Patrones de riqueza altitudinal de Papilionidae, Pieridae y Nymphalidae (Lepidoptera: Rhopalocera) en áreas montañosas de México / Altitudinal richness patterns of Papilionidae, Pieridae and Nymphalidae (Lepidoptera) in Mexican mountain areas

Butterflies constitute an useful group to investigate biodiversity patterns in specific geographic areas. The aim of this study was to describe the altitudinal patterns distribution and to recognize the main grouping factors of these families. We conducted a comparative study between the butterfly fauna (Papilionidae, Pieridae and Nymphalidae) of five Mexican mountain ranges (Sierra de Manantlán, Sierra de Atoyac de Álvarez, Loxicha Region, Teocelo-Xalapa and Sierra de Juárez), that included 34 sites of altitudinal ranges from 100 to 2 820m. Data was obtained from the Zoology Museum of the National University of Mexico, and comprised more than 60 000 butterfly records of 398 taxa (subspecies level) proceeding during the last 35 years. Fauna similarity between localities were analyzed using a cluster analysis by Sorensen similarity coefficient. Species richness showed a general tendency to decrease with altitude; the main difference was found between the locality with higher altitude and the rest of the sites. The principal factors affecting the identified clusters followed this order: the location in Pacific or Atlantic slope, and location on a particular mountain range. Three altitudinal levels (low elevations, up to 1 200m; intermediate elevations, from 1 200 to 1 800m; and high elevations, from 1 800 to 2 500m) were described in accordance to their main characteristic taxa. While Neartic elements were common in the highest altitudinal floor, Neotropical taxa were common in the lowest one. It was more difficult to characterize the intermediate level in which a high number of localities were clustered; this intermediate level was characterized by the presence of some endemic species. The results suggest that historical factors are preeminent in butterfly fauna composition in these areas. Future studies may include other Mexican mountain areas to obtain more information on the different factors (latitude, altitude, slope) influencing biodiversity patterns.

Las mariposas diurnas integran uno de los grupos más utilizados para el reconocimiento y monitoreo de la diversidad de una biota. Se realizó un estudio comparativo de las faunas de mariposas de las familias Papilionidae, Pieridae y Nymphalidae de cinco áreas montañosas de México, situadas en las vertientes Atlántico y Pacífico: las sierras de Atoyac de Álvarez, Manantlán, Juárez, y las áreas de Teocelo-Xalapa y la región Loxicha, con un total de 34 localidades representativas de los cinco transectos altitudinales, que comprenden de los 300 a los 3 100m de altitud. Se observó una tendencia general a la disminución de la riqueza con la altitud. Se analizó la similitud entre el total de localidades mediante el índice de Sørensen, diferenciándose en primer lugar las dos estaciones de elevaciones superiores (sobre los 2 500msnm), caracterizadas por pobres lepidóptero-faunas. En el grupo principal (32 sitios) las principales agrupaciones se dan de acuerdo, en primer lugar, a la pertenencia a la vertiente pacífica o atlántica, evento más histórico que ecológico y, después, las estaciones de una misma sierra o según tres diferentes pisos altitudinales, que se caracterizan de acuerdo con los táxones predominantes.

Coleópteros necrófilos (Scarabaeidae, Silphidae y Trogidae) de Malinalco, Estado de México, México / Necrophilous coleoptera (Scarabaeidae, Silphidae y Trogidae) of Malinalco, State of Mexico, Mexico

Collections were made during one year, between August 2005 and July 2006, in Malinalco, State of Mexico, in three sites of tropical deciduous forest, a pasture and a induced forest of pine-oak, established in a altitudinal gradient ranging from 1,253 m to 2,300 m. The total of 7,680 specimens Scarabaeidae, Silphidae and Trogidae were captured through NTP-80, representing 18 genera and 38 species. Onthophagus and Canthon contained 46 percent of the richness of Scarabaeidae. The more distant sites were complementary in their species composition. The lowest complementarity occurred between sites with tropical deciduous forest. It revises the material collected through pitffal traps and light traps funnel type, increasing the list of 38 to 50 species in the study area. Between 40 percent and 50 percent of the species in Malinalco are distributed in localities of the province of the basin Balsas and localities of the province of the Sierra Madre del Sur, and 30 percent in the localities of the province of Pacifica coast. For the first time 17 species of Scarabaeidae and three Trogidae were reported for the State of Mexico.