Sphaeroderma jungchani sp. nov.

Figs 7A, C, D; 8G-I, 10

Types.

Holotype ♂ (TARI). Taiwan: Pingtung, Nanjenhu (南仁湖), 31.III.2011, leg. J.-C. Chen. Paratypes. 3♂ (BMNH: 2♂; TARI: 1♂), same data as holotype; 1♂ (TARI), same but with “11.IV.2011”; 1♂ (TARI), same but with “3.IV.2023” .

Description.

Length 2.9-3.3 mm, width 2.1-2.3 mm. Body color (Fig. 8G-I) blackish-brown; head and prothorax reddish-brown; antennae blackish-brown except three basal antennomeres reddish-brown; elytron with one large white round spot, elytra basally and apically reddish-brown; abdominal ventrite V reddish-brown; legs dark brown but front legs paler. Antennae filiform in males (Fig. 7A), apex of antennomere III angular, much smaller than IV, length ratios of antennomeres I-XI 1.0:0.5:0.4:0.5:0.6:0.6:0.7:0.7:0.7:0.7:1.1, length to width ratios of antennomeres I-XI 2.9:1.7:1.6:2.1:2.3:2.1:2.1:2.2:2.1:2.1:3.4. Pronotum 1.7-1.8 × wider than long, disc with coarse, scattered punctures, mixed with fine punctures; lateral margins slightly rounded; anterolateral callosity protruding forward; posterolateral callosity poorly developed. Elytra 1.1-1.2 times longer than wide, sides widely rounded; disc with punctures arranged into longitudinal striae but mixed with additional punctures; humeral calli well developed. Abdominal ventrite V with median internal ridge in males. Antennal calli transverse, with supracallinal sulci well developed. Male genitalia: aedeagus (Fig. 7C, D) narrow in dorsal view, 5.2 × longer than wide; parallel-sided, apex narrowly rounded, strongly widened at apical 1/6; almost straight at middle in lateral view and narrow, apex sinuate; ostium membranous and with long median longitudinal sclerite; internal sac with one pair of curved sclerites.

Females unknown.

Diagnosis.

Adults of S. jungchani sp. nov. and S. flavonotatum Chûjô are easily separated by the color surrounding the single pair of large white spots on the elytra: surrounded by reddish-brown elytra in S. jungchani; black borders surrounding spots on reddish-brown elytra of S. flavonotatum sp. nov. Middle tibiae of S. jungchani sp. nov. males not modified (sexually dimorphic middle tibiae in S. flavonotatum). Aedeagus narrow in S. jungchani sp. nov., 5.2 × longer than wide, and thin in lateral view (Fig. 7C, D) [aedeagus broad, 3.6 × longer than wide, and thick in lateral view in S. flavonotatum (Fig. 9C, D)].

Host plants.

Chloranthus oldhamii Solms ( Chloranthaceae).

Etymology.

The species is named for Mr Jung-Chan Chen (陳榮章) for collecting type specimens of this new species.

Distribution.

Only known in type locality, Nanjenhu (南仁湖), in southern Taiwan (Fig. 10). This new species is allopatric from S. flavonotatum .