Plateumaris weisei (Duvivier, 1885)

Geiser, Elisabeth, 2023, Revision of the Palaearctic species of the genus Plateumaris C. G. Thomson, 1859 (Coleoptera, Chrysomelidae, Donaciinae), ZooKeys 1177, pp. 167-233 : 167

Plateumaris weisei (Duvivier, 1885)

Fig. 17

Donacia weisei Duvivier, 1885: cxvi.

Donacia borealis Mannerheim [nomen nudum].

Plateumaris hirashimai Kimoto, 1963: 13.

Donacia (Plateumaris) mongolica Semenov, 1895: 267.

Plateumaris morimotoi Kimoto, 1963: 13.

Plateumaris consimilis orientalis Shavrov, 1948: 49.

Plateumaris sachalinensis L. N. Medvedev, 1973: 876.

Type localities.

Plateumaris weisei : Siberia. Original label text: “Sibérie coll. Duvivier"; Plateumaris consimilis orientalis : Far East, Vladivostok, Sedanka, Russia; Plateumaris hirashimai : Hokkaido, Ashoro in Tokachi, Japan; Plateumaris mongolica : North Mongolia, Borcha-Urga, Mongolia; Plateumaris morimotoi : Hokkaido, Tenninkyo Mt. Daisetsu, Japan; Plateumaris sachalinensis : Far East, Sakhalin, Yuzhno-Sakhalinsk, Russia.

Type material.

Type of Plateumaris weisei : 1 syntype, Siberie coll. Duvivier; Museum Paris coll. H. Clavareau 1932, vid. I.S. Askevold 1984 (MNHN-EC-EC2129). Image of type specimen: https://science.mnhn.fr/institution/mnhn/collection/ec/item/ec2129?listIndex=2&listCount=6.

Type series of P. consimilis orientalis : Russia • 3 ♀; Far East, Vladivostok, Sedanka; 19 Jun. 1937 [present depository unknown].

Type of P. hirashimai : Japan • 1 ♀; Hokkaido, Ashoronuma in Tokachi; 28 Jul. 1949; R. Matsuda leg.; collection Entomological Laboratory, Faculty of Agriculture, Kyushu University, Fukuoka, Japan.

Type of P. mongolica : Mongolia • 1 ♂; valley of the river Borcha, from Urga to the East; 6 Jul. 1894, B. Kaschkarow leg.; collection Semenov [present depository unknown].

Type of P. morimotoi : Japan • 1 ♂; Hokkaido, Tenninkyo Mt. Daisetsu; 27 Jul. 1955; K. Morimoto leg.; collection Entomological Laboratory, Faculty of Agriculture, Kyushu University, Fukuoka, Japan.

Type of P. sachalinensis : Russia • 1 ♂; Far East, Sakhalin, Yuzhno-Sakhalinsk; 12 Jul. 1955; collection of N.N. Filippov [present depository unknown]. Paratype: Russia • 1 ♂; Far East, Sakhalin, Yuzhno-Sakhalinsk; 10 Jul. 1955; [red label:] Paratype Plateumaris sachalinensis Medvedev, Plateumaris weisei Duv. E. Geiser 2021 det.; NMEG.

The photographs of the syntype of P. weisei and the paratype of P. sachalinensis were examined.

Taxonomic history and synonymies.

This list of synonyms and their shifting positions (see below) indicate the main systematic problems with P. weisei . First, it is difficult to distinguish it from other Plateumaris species. The variety of conspicuous morphological characters (colour, relative length of antennomeres, shape and structure of pronotum, shape of metafemoral tooth, etc.) overlap with other species. Second, the locality name in the first description “Siberie” is anything but precise. Third, P. weisei has a particularly wide distribution range, from northern Fennoscandia through European Russia and Siberia to Far East, Mongolia, Northern China, the Korean peninsula, and Japan. Altogether this resulted in the new descriptions of Plateumaris species when a specimen was found outside Siberia with slightly different characters.

Donacia borealis (Mannerheim), nomen nudum: the first who recognised that a specimen of still undescribed Plateumaris weisei belonged to a new species was Carl Gustav Mannerheim, a Finnish entomologist (1797-1854). He labelled a specimen (possibly more than one specimen, but I only found this one) from “Lapponica” with " Donacia borealis ", which clearly is P. weisei (vid. E. Geiser 20 Jul. 2022). This specimen is stored in the coll. Mannerheim (LUOMUS). Mannerheim had the intention to describe it, but he died before he could publish a description.

Plateumaris hirashimai was first described by Kimoto (1963) from Japan, Hokkaido. Askevold (1991: 58) synonymised it with the statement "The endophallus of specimens of P. hirashimai is indistinguishable from that of specimens of P. weisei from Finland in any significant way nor do they differ significantly in external structure".

