Search

Se utilizaron como indicadores biogeográficos siete especies de Deltochilina (Anomiopus cirulito, Canthon triangularis, C. lituratus, C. edmondsi, C. morsei, C. angustatus y C. lucreciae), para ejemplificar la influencia de la fauna sudamericana en la diversidad tropical mexicana, buscando explicar por qué México, al sur del Istmo de Tehuantepec, es cada vez más Neotropical. La escala temporal empleada es del fin del Pleistoceno a la época actual y se consideraron tres niveles de información: 1) Penetración con presencia mínima, 2) Penetración con poblaciones marginales y 3) Penetración con poblaciones establecidas. Se ofrecen ejemplos de invasores foráneos que han tenido éxito en lugares ganaderos, sin desplazar a ninguna especie autóctona. Los fenómenos naturales que han condicionado la distribución actual de las especies indicadoras seleccionadas se corresponden con procesos geológicos y macroclimáticos, que influyeron en la composición y los movimientos de las horobiotas a nivel continental. La tendencia de Deltochilini de Centro y Sudamérica por invadir México ha sido muy intensa, empleando el Puente Panameño o incluso el puente inter-Caribe para dispersarse, avanzando con las selvas y, su número supera a las especies incipientes de penetración reciente, de cualquier otro borde de México.

The unique Neotropical species of the alderfly genus Protosialis van der Weele, 1909, P. bifasciata (Hagen, 1861), is herein transferred to the newly described genus Caribesialis gen. nov. This new taxon is proposed to be sister to the clade Protosialis + Sialis Latreille, 1802, after a phylogenetic analysis that included male genital characters scored on a previous morphological matrix of the family. Also, Ilyobius nigrocephalus sp. nov., a remarkable new species from Ecuador, is described and its phylogenetic position is discussed. Furthermore, Ilyobius bimaculatus (Banks, 1920) from Bolivia, known solely from the female holotype, is redescribed. Based on the present study, the Neotropical fauna of Sialidae is proposed to be constituted by two genera, one insular (Cuba) and one continental (Mexico to Chile and Argentina).

The anatomy of the internal male reproductive systems of 12 species of Melolonthinae (Phyllophaga, Chlaenobia, Macrodactylus, Isonychus), six species of Dynastinae (Cyclocephala), and three species of Rutelinae (Paranomala) (Coleoptera, Scarabaeoidea) of Mexico are described. A total of 350 male specimens representing 21 species were collected. From each species, the reproductive systems were obtained by micro-dissection, placed in a liquid fixative, stained, and drawn to scale. The internal genitalia of each species was described and compared among the species examined. The reproductive system of the Melolonthinae species is comprised of two testicles, each with six follicles, two deferent ducts, two accessory glands, two glandular ducts, an ejaculatory duct, and the aedeagus (not described for any of the species examined). The number of testicular follicles per testicle is as reported in different species of other Scarabaeoidea subfamilies. The length of the accessory glands and the ejaculatory duct varies in the species studied. The ejaculatory bulb is present in all of the species of Dynastinae and Rutelinae examined but in only three species of Melolonthinae.

La investigación en biodiversidad y conservación en México ha avanzado en gran medida porque están vinculadas a la existencia de estaciones biológicas, reservas de la biosfera o áreas naturales protegidas. El Centro de Investigaciones Costeras La Mancha (CICOLMA) es una de las estaciones pioneras del país en la investigación de ecosistemas costeros, sin embargo, los estudios sobre la fauna de escarabajos en esta área han sido mínimos. El objetivo del presente trabajo fue documentar la fauna de Scarabaeoidea presente en el CICOLMA de abril de 2003 a marzo de 2004, donde se realizaron colectas de escarabajos con técnicas directas e indirectas. Se obtuvo una muestra de 865 individuos de Coleoptera, Scarabaeoidea, de las familias Cetoniidae, Melolonthidae, Passalidae, Scarabaeidae y Trogidae, que representan 66 especies de 41 géneros. Las especies Cotinis pauperula Burmeister, 1847, Euetheola bidentata (Burmeister, 1847), Paranomala flavilla (Bates, 1888) y Pelidnota virescens Burmeister, 1844, representan nuevos registros para el estado de Veracruz. Se incluye una clave dicotómica para separar las especies de Scarabaeoidea de la región y datos sobre su fenología.

