Corresponding author: Bert Kohlmann (
Academic editor: A. Frolov
An analysis of vicariant speciation of
Se realiza un análisis de especiación vicariante de
Kohlmann B, Arriaga-Jiménez A, Rös M (2018) Dung beetle vicariant speciation in the mountains of Oaxaca, Mexico, with a description of a new species of
Recent collecting and taxonomic studies of dung beetles of the genera
In this paper
This new species brings the number of known Mexican
An updated key as well as new localities and commentaries for species of the
The superb personal collection of Julián Blackaller, in Soria, Guanajuato, Mexico, was reviewed; as well as the collection of the National Museum in Costa Rica and the Canadian Museum of Nature in Ottawa, Canada. Collections made by Arriaga-Jiménez as part of her studies on mountain dung-beetles, which are deposited in the entomology collection at the Institute of Ecology, Xalapa, Mexico, were also studied. Body measurements were made to the nearest 0.1 mm using an ocular micrometer with a Stemi DV4 stereoscope. Genital dissections and preparations were done following the techniques described by
The photos were taken by Alfonso Aceves from the Instituto de Ecología (
The holotype, allotype, and two paratypes of
Holotype male, pinned, with genitalia in a separate microvial. Original label: “México. La Mesita San Pablo Etla. Oaxaca.
23-VI-17, coprotrampa,
(5 males, 5 females). Paratypes: “Mexico. Reserva Comunitaria San Pablo Etla. Oaxaca. 27-IV-17, coprotrampa,
La Mesita San Pablo Etla (
Colección Entomológica
Distinctly granulate male pronotal disk; sagittal furrow present on the female pronotum; unmodified sutural margin of the elytra; pygidium longer than wide. Its basal border forming a small indentation medially, usually all-black color.
Major male habitus in
Pygidia of
Female habitus of
Length: 12.6–18.7 mm. Humeral width: 7.9–11.1 mm. Pronotal disk of males may vary from black without reflections to having a green or red lustre. Minor male (Fig.
Dorsal habitus of a minor male of
Due to the fact that this species has been collected in association with
So far, this species is only known from San Pablo Etla in the Sierra Norte (Sierra de Ixtlán) in Oaxaca (Fig.
Map of the known distribution of
Drone photographs of the dry oak forest where
The known distribution of
Major male habitus in
We therefore revalidate
Recently this species has been described as found in Guerrero. Here we complement its poorly known distribution with new localities from the Blackaller private collection:
Guerrero (38 specimens): S. del Alquitrán, 1470 m 22-VI-1990 Luz L. Delgado, J. Blackaller col.; Palo Blanco, 20-VI-1990 Alt. 1400 m Bosque de pino-encino; Bosque Mesófilo, Alt. 1,710 mts. Coprotrampa exc. humano, 28 jun-24 jul/2055 EPE 5 mts.,
This study identifies new localities of this species present in the Blackaller private collection, which seems to have a rather restricted distribution in the State of Mexico.
Estado de México (8 specimens): Sierra de Nanchititla, 6 km al Este de Nanchititla, Bosque de Pino-Encino, CD en Hongos, 1840 m, 15-VIII-2015,
Comparing this species with its closest relative,
Recently this species has been described as from Jalisco and Nayarit. We register here the northernmost and first locality of this species from the state of Sinaloa using material from the Blackaller private collection:
MEXICO (1 male, 1 female). Sinaloa. La Venada. 4 km al Noroeste de Microondas. Loberas. Bosque de pino-encino. 1780 msnm en excremento. 16-18/VIII/2007 EPE 5 metros CG
1 | Sutural margin of each elytron upturned to form a sharp ridge, which is progressively more elevated posteriorly and prolonged into a small, sharp tooth at apical angle; elytral margin slightly excised adjacent to this tooth |
|
– | Sutural margin of elytra simple. Color and distribution variable |
|
2 | Major male with a tooth in the middle of anterior pronotal margin, pronotal triangle sides’ straight, pygidium covered with coarse punctures. State of Mexico |
|
– | Major male lacks a tooth in the middle of anterior pronotal margin, pronotal triangle sides’ curved, pygidium covered with faintly impressed small punctures. Central Guerrero |
|
3 | Triangular pronotal disk of male evenly and densely but finely granulated (×10), granules in most specimens larger and becoming squamose along lateral margins of disk and extending onto posterolateral angles (when distinctly developed); sides of pronotum roughened (×10), lacking distinct punctures except behind lateral fossae. Female pronotum minutely roughened, evenly, distinctly punctate (×10), punctures becoming smaller dorsally but not disappearing altogether; disk impressed medially as a distinct furrow visible to unaided eye, extending forward from posterior margin to near middle of disk. Oaxaca |
|