Donacia mongolica was described by Semenov (1895) based on a single male specimen from Mongolia, east of Ulaanbaatar. He also regarded Plateumaris as a subgenus to Donacia where this new species should be allocated. The description is very detailed ( Geiser and Geiser 2023). Additionally, Semenov listed many characters to distinguish the new species from P. consimilis , P. rustica and P. weisei . Nevertheless, he suspected that this new species could be an aberration of P. weisei , which he had never seen then. Askevold (1991: 58) checked the description and suggested that P. mongolica is probably a synonym of P. weisei . It is regarded as a genuine synonym by Hayashi (2001, 2020), Warchałowski (2010) and Silfverberg (2010). I examined 9 specimens from northern and central Mongolia identified as P. mongolica (stored in coll. Frey in NHMB, in NMEG, and in ZFMK). They show completely yellow legs and almost completely yellow antennomere (only some distal antennomeres are darkened at the apex). Their metafemoral tooth is clearly visible but well within the variation of P. weisei and not so prominent as in P. amurensis . They all are typical P. weisei and P. mongolica is a synonym of P. weisei .

Plateumaris morimotoi was first described by Kimoto (1963) from a single male specimen from Japan Hokkaido. After studying additional material Kimoto (1981: 25) concluded that P. morimotoi is only an infraspecific variation of P. hirashimai and therefore synonymised it with the latter. Then Askevold (1991: 58) synonymised P. hirashimai with P. weisei (see above). Subsequently, P. morimotoi became a synonym to P. weisei , too.

Plateumaris consimilis orientalis was described by Shavrov (1948) as a new subspecies of P. consimilis from Vladivostok, based on three female specimens. His detailed description ( Geiser and Geiser 2023) fits to P. consimilis as well as P. weisei . He also discussed the controverse opinion of Kolossow (1930) that P. consimilis is distributed only in the western Palaearctic, whereas Reitter indicated "Europa, Sibirien, Japan". For Shavrov this new subspecies was a proof or a very strong likelihood that P. consimilis occurred in the whole Palaearctic region. He also recognised that some features are different from the European specimens, but he deduced that such differences are due to the huge distance. Therefore, separate subspecies of European species are common in beetles of the Far East.

Askevold (1991: 58) assessed P. consimilis orientalis as a "probable new synonymy" by studying the original description. However, he also considered P. amurensis as synonym to P. weisei . Therefore, it is not clear, to which of these two species it is synonym because P. amurensis also occurs in the same area. Hayashi (2001) studied P. weisei and P. amurensis thoroughly and worked out that these are unambiguously two different species. Plateumaris amurensis has (mostly!) a prominent, blade like metafemoral tooth whereas P. consimilis orientalis has no metafemoral tooth or only a slight protrusion. He also listed P. consimilis orientalis as synonym with P. weisei .

In the coll. Frey (NHMB) I found two specimens from Japan, Honshu, Fukushima, labelled " Plateumaris consimilis Schrank det. M. Chȗjȏ”, both collected in 1948. These two specimens refer not to P. consimilis orientalis Shavrov but were only misidentifications of P. constricticollis . At this time, the distribution area of P. consimilis was regarded to reach as far as Japan. I never saw a specimen from East of Ural which had some similarity with P. consimilis .

Plateumaris sachalinensis was described by Medvedev (1973) as a new Plateumaris species from the Sakhalin Island ( Geiser and Geiser 2023). He compared it with P. weisei in some characters (long antennae, metaformal tooth very weak) but put it close to P. obsoleta (which is synonymous with P. sericea or P. shirahatai ). He regarded it as an intermediate form between the P. weisei and P. amurensis group and the P. sericea group. Later, Medvedev (1978) even regarded P. sachalinensis as a synonym of P. obsoleta . I studied the paratype specimen from NMEG: In contrast to many P. weisei specimens which have reddish antennae and legs, in this specimen large parts of the legs are metallic darkened. Probably, this colouration of the legs prompted Medvedev (1973) to place this species close to P. obsoleta . Also, the apical part of each antennomere is darkened. This and the other characters fit easily into the range of variability shown by P. weisei (for more morphological details see Hayashi 2001).

