Research Article |
Corresponding author: Si-Qin Ge ( gesiqin12@hotmail.com ) Academic editor: Alexander Kirejtshuk
© 2020 Zheng-Zhong Huang, Xing-Ke Yang, Si-Qin Ge.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Huang Z-Z, Yang X-K, Ge S-Q (2020) A new genus of Languriinae from Mexico (Coleoptera, Erotylidae), with comments on the potential mimic phenomenon of some languriines. ZooKeys 935: 93-101. https://doi.org/10.3897/zookeys.935.49957
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A new genus of Languriinae, Tomolanguria Huang, gen. nov. is erected for a single species, Languria aculeata Gorham, 1887 from Mexico. It is similar to the Neotropical genus Languria Latreille, 1802. The differential diagnosis of this new genus is based on the structural features of the elytral apices and slight impressions present on each elytron. Languria aculeata is designated as the type species of the new genus. This species is redescribed and illustrated (all the three specimens examined are shown in the dorsal, ventral, and lateral views). Finally, a mimic relationship between this new genus and genus Paederus Fabricius, 1775 (Staphylinidae) is discussed.
Cucujoidea, Neotropical Region, new combination, Tomolanguria
Languria aculeata was first described by
The type series of Tomolanguria gen. nov., Anadastus ornatus Arrow, 1925, A. pulchellus Arrow, 1925, A. jucundus (Gorham, 1903), Clerolanguria tricolor (Fabricius, 1787), and Stenolanguria tricolor Fowler, 1885 are deposited in the Natural History Museum, London, United Kingdom (
All photographs were taken with a Canon 5D Mark III digital camera equipped with a Canon MP-E 65 mm lens. The images were stacked with Helicon Focus 6.7.1 and modified in Adobe Photoshop CS6 to correct for contrast, brightness, and imperfections.
Body length was measured from the apices of mandibles to the apices of elytra.
Subfamily Languriinae Hope, 1840
Tribe Languriini Hope, 1840
Languria aculeata Gorham, 1887.
The new genus is a member of tribe Languriini, based on the presence of a frontoclypeal suture; the antennal club composed of more than three antennomeres and relatively oval in cross-section. The only species of Tomolanguria can be separated from other languriine genera by the following combination of characters: body length 8.5–9.5 mm, body slender without unified metallic luster, at least prothorax without any metallic luster; antennal club not very dilated; eyes moderate in size and with fine facets; mandibles similar to each other; pronotum finely punctured, without basal foveae; lateral sides of pronotum rounded and prothorax more or less subcylindric, not flattened; elytral epipleura distinct, each elytron with transverse and very weak depressions, apices of elytra being produced and strongly tapering, rounded and with several small denticles.
The elytral structure, which often shows the differences among genera of Languriinae, is a relatively reliable morphological character. Tomolanguria is closely related to genus Languria Latreille, 1802, sharing with the latter a similar external appearance. From Languria, it can be distinguished by having the antennal club not very dilated; lateral sides of pronotum rounded and prothorax more or less subcylindric; each elytron with transverse and weak depressions, and apices of elytra being more or less produced and strongly tapering, and also with several small denticles. However, the elytral apex of Languria is simply rounded and somewhat tapering, and neither produced nor with denticles. Tomolanguria also resembles the Neotropical genera Acropteroxys Gorham, 1887 and Langurites Motschulsky, 1860. Tomolanguria differs from Acropteroxys in having the pronotum finely punctured, with lateral side rounded, and apices of the elytra produced and bearing small denticles. Tomolanguria differs from Langurites in having the lateral side of pronotum rounded and the apices of the elytra with neither a sharp sutural angle nor an outer angle.
On the other hand, a similar structure of the elytra is demonstrated in the Oriental genus Paederolanguria Mader, 1939 and African genus Stenolanguria Fowler, 1885 (Fig.
The name is derived from the Greek word Τομός (Latin transliteration as tomós, meaning “sharp”, referring to the apex of the elytra) and the generic name Languria (as in Paederolanguria, Megalanguria, Caenolanguria, etc.). Gender feminine.
