ZooKeys 317: 81–87, doi: 10.3897/zookeys.317.5112
A new species of Scelidopetalon Delkeskamp (Coleoptera, Erotylidae) from China with a key to world species of the genus
Cong-Chao Dai 1,†, Mei-Jun Zhao 1,‡
1 Department of Biology, College of Life and Environmental Sciences, Shanghai Normal University, Shanghai, 200234, P. R. China

Corresponding author: Mei-Jun Zhao (mjzhao@shnu.edu.cn)

Academic editor: Michael Thomas

received 12 March 2013 | accepted 15 July 2013 | Published 19 July 2013

(C) 2013 Cong-Chao Dai. This is an open access article distributed under the terms of the Creative Commons Attribution License 3.0 (CC-BY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

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A new species Scelidopetalon biwenxuani sp. n. is described from China, representing the first occurrence of the genus in Hainan province. A key to the world species of this genus is provided.


Coleoptera, Erotylidae, Scelidopetalon, Pseudamblyopus identification key , new record genus, new species, China


The subfamily Erotylinae includes colorful fungus-feeding beetles commonly called “pleasing fungus beetles”. They are worldwide in distribution with over 2500 described species. In general, species of the tribe Tritomini are characterized by an antennal club of 3 to 5 antennomeres, dilated maxillary palpi, closed procoxal cavities (with prosternal-proepimeral suture located at the midpoint posterior to the procoxae), meso-metasternal suture having a broadened dicondylic connection, and pseudotetramerous tarsi (tarsomere IV small and hidden by an expanded tarsomere III). Larvae and adults feed on larger basidiomycete fungi (e.g. mushrooms, polypore or bracket fungi, etc.). The name “pleasing fungus beetle” is likely derived from the large size and colorful patterns of many species.

While examining Burmese specimens of Amblyopus Lacordaire, Gorham (1896) established Petaloscelis based on its small and finely facetted eyes (Fig. 1), which are large and coarsely facetted in Amblyopus (Fig. 2). Arrow (1925, 1926) described four additional species in Petaloscelis. While examining the African species, Arrow (1945) noted that Gorham confused African species with an Indian species and considered Petaloscelis a synonym of Amblyscelis Gorham. Delkeskamp (1957) thought Petaloscelis and Amblyscelis were distinct based on eye characters as mentioned above and on differences in tibial dilation. Because the name Petaloscelis Gorham was a junior homonym of Petaloscelis Bergoth (see Chûjô and Chûjô 1990), Delkeskamp (1957) proposed the name Scelidopetalon for the species of Petaloscelis Gorham with Petaloscelis instabilis Gorham, 1896, as the type.

Araki (1941) described Pseudamblyopus for the Japanese species Amblyopus palmipes Lewis. Araki noted Pseudamblyopus is easily distinguished from Amblyopus by the small and finely facetted eyes and mentioned this genus differs from Petaloscelis in the antennal club structure. But neither Arrow nor Delkeskamp were aware of Araki’s work. Thus, Scelidopetalon and Pseudamblyopus were both separated from Amblyopus based on the same characters.

Because no specimens of Pseudamblyopus are available for study, we are not treating Scelidopetalon as a synonym to Pseudamblyopus. This should be considered in future revisionary work.

Previously, a total of six species have been reported for Scelidopetalon and two species for Pseudamblyopus worldwide.

Scelidopetalon instabilis (Gorham 1896) (Burma, Viet-Nam)

Scelidopetalon similis (Arrow 1925) (Assam Valley)

Scelidopetalon varicolor (Arrow 1925) (India)

Scelidopetalon solidus (Arrow 1925) (India)

Scelidopetalon fasciatus (Arrow 1926) (Sumatra, N. Borneo)

Scelidopetalon arrowi Delkeskamp (1957) (Singapore)

Pseudamblyopus palmipes (Lewis 1889) (Japan)

Pseudamblyopus similis (Lewis 1887) (Far East, Japan)

In this work, one new species of Scelidopetalon is described and illustrated: Scelidopetalon biwenxuani sp. n. from Hainan Province, China.

Material and methods

To examine the genitalia, the abdominal segments were detached from the body after softening in hot water. The genitalia, together with other dissected parts, were mounted in Euparal (Chroma Gesellschaft Schmidt, Koengen, Germany) on plastic slides. Photos of sexual characters were taken with a FUJIFILM X10 camera attached to an Olympus SZX 16 stereoscope; habitus photos were taken with a Canon macro photo lens MP-E 65 mm attached to a Canon EOS7D camera.

The specimen treated in this study is deposited in the following public collection:

SNUC Department of Biology, Shanghai Normal University, P. R. China

Scelidopetalon Delkeskamp and Pseudamblyopus Araki

Diagnosis. These two generacan be distinguished from other Tritomini genera by eyes small and finely facetted (Fig. 1). Tibiae (Fig. 8) triangular, with the extremities very broad and hollowed for the tarsi. Prosternal lines of prosternum (Fig. 7) short, not extending in front of procoxal cavities. These three characters have not existed together in other genera of Tritomini. The distinct difference between species of these two genera is antennal club structure. Most species of Scelidopetalon with antennomere XI much broader than long, one species of Scelidopetalon and all the species of Psudodamblyopus with antennomere XI almost as long as broad.

