Elytra, Tokyo, New Series, 11 (1): 85–92 August 16, 2021 New Aphanocephalus from Vietnam 85

A New Species of the Genus Aphanocephalus (Coleoptera, , Discolomatidae) from Vietnam

1) 2), 3) Hiroyuki Yoshitomi and Thai Hong Pham 1) Entomological Laboratory, Faculty of Agriculture, Ehime University, Tarumi 3–5–7, Matsuyama, 790–8566 Japan 2) Mientrung Institute for Scientific Research, Vietnam Academy of Science and Technology, 321 Huynh Thuc Khang, Hue, Vietnam 3) Vietnam National Museum of Nature & Graduate School of Science and Technology, Vietnam Academy of Science and Technology, 18 Hoang Quoc Viet, Hanoi, Vietnam

Abstract A new species of the genus Aphanocephalus, A. hiranoi sp. nov., is described from Vietnam. Three known species from Vietnam and Laos are briefly redescribed. An identification key to species and the list of previous records of Aphanocephalus from Vietnam and Laos are provided. Keywords: , Aphanocephalinae, Aphanocephalini, male genitalia, Laos.

Introduction

The family Discolomatidae includes about 400 species, 16 genera, within five subfamilies C( line & Ślipiński, 2010), and is distributed throughout tropical to temperate regions in the Old World, but only tropical areas in the New World. They are mycophagous or saprophagous, and some genera are known as a myrmecophiles (Cline & Ślipiński, 2010). The genus Aphanocephalus Wollaston, 1873 (Aphanocephalinae, Aphanocephalini) is one of the largest genera in the family (John, 1959), and is represented by more than 100 species from Central and East Africa, East to Southeast Asia, Pacific Islands, and northern Australia P( al, 1992). From Vietnam and Laos, nine species have been recorded, but most species are known from a few sites (Table 1). In the present paper, a new species from Vietnam is described, and three previously known species are recorded and briefly redescribed based on the additional specimens.

Material and Methods The materials examined in this paper are located in Ehime University Museum, Matsuyama, Japan (EUMJ) and Vietnam National Museum of Nature (VNMN). The numbers in the specimen data (e.g. LA35, VN49) indicate the collecting sites, and their additional information and photos of the collection sites are available in: https://sites.google.com/site/waterbeetlesofjapan/home/field- investigation. General observations, dissections and observations of microstructures of dissected parts were made under a Leica MZ95. After observation, the dissected parts were mounted on the same card with the specimen. Photographs were taken with a Leica MZ95. The male genitalia of this family are complicated. Some species possess asymmetrical genitalia with extra appendages, but the male genitalia were examined and figured under condition of con- necting penis and tegmen in the previous study. In this paper, we disarticulated the penis and tegmen and figured them independently for the purpose of better discerning diagnostic features. 86 Hiroyuki Yoshitomi and Thai Hong Pham

Table 1. Records of Aphanocephalus spp. from Vietnam and Laos.

Species Country Locality Altitude Reference

A. annamensis Vietnam Goa, Annam (type loc.) John (1956) Vietnam Tonkin, Hoa Binh John (1956)

A. decoomani Laos betw. Vientiane and Luang Prabang (type loc.) John (1954) Vietnam Tonkin, Hoa Binh John (1956) Vietnam Ha Son Binh, Da Bac Schawaller (1993) Vietnam Kui-Tshau 200 m Schawaller (1993) Laos LA35 575 m present study

A. ebeninus Vietnam Tonkin, Reg. de Hoa-Binh John (1956) Vietnam 40 km NE Thai-Nguen 700–800 m Schawaller (1993) Vietnam NE Thai-Nguen Schawaller (1993) Vietnam Bakshon 600 m Schawaller (1993) Vietnam Shan-Hoa, Ngoklak Schawaller (1993) Vietnam VN49 Cuc Phuong NP., Ninh Bình Prov. 369 m present study Vietnam VN50 Cuc Phuong, Ninh Bình Prov. 165 m present study

A. formosanus Vietnam Tam-Dao 900 m Schawaller (1993) Vietnam VN43 Tam Dao, Vinh Phuc Prov. 960 m present study Vietnam VN45 Tam Dao, Vinh Phuc Prov. 1,023 m present study A. hiranoi sp. nov. Vietnam Deo O Quy Ho, Lao Cai (type loc.) 1,750 m present study

A. poesi Vietnam Prov. Ha-Tinh, forestiere Huong-son (type loc.) 200 m John (1965) Vietnam Prov. Ha-Tinh, forestiere Huong-son 150 m John (1965)

