Jorge Víctor Horta-Vega

Community Structure of Ichneumonidae (Hymenoptera) in a Mangrove Area in the Coastal Zone of Tamaulipas, Mexico.

espanolSe describe la estructura de las comunidades de Ichneumonidae en un area de manglar y 2 localidades cercanas con diferentes tipos de vegetacion. El area de estudio esta ubicada en los limites de las regiones Neartica y Neotropical en sur del estado de Tamaulipas, Mexico. Las muestras se recolectaron con una trampa Malaise en cada sitio durante 1 ano. La riqueza potencial de especies se determino con el modelo de Clench, los indices de diversidad de Simpson y Shannon-Wiener, asi como las posibles diferencias entre las comunidades con el analisis multivariado de Permanova. Los grados relativos de influencia de las variables espaciales, de tiempo y de distribucion biogeografica en las estructuras comunitarias se determinaron mediante analisis de correspondencia multiple. Los datos mostraron que el area de manglar tiene la mayor riqueza potencial de especies y que hubo diferencias significativas entre las 3 comunidades de ichneumonidos. Las estructuras comunitarias dependen de la distribucion biogeografica de las especies y del mes de recolecta, mientras que las estructuras poco dependientes, del tipo de vegetacion. Tres especies obtenidas en este estudio representan nuevos registros para Mexico y 5 para el estado de Tamaulipas. EnglishThe structure of Ichneumonidae communities in a mangrove area and 2 nearby locations with different vegetation types are described. The study area is located within the limits of the Nearctic and Neotropical regions in the southern part of the state of Tamaulipas, Mexico. Samples were collected with a Malaise trap at each site over a one-year period. We estimated the potential species richness with the Clench model, the Simpson and Shannon-Wiener diversity indexes and the possible differences among communities at different sites using Permanova multivariate analysis. The relative degrees of influence of space, time, and biogeographical distribution on the community structures of ichneumonid wasps were determined using multiple correspondence analyses. Our results showed that the mangrove area had the highest potential species richness, and that there were significant differences among the 3 ichneumonid communities. The community structures depend primarily on the biogeographical distribution of species and secondarily on the month of collection, whereas the type of vegetation contributed with lower variation. Three species obtained in this study are new records for Mexico, and 5 for Tamaulipas.

Diversidad y zoogeografía de los moluscos terrestres de la sierra de Tamaulipas, México

Diversity and biogeography of Mexican terrestrial gastropods is poorly known. The terrestrial mollusks of the Sierra of Tamaulipas were surveyed from October 1988 to November 2005. A total of 482 samples were obtained from 30 localities, characterized with different vegetation types. Thirty-one genera and 46 species belonging to 18 families are recorded. The primary zoogeographical relationships are characterized by the presence of neotropical and neartic affinities (17 species: 37%) and the endemic taxa (11 species: 24%). The family Spiraxidae has the largest number of endemic species (6). The biogeographical value in this area is 3.78.