Halyomorpha Mayr, 1864

Kment, Petr, Rédei, Dávid & Rider, David, 2021, Halyomorpha halys fixed as the type species of the genus Halyomorpha (Hemiptera: Heteroptera: Pentatomidae), Acta Entomologica Musei Nationalis Pragae 61 (2), pp. 615-630 : 616-618

Halyomorpha Mayr, 1864

Halyomorpha Mayr, 1864:911 (original description). Type species: Halys timorensis Westwood, 1837 , by monotypy.

Halyomorpha : Mൺඒඋ (1866): 47–50 (redescription, differential diagnosis); Sඍචඅ (1868a): 515 (key to genera); Sඍචඅ (1876): 57 (key to genera), 74–75 (key to species, catalog); Aඍκංඇඌඈඇ (1888): 23 (diagnosis); LൾඍΗංൾඋඋඒ & Sൾඏൾඋංඇ (1893): 117–118, 267 (World catalog);Dංඌඍൺඇඍ (1902): 148 (key to genera), 152 (diagnosis); OඌΗൺඇංඇ (1906): 106 (Palearctic catalog); BൾඋǤඋඈඍΗ (1908): 161 (catalog); Kංඋκൺඅൽඒ (1909): 49–50 (World catalog); OඌΗൺඇංඇ (1912): 12 (Palearctic catalog); Jൾൺඇඇൾඅ (1913):61, 67–68 (diagnosis, key and catalog ofAfrican species); BൾඋǤඋඈඍΗ (1921): 4–8 (systematics, possible placement in Halyini ); Hඈൿൿආൺඇඇ (1932): 7 (checklist); TൺඇǤ (1935): 313–314 (Chinese catalog); Bൾංൾඋ (1938): 2187 (list); CൺർΗൺඇ (1952): 397, 402 (key, redescription; included in Carpocorini ); Vංඅඅංൾඋඌ (1952): 68 (diagnosis); SඍංർΗൾඅ (1961): 752 (Palearctic catalog); SඍංർΗൾඅ

(1962): 233 (Palearctic catalog); AΗආൺൽ et al. (1974): 22, 77 (key to genera); Hඌංൺඈ et al.(1977):102 (key to genera); Mൾൽඅൾඋ (1980): 125 ( Nigeria, checklist); AΗආൺൽ (1981): 21 (key to genera); Lංඇඇൺඏඎඈඋං (1982): 114–118 (key to genera, diagnosis, species-groups and key to Afrotropical species); Aൻൻൺඌං (1986): 28 (key to genera), 65–66 (diagnosis); AΗආൺൽ & Zൺංൽං (1989): 238–239 (redescription, key to Indo-Pakistan species), 248–253 (phylogenetic relationships); Zൺංൽං et al. (1990): 41–47 (phenetics); Hൺඌൺඇ (1993): 209–210 (redescription, key to species of Malayan subregion); Lංඇ & ZΗൺඇǤ (1993): 119 (key to genera); Zൺංൽං & SΗൺඎκൺඍ (1993): 60–65 (phenetics); CΗൺκඋൺൻඈඋඍඒ & GΗඈඌΗ (1999): 392 (list), 397 (key to genera); Gൺൽൺඅඅൺ (2004): 49 (diagnosis); Lංඎ & WൺඇǤ (2004): 183 (key to genera); WൺඇǤ & Lංඎ (2005):285 (key to genera); Rංൽൾඋ (2006): 261 (Palearctic catalog); Bංඌඐൺඌ & Bൺඅ (2007):313 (key to genera); Rංൽൾඋ (2012): 330 (key to genera); Sඐൺඇඌඈඇ (2012): 297 (list); Aඎκൾආൺ et al. (2013): 448 (Palearctic catalog); Sൺඅංඇං & VංඋൺκඍൺආൺඍΗ (2015): 12, 16–17 (key to genera, checklist, India); Rංൽൾඋ et al. (2018): 76, 100, 105–106, 134, 197, Fig. 2.28 (systematic placement); Rඈർൺ- CඎඌൺർΗඌ & JඎඇǤ (2020): 37, 46 (in key, fauna of South Korea); Sൺඅංඇං (2020): 129 (key).

