Ennearthron jizushanense, Li & Mo & Mao & Xu, 2024

Li, Nan, Mo, Da-Rui, Mao, Ben-Yong & Xu, Ji-Shan, 2024, Two new species of the genus Ennearthron Mellié, 1847 (Coleoptera: Ciidae) from Yunnan Province, China, Zootaxa 5506 (2), pp. 281-289 : 284-288

Ennearthron jizushanense sp. nov.

Figs. 3 (A–B), 4(A–H), 5(A–F), 6–7

Chinese vernacular name: ḚAEƜM刻Ìdzę

Type material. Holotype: CHINA: male, “China: Yunnan, Dali Bai Autonomous Prefecture (大OiHNJÞàṅ), Jizu Mountain ( ḚAEƜ), 25°57’29’’N, 100°23’16’’E, 2400 m, 10.VIII.2020, leg. Ji-Shan Xu ” . Paratypes: CHINA: 9 males, 4 females, same data as the holotype .

Diagnosis. This species is similar to Ennearthron acuticornum sp. nov. but differs from it by the pronotal horns, lateral edge, and male genitalia ( E. jizushanense sp. nov. with pronotal horns thick and slightly shorter than E acuticornum sp. nov., lateral edge slightly broad, visible from above, with the middle margin somewhat emarginate in tegmen; E. acuticornum sp. nov. with pronotal horns slender and acuity, lateral edge narrow, barely visible from above, with the middle margin not emarginate in tegmen).

Description. Male. Fully pigmented adult. Measurements in mm: TL 2.33, PL 0.67, PW 0.91, EL 1.62, EW 1.04, GD 0.90. Ratios: PL/PW 0.74, EL/EW 1.56, EL/PL 2.42, GD/EW 0.87, TL/EW 2.24.

Body ( Fig. 3A ) elongate, convex, brown to dark brown; dorsal with thick and long setae, ventral with slender setae.

Head with sparse punctures and setae, anterocephalic edge strongly elevated forming a pair of broad-based, subtriangular plates, narrowly separated by a small, distinct notch. Antennae ( Fig. 4B ) bearing nine antennomeres with the following lengths (in mm, left antenna measured): 0.08, 0.06, 0.06, 0.04, 0.03, 0.03, 0.07, 0.07, 0.11, with 3-segmented subglobose to elliptic. Compound eyes finely facetted, each bearing approximately 80 ommatidia; GW 0.20 mm.

Pronotum ( Fig. 3A ) with deep and fine punctures bearing thick and long setae (~ 0.03 mm), the surface between punctures smooth; anterior angles produced forward, obtuse; posterior angles rounded; anterior edge strongly produced forward and deeply emarginate medially forming a pair of thick and long horns (the largest spacing of horns about 0.21mm); lateral edge usually broad, weakly crenulate ( Fig. 4C , arrow) (best seen in ventral view), visible from above.

Scutellar shield developed, with a few punctures and setae; subtriangular, rounded at apex; BW 0.11 mm.

Elytra ( Fig. 3A ) with punctation which is shallower and coarser than pronotum; setae thick and long (~ 0.03 mm); sides subparallel at basal two-thirds; apex broadly rounded.

Protibia with outer apical angle produced to form a tooth; pro, meso and metatibiae with similar shape and length, slightly expanded.

Prosternum ( Fig. 3B ) in front of coxae slightly convex, the surface microreticulate; prosternal process parallelsided and rounded at apex, higher than the procoxae (best seen in lateral view).

Metaventrite ( Fig. 3B ) is slightly emarginate in the middle, with sparse punctuation and setae; discrimen is about half the length of the ventrite. Abdominal ventrites with fine setae and shallow punctures, the surface between them microreticulate; first abdominal ventrite bearing a circular, setose and margined sex patch in the middle, with a transverse diameter of 0.05 mm; length of the ventrites (in mm) as follows: 0.28, 0.14, 0.14, 0.13, 0.13.

The posterior edge of sternite VIII ( Fig. 4H ) in males is moderately emarginate. Aedeagus is about 2.4 times as long as ventrite 5. Tegmen ( Fig. 4F ) about 3.6 times as long as wide, widest at apical eighth, narrower at the middle ( Fig. 4E , arrows); sides gradually diverging to apical fourth, where on each side there is a slender, apically directed lobe; apex broadly rounded. Penis ( Fig. 4G ) is as long as a tegmen, about 4.9 times as long as wide, with a subacute ape, both sides are nearly parallel.

