Cheleion watanabei sp. n., a new species of Stereomerini (Coleoptera, Scarabaeidae, Aphodiinae), and description of the male of C. jendeki
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Cheleion watanabei sp. n., a new species of Stereomerini (Coleoptera, Scarabaeidae, Aphodiinae), and description of the male of C. jendeki
Showtaro Kakizoe 0
Munetoshi Maruyama
Kimio Masumoto 1
0 Entomological Laboratory, Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University , Motooka 744, Nishi-ku, Fukuoka, 819-0395 , Japan 2 Japan Society for the Promotion of Science (DC1), Tokyo, Japan 3 The Kyushu University Museum , Hakozaki 6-10-1, Higashi-ku, Fukuoka, 812-8581 , Japan
1 Kamezawa 3-cho?me 14-13-1001, Sumida-ku, Tokyo , 130-0014 , Japan
Cheleion watanabei sp. n. is described from Pahang, Peninsular Malaysia and represents the third species of the genus Cheleion V?rdal & Forshage, 2010 (Coleoptera, Scarabaeidae, Aphodiinae, Stereomerini). A description of the previously unknown male of C. jendeki Kr?l & H?jek, 2015, and a key to the species of the genus Cheleion are also provided.
eol>Aphodiines; new species; Oriental region; Peninsular Malaysia; Southeast Asia; taxonomy
Introduction
The Oriental species are known to be extremely rare; all of them are known from single
or a few specimens collected so far. Therefore, the males are rare and consequently most
entomologists have avoided dissection of the genitalia; male genitalia of Stereomerini
have been described only for two Australian species
(Howden and Storey 1992; Storey
and Howden 1996)
. Recently we examined two Stereomerini specimens from
Peninsular Malaysia: one was found to be a female of an undescribed species belonging to
the genus Cheleion and the other was identified as a male of Cheleion jendeki Kr?l &
H?jek, 2015. The description of the new species and the previously unknown male of
C. jendeki as well as a key to the species of Cheleion are provided herein.
Materials and methods
All specimens were dried and mounted on paper cards for morphological observation;
dissected genitalia were mounted in Euparal on a small glass plate (10?5 mm), and
subsequently glued onto a paper card (6?5 mm) and pinned under the specimen
(Maruyama
2004)
. Specimen photographs were taken with an Olympus OM-D E-M1 Mark II with
a Canon MP-E 65 mm 1?5? macro lens and KIPON EF-MFT AF adapter for Figures
1?6, with a Canon EOS 7D Mark II with a Mitutoyo M Plan Apo 20? and a Raynox
DCR-150 for Figures 8?11, and subsequently stacked using CombineZP software.
Images were edited using Adobe Photoshop CS6. Terminology of the species description
follows
Howden and Storey (1992)
,
V?rdal and Forshage (2010)
and
Kr?l and H?jek (2015)
.
Taxonomy
Cheleion watanabei Kakizoe, Maruyama & Masumoto, sp. n.
http://zoobank.org/9186941F-6E3F-4EB8-829D-78AB1D4C594F
Figs 1?4, 9, 11
Type material. Holotype, female, deposited in the National Museum of Nature and
Science, Tsukuba, Japan: ?PENINSULAR MALAYSIA, Pahang, Cameron Highlands,
Tanah Rata, 8?12. III. 2006, T. Watanabe leg., by FIT [= flight interception trap]?.
Distribution. (Fig. 12) Peninsular Malaysia, Pahang, Cameron Highlands, Tanah Rata.
Etymology. Dedicated to Mr Takashi Watanabe, the collector of the type specimen.
Diagnosis. This new species is easily distinguished from all known congeners by
the following character states: 1) larger body size (total body length ca. 2.5 mm); 2)
anterior ridges of the two distinct pronotal depressions short; 3) pads bearing lanceolate
scale on the elytra slightly developed; 4) elytral posterior margin strongly depressed;
and 5) elytral ridges indistinct.
Description. Holotype female. Large species (2.51 mm). Body (Figs 1?4) slightly
convex dorsally, dorsal surface more or less covered with appressed lanceolate scales,
general color uniformly matte brown. Head (Figs 1?4) wide, subrectangular in
dorsal view, with densely appressed lanceolate scales. Clypeus impunctate, shiny, apically
pointed and reflexed under head. Frons flat with five anteriorly divergent furrows,
second and fourth furrows strongly curved medially. Genal tip slightly obtusely angular
in dorsal view. Eyes large, visible ventrally, less visible dorsally. Occiput with numerous
small, longitudinal punctures. Antennae long, amber colored, with long setae; club
lamellae long. Maxillary palpi as long as head, amber colored, with securiform ultimate
palpomeres. Prothorax (Figs 1?4) large and transverse, anterior edge slightly bisinuate,
side edges weakly rounded in dorsal view. Base of pronotum with a median protrusion,
wider than base of elytra. Pronotal disc with seven furrows medially, concave at middle
of hourglass pattern, with tufts of dense trichomes, with densely appressed lanceolate
scales; mid furrow shallower than lateral furrows. Lateral furrows large, flat.
Subtriangular depressions delineated by more furrows sparsely appressed lanceolate scales
medially. Anteromedial disc distinctly high, tuberculate; promedial disc and posterolateral
sides slightly low, less tuberculate than anteromedial disc. Prosternum fairly elevated
and expanded anteriad and posteriad, rugos (...truncated)