Research Article |
Corresponding author: Geovanni M. Rodríguez-Mirón ( geo20araa@yahoo.com.mx ) Academic editor: Fedor Konstantinov
© 2025 Geovanni M. Rodríguez-Mirón, Sara López-Pérez.
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:
Rodríguez-Mirón GM, López-Pérez S (2025) Redescription of the Neotropical genus Agathomerus (Coleoptera, Megalopodidae, Megalopodinae) and description of three new species from Mexico. ZooKeys 1227: 143-158. https://doi.org/10.3897/zookeys.1227.118934
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Agathomerus Lacordaire and A. pulcher Lacordaire are redescribed, and three new species of the genus are described: Agathomerus magdalenae sp. nov., A. espinosaorganistai sp. nov., and A. santiagoi sp. nov. Illustrations of the habitus, aedeagus and spermatheca of the four species are provided. Agathomerus bichito Monrós, A. batesi Baly, and A. superbus Pic are proposed as new synonyms of Agathomerus pulcher Lacordaire.
Distribution, genitalia, Megalopodina, Megalopodini, new synonyms, spermatheca
Three genera and 33 species of Megalopodidae are recorded from Mexico (
Agathomerus contains the species previously described in Megalopus Fabricius that lack costate elytra and a medial conical tubercle on the metaventrite.
This work aims to redefine the genus Agathomerus and illustrate its diagnostic characters. Additionally, three new species of Agathomerus are described.
The specimens examined were obtained on loan from different collections:
National Museum of Natural History, Smithsonian Institution, Washington, DC, USA (
Terms for anatomy and male genitalia structures follow
Megalopodinae Latreille, 1802
Megalopodini Latreille, 1802
Megalopodina Latreille, 1802
Agathomerus pulcher Lacordaire, 1845, designated by
Agathomerus differs from the other genera of Megalopodina by the spatulate shape of the spiculum gastrale; in the other genera it is forked or straight. Moreover, it is also distinguished by the following character states: mesoscutum apex emarginate, metatarsomeres I–III conical, metatarsomeres V longer than I–III and, usually, tergite II with three sclerotized portions. Whereas in Plesioagathomerus Monrós, Mastostethus and Homalopterus Perty the mesoscutum apex is rounded, metatarsomeres I–III are subcylindrical, metatarsomeres V are as long as I–III (except in Homalopterus where they are variable); in Plesioagathomerus and Homalopterus tergite II has two sclerotized portions and in Mastostethus tergite II is uniformly sclerotized.
In addition, Agathomerus differs from Mastostethus by the generally longer antennae and convex metaventrite. In Mastostethus the antennae are short and the metaventrite has a conical tubercle medially. It is distinguished from Homalopterus by the mandible with a lateral groove, last labial palpomeres fusiform, elytra without costae and long parameres. In Homalopterus the mandibles lack a lateral groove, the last labial palpomeres are bullet-shaped, the elytra is costate and the parameres are short. Agathomerus can be separated from Plesioagathomerus by the abdominal process projected between the metacoxae and by the long empodium. In Plesioagathomerus, the abdominal process is short and not projected between metacoxae, and the empodium is short.
Agathomerus differs from Pseudohomalopterus by the meso- and metaventral processes not joined in lateral view and the emarginate ventral apex of tarsomeres V. In Pseudohomalopterus, the meso- and metaventral processes are joined (as in Mastostethus), and the ventral apex of tarsomeres V is emarginated and notched. Agathomerus is easily distinguished from Barticaria, Bothromegalopus Monrós, and Megalopus by the elongate and robust shape of the body and the subparallel external edges of the elytra. Whereas in Barticaria, the body is compact and subcylindrical; in Megalopus and Bothromegalopus, the elytra are raised behind the scutellum, the elytral suture is depressed, and the body narrows towards the apex (as in Pseudohomalopterus).
Head. Constricted behind eyes; frontal surface along eye margins with ocellate punctures (Figs
Type specimens and polymorphism among Agathomerus pulcher A A. batesi Baly, type specimen B A. superbus Pic, type specimen C A. bichito Monrós, type specimen D label of type specimen of A. batesi E label of type specimen of A. superbus Pic F label of type specimen of A. bichito Monrós G A. pulcher with elytral disc blue H A. pulcher with elytral disc orange I head orange of A. pulcher.
Thorax. Pronotum trapezoidal (Fig.
