Helictopleurus halffteri Balthasar 1964

Rossini, Michele, Montanaro, Giulio, Montreuil, Olivier & Tarasov, Sergei, 2024, Towards computable taxonomic knowledge: Leveraging nanopublications for sharing new synonyms in the Madagascan genus Helictopleurus (Coleoptera, Scarabaeinae), Biodiversity Data Journal 12, pp. e 120304-e 120304 : e120304-

Helictopleurus halffteri Balthasar 1964

Helictopleurus halffteri Balthasar 1964: 623 (Figs 2 b, 3 d); Montreuil 2005 b: 346;

Helictopleurus dorbignyi Montreuil 2005 a: 123 (syn. nov.) (Figs 2 a , 3 d );

Materials

Type status: Holotype. Occurrence: individualCount: 1; sex: female; lifeStage: adult; preparations: dry; disposition: in collection; occurrenceID: CFD3997A-2906-5551-BCF5-C12E9C1DFE2F; Taxon: scientificName: Helictopleurus halffteri Balthasar, 1963 ; namePublishedIn: Balthasar V. 1964. Neue Oniticellinen-Arten. (119. Beitrag zur Kenntnis der Scarabaeoidea ( Coleoptera )). Beiträge zur Entomologie, 14 (5-6): 619 – 624; class: Insecta; order: Coleoptera ; family: Scarabaeidae ; genus: Helictopleurus ; specificEpithet: halffteri ; taxonRank: species; scientificNameAuthorship: Balthasar, 1963; nomenclaturalCode: ICZN; taxonomicStatus: accepted; Location: continent: Africa; country: Madagascar; locality: Antsianaka ; Identification: identifiedBy: V. Balthasar; dateIdentified: 1963; Event: eventDate: 1893-07 / 12; year: 1893; verbatimEventDate: 2 e Semestre 1893; Record Level: institutionCode: NMPC; basisOfRecord: PreservedSpecimen

Type status: Holotype. Occurrence: individualCount: 1; sex: male; lifeStage: adult; preparations: dry; disposition: in collection; otherCatalogNumbers: MALP 0657; occurrenceID: 0026A7F3-DD0E-5D00-990A-33F6FE3C919F; Taxon: scientificName: Helictopleurus dorbignyi Montreuil, 2003 ; namePublishedIn: Montreuil O. 2005. Nouveaux Helictopleurus d’Orbigny, 1915 de Madagascar et révision du « groupe semivirens » sensu Lebis, 1960. Zoosystema, 27 (1): 123-135; class: Insecta; order: Coleoptera ; family: Scarabaeidae ; genus: Helictopleurus ; specificEpithet: dorbignyi ; taxonRank: species; scientificNameAuthorship: Montreuil, 2005; nomenclaturalCode: ICZN; taxonomicStatus: subjective synonym; Location: continent: Africa; country: Madagascar; locality: Antsianaka, lac Alaotra ; verbatimLocality: Antsianaka et lac Alaotra; Identification: identifiedBy: O. Montreuil; dateIdentified: 2003; Event: eventDate: 1889-07 / 12; year: 1889; verbatimEventDate: 2 e Semestre 1889; Record Level: institutionCode: MNHN; basisOfRecord: PreservedSpecimen

Type status: Lectotype. Occurrence: individualCount: 1; sex: male; lifeStage: adult; preparations: dry; disposition: in collection; otherCatalogNumbers: MALP 0652; occurrenceID: F41F1258-D172-5CFC-AF96-A9612C20D073; Taxon: scientificName: Helictopleurus seminiger d'Orbigny, 1915 ; namePublishedIn: d'Orbigny, H. (1915) Synopsis d’un genre nouveau d’Oniticellides ( Scarabaeidae Coprini) spécial à Madagascar. Annales de la Société entomologique de France, 84, 402–434.; class: Insecta; order: Coleoptera ; family: Scarabaeidae ; genus: Helictopleurus ; specificEpithet: seminiger ; taxonRank: species; scientificNameAuthorship: d'Orbigny, 1915; nomenclaturalCode: ICZN; taxonomicStatus: accepted; Location: continent: Africa; country: Madagascar; locality: Antsianaka ; verbatimLocality: Antsianaka; Identification: identifiedBy: O. Montreuil; dateIdentified: 2003; Event: eventDate: 1892-01 / 06; year: 1892; verbatimEventDate: 1 re Semestre 1892; Record Level: institutionCode: MNHN; basisOfRecord: PreservedSpecimen

Diagnosis

Within the semivirens group, H. halffteri may be related to H. seminiger . Males can be distinguished by the clypeal tubercle simple (laterally connected to two ridges in H. seminiger ) and the frontoclypeal carina trituberculate (simple in H. seminiger ). No female specimens of H. seminiger are known, as the type series includes the male lectotype only (see " Taxon discussion " below).

