Molecular phylogenetic studies of Sino-Himalayan butterflies

The Sino-Himalayan subregion is a widely extended transition zone between the Oriental Region and the Palaearctic Region. It comprises two of the most representative biodiversity hotspots of the Eurasian Continent, i.e.: the whole Himalayan range, part of the Tibetan Plateau and the South-West China Mountains, and to a little extent also the Indo-Burma Hotspot. A most interesting feature of this area is the unique nature of many of the animal and plant taxa characteristic of its biota. In fact, the Sino-Himalayan subregion although representing the transition zone between broadly overlapping elements from two zoogeographical regions, is also the abode of several endemic plant and animal taxa. This feature is well testified by the butterfly fauna which include several genera typical of this area. A second feature is that several of these genera are represented by many species, all or most of them confined to restricted ranges particularly in the Hengduan range and in other mountain area of South-West China. We are interested in the times and modes of the impressive cladogenetic events leading to the evolution of several Sino-Himalayan speciose butterfly genera, such as Aporia (Pieridae), Byasa andPazala (Papilionidae), Callerebia, Loxerebia, Hemadara and Argestina (Nymphalidae, Satyrinae), Calinaga (Nymphalidae, Calinaginae) and a few other genera. While speciation events could be related to the complex topography of this region, with steep mountains alternated to deep valleys resulting in a wide range of local climatic conditions, also tectonic and other historical processes could have driven older cladogenetic processes. In order to contribute to clarify these questions, that also apply to a number of animal and plant taxa, we have approached the butterfly studies from a molecular phylogenetic point of view. Here we show the status of advancement of our studies by presenting data on molecular phylogenies for the genera Aporia, Byasa and the whole group of Satyrine butterflies belonging to the genus Callerebia and allied genera. At this stage we discuss in particular the correspondences and discordances found in respect of traditional classifications, and discuss the value of mtDNA sequences to predict the specific status of related taxa, offering a preliminary view of the inferred times of the main speciation events in the Sino-Himalayan butterflies.