bands reach posterior border 3. Narrow longitudinal pronotal bands not reaching posterior border

4. Metasternal process between mesocoxae flat ( Fig. 4 ) 4. Metasternal process between mesocoxae cone-shaped ( Fig. 4 )

are given for localities reported in the literature. Double slashes (//) separate localities. Chinese Provinces are composed of counties. Acronyms for sources of specimens are as follows:

BPBM Bernice P. Bishop Museum, Honolulu, Hawaii

BMNH British Museum Natural History, London, UK

BMNHA British Museum Natural History, G. J. Arrow Collection, London, UK

MNHN Muséum national d’ Histoire naturelle, Paris, France

MNHNO Muséum national d’ Histoire naturelle, Oberthur Collection, Paris, France

RMYC Ronald M. Young Collection, Cody, Wyoming

Dicronocephalus adamsi Pascoe. CHINA: Chung King [Chongqing]// Daba Shan// Emei Han Yuan Co.: Wu He Shi, Jinfo Shan// Gansu Prov: Keng Xiang Co.: Tangtien// Gansu Province :

Min-Shan, Su Tchuen// Guizhou Province: Meitan Co.: Yanzing// Hpoung-Syou-Ouen// Jilin Province: Yang City// Mt. Chang Bai Shan// Mt. Pong Shan ( Pouillaude 1914a; BMNH; MNHNO); Sichuan: Mt. Jinfo-shan// Shanxi: Mt. Zhongtiao (Sagai and Nagai 1998); Xizang (Tibet): Maenia (Moenia)// Siao-Lou-Lou Chen// Se-Pin-lou- Chan// Su-Tchuen// Siao-Lou// Ta-Chien// Ta- Tsien-Lou// Ta-Tong-Kio// Shangzou County: Sha ha Zhi// Youyang Co.// Ya-Tcheou ( Legrand 2005; MNHN); Linzhi Co.: Famudi// Liaoning Province: Mt. Wulong (RMYC). VIETNAM: Dong Van (ca. 23.21°N 105.23°E)// NW of Bao Lac (23.21°N 105.40°E) (RMYC). KOREA: Chosun at Hpoung-Syou Ouen (40.47°N 125.45°E) (RMYC); Sinan Co.: Mt. Ginfu Shan// Mt. Hua Wenhuan// Moupin (Bao Xing)// Phot// Ta Tsien Lou.

Dicronocephalus bieti Pouillaude. CHINA: Tsekou// Oui-Sy ( Pouillaude 1914a)// Yunnan Prov: Xishan (43.54°N 127.20°E)// Kunmin (23.04°N 102.41°E ( Pouillaude 1914a, 1914b). This species was considered a synonym of D. dabryi by Pouillaude (1914a).

Dicronocephalus dabryi (Auzoux) . CHINA: Han Keou (Hankou)// Mou Pin// Siro-Lou//Su- Tchuen//Ta-Tsien-nan ( Pouillaude 1914b); Xizang (Tibet): Siao-chen// SePin -Lou-Chan// Siao-Lou// Su-Tchuan// Tatto// Yen-Kalo ( LeGrand 2005, BMNH, MNHNO).

Dicronocephalus diminuata Young. CHINA: Xizang (Tibet): Linzhi Co: Linzhi (29.51°N 96.10°E) ( BPBM; RMYC) .

Dicronocephalus shimomurai Kurosawa. TAIWAN: Kao-Hsiung ( Kurosawa 1986); Taoyuan, Palin (Sakai and Nagai 1998); Hualien: Lo-Sau ( RMYC); Tao-Yuan-Hsieng (25.00°N 120.54°E ( Kurosawa 1986).

