Copelatus baculiformis Guignot, 1955

Ranarilalatiana, Tolotra, Raveloson Ravaomanarivo, Lala Harivelo & Bergsten, Johannes, 2019, Taxonomic revision of the genus Copelatus of Madagascar (Coleoptera, Dytiscidae, Copelatinae): the non- erichsonii group species, ZooKeys 869, pp. 19-90 : 19

Copelatus baculiformis Guignot, 1955 Fig. 7B

Copelatus baculiformis Guignot, 1955b: 193.

Type locality.

Madagascar, Massif Ankaratra, Manjakatompo, alt. 1700-1800 m.

Type information from original description.

based on a single female specimen (holotype), collected December 1951 by R. Benoist.

Type material studied.

Antananarivo. Vakinankaratra: Ambatolampy: -HT ♀ (MNHN "coll. Guignot"): // Data in NHRS | JLKB | 000030226 // Madagascar: Massif An- | karatra 1700/1800 Man- | jakatompo XII-51 Benoist // Type [red label] // Guignot det., 1954 | Copelatus | baculiformis n. sp. | Type ♀ //

Diagnosis.

Small size (4 mm). Elytra uniformly dark brown ferrugineous, without a basal testaceous area ( Fig. 7B ) which separates the species from small species of Madaglymbus . The absence of deep impressed elytral striae (remnants of four elytral striae present) separates this species from all other Copelatus of Madagascar except Copelatus peridinus , a larger species (5.7-6.6 mm).

Description.

(based on holotype ♀):

Body length 4 mm. Body shape elongate oval and dark brown to blackish ferrugineous. Head uniformly dark brown ferrugineous to slightly darker posteriorly inside eyes, with thin sparse punctation. Pronotum dark brown ferrugineous, same colour medially and laterally but darker along anterior and posterior third. Disc of pronotum less densely punctuated, posterolateral corners with dense superficial strioles. The entire dorsal surface covered with a microsculpture. Elytra uniformly coloured in same dark brown to blackish ferrugineous colour as anterior and posterior parts of pronotum ( Fig. 7B ). Impressed striae absent but four elytral rows of impressed points present. Innermost, a presumed first row completely lacking, row 2, 3, and 4 visible from base but row 3 less distinct than 2 and 4. Row 5 very vague and only visible posteriorly. Elytra densely covered with punctures which laterally of approximately the third row of points is replaced by strioles (probably only in the female). Appendages testaceous.

Ventral side testaceous to weakly infuscated. Prosternal process carinate also onto apical process. Lateral parts of metaventrite ("metasternal wings") rather broad. Metacoxal lines anteriorly diverging and abbreviated before metaventral margin. Metacoxa with fine and long longitudinal strioles, continuing onto abdominal ventrites, and with 6-7 transverse “wrinkles” anterolaterally.

Male: unknown.

Distribution.

Madagascar, central highlands, only known from type locality Manjakatompo, Ankaratra Massif ( Fig. 11A ).

Habitat and ecology.

Unknown, but according to original description collected at at an altitude of 1700-1800 m. See Hjalmarsson et al. (2013) for a description of the locality Manjakatompo and its conservation priority.

Comments.

No other specimen than the female holotype is known of this species and it is a bit of a "mystery species". We have conducted fieldwork at the type locality Manjakatompo multiple times (2011, 2012, 2014, and 2016) but never found any specimens resembling this species. The species belongs in the hydroporoides species group of Copelatus , but two other Malagasy species placed in this group have turned out to be misidentified Madaglymbus or Exocelina (see above). Copelatus baculiformis was described by Guignot the same year (1955) that he described C. bilunatus , considered mislabeled ( Balke et al. 2014) from the Zimmermann collection. It is certainly possible that also C. baculiformis is based on a mislabeled specimen, but in contrast to C. bilunatus the type locality data is more exact; Massif Ankaratra (mountain), Manjakatompo (locality), 1700-1800 m (altitude in meters), XII-51 (collecting month and year), and R. Benoist (collector), speaking against such a mistake. Based on general external morphology, body shape and lack of striae the species resembles C. peridinus . It is much smaller and therefore likely not conspecific, but they could be closely related, as well as with the female sequenced from Andasibe (NHRS-JLKB000065698).

Figures

Figure 7. Habitus, dorsal view. A Male: Copelatus peridinus B Female: Copelatus baculiformis C Female: Copelatus sp. 2 (Andasibe) D Female: Copelatus distinguendus.

Figure 11. Distribution maps of Copelatus species. A C. marginipennis (circle), C. baculiformis (square) B C. mahajanga (circle), C. sp. 2 (square) C C. pulchellus (circle), C. peridinus (square) D C. distinguendus (circle), C. sp. 1 (square).