A. pseudatomus Vietnam Tonkin, Hoa Binh (type loc.) John (1954) Vietnam Tonkin, Hoa Binh John (1956)

A. pubescens Vietnam 30 km SE Hanoi Schawaller (1993)

A. tonkinensis Vietnam Tonkin, Hoa Binh (type loc.) John (1954) Vietnam Tonkin, Hoa Binh John (1956) Vietnam 125 km NW Than-Hoa, Batok 500 m Schawaller (1993)

A. wollastoni Vietnam Tonkin, Hoa Binh John (1956) Vietnam 100 km W Shan-Hoa, Lang-Gang 100 m Schawaller (1993)

Morphological abbreviations used in this study are as follows: EL — elytral length from anterior margin to elytral apex; EW — maximum elytral width; PL — pronotal length in median line; PW — pronotal maximum width; TL — total length (PL + EL). The average is given in parenthesis after the range.

Taxonomy

Genus Aphanocephalus Wollaston, 1873 Aphanocephalus Wollaston, 1873: 278 [type species: Aphanocephalus hemisphaericus Wollaston, 1873]; John, 1956: 1; 1959: 34; Fukuda, 1969: 20 [description of larva]; Pal, 1992: 46.

Diagnosis. Body oval to circular, hemispherical, shiny, glabrous or pubescent. Coloration of body evenly brown or black in most species, with weak greenish luster in some species; elytra with 2 to 6 spots in some species. Head completely obscured by pronotum, not visible in dorsal view. Anten- New Aphanocephalus from Vietnam 87

Fig. 1. Habitus of Aphanocephalus spp. — A, A. decoomani; B, A. ebeninus; C, A. formosanus; D, A. hiranoi sp. nov. Scale bar = 1.0 mm. nae 9-segmented, with 1-segmented apical club. Pronotum transverse, with two pairs of tubular gland openings near front and hind angles; anterior margin gently arcuate; anterior angles broadly rounded; posterior angles acute. Elytra with six pairs of tubular gland openings along lateral margins. Legs short; tarsal formula 3-3-3; claws simple; empodium well developed, bisetose.

Key to the Species of Aphanocephalus from Vietnam and Laos

1. Elytra black, with a pair of reddish brown spots. ························· A. pseudatomus John, 1954 — Elytra fully black. ···························································································· 2 2. Pronotum and elytra bearing long setae. ·································································· 3 — Pronotum and elytra glabrous or bearing sparsely distributed short setae. ··························· 4 3. Elytral punctures evenly small. ········································ A. pubescens Grouvelle, 1912 — Elytra closely and irregularly covered with small and moderate punctures. ························· 5 88 Hiroyuki Yoshitomi and Thai Hong Pham

4. Punctures in basal area of elytra consisting of three size, large, moderate and small. ················· ························································································· A. pocsi John, 1965 — Punctures in basal area of elytra consisting of two size, small and moderate. ·························· ················································································· A. annamensis John, 1956 5. Small body size species, TL ˂ 1.5 mm. ··································································· 6 — Large size species, TL > 2.2 mm. ·········································································· 7 6. Tegmen reduced, smaller than penis. ········································· A. tonkinensis John, 1954 — Tegmen developed, larger than penis. ·········································· A. wollastoni Rye, 1873 7. Apex of tegmen simply acute. ·············································································· 8 — Apex of tegmen with two or three pairs of lateral projections. ········································ 9 8. Smaller species, TL ˂ 2.2 mm; penis short, projecting dorsally in apico-lateral parts. ················ ····················································································· A. ebeninus John, 1956 — Larger species, TL > 2.5 mm; penis long, projecting apically. ···················· A. hiranoi sp. nov. 9. Apical part of tegmen distinctly asymmetrical; apex of penis with large projection in right-dorsal corner. ········································································· A. decoomani John, 1954 — Apical part of tegmen slightly asymmetrical; apex of penis flat dorsally. ······························· ················································································· A. formosanus John, 1956

Aphanocephalus decoomani John, 1954 (Figs. 1A & 2A–E)

Aphanocephalus decoomani John, 1954: 302. Schawaller, 1993: 32. Specimens examined. 2 males, 4 females & 3 exs. (EUMJ), “[LA35] Hot Spring, Xieng Kh- ouang Prov., Laos, 28. IV. 2018, 19.332993, 103.411440 575 m, H. Yoshitomi leg.”. Redescription. For full description see John (1954). PW/PL 1.93–2.14 (2.05); EL/EW 0.90–0.97 (0.94); EL/PL 2.32–2.57 (2.46); EW/PW 1.19–1.33 (1.28); TL/EW 1.28–1.37 (1.32). Tegmen (Fig. 2A–C) distinctly asymmetrical; right paramere with three projections, inner one long and pointed at apex, middle and outer ones obtuse; left paramere with two obtuse projections. Penis (Fig. 2D & E) long, asymmetrical, with large projection in right-dorsal corner of apex. Measurement (N = 7). TL 2.28–2.80 (2.56) mm; PW 1.40–1.70 (1.52) mm; PL 0.68–0.82 (0.74) mm; EL 1.60–1.98 (1.82) mm; EW 1.78–2.12 (1.94) mm. Distribution. Laos, Vietnam.