Dicronocephalus uenoi uenoi Kurosawa. TAIWAN: Fen-chi-hu ( Kurosawa 1968)

Dicronocephalus uenoi katoi Kurosawa. TAIWAN: Puli, Nant’ ou (23.54°N 120.42°E)// nr. Mt.Kantozan and environs of Masha// Banta-sha ( Kurosawa 1968)

Dicronocephalus wallichii bourgoini Pouillaude. TAIWAN: Kaohsiung // Kosempo// Liukuei// Kenting// Kachsuing// Kew-shan// Tar-yuan// Pintung ( Pouillaude 1914b; Kurosawa 1968; Sakai and Nagai 1998; RMYC).

Dicronocephalus wallichii bowringi Pascoe. CHINA: Guangxi Province: Guilin (25.21°N

110.11°E)// Hainan (19.00°N 109.30°E)// Sichuan: Mt. Emeishan // Yunnan Province : Funing ( 32.05°N 108.08°E (Sakai and Nagai 1998; RMYC). RUSSIA: Maritime Territory, Vladivostok (43.09°N 131.53°E) ( Medvedev 1972). VIETNAM: (no specific record). TAIWAN: (no specific record). THAILAND: Muang Chi Rai (19.56°N 99.51°E)// Wiang Pa Pao (19.21°N 99.29°E) (Sakai and Nagai 1998) .

Dicronocephalus wallichii wallichii Hope. CHINA: Guangdong Province: Shilong (23.05°N 113.50°E). INDIA: Assam State // British Bootan// Chirra Boongee// Darjiling (27.02°N 88.20°E)// Kurseong// Maria-Basti// Maghdaya State: Khasi Hills District ( Arrow 1925; Kurosawa 1968); Sikkim: Gantok (BMNHA). THAILAND: Chiang Mai (18.48°N 98.59°E)// Chiang Rai (19.56°N 99.51°E)// Wiang Pa Pao (19.21°N 99.29°E) (RMYC). VIETNAM: Sapa, Vinh Phu, Mt Tarn Dao (Sakai and Nagai 1998).

Dicronocephalus yui yui Kurosawa : TAIWAN: Puli ( Kurosawa 1968).

Dicronocephalus yui cheni Kurosawa. TAIWAN: Tongtze//Koo-Hsiung ( Kurosawa 1986)// Kaohsiung, Liukuei (Sakai and Nagai 1998).

Figures

Fig. 2. Parameres of Dicronocephalus dabryi (left) and Dicronocephalus diminuata (right).

Fig. 3. Dicronocephalus species. a) D. diminuata, allotype female, length 19 mm, b) D. diminuata, holotype male, length including clypeal extensions = 25 mm, c) D. wallichii bowringi, typically sized male from Yunnan Province, southwestern China, length including clypeal extensions = 38 mm.

Fig. 4. Metasternal projections of Dicronocephalus diminuata (left) and Dicronocephalus dabryi (right). a = metasternal projection, b = mesofemur, c = mesotrochanter.

Fig. 5. Heads of Dicronocephalus species. a) D. wallichii wallichii (northern Thailand), b) D. wallichii wallichii (northern Vietnam, Mt. Tarn Dao), c) D. wallichii bowringi (Sichuan), d) D. wallichii bourgoini (Taiwan), e) D. bieti (Yunnan), f) D. dabryi (Shaanxi), g) D. adamsi (Shaanxi, Sichuan), h) D. shimomurai (Taiwan), i) D. yui yui (central Taiwan), j) D. yui cheni Kurosawa (southern Taiwan), k) D. uenoi uenoi Kurosawa (southern Taiwan), l) D. uenoi katoi Kurosawa (central Taiwan).

Fig. 1. Distribution of Dicronocephalus. The wide black line marks the border of China. A = West Bengal, India, B = Nepal, C = Sikkim, India, D = Bhutan, E = Bangladesh, F = Assam, India, G = Myanmar, H = Thailand, I = Laos, J = Vietnam, K = Yunnan, China, L = Taiwan, M = Hainan, China, N = Guangxi, China, O = Guangdong, China, P = North Korea, Q = Vladivostok, Russia, R = Jilin, China, S = Shaanxi, China, T = Gansu, China, U = Qinghai, China, V = Xizang Zizhiqu (Tibet Autonomous Region), China, W = Russia.