Female ( Fig. 5 ). Similar to male, except for the following points: anterocephalic edge without strongly subtriangular plates, but with an arcuate lamella on each side; pronotum with anterior edge broadly rounded, without horns; first abdominal ventrite without a sex patch. Ovipositor ( Fig. 5E ) 2.5 times as long as wide, widest at the base; paraprocts 1.15 times as long as gonocoxites, longitudinally oriented; gonocoxites 1.12 times as long as their combined widths, each slightly wide basally and gradually narrowed, rounded at apex; each gonostylus 0.19 times as long as respective gonocoxite, 4.61 times as long as wide.

Measurements. Males (n = 9, including the holotype; mm): TL 2.18–2.49 (2.32 ± 0.10); PL 0.58–0.78 (0.69 ± 0.06); PW 0.87–1.06 (0.95 ± 0.06); EL 1.46–1.70 (1.59 ± 0.08); EW 1.04–1.19 (1.08 ± 0.04); GD 0.81–0.99 (0.88 ± 0.05). PL/PW 0.66–0.79 (0.72 ± 0.04); EL/EW 1.36–1.60 (1.48 ± 0.07); EL/PL 1.96–2.81 (2.33 ± 0.26); GD/EW 0.75–0.93 (0.82 ± 0.05); TL/EW 1.90–2.33 (2.15 ± 0.14).

Females (n = 4; mm): TL 1.90–2.15 (2.05 ± 0.10); PL 0.53–0.66 (0.60 ± 0.06); PW 0.74–0.82 (0.78 ± 0.04); EL 1.32–1.52 (1.44 ± 0.09); EW 0.90–1.01 (0.94 ± 0.06); GD 0.81–0.90 (0.85 ± 0.04).

PL/PW 0.71–0.81 (0.77 ± 0.05); EL/EW 1.41–1.70 (1.54 ± 0.12); EL/PL 2.17–2.85 (2.41 ± 0.30); GD/EW 0.76–0.94 (0.88 ± 0.08); TL/EW 2.07–2.30 (2.18 ± 0.10).

Distribution. Jizu Mountain, Yunnan, China ( Fig. 7 )

Biology. All specimens of E. jizushanense sp. nov. were collected in unidentified polypore basidiomes growing on rotten wood ( Fig. 6 B & C ).

Etymology. The specific name ‘jizushanense’ is taken from the type locality, Jizu Mountain.

Figures

FIGURE 3. A–B. Ennearthron jizushanense sp. nov., (A–B) male, holotype. A. Dorsal view; B. Ventral view. Scale bars: 1 mm in A & B.

FIGURE 4. A–H. Ennearthron jizushanense sp. nov., (A) male, holotype; (B–H) male paratype. A. Lateral view; B. Antenna; C. Left lateral edge of pronotum (ventral view); D. Aedeagus (overall) ventral view; E. Aedeagus (dorsal view, tegmen (teg) and penis (pen)); F. Tegmen (dorsal view); G. Penis (dorsal view); H. Sternite VIII (dorsal view). Scale bars: 1 mm in A; 0.1 mm in B–H.

FIGURE 5. A–F. Ennearthron jizushanense sp. nov., (A–F) female, paratype. A–C. Dorsal, Ventral, and Lateral views; D. Sternite VIII (dorsal view, sv = spiculum ventrale); E. Ovipositor (ventral view, b.pp = paraproctal baculi; b.pt = proctigeral baculi; gc = gonocoxites; gs = gonostylus); F. Segment IX and X (dorsal view). Scale bars: 1 mm in A–C; 0.1 mm in D–F.

FIGURE 6. Habitat of Ennearthron jizushanense sp. nov. A. General environment; B. Rotten wood with polypore basidiomes; C. Live specimen of Ennearthron jizushanense sp. nov. on the surface of a polypore basidiome.

FIGURE 7. Distribution of the E. jizushanense sp. nov. & E. acuticornum sp. nov. in Yunnan, China.