Halymorpha [incorrect subsequent spelling]: Nඈඇඇൺංඓൺൻ (1986): 117 (key to genera), 206 (diagnosis).

Cappaea [misidentification]: Mൾൽඅൾඋ (1980): 124 ( Nigeria, checklist).

Material examined. Halyomorpha halys : 2 ♁♁ 1 ♀, ‘Novara Exp. /

China. [hw] // timorensis [hw] / det. Mayr [p, black line submarginally]

// SPECIMEN USED / FOR DESCRIPTION / OF HALYOMORPHA /

MAYR, 1864 [p] // HALYOMORPHA / HALYS / ( Stål, 1855) / det. P.

KMENT 2021 [p]’ ( NHMW). Body lengths: ♁♁ 12.80 mm ( Fig. 1 ) and

13.17 mm, ♀ 14.92 mm.

Halyomorpha picus : 1 ♁ ( Fig. 2 ), ‘Novara Exp. / China. [hw] //

timorensis [hw] / det. Mayr [p, black line submarginally] // SPECIMEN

USED / FOR DESCRIPTION / OF HALYOMORPHA / MAYR,1864 [p] //

HALYOMORPHA / PICUS / ( Fabricius, 1794) / det. P. KMENT 2021

[p]’ ( NHMW). Body length: 14.63 mm.

Nomenclature. The exact date of publication of the paper containing the original description of the genus Halyomorpha is uncertain. The manuscript was presented by G. L. Mayr at the meeting (Sitzung) of the Kaiserlich-Königliche Zoologisch-Botanische Gesellschaft in Wien [= Imperial and Royal Zoological and Botanical Society in Vienna] on the 7th of December 1864 (cf. Mൺඒඋ 1864: 903). The receipt of a published preprint of the article was mentioned in the record of the meeting of the Matematisch-Naturwissenschaftliche Classe der Kaiserlichen Akademie der Wissenschaften [= Imperial Academy of Sciences, Branch of Mathematics and Natural Sciences] on the 9th of February 1865 (cf. Sitzungsberichte der Matematisch-Naturwissenschaftliche Classe der Kaiserlichen Akademie der Wissenschaften, vol. 51, issue 2, p. 135). The first traceable record of the entire published volume (vol. 14, for 1864) of Verhandlungen der Kaiserlich-Königlichen Zoologisch- -Botanischen Gesellschaft in Wien, consisting of three issues (1–2, 3 and 4), mentioned it with the date of 23 February 1865 (cf. vol. 15, p. 17 of the same journal); the Allgemeine Bibliographie für Deutschland recorded it on p. 68 of issue 9 of its 1865 volume, published on 2 March 1865. Mayr’s article (contained in issue 4) was certainly published and distributed as a preprint after 7 December 1864 but before 9 February 1865, possibly only in early 1865. Because a publication in late December 1864 cannot be excluded, the date printed on the front page of the volume (1864) is, however, accepted. The correct publication date of Mൺඒඋ (1866) was discussed by HංǤǤංඇඌ (1963).

