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A new fossil species of mayfly of the genus Cloeon Leach, 1815 (Ephemeroptera, Baetidae) is described. The type material comprises female imagines from 24 amber inclusions, from Miocene strata of Chiapas in southern Mexico. The fossil species, Cloeon tzeltal sp. nov., closely resembles those in the genus Cloeon by the following diagnostic characters: absence of hind wings; two major crossveins between R1 and R2 not in line with the crossveins below them; single marginal intercalaries; and basal crossveins between veins R and Rs situated more basally than the following vein. The new species can be distinguished from extant species of Cloeon by the absence of colored costal and subcostal fields in the forewings and the absence of transversal veins in vitta broadly bordered with white. Extant species of the genus Cloeon in America have an exclusive distribution in the northern part of the continent; with the exception of one introduced taxon, no valid species have been recorded in the tropics. As such, the fossil record of Cloeon in the southernmost part of North America suggests a broader geographic distribution of this genus in the geological past, including the southernmost part of North America.

A fossil species of Pheidole Westwood, 1839 (Formicidae, Myrmicinae) was described based on an amber inclusion found in the Miocene strata at Chiapas, southwestern Mexico. It was named Pheidole pauchil sp. nov., which is the first described species of the genus in Mexican amber. This broadens our understanding of the diversity of Pheidole in the Miocene in the southernmost part of North America.

The occurrence of species is inadequately known for Morelos, one of the smallest states at the center of Mexico. Our research documented the occurrence of ant species in the State. Specimens were collected in four conserved areas and a range of disturbed habitats. Morphological traits and molecular sequences of the Cytochrome Oxidase subunit I (COI) were used as complementary tools to identify species. We identified 164 ant species of which 48 were new records for the State. Molecular analysis helped confirm and document the identity of species in groups of ants. The study could be used as a model to assess ecosystem health across extensive geographical regions.

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A lo largo de los años se han hecho estudios sobre relaciones filogenéticas de las hormigas, éstos han ido cambiando con el tiempo porque se van aumentando nuevos conocimientos empíricos y objetivos para contribución de los anteriores estudios. La historia filogenética de las hormigas se puede dividir en dos etapas, la precladística y la cládistica. En la etapa precladística se creaban hipótesis de relaciones genealógicas de las hormigas, pero sin métodos rigurosos, era un análisis subjetivo, a comparación con la cládistica en donde se nota un método de análisis de datos morfológicos y de datos moleculares. Dentro de este artículo se exponen diferente información sobre el tema filogenético de las hormigas para dar un mayor panorama de todos los estudios que se han realizado a partir de mediados del siglo pasado hasta la actualidad.

Mexico is one of the most biodiverse countries in the world, with an important proportion of endemism mainly because of the convergence of the Nearctic and Neotropical biogeographic regions, which generate great diversity and species turnover at different spatial scales. However, most of our knowledge of the Mexican ant biota is limited to a few well-studied taxa, and we lack a comprehensive synthesis of ant biodiversity information. For instance, most of the knowledge available in the literature on Mexican ant fauna refers only to species lists by states, or is focused on only a few regions of the country, which prevents the study of several basic and applied aspects of ants, from diversity and distribution to conservation. Our aims in this data paper are therefore (1) to compile all the information available regarding ants across the Mexican territory, and (2) to identify major patterns in the gathered data set and geographic gaps in order to direct future sampling efforts. All records were obtained from raw data, including both unpublished and published information. After exhaustive filtering and updating information and synonyms, we compiled a total of 21,731 records for 887 ant species distributed throughout Mexico from 1894 to 2018. These records were concentrated mainly in the states of Chiapas (n = 6,902, 32.76%) and Veracruz de Ignacio de la Llave (n = 4,329, 19.92%), which together comprise half the records. The subfamily with the highest number of records was Myrmicinae (n = 10,458 records, 48.12%), followed by Formicinae (n = 3,284, 15.11%) and Ponerinae (n = 1,914, 8.8%). Most ant records were collected in the Neotropical region of the country (n = 12,646, 58.19%), followed by the Mexican transition zone (n = 5,237, 24.09%) and the Nearctic region (n = 3,848, 17.72%). Native species comprised 95.46% of the records (n = 20,745). To the best of our knowledge, this is the most complete data set available to date in the literature for the country. We hope that this compilation will encourage researchers to explore different aspects of the population and community research of ants at different spatial scales, and to aid in the establishment of conservation policies and actions. There are no copyright restrictions. Please cite this data paper when using its data for publications or teaching events.

Gall formation is a specialised form of phytophagy that consists of abnormal growth of host plant tissue induced by other organisms, principally insects and mites. In the mainly parasitoid wasp subfamily Doryctinae, gall association, represented by gall inducers, inquilines and their parasitoids, is known for species of seven genera. Previous molecular studies recovered few species of six of these genera as monophyletic despite their disparate morphologies. Here, we reconstructed the evolutionary relationships among 47 species belonging to six gall-associated doryctine genera based on two mitochondrial and two nuclear gene markers. Most of the Bayesian analyses, performed with different levels of incomplete taxa and characters, supported the monophyly of gall-associated doryctines, with Heterospilus (Heterospilini) as sister group. Percnobracon Kieffer and Jörgensen and Monitoriella Hedqvist were consistently recovered as monophyletic, and the validity of the monotypic Mononeuron was confirmed with respect to Allorhogas Gahan. A nonmonophyletic Allorhogas was recovered, although without significant support. The relationships obtained and the gathered morphological and biological information led us to erect three new genera originally assigned to Psenobolus: Ficobolus gen.n. (F. paniaguai sp.n. and F. jaliscoi sp.n.), Plesiopsenobolus gen.n. (Pl. mesoamericanus sp.n., Pl. plesiomorphus van Achterberg and Marsh comb.n., and Pl. tico sp.n.), and Sabinita gen.n. (S. mexicana sp.n.). The origin of the gall-associated doryctine clade was estimated to have occurred during the middle Miocene to early Oligocene, 16.33–30.55 Ma. Our results support the origin of true gall induction in the Doryctinae from parasitoidism of other gall-forming insects. Moreover, adaptations to attack different gall-forming taxa on various unrelated plant families probably triggered species diversification in the main Allorhogas clade and may also have promoted the independent origin of gall formation on at least three plant groups. Species diversification in the remaining doryctine taxa was probably a result of host shifts within a particular plant taxon and shifts to different plant organs. Fil: Zaldivar Riverón, Alejandro. Universidad Nacional Autónoma de México; México Fil: Martinez, Juan Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentina Fil: Belokobylskij, Sergey A.. Polish Academy of Sciences; Argentina Fil: Pedraza Lara, Carlos. Universidad Nacional Autónoma de México; México Fil: Shaw, Scott. University of Wyoming; Estados Unidos Fil: Hanson, Paul E.. Universidad de Costa Rica; Costa Rica Fil: Varela Hernández, Fernando. Universidad Nacional Autónoma de México; México