Research Article |
Corresponding author: Bert Kohlmann ( bkohlmann64@gmail.com ) Academic editor: Andrey Frolov
© 2018 Bert Kohlmann, Alfonsina Arriaga-Jiménez, Matthias Rös.
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:
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 Phanaeus (Coleoptera, Geotrupidae, Scarabaeidae). ZooKeys 743: 67-93. https://doi.org/10.3897/zookeys.743.23029
|
An analysis of vicariant speciation of Geotrupes and Phanaeus (Coleoptera, Geotrupidae, Scarabaeidae) from the mountains of Oaxaca, Mexico is undertaken. The new species of dung beetle (Coleoptera: Scarabaeidae) from Oaxaca, Mexico, Phanaeus dionysius sp. n. is described. Photos of the habitus and a distribution map are provided. Phanaeus malyi Arnaud is revalidated. An updated key for the Phanaeus endymion species group and new localities are also presented. An updated key for the Geotrupes of Oaxaca and new locality records are also submitted.
Se realiza un análisis de especiación vicariante de Geotrupes y Phanaeus (Coleoptera, Geotrupidae, Scarabaeidae) de las montañas de Oaxaca, México. La siguiente especie nueva de escarabajo estercolero (Coleoptera: Scarabaeidae) se describe de Oaxaca: Phanaeus dionysius sp. n. Se incluyen fotografías, así como el respectivo mapa de distribución. Se revalida a la especie Phanaeus malyi Arnaud. Se presenta una clave puesta al día del grupo de especies de Phanaeus endymion, así como nuevos registros de distribución. Se incluye también una clave puesta al día para los Geotrupes de Oaxaca.
Biogeography, dry oak scrub-forest, last glacial maximum, Phanaeus endymion species group, Phanaeus malyi , revalidation, Sierra Norte, Sierra Sur, sister species, sky-islands dynamic
Biogeografía, dinámica de islas celestes, encinar seco chaparro, especies hermanas, grupo de especies de Phanaeus endymion, Phanaeus malyi , revalidación, Sierra Norte, Sierra Sur, último máximo glacial
Recent collecting and taxonomic studies of dung beetles of the genera Geotrupes Latreille (Coleoptera: Geotrupidae) and Phanaeus MacLeay (Coleoptera: Scarabaeidae) in the mountains of Oaxaca have evidenced the existence of a repeated vicariant speciation pattern. This pattern seems to be located at present between the northern (Sierra Norte) and southern (Sierra Sur) mountain ranges of this state. An analysis of this vicariant speciation mechanism is presented, based on the great taxonomic similarity (sister species) shown by the Geotrupes viridiobscurus Jekel-Geotrupes pecki Howden and Phanaeus dionysius sp. n.-Phanaeus zapotecus Edmonds species pairs where the first species inhabits the northern and the second one the southern mountain systems.
In this paper Phanaeus (Notiophanaeus) dionysius sp. n. is also described, a species that inhabits dry oak scrub forest in the Mexican state of Oaxaca, between 1900 and 2200 m above sea level and belongs to the Phanaeus endymion species group. The number of Phanaeus in Mexico has been increasing during the last years. Since Edmonds and Zídek’s monographic analysis in 2012, three new species have been described just in 2017 from Mexico (
This new species brings the number of known Mexican Phanaeus species to 32 (see
An updated key as well as new localities and commentaries for species of the Phanaeus endymion species group are also presented. We revalidate Phanaeus malyi Arnaud, a member of the aforementioned species group. New distribution records for Phanaeus endymion species group (Ph. bravoensis, Ph. halffterorum and Ph. huichol) are included. New distribution records for Geotrupes viridiobscurus and Geotrupes pecki also are added (G. pecki was last reported 40 years ago;
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 (INECOL), Xalapa, Mexico, using a Canon T2i camera, extension tubes, a 100 mm macro, and an external Canon flash. The photos of Ph. malyi and Ph. pyrois were taken by Ángel Solís from the Museo Nacional de Costa Rica using an Olympus OM-D E-M5 digital camera. Susana Guzmán-Gómez from the Instituto de Biología, UNAM, Mexico, took the photo of the pygidium of Ph. zapotecus, using a Zeiss AXIO Zoom V16 microscope, a Zeiss AxioCam MRc5 camera, and the ZEN (Zeiss Efficient Navigation) multifocal technology programme. The photos of Ph. zapotecus and the Suppl. material
The holotype, allotype, and two paratypes of Ph. dionysius are deposited in the Colección Entomológica (Entomology Collection), Instituto de Ecología, Xalapa, Mexico (IEXA). Further paratypes are deposited in: two paratypes (male and female) in the Canadian Museum of Nature, Ottawa (CMN); two paratypes (male and female) in the Julián Blackaller (JB) personal collection, Soria, Mexico; two paratypes (male and female) in the Patrick and Florent Arnaud (CPFA) personal collection, Saintry sur Seine, France; and two paratypes (male and female) in the Seção de Entomologia da Coleção Zoológica da Universidade Federal de Mato Grosso, Cuiabá (CEMT), Brasil.
