3Autor para la correspondencia: arturosg@uaeh.edu.mxResumen: Los helechos arborescentes (Cyatheaceae) constituyen un componente conspicuo del bosque húmedo de montaña de las regiones tropicales y subtropicales del mundo. En México su distribución se circunscribe casi por completo al bosque húmedo de montaña, y pese a que algunas de las especies se incluyen dentro de la Norma Ofi cial Mexicana y en las listas rojas internacionales, no se cuenta con información sobre el estado actual de sus poblaciones. En el presente estudio se generó información básica acerca de la estructura, densidad poblacional y las características del hábitat de Alsophila fi rma y Cyathea fulva para establecer en qué grado las condiciones actuales de su hábitat ponen en riesgo su supervivencia. Estas dos especies son de amplia distribución dentro del bosque húmedo de montaña, consideradas como "sujetas a protección especial" en la legislación mexicana. Se encontró que las poblaciones de ambas especies son normales o dinámicas, con alto potencial de regeneración, formando parte del sub-dosel en sitios con cobertura arbórea alta, por lo que son tolerantes a la sombra. Las variables que mejor explicaron las diferencias en la densidad poblacional fueron la altitud, la pendiente, la presencia de caminos y la cobertura del suelo para A. fi rma; mientras que en C. fulva fue la cobertura del dosel. El establecimiento y supervivencia de las poblaciones de ambas especies depende en gran medida de la conservación de su hábitat, debido a que requieren de la existencia de un alto porcentaje de cobertura vegetal. Palabras clave: Alsophila fi rma, bosque húmedo, Cyathea fulva, estructura de tamaños, riesgo de extinción. Abstract:The tree ferns (Cyatheaceae) are a conspicuous component of the humid montane forest in the tropical and subtropical regions of the world. In Mexico, the tree ferns distribution is limited almost entirely to the humid montane forest (cloud forest). Although some species are included in the Norma Ofi cial Mexicana (governmental regulations normalized) and international red lists, there is no information on the current status of their populations. Two species widely distributed within the montane rainforest, and classifi ed as "subject to special protection" under Mexican law, are Alsophila fi rma and Cyathea fulva. In the present study, basic data was collected about the structure, population density and habitat characteristics of these tree ferns, in order to determine to what extent the current state of their habitat threatens their survival. We found that populations of both species are normal or dynamic, with high regeneration potential, forming part of the sub-canopy at sites with high tree cover, making them tolerant to shade. The variables that best explained differences in population density for A. fi rma were elevation, slope, presence of roads, and ground cover, while for C. fulva it was canopy cover. The establishment and survival of populations of both species depends heavily from conservation of their habitat (humid mo...

Aedes gabriel is one of the rare species endemic in Mexico. This species was originally described from specimens collected in the state of Morelos in 1970; however, very few occurrence records have been published since. During an ovitrap survey of mosquitoes in 2018, eggs of Ae. gabriel were collected for the 1st time in the state of Hidalgo, Mexico. Aedes gabriel appears to have become common and the species is frequently found in ovitraps, and often confused with other common species of Aedes, such as Ae. epactius, Ae. podographicus, Ae. aegypti, and Ae. albopictus. Females of Ae. gabriel are highly anthropophagous and persistent biters in wild habits during the rainy season. Although the medical importance of Ae. gabriel is unknown, its biting habitats and increasing abundance indicate that the potential importance of this species should not be neglected by the public health officials of Mexico.