Abdomen. Last spiracle smaller than others (Fig.
Male genitalia. Aedeagus: dorsal portion of median lobe membranous; struts and lateral margins of median lobe sclerotized (Fig.
Female genitalia. Spermatheca complex (Fig.
Agathomerus pulcher
Agathomerus batesi Baly, 1859: 199 syn. nov.
Agathomerus superbus Pic, 1916: 20 syn. nov.
Agathomerus bichito Monrós, 1945: 144 syn. nov.
Megalopus injunctus Pic, 1938: 16.
Holotype. Agathomerus batesi Baly (designated here) (Fig.
♂, pinned. Original label: “Perou Chanchamayo, Ch O Schunke // F. Monrós ES Collection, 1959”, (
Agathomerus pulcher differs from other species by the following combination of character states: interocular region (Figs
Length 10–12 mm, width 3.8–4.8 mm. Head (Fig.
Head
(Figs
Thorax. Pronotum (Fig.
Abdomen. Tergite I with two sclerotized regions, tergite II with three sclerotized regions (Fig.
Female. Femora fusiform, tibiae swollen near apex; last abdominal ventrite with apex emarginate, pygidium with apex rounded. Spermatheca (Fig.
Argentina, Bolivia, Brazil, Mexico, and Peru (
The color pattern in Agathomerus pulcher exhibits a high degree of polymorphism (Fig.
After reviewing the specimens from Francisco Monrós’ collection deposited in the
The type specimen of Agathomerus pulcher was collected in Mexico (Lacordaire, 1845), although the exact locality is not specified; for many years this species was considered restricted to this country. However, after the present study, A. pulcher is now considered a species with a wide distribution, from Mexico to Argentina. It should be noted that after reviewing main collections from different countries, no specimens of A. pulcher from Mexico were found, which calls into question its presence in this country.
Holotype. Mexico • 1♂; Chiapas, Aguacero; 6 June 1987; W. B. Warner leg; pinned, with genitalia in a separate microvial; CNIN. Paratypes. MEXICO • 1♀; Same data as holotype; CCFEZ-Z. • 1 ♀; Guerrero, Taxco A., Santiago Temixco; 18°28'46"N, 99°37'50.1"W; alt. 1251 m; 23 May 2008; S. López leg.; 15:55; SBC; CCFEZ-Z • 1♂; Oaxaca, Candelaria Loxicha, Portillo del Rayo; 24 May 1990; A. C. Deloya; Bosque tropical y cafetal; CCFEZ-Z.
Agathomerus magdalenae sp. nov. is similar to santiagoi sp. nov. and it is distinguished by the following combination of character states: ocular canthi surface convex, scapes longer than antennomeres III, II twice as long as III, pronotum (Fig.
Length 10.8–11.6 mm, width 4.7–5.0 mm. Body (Fig.
Head
(Fig.
Thorax. Pronotum bell-shaped (Fig.
Abdomen. Tergites evenly sclerotized; pygidium apically sparsely punctate and sparsely pubescent, apex rounded; last abdominal ventrite sparsely punctate and pubescent; setae decumbent; surface concave apically; apical margin subtruncate.
Aedeagus. median lobe (Fig.
Female. Pronotal disc without depression (Fig.
Mexico: Chiapas, Guerrero, Oaxaca.
The new species is named after Ma. Magdalena Ordóñez Reséndiz, the degree advisor of the authors.
Holotype. Mexico • 1♂; Morelos, 2.5 km, 4 km O Huautla, Estacion CEAMISH; 18°27'671"N, 99°02'475"W; Alt. 940 m, 7–12 July 1996; A. Pérez leg.; ex vegetación; pinned, with genitalia in a separate microvial; CNIN.
Agathomerus santiagoi sp. nov. is similar to magdalenae sp. nov. and it is distinguished by the following combination of character states: ocular canthi surface concave, scapes as long as antennomeres III, II half as long as III, pronotum (Fig.
Length 11.6 mm, width 4.4 mm. Body (Fig.
Head
(Fig.
Thorax. Pronotum (Fig.
Abdomen. Tergites evenly sclerotized; pygidium sparsely, setigerously punctate, apex rounded; last abdominal ventrite concave, sparsely, setigerously punctate, setae decumbent, apex truncate. Aedeagus: median lobe (Fig.
Mexico: Morelos.
The new species is named after Santiago Zaragoza Caballero, the PhD advisor of the authors.