Key to world species of genus Scelidopetalon and Pseudamblyopus

Parts of the following key were taken from Arrow (1925).

1 Antennomere XI almost as long as broad 2
Antennomere XI much broader than long 4
2 Pronotum yellow, elytra with rather indefinite reddish patch at base Scelidopetalon varicolor (Arrow)
Pronotum orange, elytra without rather indefinite reddish patch at base 3
3 Legs black Pseudamblyopus palmipes (Lewis)
Legs brown Pseudamblyopus similis (Lewis)
4 Elytra with markings 5
Elytra without markings 8
5 Pronotum black Scelidopetalon biwenxuani Dai & Zhao, sp. n.
Pronotum orange to red 6
6 Pronotum with a black median line Scelidopetalon fasciatus (Arrow)
Pronotum without a black median line 7
7 Pronotum with black spots, elytra with X-shaped orange markings Scelidopetalon instabilis (Gorham)
Pronotum without black spots, elytra with orange markings not X-shaped Scelidopetalon arrowi Delkeskamp
8 Dark above Scelidopetalon similis (Arrow)
Pale above and beneath Scelidopetalon solidus (Arrow)
Type material.

Holotype: CHINA: Hainan Prov.: 1♀, Jianfengling N.R., Mingfenggu Valley, 18°44'N, 108°50'E, alt. 1000 m, 15.V.2011, Bi Wen-Xuan leg. (SNUC).


Body (Figs 3, 4) oval, convex, shining; length: 6.50 mm; width: 3.79 mm. Body black; legs, palpi and antennae reddish-brown. Elytron black, with red at basal third.

Head (Fig. 1) width between eyes = 5.5 times eye diameter in dorsal view; punctation coarse, separated by 0.5–1.0 puncture diameters laterally and 2–4 puncture diameters medially; stridulatory files not evident. Antennae (Fig. 5) short, not extending behind posterior border of pronotum; antennomere III about 2.0 times as long as IV; antennomeres IV to VIII short; antennomeres IX to XI broad and transverse; relative lengths of antennomeres II–XI: 9.0: 14.0: 7.0: 7.0: 7.0: 7.0: 6.5: 9.0: 9.0: 8.0. Maxillary terminal palpomeres trapezoidal, 1.67 times wider than long. Mentum broad with anterior projection, almost pentagonal, 1.75 times wider than long.

Figures 1–2.

Head of 1 Scelidopetalon biwenxuani and 2 Amblyopus vittatus in dorsal view. Scale = 0.5 mm.

Figures 3–4.

Habitus of Scelidopetalon biwenxuani in dorsal and ventral view. Scale = 2 mm.

Pronotum transverse, convex above, widest at base (pl/pw = 0.70); anterior angles weakly projecting; lateral margins gently curved toward eyes. Pronotum distinctly punctured medially, finely and closely punctured laterally.

Prosternum (Fig. 7) strongly punctured, the front margin is produced to a short point in the middle, prosternal lines short, not extending in front of procoxal cavities; Mesosternum coarsely punctured. Metasternum coarsely punctured at the sides and almost smooth in the middle, with distinct coxal lines. Abdomen fairly strongly and closely, its sides coarsely, punctured, with distinct coxal lines on first ventrite nearly attaining posterior margin.

Scutellum pentagonal, finely and sparely punctured.

Legs short, tibiae triangular, with the extremities very broad and hollowed for the tarsi.

Elytra widest at middle, then gradually narrowing to apex; each with 9 punctate lines.

Female genitalia (Fig. 9) with gonostyli fringed apically with some elongate setae; female spermatheca (Fig. 6) with capsule almost egg-shaped.

Figures 5–9.

Scelidopetalon biwenxuani. 5 antenna 6 spermatheca 7 prosternum 8 tibia and tarsus female genitalia. Scales = 0.5 mm (5, 7, 9), Scales = 0.1 mm (6), Scales = 1.0 mm (9).


China (Hainan Province).


The new species can be distinguished from other species in this genus by the black pronotum and red markings of the elytra.


This species is named in honor of Mr. Wen-Xuan Bi, collector of the new species.


We thank Paul E. Skelley, Florida State Collection of Arthropods, USA and Richard A.B. Leschen, New Zealand for all of their assistance providing methods and information for this study. We thank Wen-xuan, Bi, the collector of this new species for providing specimens for this work. The research was supported by the National Natural Science Foundation of China (No. 31101659 and No. 31172134), the Innovation Program of Shanghai Municipal Education Commission (No. 12YZ077) and by Shanghai Normal University (DZL125).

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