Aphanocephalus ebeninus John, 1956 (Figs. 1B & 2F–I)

Aphanocephalus ebeninus John, 1956: 8. Schawaller, 1993: 32. Specimens examined. 1 male, 1 female & 2 exs. (EUMJ), “[VN49] Cuc Phuong NP., Ninh Bình Prov. (369m), 20.210076, 105.353544, 4-8. III.2015, H. Yoshitomi leg.”; 1 female (EUMJ), “[VN50] Cuc Phuong, Ninh Bình Prov. (165m), 20.140595, 105.420878, 6. III. 2015, H. Yoshitomi leg.” Redescription. For full description see John (1956). PW/PL 1.85–2.03 (1.95); EL/EW 0.93–0.95 (0.94); EL/PL 2.05–2.31 (2.17); EW/PW 1.17–1.20 (1.19); TL/EW 1.36–1.39 (1.37). Tegmen (Fig. 2F & G) small, slightly asymmetrical, lacking lateral projection in apical parts. Pe- nis (Fig. 2H & I) short, slightly asymmetrical, projecting dorsally in apico-lateral parts. Measurement (N = 4). TL 2.08–2.23 (2.16) mm; PW 1.30–1.35 (1.33) mm; PL 0.65–0.73 (0.68) mm; EL 1.43–1.50 (1.48) mm; EW 1.52–1.60 (1.58) mm. Distribution. Vietnam. New Aphanocephalus from Vietnam 89

Fig. 2. Male genitalia and antenna of Aphanocephalus spp. — A–E, A. decoomani; F–I, A. ebeninus; J–N, A. formosanus. — A–C, F, G, K & L, Tegmen in dorsal (A, F, K), right lateral (B), and left lateral (C, G, L) aspects; J, antenna; D, E, H, I, M & N, penis in dorsal (D, H, M) and lateral (E, I, N) aspects.

Aphanocephalus formosanus John, 1956 (Figs. 1C & 2J–N)

Aphanocephalus formosanus John, 1956: 16. Schawaller, 1993: 32.

Specimens examined. 1 male, 1 female & 18 exs. (EUMJ), “[VN43] Tam Dao, Vinh Phuc Prov., Vietnam (960m), 21.282298, 105.381738, 1, 3. III.2015, H. Yoshitomi leg.”; 3 males & 21 exs. 90 Hiroyuki Yoshitomi and Thai Hong Pham

(EUMJ), “[VN45] Tam Dao, Vinh Phuc Prov., Vietnam (1,023m), 21.263226, 105.384894, 2. III. 2015, H. Yoshitomi leg.”. Redescription. For full description see John (1956). PW/PL 1.90–2.20 (2.06); EL/EW 0.95–1.08 (1.00); EL/PL 2.31–3.00 (2.58); EW/PW 1.20–1.30 (1.26); TL/EW 1.33–1.44 (1.38). Tegmen (Fig. 2K & L) slightly asymmetrical; apex with three pairs of projections. Penis (Fig. 2M & N) long, slightly asymmetrical, flat dorsally in apical part. Measurement (N = 9). TL 2.38–2.80 (2.55) mm; PW 1.40–1.54 (1.46) mm; PL 0.68–0.80 (0.71) mm; EL 1.70–2.10 (1.84) mm; EW 1.79–1.95 (1.84) mm. Distribution. Taiwan, Vietnam.