Holotype male, pinned, with genitalia in a separate microvial. Original label: “México. La Mesita San Pablo Etla. Oaxaca.
23-VI-17, coprotrampa, 17°9'54"N, 96°44'18"W, bosque de Encino, 1976 m, Arriaga A. and Arenas A. Col.” “HOLOTYPE/Phanaeus dionysius Kohlmann, Arriaga-Jiménez, Rös [red printed label]”. Allotype female: “Mexico. La Mesita San Pablo Etla. Oaxaca. 23-VI-17, coprotrampa, 17°9'54"N, 96°44'19"W, bosque de Encino, 1976 m, Arriaga A. and Arenas A. Col.”
(5 males, 5 females). Paratypes: “Mexico. Reserva Comunitaria San Pablo Etla. Oaxaca. 27-IV-17, coprotrampa, 17°9'53"N, 96°44'20"W, bosque de Encino, 1974 m, Arriaga A. and Arenas A. Col.” (1 males, 2 females) (CMN, CEMT, CPFA); “Mexico. La Mesita San Pablo Etla. Oaxaca. 23-VI-17, coprotrampa, 17°9'54"N, 96°44'18"W, bosque de Encino, 1976 m, Arriaga A. and Arenas A. Col. (2 males, 2 females) (CMN, CEMT, IEXA, CPFA); 14-VII-17, 17°9'54"N, 96°44'54"W, 1954 m, (1 male) (IEXA); 27-IV-17, 17°10'16"N, 96°43'50"W, 2219 (1 male) (JB). 23-VI-17, 17°09'54"N, 96°44'19"W, 1976 m, (1 female) (JB).
La Mesita San Pablo Etla (17°9'54"N, 96°44'19"W, 1976 m), Oaxaca, Mexico.
Colección Entomológica IEXA, Instituto de Ecología, Xalapa, Mexico.
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.
Holotype. Major male (Fig.
Female. Allotype (Fig.
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.
Due to the fact that this species has been collected in association with Ph. damocles Harold, this new species (a noun in the nominative singular) is named after Dionysius II of Syracuse, one of the main characters alluded to in the moral anecdote of the “Sword of Damocles”.
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 Geotrupes pecki, G. viridiobscurus, Phanaeus dionysius sp. n., and Ph. zapotecus. Orography of Oaxaca is shown, based on the Digital Elevation Model downloaded from INEGI (2017, http://www.inegi.org.mx). Grey area shows the limits of Mexico with the Gulf of Mexico in the North and the Pacific Ocean in the South.
Phanaeus dionysius sp. n. has been collected simultaneously in dung-baited traps with Canthidium quercetorum Kohlmann, Arriaga-Jiménez and Rös, Canthon humectus (Say), Copris klugi Harold, Deltochilum mexicanum Burmeister, Dichotomius colonicus (Say), Onthophagus near anthracinus Harold, O. aureofuscus Bates, O. chevrolati retusus Harold, O. mexicanus Bates, O. zapotecus Zunino and Halffter and Phanaeus damocles Harold, in the oak forest. Although its closest relative, Ph. zapotecus Edmonds, seems to be a strictly mycetophagous species, Ph. dionysius has only been collected in dung, despite the presence of fungi-baited traps put in the forest. Interestingly, no big fleshy fungi (toadstools) were observed in this type of forest, only small “clavitos” (Lyophyllum), which could probably explain why this species does not exploit fungi.
Phanaeus dionysius sp. n. belongs to the Ph. endymion species group and due to its close taxonomic similarity discussed below is postulated to be the sister species of Ph. zapotecus Edmonds, 2006. Phanaeus dionysius will key out to Ph. zapotecus in the key of
The known distribution of Ph. dionysius sp. n. is relatively near to its closest relative, Ph. zapotecus, 90 km distance in a straight line, which is distributed in dry pine-oak and pine-oak-juniper forests on the internal slope of the Sierra Sur (Sierra de Tlaxiaco), going from 1850 m to 2150 m altitude. Interestingly, attempts at trying to collect Ph. zapotecus in the environs of San José del Pacífico in the Sierra Sur (Sierra de Miahuatlán) with fungi-baited traps did not produce any results.