Holotype. Mexico • 1♂; Sinaloa, El Palmito, 8mi W; 24–64 July // UC Berkeley;
Agathomerus espinosaorganistai sp. nov. is similar to A. signatus (Klug) and it is distinguished by the following combination of character states: pronotum with anterior groove interrupted medially (Fig.
Length 9.6 mm, width 4 mm. Body (Fig.
Head
(Fig.
Thorax. Pronotum (Fig.
Scutellum depressed with respect to elytral surface, sparsely and coarsely punctate, subtriangular, apex subtruncate; elytra external margins subparallel, epipleura with lateral edge rounded; humeri rounded, projecting anterolaterally; disc convex, sparsely and coarsely punctate. Metaepisternum (Fig.
Abdomen. Tergites evenly, weakly sclerotized; pygidium sparsely punctate and pubescent, apex truncate; last abdominal ventrite sparsely punctate, pubescent, setae decumbent, apical region with a transverse groove, apex truncate. Aedeagus: median lobe (Fig.
Mexico: Sinaloa.
The new species is named after David Nahum Espinosa-Organista, the Masters advisor of the first author. The specific epithet is a combination of the last names of Dr David Espinosa-Organista.
We want to thank Alexander Konstantinov (
The authors have declared that no competing interests exist.
No ethical statement was reported.
This research was supported by DGAPA-PAPIIT-UNAM.
Conceptualization: GMRM. Funding acquisition: GMRM. Investigation: GMRM, SLP. Methodology: GMRM, SLP. Visualization: GMRM, SLP. Writing - original draft GMRM, SLP.
Geovanni M. Rodríguez-Mirón https://orcid.org/0000-0003-0751-4672
Sara López-Pérez https://orcid.org/0000-0002-9925-0186
All of the data that support the findings of this study are available in the main text.
Familia Megalopodidae Latreille, 1802 | |
Subfamily Megalopodinae Latreille, 1802 | |
Tribe Megalopodini Latreille, 1802 | |
Subtribe Megalopodina Latreille, 1802 | |
Agathomerus Lacordaire, 1845:673 | |
Type species: Agathomerus pulcher Lacordaeri, 1845, designated by Jacoby and Clavareu (1905). | |
A. flavomaculatus (Klug, 1824: 57) | Argentina: Misiones, San Ignacio, Bonpland, Departamento Concepción: Sta. María. Brazil: Rio de Janeiro, San Paulo, Paraná. Paraguay: Puerto Cantera, Sierra de Ambay, Cerro Mirón |
Megalopus flavomaculatus, Klug, 1824: 57 | |
A. almeidai Guérin, 1946:205 | Brazil: Minas Gerais |
A. affinis Jacoby, 1880: 25 | Mexico |
A. atripennis Jacoby, 1880: 25 | Mexico |
A. atripes Pic, 1947: 13 | |
A. azureipennis Lacordaeri, 1845: 680 | French Guiana: Cayenne |
A. basalis Pic, 1916: 20 | Brazil |
A. bifasciatus (Klug, 1824: 53) | Brazil: Brazilia |
Megalopus bifasciatus Klug, 1824: 53 | |
A. bipartitus Pic, 1955: 13 | Bolivia |
A. coeruleus Bates, 1866: 81 | Brazil: Tapajós |
A. cyaneus Clark, 1845: 84 | Brazil: Rio grande |
A. cyanopterus Lacordaeri, 1845: 677 | Brazil |
A. discoideus (Klug, 1824: 49) | Argentina. Brazil: Rio de Janeiro, Brazilia |
Megalopus discoideus Klug, 1824: 49 | |
Megalopus cinctus Serville, 1825:319 | |
A. dubiosus Jacoby, 1876: 808 | Mexico |
A. elegans (Klug, 1834: 210) | Brazil |
Megalopus elegans Klug, 1834: 210 | |
A. egregius (Germar, 1824: 525) | Brazil |
Megalopus egregius Germar, 1824: 525 | |
A. ephippium Lacordaeri, 1845: 693 | Brazil |