Aphanocephalus hiranoi sp. nov. (Figs. 1D & 3) Type series. Holotype, male (EUMJ): “Deo O Quy Ho 1750m, Lao Cai N. Vietnam 16-V-1995 Y. Nishikawa leg.”. Paratypes (EUMJ, VNMN), 1 male & 1 female, same data as for the holotype. Description. Body hemispherical, shiny. Coloration of body black, with weak greenish luster; anterior part of head, mouth parts, antennae, and legs pale brown; lateral and anterior parts of prono- tum widely tinged with yellowish brown. Head completely covered with pronotum, obscured in dorsal view, finely and closely punctate, sparsely covered with fine short setae. Antennae 9-segmented, with 1-segmented apical club. Pronotum sparsely covered with moderate-sized punctures and fine short setae; punctures separated by 1.0–3.0 times their diameter; PW/PL 1.93–1.94 (1.94). Scutellar shield equilateral triangular, finely punctate. Elytra sparsely covered with punctures; punctures separated by 1.0–2.0 times their diameter; indistinct and sparsely distributed; tubular gland openings situated in lateral margin near anterior angle, anterior 1/3, 1/2, 2/3, 5/6, and near apex; EL/EW 0.96–0.97 (0.96); EL/PL 2.37‒2.50 (2.43); EW/PW 1.26–1.35 (1.31); TL/EW 1.34–1.38 (1.36). Tegmen (Fig. 3B & C) slightly asymmetrical, lacking lateral projections, simply acute at apices. Penis (Fig. 3D–F) long, slightly asymmetrical, acute at apex, with projecting duct of gonopore. Sexual dimorphism indistinct. Measurement (N = 2). TL 3.03–3.08 (3.06) mm; PW 1.70–1.75 (1.73) mm; PL 0.88–0.90 (0.89) mm; EL 2.13–2.20 (2.17) mm; EW 2.20–2.30 (2.25) mm. Remarks. This species is easily distinguished from other species by the larger body size and male genital structures. Distribution. Vietnam (so far known from the type locality, Lao Cai). Etymology. This species is dedicated to the late Mr. Yukihiko Hirano, who was an amateur cole- opterologist and published many faunistic paper about minor families of Japanese including the family Discolomatidae (Hirano, 2014).

Acknowledgements

We thank Hiroyuki Wakahara, Wataru Toki, Tomoki Hirano and Ryosuke Okano for their help in the field investigation. This study is supported in part by KAKENHI (24405028; principal in- vestigator: S. Okajima). New Aphanocephalus from Vietnam 91

Fig. 3. Male genitalia and antenna of Aphanocephalus hiranoi sp. nov. — A, Antenna; B & C, tegmen in right (B) and left (C) aspects; D, left lateral aspect of penis; E, projecting duct of gonopore in dorsal aspect; F, apex of penis in ventral aspect.

要約

吉富博之・Thai Hong Pham：ベトナムから Aphanocephalus（鞘翅目ミジンムシダマシ科）の 1 新種記載． — ベトナム北部から 1 新種 Aphanocephalus hiranoi sp. nov. を記載した．種小名はミジンムシダマシ科 を含む鞘翅目のマイナーな科を研究された故平野幸彦氏に因む．本種は大きな体⻑と特徴的な雄交尾器によ り同属他種から容易に区別できる．また，ベトナムとラオスから知られる 3 種の追加標本を記録するととも に雄交尾器の図示を含め簡単な再記載を行った．ベトナムとラオスから記録される同属の種の検索表とこれ までの記録を整理した．

References

Cline, A. R., & Ślipiński, A., 2010. 10.31. Discolomatidae Horn, 1878. Pp. 435–442. In Leschen, R. A. B., R. G. Betuel & J. F. Lawrence (eds.), Handbook of Zoology. Insecta. Coleoptera, Beetles, Volume 2. Morphology and Systematics (Elateroi- dea, , partim). 786 pp. De Gruyter, Berlin. Fukuda, A., 1969. Description of larva of Aphanocephalus hemisphericus Wollaston, with the relationship of the related gen- era (Coleoptera: Notiophygidae). Kontyû, Tokyo, 37: 20–26. Hirano, Y., 2014. Japanese Discolomatidae (preliminary report). Kanagawa-Chûhô, Odawara, (184): 1–6. (In Japanese.) John, H., 1954. Neue Notiophygidae (Coleoptera). Bulletin of the British Museum (Natural History), Entomology, London, 3: 297–313, pls. 13–17. John, H., 1956. Revision der Gattung Aphanocephalus Woll. (Notiophygidae, Col.). Entomologische Blätter, Berlin, 352: 1–35. 92 Hiroyuki Yoshitomi and Thai Hong Pham

John, H., 1959. Coleoptera Clavicornia. Fam. Discolomatidae (= Notiophygidae). In Wytsman, P. (ed.), Genera Insectorum, Fascicle 213. 56 pp. SPRL Imprimerie & Éditions Mercurius, Brussels. John, H., 1965. Eine neue Spezies von Aphanocephalus Woll. (Discolomidae, Coleoptera). Annales Historico-Naturales Mu- sei Nationalis Hungarici, Budapest, 57: 273–274. Pal, T. K., 1992. Discolomidae, a family new from India. Hexapoda (Insecta Indica), Madras, 4 (1): 45–56. Schawaller, W., 1993. Aphanocephalus Wollaston, 1873 species from continental southeastern Asia (Coleoptera: Discol- omidae). Elytron, Barcelona, 7: 31–36. Wollaston, T. V., 1873. On new Coleoptera from Japan. The Entomologist’s Monthly Magazine, Oxford, 10: 167–172.

Manuscript received 2 December 2020; revised and accepted 3 March 2021.