The Onthophagus brevifrons species complex (Coleoptera: Scarabaeidae: Scarabaeinae: Onthophagini) consists of the five species: Onthophagus cavernicollis Howden and Cartwright, Onthophagus subtropicus Howden and Cartwright, Onthophagus brevifrons Horn, Onthophagus cuevensis Howden and Onthophagus moroni Zunino and Halffter, all of which are strictly associated with underground habitats (caves or burrows) and are consequently considered troglobites. Nevertheless, the biology of Onthophagus Latreille species reported from caves is lacking. In this study, four grottoes in the Cuetzalan region were explored: Trompa de Elefante, El Fosil and El Nido del Murcielago (which belong to the poorly explored Gruta de Atepolihui), and the Tasalolpan cave, in the search for dung beetles. Onthophagus moroni was collected inside El Nido del Murcielago and Tasalolpan cave, representing a new record for El Nido del Murcielago, since its presence was previously recorded inside the Tasalolpan cave in 1988. Adults of O. moroni were collected alive 70 m inside the Tasalolpan cave, under a latrine of Peters' climbing rat, Tylomys nudicaudus (Peters) (Rodentia: Cricetidae). We redescribe the species, discuss its biogeography and provide an updated dichotomous key to enable the identification of the constituent species in the O. brevifrons species complex.

Megaloptera belong to a large monophyletic group, the Neuropteroidea, together with Coleoptera, Strepsiptera, Raphidioptera, and Neuroptera. With the latter two, this order constitutes the Neuropterida, a smaller monophyletic subset among which it is the only entirely aquatic group, with larvae of all species requiring submersion in freshwater. Megaloptera is arguably the oldest extant clade of Holometabola with aquatic representatives, having originated during the Permian before the fragmentation of Pangea, since about 230 Ma. It includes 54 genera (35 extant and 19 extinct genera), with 397 extant described species and subspecies. Recent Megaloptera are divided into two families: Corydalidae (with subfamilies Corydalinae—dobsonflies and Chauliodinae—fishflies) and Sialidae (alderflies), both widely yet disjunctively distributed among zoogeographical realms. All species of Megaloptera have aquatic larvae, whereas eggs, pupae, and adults are terrestrial. The anatomy, physiology, and behavior of megalopteran larvae are specialized for an aquatic predatory habit, yet their ecological significance might still be underappreciated, as their role in food webs of benthic communities of many temperate and tropical streams and rivers is still understudied and largely unquantified. In many freshwater ecosystems, Megaloptera larvae are a conspicuous benthic component, important in energy flow, recycling of materials, and food web dynamics.

As partial results of a long-term project for the revision of the supraspecific classification of the American Melolonthini, using phylogenetic methods, interesting information on the relationships between the subgeneric groups of Phyllophaga Harris proposed by Saylor were obtained. The genus Listrochelus was described by Blanchard in 1851. However, in 1940, Saylor reduced it as a subgenus of Phyllophaga. The objective of the present study is to confirm the monophyly of Listrochelus by means of a phylogenetic analysis. A total of 132 species were analyzed; 31 species of them belong to Listrochelus, 76 are from other groups of Phyllophaga, and 25 species are from the outgroup. A morphological matrix with 281 characters was codified. A traditional search with 1000 iterations was performed in TNT. Branch support was investigated using the bootstrap method. Parsimony analysis resulted in ten equally parsimonious trees. The topology obtained in the strict consensus tree shows that the limits of Listrochelus are very clear (bootstrap 99%), supported by five synapomorphies and a combination of eight character states that are not exclusive to the group. Based on the hypothesis obtained, the restitution of the genus Listrochelus is proposed.