Phanaeus
pyrois
malyi
:
Phanaeus malyi Arnaud, Solís & Kohlmann (2012: 10).
Phanaeus pyrois Bates, Edmonds & Zídek (2012: 1, 3, 13, 52–53, 57)
We therefore revalidate Ph. malyi to full species status based on the previously mentioned mitochondrial DNA analysis (
Phanaeus malyi follows a characteristic distribution pattern described by
Phanaeus
bravoensis
:
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., 17°22'N, 99°30'W L. Muñoz and J. Blackaller col.; Pino-Encino, alt. 1100-1380 m, En hongos (dentro de galería), 31/Jul/2004, 17°21'N, 99°30'W; 1100–1250 mts., 11/Jul/2004, 17°21'N, 99°29'W. Mochitlán, San Roque (8 km al este de Acahuizotla) Bosque Tropical y Bosque de Encino, Alt. 1130 m, CD en hongos, Ago-sept. 2013, 17°22'N, 99°25'W EPE 5 mts. Blackaller col.; (8 km al noreste de Ximilcotitlán), Bosque de Pino y de Encino, Alt. 2140 m, 7-VIII-2015 CD en hongos, 17°23'N, 99°23'W; 2 km al este de Ximilcotitlán, Alt. 1680 m, 07-08-VI-2009, en hongos, 17°22'N, 99°25'W; 5 km al este de Acahuizotla (camino a San Roque), Bosque de Encino y ET, Julio-2007, Alt 1010 msnm Trampa de luz CG 17°21'N, 99°26'W.
Phanaeus
halffterorum
:
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, 18°52'N, 100°24'W, J.Blackaller y L. Zacarías cols.; 06-VIII-2011, Trampa de Luz, Blackaller y Robacker cols.; 21-VIII-2011, J. Blackaller col.
Comparing this species with its closest relative, Ph. bravoensis, one can add as a further difference between the two species the fact that Ph. halffterorum has its pygidium covered with coarse punctures while Ph. bravoensis has faintly impressed small punctures. Although it is not specified in the original description of this species (Edmonds 1979), specimens were collected directly by hand feeding on fungi pertaining to the genus Boletus.
Phanaeus
huichol
:
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 23°30'N, 105°52'W Blackaller y Folschveiller Cols.
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 | 2 |
– | Sutural margin of elytra simple. Color and distribution variable | 3 |
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 | halffterorum Edmonds |
– | 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 | bravoensis Moctezuma, Sánchez-Huerta & Halffter |
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 | 4 |
– | 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 | 5 |
4 | Major males with long and slender posterolateral angles of pronotum (Fig. |
dionysius sp. n. |
– | Major males with short and rounded posterolateral angles of pronotum (Fig. |
zapotecus Edmonds |
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 | 6 |
– | 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 | 8 |
6 | Major males with short and rounded posterolateral angles of pronotum (Fig. |
malyi Arnaud |
– | Major males with long and slender posterolateral angles of pronotum (Fig. |
7 |
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 | arletteae Arnaud |
– | 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 | pyrois Bates |
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 | endymion Harold |
– | Dorsum metallic green. Anterior margin of pronotum projected upwards. Acute posterolateral angles of pronotum | 9 |
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 | zoque Moctezuma & Halffter |
– | Anterior metasternal angle almost right angled but with rounded apex in lateral view. Lateral metasternal angles evanescent. Jalisco and Nayarit | huichol Moctezuma, Sánchez-Huerta & Halffter |
Geotrupes
pecki
:
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 Geotrupes in Oaxaca is presented. G. truncaticornis Howden is not included in the key; because it is known only from Guerrero.
Material (6 males, 8 females). Holotype: México.10 km E Sn Sebastián Río Hondo, Miahuatlán, Oaxaca. 31-VIII-17, coprotrampa, 16°11'56"N, 96°21'54"W, bosque pino/pingüica, 2930 m, Arriaga J. A. Col. Allotype: México. 4 km NO Sto. Domingo Ozolotepec, Miahuatlán, Oaxaca. 31-VIII-17, coprotrampa, 16°11'57"N, 96°21"W, bosque pino/pingüica, 2920 m, Arriaga J. A. Col. Paratypes: México. 4 km NW Sto. Domingo Ozolotepec, Miahuatlán, Oaxaca. 31-VIII-17, coprotrampa, 16°11'56"N, 96°21'56"W, bosque pino/pingüica, 2930 m, Arriaga J. A. Col. (1 male, 1 female), 16°11'57"N, 96°21"W, 2920 m, (one male, three females); 3 km NW Sto. Domingo Ozolotepec, 16°11'53"N, 96°20"W, 2740 m, (2 males); 8 km E San Sebastián Río Hondo, 30-VIII-17, C. D. exc. Vaca, 16°11'15"N, 96°23'15"W, 2900 m, (1 male, 3 females).