Halyomorpha was established for a single included species (i.e., type species by monotypy), cited as Halyomorpha timorensis Hope’ (Mൺඒඋ 1864); however, this taxon name must be attributed to J. O. Westwood (see Kංඋκൺඅൽඒ 1907). Subsequently, Mൺඒඋ (1866) provided a detailed redescription of Halyomorpha and compared it with Pentatoma Olivier, 1789 and Oncocoris Mayr, 1866 ; he listed the single included species as ‘ Halys timorensis Westwood’. The original description and subsequent redescription of the genus and the included species (Mൺඒඋ 1864, 1866) were all said to be based on specimens from Hongkong and Shanghai, China. Sඍචඅ (1876) listed both Halyomorpha timorensis and H. halys (the latter species described from China) as junior subjective synonyms of H. picus . His taxonomic framework was almost universally accepted for the following one hundred years, and H. picus was accordingly considered as a species widely distributed in eastern and southeastern Asia (e.g., Dංඌඍൺඇඍ 1902, Kංඋκൺඅൽඒ 1909, Hඌංൺඈ & ZΗൾඇǤ 1977). However, starting with Eඌൺκං (1955: 165), most Japanese authors of the 20th century distinguished the Japanese populations of Halyomorpha as a separate species, H. brevis Walker, 1867 , originally described also from Hongkong (Wൺඅκൾඋ 1867a). Jඈඌංൿඈඏ & KൾඋඓΗඇൾඋ (1978) examined representative material of Halyomorpha specimens from the Palearctic East Asia ( Japan, Korea and east China), and concluded that they belong to a single species, distinct from H. picus distributed in the Oriental Region. Accordingly, they resurrected H. halys as the oldest available name for the East Palearctic species, but they accepted H. timorensis as a junior synonym of H. picus . All subsequent authors accepted H. picus as the type species of Halyomorpha (Nඈඇඇൺංඓൺൻ 1986, AΗආൺൽ & Zൺංൽං 1989, Hൺඌൺඇ 1993, Gൺൽൺඅඅൺ 2004, Rංൽൾඋ 2006), despite the fact that Mൺඒඋ (1864, 1866) purportedly based the generic description on specimens from southeast China, where only H. halys is known to occur (see Hඌංൺඈ & ZΗൾඇǤ 1977, as H. picus ; Jඈඌංൿඈඏ & KൾඋඓΗඇൾඋ 1978; Rංൽൾඋ et al. 2002; Rංൽൾඋ 2006; Vඣඍൾκ et al. 2014; Hൺආංඅඍඈඇ et al. 2018).

To elucidate the contradiction concerning the identity of the type species of Halyomorpha , we borrowed the voucher specimens from Mayr’s collection, now housed in the Naturhistorishes Museum in Vienna. Due to the courtesy of Herbert Zettel, we examined four specimens bearing the original locality labels of Novara Expedition and identification labels by Mayr. Among them we identified two males and one female of H. halys (male and female external genitalia corresponding with illustrations in Vඣඍൾκ et al. 2014 and Sൺඅංඇං et al. 2021a) and one male of H. picus (external male genitalia corresponding with Sൺඅංඇං et al. 2021a, Kආൾඇඍ et al. 2021, and a male syntype of H. picus in ZMUC – P. Kment, pers. observ.). Concerning the presence of H. picus among the examined material from ‘China’, we were convinced about the mislabelling of the specimen, originating most probably from Ceylon [= Sri Lanka] or Madras [= Chennai, India], areas that were also visited and sampled during the Novara Expedition (SർΗൾඋඓൾඋ 1861a,b). We further examined the only available syntype of Halys timorensis held in the collection of the Oxford University Museum. Based on its examination we accept H. timorensis as a valid species distinct from H. picus (see below).

These discoveries result in a rather unusual case of double misidentification of the type species of Halyomorpha . In such a situation, Article 70.3 of the ICZN (1999) applies, and we are supposed to select, and thereby fix as type species, the species that will best serve stability and universality of zoological nomenclature, either i) the nominal species previously cited as type species (i.e., Halys timorensis Westwood, 1837 , Art. 70.3.1) or ii) the taxonomic species actually involved in the misidentification (i.e., either Cimex picus Fabricius, 1794 or Pentatoma halys Stål, 1855 , Art. 70.3.2). As H. timorensis is a poorly known species with male characters unknown, and there is no doubt that the description of Halyomorpha (Mൺඒඋ 1864, 1866) was based on a study of other species, we consider the first possibility as inadvisable. Of the two remaining taxa, we prefer to choose H. halys , the species native in Hongkong and Shanghai area and currently by far the best known and intensively studied species of Halyomorpha (cf. Hൺආංඅඍඈඇ et al. 2018). Therefore, we fix here Pentatoma halys Stål, 1855 [= Halys timorensis (non Westwood, 1837): Mൺඒඋ (1864) (partim), misidentification] as the type species of Halyomorpha Mayr, 1864 acting as first revisers according to the Article 70.3 of the ICZN (1999).

Figures

Figs 1–3. Specimens of Halyomorpha Mayr, 1864 from Mayr collection (NHMW): 1 – Halyomorpha halys (Stål, 1855), male (body length 12.80 mm); 2 – Halyomorpha picus (Fabricius, 1794), male (14.63 mm); 3 – labels. Orig. P. Kment.