Coelostoma (Coelostoma) vitalisi Orchymont, 1923

Liu, Hsing-Che, Hu, Fang-Shuo & Fikáček, Martin, 2020, Review of the genus Coelostoma of Taiwan with description of a new species (Coleoptera: Hydrophilidae), Acta Entomologica Musei Nationalis Pragae 60 (1), pp. 155-162 : 160-161

Coelostoma (Coelostoma) vitalisi Orchymont, 1923 ( Figs 2B , 3F )

Coelostoma vitalisi Orchymont, 1923: 418 .

Material examined. TAIWAN: TAIPEI: 4 ( NCHU, HCLC): Neihu District [Hẽdz], 25.0546204°N 121.5843285°E, 29.vi.2018, Bin-Hong Ho leg.

Diagnosis. Body length 4.1–4.7 mm, maximum body width 2.5–2.8 mm. Body oval, strongly convex, dorsal surface black. Labrum black with yellow edges, Elytra surface densely punctate, without traces of series, sutural stria reaching basal half of elytra. Mesofemora with sparse strong setae. Abdominal ventrite V without stout setae.

Male genitalia ( Fig. 2B ): Aedeagus 0.8 mm long; medi- an lobe short and wide, shorter than parameres, apex widely angulate; gonopore large and wide, situated subapically; parameres bent inward, with tuft of setae at apex.

Differential diagnosis. Coelostoma vitalisi is similar to C. fallaciosum and C. vividum; it can be differentiated by the parameres being bent inwards, with a tuft of setae at the apex.

Bionomics. ( Fig. 3F ). All examined specimens were attracted to light; the locality is situated near Keelung River in Taipei City.

Distribution. This species is known from China (Guangdong, Guangxi, Hainan, Shandong, Yunnan), India, Indonesia, Japan, Malaysia, Nepal, Singapore, Sri Lanka, Vietnam ( JIA et al. 2014, HAYASHI 2015, MINOSHIMA 2017). First record for Taiwan ( Fig. 4 ).

Figures

Fig. 2. male genitalia and front view of the head of Taiwanese Coelostoma species.A–F – genitals in dorsal view:A – C. fallaciosum Orchymont, 1936; B – C. vitalisi Orchymont, 1923; C – C. phallicum Orchymont, 1940; D – C. wui Orchymont, 1940; E – C. bhutanicum Jayaswal, 1972; F – C. stultum (Walker, 1858), specimen from Japan: Iriomote Island; G–H – front view of head with labrum: G – C. taiwanense sp. nov., paratype; H – C. fallaciosum.

Fig. 3. Habitat of Coelostoma species.A – Hsinchu County, Zhudong: habitat of C. stultum (Walker, 1858); B – Hsinchu County, Hengshan Township: habitat of C. wui Orchymont, 1940; C – Taichung City, Wufeng District:habitat of C. taiwanense sp.nov.and C. bhutanicum Jayaswal, 1972; D – Hsinchu County, Beipu Township: habitat of C. fallaciosum Orchymont, 1936; E – Yilan County, Jiaoxi Township: habitat of C. phallicum Orchymont, 1940; F – Taipei city, Neihu District: habitat of C. vitalisi Orchymont, 1923. Photos by H.-C. Liu (A–C, F), R. Matsushima (D) and F.-S. Hu (E).

Fig. 4. Map of Taiwan showing distribution of species of the Coelostoma species.