After the study of the original description Askevold (1991: 58) suggested that P. sachalinensis should be regarded as a "probable new synonymy" to P. weisei . Hayashi (2001, 2020) and Silfverberg (2010) regarded it as a synonym, Bieńkowski (2014) considered it as a valid species. Warchałowski (2010) separated it in his key from other Plateumaris species because of the dark metallic legs but also mentioned that it is regarded as synonym to P. weisei by some authors. Although Askevold (1991) regarded P. amurensis as synonym to P. weisei , the weak metafemoral tooth of P. sachalinensis is a typical character of P. weisei and excludes P. amurensis here. Hayashi (2001), who finally separated P. weisei and P. amurensis , confirmed the synonymy of P. sachalinensis with P. weisei .

Diagnosis.

Pronotal disc finely rugose and punctured, sometimes with microsculpture, median line obsolete, sometimes shallowly furrowed (similar to P. shirahatai ), metafemur with a small, not blade-like tooth, usually rufous at the base; aedeagus with apex of median lobe arced on both sides, gradually narrowed apically, without a median lip.

Description.

Size: Males 6.2-7.0 mm, females 6.8-8.0 mm.

Colour: Most specimens dorsally cupreous or bronze, sometimes metallic green, blue, purple, or non-metallic brown.

Head: Eyes small, supraocular furrow indistinct, vertex pubescent with deep median line, antenna entirely rufous in most specimens but in some specimens darkly rufous or apically metallic, antennomeres: A5 longest in second to A6 and ca 3.5 × as long as wide, A4 ca 2.2 × as long as A2.

Pronotum: Outline subquadrate, slightly longer than wide, basal part narrowed, slightly cone-shaped, anterior tubercles distinctly visible or almost entirely smooth, disc more or less punctate, rugulose, median groove indistinct or shallowly furrowed.

Elytra: Transverse rugae between the rows of punctures, especially on interstices 1-4.

Legs: Yellow-reddish, in some specimens more or less darkened, femur, tibia, and tarsomere pubescent, outer apical angles of pro- and mesotibiae with a spine, outer apical angles of metatibiae with a small spine, metafemoral tooth mostly blunt or moderate.

Aedeagus: Apex of median lobe arced on both sides, gradually narrowed apically, without a median lip, cap of tegmen rounded at apex (Fig. 17 ).

The main different features between P. amurensis and P. weisei are shown in Table 3. The east Palaearctic Plateumaris species are not easy to distinguish which was also explained in the comments to the synonyms. Misidentifications are common. Oddly enough, in several collections I found the label " Plateumaris [or Donacia ] Plateumaris weisei Duvivier" attached to blue specimens from central Asia, collected circa 1900, which in fact were Donacia bactriana Weise, 1887. Somehow the author’s name has been shifted and was then regarded as the species name.

Biology.

Larvae were found at the roots on Carex sp. ( Bieńkowski and Orlova-Bieńkowskaja 2004; An 2019). Narita (2003) described the last instar of the larvae which he gained from the host plant Carex middendorfii .

Distribution.

Plateumaris weisei is a Trans Palaearctic species, it occurs from northern Fennoscandia through Siberia to the Far East, northern China, the Korean peninsula, and Japan. Also, it occurs in a broad span of latitudes, from the arctic polar circle (67°N) to 35°N in Korea. Records exist for Europe: Sweden, Finland, Russia (north and central part of European Russia).

Asia: China (Heilongjiang [new in PalCat], Inner Mongolia), Japan (Hokkaido), Mongolia, Russia (west, east, and south Siberia [new in PalCat], Far East), South Korea [new in PalCat].

In Japan records exist only from Hokkaido so far ( Hayashi 2020), whereas fossil and subfossil records are known from Honshu and Kyushu, too ( Hayashi and Shiyake 2011).

New country records additional to Silfverberg (2010).

China • 1 ex.; Heilongjiang, “Manchuria“ Harbin; Plateumaris weisei E. Geiser 2020 det.; SDEI [coll. K.-H. Mohr]. Remarks: Silfverberg (2010) recorded P. weisei for China with “NE” because the specimens are labelled only with the locality “Manchuria”, a historical region in northeast China. NE China today comprises the provinces of Heilongjiang and Jilin, and Harbin belongs to Heilongjiang. I examined 8 of these specimens stored in BMNH, in coll. Frey in NHMB, and in SDEI.

Russia • 5 ex.; South Siberia, Angara (near Baikal); I. Askevold 1985 det., E. Geiser 2019 vid.; Sharp-coll. 1905 - 313, BMNH; Bieńkowski (2014).

South Korea: Hayashi and Cho (2017); An (2019).

Material examined.

More than 80 specimens from Europe and Asia.

Figures

Figure 17. Plateumaris weisei A habitus B, C aedeagus: Median lobe and cap of tegmen (photographs by K. Matsumoto) D cap of tegmen E median lobe (from Hayashi 2020). Scale bars: one unit - 1 mm (A); 0.5 mm (D, E).