Distribution

Antsianaka and Lac Alaotra (Fig. 3 d ).

Taxon discussion

The Helictopleurus semivirens species-group includes 10 species: H. aeneoniger Lebis, 1960 , H. cambeforti Montreuil, 2005 , H. halffteri Balthasar, 1964 , H. heidiae Montreuil, 2007 , H. niger d’Orbigny, 1915 , H. pseudoniger Montreuil, 2005 , H. seminiger d’Orbigny, 1915 , H. semivirens d’Orbigny, 1915 , H. steineri Paulian & Cambefort, 1991 and H. tamatavensis Montreuil, 2005 ( Montreuil 2005 a).

Helictopleurus halffteri shares exclusive phenotypic traits with the members of the group, such as head ogival-shaped and elongated (unique within Helictopleurus ); head of male often with clypeal tubercles, frontoclypeal carina and frontal tubercles and / or curved carina; dorsal side of the body very polished, fairly dark, dull to feebly shining; elytra visibly longer than pronotum with respect to the majority of Helictopleurus species.

Balthasar (1964) described H. halffteri on a single female specimen collected by the Perrot brothers in 1893 in Antsianaka and, after its description, the species name appeared only in one checklist ( Montreuil 2005 a). On studying the Helictopleurus of the semivirens group, Montreuil (2005 a) discovered that the type series of H. seminiger , which allegedly consisted of one male and one female specimen, included instead two distinct species. Actually, the specimen that d’Orbigny (1915) identified as female turned out to be a male and was designated by Montreuil (2005 a) as the holotype of the new H. dorbignyi . Therefore, the type series of H. seminiger currently consists of a unique male designated as the lectotype ( Montreuil 2005 a).

The type series of H. dorbignyi is composed of the male holotype collected in Antsianaka, lake Alaotra and multiple male and female paratypes collected further south, in the Ranomafana National Park and nearby localities (Fianarantsoa) (Fig. 3 d ). On studying the external morphology and genitalia of the type specimens of H. dorbignyi deposited in the MNHN, we realised that the type series is composed of at least two distinct species: one represented by the male holotype alone; the other represented by several males and females collected in Ranomafana. Therefore, in the light of the abovementioned facts and after examination of the holotype of H. halffteri , we conclude that:

(i) the morphology of the female holotype of H. halffteri and its type locality suggest that this specimen is conspecific with the male holotype of H. dorbignyi . Thus, H. dorbignyi is established as junior subjective synonym of H. halffteri ( H. dorbignyi syn. nov.).

(ii) The study of the female genitalia of H. halffteri and female paratypes of H. dorbignyi collected in Ranomafana indicates that they belong to different species. Therefore, a new Helictopleurus species from Ranomafana is waiting formal description.

Interestingly, the unique type specimen of H. seminiger was collected from Antsianaka – which is the same type locality as H. halffteri – and the species has never been recollected since 1892. These circumstances would make the identity of this taxon questionable. However, during our visit to the Paris museum, we could not study the genitalia of the lectotype of H. seminiger . Possibly, the differences observed on the cephalic processes between H. seminiger and H. halffteri represent a simple variation of a same species. An extensive review of the semivirens group would help to sort out unresolved questions that still hamper the correct identification of these cryptic taxa.

Figures

Figure 2 b. Dorsal and frontolateral habitus and labels of the holotype of H. halffteri;

Figure 3 d. H. halffteri (red arrow indicates the type locality of H. halffteri and H. dorbignyi). Question mark indicates the collecting localities of some of the type specimens of H. dorbignyi syn. nov. (= H. halffteri). These specimens may belong to an undescribed species.

Figure 2 a. Dorsal habitus and labels of the holotype of H. dorbignyi;