A. espinosaorganistai sp. nov. | Mexico: Sinaloa |
A. flavomaculatus (Klug, 1824: 57) | Argentina: Misiones, San Ignacio, Bonpland, Departamento Concepción: Sta. María. Brazil: Rio de Janeiro, San paulo, Paraná. Paraguay: Puerto Cantera, Sierra de Ambay, Cerro Mirón |
Megalopus flavomaculatus, Klug, 1824: 57 | |
A. freudi Guerin-Meneville, 1852: 437 | Mexico |
A. hahneli Pic, 1955: 234 | “Amazonas” |
A. humeralis Serville, 1825: 320 | Brazil |
Megalopus humeralis Serville, 1825: 320 | |
Megalopus axillaris Klug 1834:212 | |
A. hieroglyphicus Guérin, 1945:256 | Brazil: Paraná |
A. inapicalis Pic, 1955: 15 | |
A. incomparabilis Clark, 1866: 81 | Brazil: Espíritu Santo |
A. interrupta Pic, 1947: 13 | Brazil |
A. lautus Bates, 1866: 83 | Brazil: Para |
A. latefasciatus Pic, 1955: 14 | “Amazonas” |
A. lemoulti Pic, 1916: 19 | Guayana |
A. lineatus Guerin-Meneville, 1852: 439 | Mexico |
A. luteoreductus Pic, 1955: 15 | |
A. magdalenae sp. nov. | Mexico: Chiapas, Guerrero, Oaxaca, |
A. marginatus (Klug, 1824: 51) | Argentina. Brazil. Paraguay |
Megalopus marginatus Klug, 1824: 51 | |
A. nicki Guérin, 1948: 70 | Brazil: Sao Paulo, Taipas |
A. nigricollis Clark, 1866: 82 | Brazil |
A. nobilis (Klug, 1834: 210) | Brazil |
Megalopus nobilis Klug, 1834: 210 | |
A. notaticollis Clark, 1866: 82 | Brazil: Bahía |
A. obliterata Pic, 1947: 13 | Brazil |
A. pauper Bates, 1866: 80 | Brazil: San Paulo |
A. pictus Lacordaeri, 1845: 691 | Brazil |
A. postmaculatus Pic, 1955: 15 | Mexico |
A. pulcher Lacordaeri, 1845: 675 | Argentina: Salta (Oran: Urundel). Bolivia. Brazil: Ega. Mexico. Peru. |
Agathomerus batesi Baly, 1859: 199 nov. syn. | |
Megalopus injunctus Pic, 1938: 16 | |
Agathomerus superbus Pic, 1916: 20 nov. syn. | |
Agathomerus bichito Monrós, 1945: 144 nov. syn. | |
A. quadrimaculatus (Guérin, 1945: 259) | Argentina. Brazil. Paraguay |
Agathomerus quadrimaculatus Guérin, 1945: 259 | |
Agathomerus varians Monrós, 1945: 146 | |
Agathomerus quadrimaculatus Monrós, 1945: 155 | |
A. rubrinotatus Clark, 1866: 83 | Mexico |
A. santiagoi sp. nov. | Mexico: Morelos |
A. sallei Baly, 1859: 153 | Mexico |
A. sellatus (Germar, 1824: 524) | Argentina. Brazil |
Megalopus sellatus Germar, 1824: 524 | |
Megalopus limbatus Mannerheim, 1826:303 | |
A. sexmaculatu s (Kirby, 1818: 444) | Brazil |
Megalopus sexmaculatus Kirby, 1818: 444 | |
Megalopus maculatus Klug, 1834: 210 | |
A. signatus (Klug, 1824: 54) | Brazil |
Megalopus signatus Klug, 1824: 54 | |
Megalopus lineatus Serville, 1825: 320 | |
Megalopus henningi Mannerh, 1826: 302 | |
A. simplicipennis Jacoby, 1880: 590 | Ecuador |
A. succinctus Klug, 1834: 212 | Brazil |
Megalopus succinctus Klug, 1834: 212 | |
A. subfasciatus (Germar, 1824: 525) | Argentina. Brazil. Paraguay |
Megalopus subfasciatus Germar, 1824: 525 | |
A. testaceus (Klug, 1824: 56) | Brazil |
Megalopus testaceus Klug, 1824:56 | |
A. viduus Clark, 1866: 84 | Brazil: Rio de Janeiro |
A. violaceofasciatus Jacoby, 1888: 64 | Brazil. Panama |
A. zikani Guérin, 1951: 576 | Brazil: Sao Paulo |
Incertae sedis ( |
|
A. bivittatus Lacordaeri, 1845: 692 | Brazil |
A. rufus (Klug, 1834: 213) | Mexico |
Megalopus rufus Klug, 1834: 153 |