– | Pronotal disk of male either lacking distinct granulation, or, if granules present, these are minute and restricted along lateral margins of disk; sides of pronotum smooth, minutely punctate. Female pronotum smooth, punctures (×50) fine and usually restricted to sides; median furrow lacking or at most indicated by a fine, scarcely visible line |
|
4 | Major males with long and slender posterolateral angles of pronotum (Fig. |
|
– | Major males with short and rounded posterolateral angles of pronotum (Fig. |
|
5 | Elytral interstriae distinctly flattened and uniformly dull (more convex and shiny in some Central American populations); striae not strongly impressed basally, anterior ends in most specimens bearing deep punctures rather than large fossae. Male: Pronotal disk dull, velvety smooth medially, finely asperate, brighter laterally. Female: Pronotum evenly convex, lacking anteromedial concavity even in largest specimens, bearing three round, smooth tubercles in transverse line near anterior margin. Head and pronotum highly shiny metallic red or green to nearly completely dull black with metallic red restricted to ridges and isolated areas on anterior part of pronotum; elytra dull to lightly shiny black; pygidium usually metallic red medially, green peripherally, in some completely red or green. Southern Nicaragua through Central America into western Colombia and Ecuador |
|
– | Elytral interstriae evenly convex and glossy midlongitudinally; striae impressed basally as distinct fossae. Male: Pronotal disk velvety smooth medially, finely asperate laterally and sometimes also medially. Female: Pronotum with anteromedial concavity bounded anteriorly by a raised U- or V-shaped ridge |
|
6 | Major males with short and rounded posterolateral angles of pronotum (Fig. |
|
– | Major males with long and slender posterolateral angles of pronotum (Fig. |
|
7 | Head and pronotum green or blue with dark green elytra; male pronotum with sparse and blunt granulation on disc; female pronotal trituberculate ridge forming a triangle. Ecuador |
|
– | Body black or with head and pronotum metallic red or green and black elytra; male pronotum with fine reticulation on disc; female pronotal trituberculate ridge forming a transverse line. Nicaragua to Ecuador |
|
8 | Dorsum dark blue or shiny green; in few specimens shiny green with strong yellow reflections. Anterior margin of pronotum projected forwards. Relatively rounded posterolateral angles of pronotum. Southwestern Mexico to Honduras |
|
– | Dorsum metallic green. Anterior margin of pronotum projected upwards. Acute posterolateral angles of pronotum |
|
9 | Anterior metasternal angle obtuse in lateral view. Lateral metasternal angles well defined and slightly curved. Few specimens olive green with golden/reddish reflections. Eastern Oaxaca and western Chiapas |
|
– | Anterior metasternal angle almost right angled but with rounded apex in lateral view. Lateral metasternal angles evanescent. Jalisco and Nayarit |
|
This species has been recorded only once in the literature, more than 40 years ago, when Howden described it in 1974 in the Sierra Sur (Sierra de Miahuatlán). Using the only two known distribution records reported by
Below, an updated key for the genus
Mexico. Oaxaca. Zempoaltéptl, 27-V-17, coprotrampa,
Oaxaca. Duraznal,
So far, this species has only been collected in Oaxaca and seems to be restricted to the Sierra Norte (Sierra de Ixtlán, Sierra Mazateca, and Nudo del Zempoaltépetl) in the northern part of the state.
Dorsal habitus of
Aedeagi of
The known distribution of
1 | Antennal club grayish-black; each mandible with a very pronounced rounded lobe. Sierra Sur (Sierra de Miahuatlán) |
|
– | Antennal club yellowish or reddish brown to brown; mandibles lacking a very pronounced rounded lobe |
|
2 | Dorsally shining, often green or blue, elytral intervals convex |
|
– | Dorsally dull black; elytral intervals flattened centrally; large species with males having the fore femora ventrally excavated near the coxae; mountains in central Mexico and Sierra Norte (Sierra de Ixtlán) |
|
3 | Posterior pronotal margin fine but distinct, except in front of scutellum. Sierra Norte (Sierra de Ixtlán) |
|
– | Posterior pronotal margin indistinct or lacking in front of third to seventh elytral striae |
|
4 | Elytral striae finely punctate or crenulated except near suture; elytra normally greenish-black, sometimes with reddish tint; pronotum punctate laterally (Fig. |
|
– | Elytral striae virtually impunctate, at most vaguely crenulate; elytra black with faint tinge of green on elytron; pronotum generally heavily and grossly punctate (Fig. |
|
In relation to this lowering of the glaciers during the LGM,
The Rufford Foundation financed the fieldwork, RSG grant 20054-1, given to AAJ. The authors thank Axel Arenas Parral, Paola González and María José Rodríguez for their help during fieldwork and to Ángel Solís, Museo Nacional de Costa Rica, for taking the photographs of
Figure S1
Figure (PNG file)
Pronota close-ups of