Dermatohomoeus pennatus, Švec, 2022

Švec, Zdeněk, 2022, Leiodidae (Coleoptera) of the Hainan Island with new faunistic records from China and with notes on the unique body modifications in the genus Agathidium, Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 62 (1), pp. 155-164 : 161-162

Dermatohomoeus pennatus sp. nov.

( Figs 12 , 19 )

Type locality. China, Hainan Island, Limushan Mts, 19°10.5–10.9′N, 109°44–45′E, 650– 900 m.

Type material. Hඈඅඈඍඒඉൾ: J, “ CHINA: Hainan Isl. [MF19] / Limushan Mts., mountains above first admin. centre / 19°10.5-10.9′N, 109°44-45′E / 650-900 m; 6.v.2011, Fikáček // sifting – small accumula- / tions of moist leaf litter along / and on trail in secondary / forest partly with Cyathea and / bamboo” ( NMPC). Pൺඋൺඍඒඉൾඌ: 3 JJ 3 ♀♀, the same locality data as holotype ( NMPC, ZSPC).

Description. Length 2.4 mm in holotype, head 0.2 mm, pronotum 0.7 mm, elytra 1.5 mm, antenna 0.8 mm, aedeagus 1.00 mm. Maximum width of head 0.6 mm at eyes,

pronotum 1.4 mm at base, elytra 1.4 mm in basal third.

Dorsum reddish-brown, A1–A6 and A8 yellow-red, A7, A9–A11 a little darker, femora and tibiae chestnut coloured, tarsi yellow-red. Underside chestnut, metaventrite and coxal margins darker. Entire dorsum punctured. Basal part of head dorsally and elytra with fine strigosites.

Head without microsculpture except for transversally strigose narrow strip on base of vertex. Eyes subglobose, well developed. Dorsal surface of head with distinct puncturation, punctures separated by 2–3 times their own diameter. Antennomeres A2–A6 and A8–A11 longer than wide. W/L of A7 = 1.6. A11 broader than A10.

Pronotum broadest at hind angles. Base straight centrally; oblique-angled laterally to very blunt abruptly rounded hind angles. Very feeble emargination before hind angles in dorsal view. Hind angles rectangular with tip abruptly rounded in lateral view. Sides evenly curved from base to anterior angles in both dorsal and lateral view. Pronotal puncturation distinct, dense, separated by 3–4 times their own diameter on disc, becoming sparser anteriorly, denser posteriorly.

Elytra broadest approximately in basal third of their length; then roundly curved to apex. Elytral surface punctured. Punctures separated predominantly by 1–2 times their own diameter. Medially, near suture, punctures tend to create two irregular double rows of punctures. Remaining surface of elytra irregularly punctured. Interval punctures very similar, irregular, a little sparser than row punctures. Elytral punctures connected by transverse or oblique strigosity. Sutural stria extending approximately to basal third of elytra.

Legs. Protarsomere 1 distinctly dilated and elongate in male. Ratio of lengths of T1: T2–T5 (without claws) of protarsus = 0.4.

Genitalia. Aedeagus possesses distinctive ventral plates extending level of top of median lobe; ventral plates terminating at apex in long bent process resembling wings of butterfly ( Fig. 19 ).

Variation and sexual dimorphism. Length of body 2.1–2.4 mm in the type series. Protarsi slender in female. Length of spermatheca 0.08 mm, width 0.10 mm. Spermatheca in Fig. 12 .

Differential diagnosis. The species of the genus Dermatohomoeus are generally very similar in their appearance, especially those that are of similar colour of dorsum and the size of body. The best way to differentiate the individual species is to compare their genitalia, especially the shape of the aedeagus, its ventral plates and the internal sac while the spermatheca is of very similar or even identical shape in the individual species (Šඏൾർ & BൺŃൺෞ 2021). Nevertheless the new species can be compared with those Chinese, Nepalese and Indian species that are larger than 2.0 mm, irregularly densely punctured on elytra, and have ventral plates reaching at least the level of the top of parameres ( D. longicollis Daffner, 1988 , D. obscuratus Daffner, 1988 , D. punctatus Daffner, 1988 , D. schuelkei Švec, 2011 , and D. strigellus Daffner, 1988 ). Dermatohomoeus pennatus sp. nov. differs from all the mentioned species in the pronotal base strongly obliquely angled toward posterior pronotal angles and mainly in the shape of ventral plates terminating at apex in long bent process resembling the wings of a butterfly.

Etymology. The name of the new species is derived from the Latin word penna (wing in English) as the shape of the ventral plates resembles wings. Adjective.

Figures

Figs 9–12. 9, 10 – aedeagus laterally and tip of aedeagus dorsally. 11 – lateral view of body.12 – spermatheca. 9–11 – Agathidium (Macroceble) apiforme sp. nov.; 12 – Dermatohomoeus pennatus sp. nov. Scale bars in Figs 9, 10 = 0.2 mm; 11 = 0.5 mm; 12 = 0.1 mm.

Figs 17–19. 17 – metatibia; 18 – metatarsus; 19 – aedeagus dorsally. 17, 18 – Agathidium (Macroceble) apiforme sp. nov.; 19 – Dermatohomoeus pennatus sp. nov.