A total of 55 first records of Ichneumonidae are reported from Mexico, raising the total number of known species from Mexico to 1,115. Two genera, Picrostigeus and Paraphylax, are reported for the first time from the Neotropical Region. Material was collected over a one year period by Malaise traps in three habitats; dry forest, savannah and coastal dune scrubland in the Ria Lagartos Biosphere Reserve, Yucatán, Southeast Mexico. A total of 1,302 individuals of Ichneumonidae are included in this paper. 45 species (81%) of the new records have a Neotropical distribution; seven species (12%) have been reported previously only from the Nearctic; and one species (2%) are recorded from both the Nearctic and Neotropical regions. Most species have a higher abundance in the rainy season, and the dry forest habitat provided more new records than the other habitats.

The Ichneumonidae (Hymenoptera: Ichneumonoidea) of Ría Lagartos Biosphere Reserve, Yucatán, Mexico

The New World Clistopyga chaconi species group is revised. Eleven species are described as new: C. amazonica sp. nov., C. cinnamoptera sp. nov., C. cuscoensis sp. nov., C. hayesiana sp. nov., C. melanoptera sp. nov., C. misionensis sp. nov., C. mocaguae sp. nov., C. orellanae sp. nov., C. porteri sp. nov., C. rondoniae sp. nov. and C. yabuquensis sp. nov. Additional morphological data are provided for the previously known species, C. caramba Castillo & Sääksjärvi and C. chaconi Gauld. An illustrated identification key to all species of the group is provided. The Clistopyga chaconi species group appears to be most diverse at the Andean and Amazonian interface in western South America.

Los ichneumónidos integran la familia con mayor diversidad de especies en el orden Hymenoptera y unade las más diversas en la clase Insecta. Para México se registran 1 291 especies (5.3% del total mundial) de 300géneros y 28 subfamilias, con 43 géneros por identificar sus especies, para un total de 343 géneros. Se estiman entre3 215 y 4 544 especies para el país, considerando la necesidad de más estudios en las regiones norte, centro, occidentey sureste. El 59% (760) de las especies son neotropicales, el 29% (371) son neotropicales y neárticas, el 10% (127)son neárticas y el 2% restante (33) tiene otra distribución. De momento, 45% (580) de las especies se consideranendémicas, situación que se debe a la descripción reciente de muchas especies nuevas y a la falta de más estudios enCentroamérica (excepto Costa Rica).