Mexico, San Andrés Tuxtla.
Only one species.
Languria aculeata:
Mexico, San Andrés Tuxtla.
Body length 8.5–9.5 mm. Body narrow and elongate, moderately convex. Integument finely and sparsely punctured. Head pitch black. Antenna brown except for last five antennomeres yellowish. Prothorax orange. Basal third of elytra coppery green or metallic blue, remainder deep brown or black, without metallic luster.
Tomolanguria aculeata (Gorham, 1887), comb. nov. A–D lectotype of T. aculeata: A dorsal habitus B ventral habitus C lateral view D labels E–H paralectotype of T. aculeata: E dorsal habitus F ventral habitus G lateral view H labels I–L second paralectotype of T. aculeata: I dorsal habitus J ventral habitus K lateral view L labels. Scale bars: 2mm.
Antenna with 11 antennomeres and club composed of five fringed antennomeres. Antennomere III almost as long as antennomere IV, antennomere V subequal to antennomere VI, both of them shorter than each of antennomeres III or IV, antennomere VII subtriangular but slightly dilated, antennomeres VIII–XI dilated, apex of antennomere XI rounded. Head with fine punctation, nearly smooth. Clypeus broader than long. Eyes large, finely faceted. Mandibles robust and with outer side nearly straight.
Pronotum slightly convex, distinctly longer than broad, with sides rounded, constricted at the base. Pronotum finely punctured, without basal foveae. Anterior angle rounded, posterior angle acute but not produced. Lateral and basal margins beaded. Prohypomera smooth, without punctation or folds. Prosternal process long, with apex strongly bent downwards. Procoxal cavities open. Mesoventrite without punctation, nearly smooth (Fig.
Comparison between Paederolanguria holdhausi Mader, 1939 and Tomolanguria aculeata (Gorham, 1887), comb. nov. A Holotype of Paederolanguria holdhausi Mader, 1939 B P. holdhausi, prosternum and mesoventrite with punctures, non-type C T. aculeata, prosternum and mesoventrite without punctures, paralectotype D P. holdhausi, abdomen, non-type E T. aculeata comb. nov., abdomen, paralectotype F lateral view of T. aculeata, black arrows show the depressions on the elytron, paralectotype G later view of body of P. holdhausi, black arrow shows the prosternal process nearly straight, non-type H same of T. aculeata, black arrow shows the prosternal process downwards, paralectotype I P. holdhausi, apex of the elytra, non-type J T. aculeata comb. nov., apex of elytra, paralectotype. Scale bars: 1 mm (A–C, I, J); 2 mm (D–H).
Scutellar shield short and cordiform, apex not acute. Elytra regularly striate-punctate, vanishing before apex. Elytral epipleura distinct, narrow. Elytra at humeri slightly broader than base of pronotum. Sides of elytra parallel, narrowed posteriorly. Each elytron with four shallow transverse depressions (Fig.
Lectotype
(
Mexico, San Andrés Tuxtla.
The potential mimicry between Languriinae and Staphylinidae has been recorded (
Body of species from different genera of Languriinae that may imitate genus Paederus. A Anadastus ornatus Arrow, 1925, syntype B A. pulchellus Arrow,1925, holotype C A. jucundus (Gorham, 1903), syntype, synonym of A. bifasciatus (Motschulsky, 1860) D Clerolanguria tricolor (Fabricius, 1787), syntype E Paederolanguria alternata (Zia, 1959), holotype F P. klapperichi Mader, 1955, holotype G Stenolanguria tricolor Fowler, 1885, syntype H S. robusta Villiers, 1958, holotype. Scale bar: 2 mm (A–D, H); 1 mm (E, F); 5 mm (G).
After discussion with Dr José Luis Navarrete-Heredia, a specialist of Staphylinidae, we suggest that Paederus signaticornis Sharp, 1886 should be a suitable model for Tomolanguria aculeata (Fig.
The genus Paederus is famous for their toxic, paederus dermatitis (
We sincerely thank Mr Maxwell Barclay (