Cheilonycha Lacordaire, 1842

Moravec, Jiří, 2019, Taxonomic and nomenclatorial revision within the Neotropical genera of the subtribe Odontocheilina W. Horn in a new sense- 22. Genus Cheilonycha Lacordaire, 1842 (Coleoptera: Cicindelidae), Zootaxa 4700 (4), pp. 501-534 : 503-504

Genus Cheilonycha Lacordaire, 1842

Cheilonycha Lacordaire, 1842: 28 (reprint Quadart, the paper (Liége) was published in 1843: 92).

Type species. Cicindela chalybea Dejean, 1825 (by original monotypy—see “Discussion” below).

Chilonycha : Agassiz 1846: 78, 80 (unjustified emendation).

Odontochila group Chilonycha : Horn 1910: 203.

Chilonycha : Horn 1910: 203.

Odontochila (Chilonycha) : Horn 1934: 124.

Cheilonycha: Reichardt 1977: 374 .

Differential diagnosis. Protarsi sexually dimorphic, first three protarsomeres in male dilated; body medium-sized with markedly wide elytra in comparison to head and pronotum, glabrous, either uniformly black-blue to cyaneous-blue, usually with violaceous lustre, or with chatoyant green, black-blue, or deep violaceous-blue head and pronotum while elytra shiny red or gold-bronze, usually with shiny green lateral areas and shiny red elytral disc, completely lacking white maculation; elytral disc mostly distinctly convex with distinct posterior declivity; elytral apices rounded towards small sutural spine, microserrulation extremely fine, indistinct, irregular or partly absent; elytral punctation either almost regular and dense, or punctures rather spaced and partly irregular; pronotum glabrous, slightly but notably wider than long, discal surface and surface of head finely or extremely finely and densely vermicular-wavy to zigzag-wavy striate-rugulose; palpi and antennomeres 1–4 metallic-black with various iridescence; labrum primarily 4-setose, metallic blue or blue-green throughout, with various violet or green iridescence, shape sexually dimorphic: male labrum either rather short with effaced or rounded anterolateral and outer anterior teeth and with only median tooth, or with notably anteriad-prolonged tridentate anteromedian lobe; female labrum with prolonged tridentate median lobe and more or less distinctly prolonged median tooth; mandibles normally shaped with arcuate lateral margins, subsymmetrical, each mandible in both sexes with four teeth (and basal molar); aedeagus elongate, widest in middle, apical half attenuated towards rounded apex; internal sac lacking any flagellum.

Distribution. Brazil, Paraguay, Argentina and Bolivia, habitat termitophilous.

Discussion. The original description of the genus Cheilonycha was first published in a reprint and spread by Lacordaire (1842). Although the main publication came out one year later ( Lacordaire 1843), the publication date should be 1842. It is also in accordance with the genus-group name Phyllodroma Lacordaire, 1842 published in the same reprint (see also Lorenz 2005a,b, Erwin & Pearson 2008 and Moravec 2018b).

Lacordaire (1842) based his original description of the genus Cheilonycha on Ch. chalybea (originally Cicindela chalybea Dejean, 1825 ). He mentioned under the description: “je ne connais que l’espece brésilienne ci-dessus qui puisse rentrer dans ce genre. Me exemplaires viennent de la province Goyaz” (freely translated: “ I only know the Brazilian species above that can fit into this genus. My specimens come from Goyaz province ”). The last sentence is somewhat puzzling, because Ch. chalybea has not been recorded from the state of Goiás (= Goyaz). Nevertheless, the state is very large and has its long boundary with the state of Minas Gerais where Ch chalybea occurs. In any event, a possibility that Lacordaire misidentified Ch chalybea with Ch. auripennis which was described 14 years later and was therefore unknown to him, would be a mere speculation, because there is no evidence of such confusion. Unfortunately, Lacordaire did not describe the dorsal body coloration which immediately differentiates the species, while the other characters are basically shared with all species of the genus. It must be noted here that it is impossible to trace the specimens which Lacordaire had in his hand, and, moreover, they might have been mislabelled. Furthermore, the confusion was almost impossible, because it was improbable that Lacordaire overlooked the fundamental distinguishing character of Ch. chalybea , which is the uniformly blue coloration clearly described by Dejean (1825) as “ Elle est entiérement tant en-dessus qu’en dessous, d’une belle couleur bleue assez brillante ”. Nevertheless, Horn (1915 and repeatedly 1926a), giving no reasons for his decision but probably influenced by the occurrence in Goiás (Goyaz) mentioned by Lacordaire (1842, 1843), gave the type species of Cheilonycha as Ch. auripennis Lucas, 1857 . From the nomenclatorial point of view, this treatment by Horn (1915, 1926a) cannot be accepted as a justified subsequent type designation, because Lacordaire (1842) mentioned only the name Cicindela chalybea Dejean, 1825 on which he based his description of his new genus Cheilonycha —see Art. 67.2.1 ( ICZN 1999). Not only that Lacordaire clearly referred to Ch. chalybea and no other species-name was mentioned by him either in the private reprint spread in 1842 or in the main paper published in 1843, but as discussed above, there is no evidence that he confused Ch. chalybea with any other species of the genus.

Recently also Lorenz (1998a, 2005a) and Erwin & Pearson (2008) have Cicindela chalybea Dejean, 1825 as the type species of Cheilonycha in accordance with the reasons mentioned above.

Blackwelder (1944) inadequately treated the genus-group name (as “subg. Chilonycha ”) as a synonym of Odon- tocheila Laporte de Castelnau, 1834 (spelled by Blackwelder as “ Odontochila ”). Horn (1910, 1915, 1926a, 1934, 1938) used the spelling “ Chilonycha ” and Odontochila , both forms of spelling arising from the unjustified emendations by Agassiz (1846). Rivalier (1970) still maintained the spelling of the genus-group name as “ Chilonycha ” (equally with “ Odontochila ” by Rivalier 1969). Reichardt (1977) was probably the first author who restituted the original name spelling as Cheilonycha ; moreover, he treated the genus in the subtribe Odontocheilina in accordance with the present revision. The restituted name spelling has been used by all subsequent authors such as Wiesner (1992), Pearson, Guerra & Brzoska (1999), Bosquet (2002), Erwin & Pearson (2008), Moravec (2018a, b).