Geotrupes
viridiobscurus
:
Geotrupes
saundersi
:
Geotrupes
felschei
:
Mexico. Oaxaca. Zempoaltéptl, 27-V-17, coprotrampa, 17°7'5"N, 96°0'W, matorral/pastizal, 3040 m Arriaga A. and Arenas A. Col.; 30-V-17, bosque de pino/aile 3190m; 17°9'7"N, 96°1'29"W, bosque de encino 2850 m. Reserva Comunitaria San Pablo, Etla, 20-IX-16 coprotrampa, 17°16'70"N, 96°68'55"W, bosque de pino 2980 m; 17°16'72"N, 96°68'50"W, 2980 m; 17°17'14"N, 96°67'26"W, 3070 m; 17°17'70"N, 96°67'27"W, 3110 m; 17°17'12"N, 96°67'20"W, bosque de pino 3100; 23-IX-16, 17°17'84"N, 96°70'38"W, bosque pino/encino 2700 m. Yucuiji, San Esteban Atatlahuca, 18-08-17, exc. caballo, 17°07'32"N, 97°40'44"W, bosque de pino 3150 m. La Chinantla, 17°35'48"N, 96°28'20"W, 2200 m; 17°35'12"N, 96°29'21"W, 2400 m; 17°34'48"N, 96°29'43"W, 2600 m. El Llano de las Flores, 17°45'N, 96°50'W, 2800 m.
Oaxaca. Duraznal, 17°1'55"N, 96°10'12"W, 1820 m.
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.
Geotrupes pecki and G. viridiobscurus have very similar aedeagi with only small differences on the parameres, as can be observed from the photographs of their genitalia (Fig.
The known distribution of G. viridiobscurus in the Sierra Norte is relatively adjacent to its closest taxonomic relative, G. pecki, in the Sierra Sur, only 125 km away in a straight line (Fig.
1 | Antennal club grayish-black; each mandible with a very pronounced rounded lobe. Sierra Sur (Sierra de Miahuatlán) | lobatus Howden |
– | Antennal club yellowish or reddish brown to brown; mandibles lacking a very pronounced rounded lobe | 2 |
2 | Dorsally shining, often green or blue, elytral intervals convex | 3 |
– | 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) | sallei Jekel |
3 | Posterior pronotal margin fine but distinct, except in front of scutellum. Sierra Norte (Sierra de Ixtlán) | nebularum Howden |
– | Posterior pronotal margin indistinct or lacking in front of third to seventh elytral striae | 4 |
4 | Elytral striae finely punctate or crenulated except near suture; elytra normally greenish-black, sometimes with reddish tint; pronotum punctate laterally (Fig. |
viridiobscurus Jekel |
– | Elytral striae virtually impunctate, at most vaguely crenulate; elytra black with faint tinge of green on elytron; pronotum generally heavily and grossly punctate (Fig. |
pecki Howden |
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 Ph. malyi and pyrois. François Génier, from the Canadian Museum of Nature, kindly sent photos for comparative purposes of black specimens of Ph. pyrois from Panama and Ecuador. We are in debt with Santiago Zaragoza Caballero, who most graciously allowed us to check the paratypes of Ph. zapotecus at the National Insect Collection of Mexico (UNAM); and to Susana Guzmán Gómez, who took the photographs of the pygidium of Ph. zapotecus. We also thank Alfonso Esteban Aceves-Aparicio from the INECOL for taking the rest of the photos. We greatly appreciate having had the possibility of studying the superb beetle collection of Julián Blackaller, from Soria, Guanajuato. Jane Segleau, Jane Yeomans, Nichole McVeigh, and Kent McLeod checked the English language. Two anonymous reviewers helped us improve the manuscript. Last but not least, Carlos Granados from EARTH’s library greatly assisted in finding bibliography. The first author (BK) thanks EARTH University for the sabbatical leave that allowed him to do the research for this paper.
Figure S1
Data type: Figure (PNG file)
Explanation note: Pronota close-ups of a Ph. pyrois olsoufieffi b Ph. malyi, and c Ph. pyrois funereus. Scale bar = 5mm.