Intellectual merits of the proposed activity. The Lycaenoidea (Lepidoptera: Lycaenidae + Riodinidae) are a large group of insects whose some 7000 species have extraordinarily variable life histories. The Lycaenoidea are distributed world-wide, with their center of diversity in Southeast Asia, but two important and understudied groups, the Riodinidae and Eumaeini, occur primarily in the Neotropics, and together represent 35-40% of lycaenoid diversity. The goal of this research is to reconstruct the evolutionary history of the Lycaenoidea by analyzing both morphological and molecular characters. Representatives of 360 genera, or just over half of the estimated 715 genera in the Lycaenoidea will be sampled; each specimen will be scored for more than 125 characters, and its DNA sequenced for 4 genes (c. 3000 base pairs). Emphasis will be on the rich but poorly known Neotropical fauna. The resulting evolutionary tree of relationships will be used to derive a stable classification for the group. It will also provide a framework to study life history evolution and test biogeographic hypotheses regarding the origin and diversification of Lycaenoidea. The work will focus on the radiation of two groups in the Neotropics: the hyperdiverse Eumaeini hairstreaks, and the enigmatic Polyommatus blues. An understanding of the evolutionary history of these insects will illuminate historical and ecological factors that have affected Neotropical biodiversity. A strength of the proposal is the complementarity of the participants: the project is a collaboration between specialists in molecular and morphological approaches to reconstructing evolutionary history, and will contribute to our understanding of how best to use disparate and independently powerful datasets. Broader impacts resulting from the proposed activity. The project will specifically train a postdoctoral fellow and a graduate student in molecular and morphological systematics, and will involve the additional participation of numerous graduate students, undergraduates, consultants and collectors. The Principle Investigators (Pierce at Harvard and Robbins at the Smithsonian) have strong records for mentoring students, including women and minorities, and collaborating with scientists in Latin America. Both are members of international entomological consortia. This project will develop a web site with a searchable database that will make the thousands of specimens in the DNA and Tissues collection at Harvard sampled as part of this research available to the professional community, and will sponsor a public exhibit on Lepidoptera (moths and butterflies) at the Harvard Museum of Natural History emphasizing research on Lycaenoidea. The sequences will contribute to a larger database being developed by museums world-wide to use DNA "barcodes" for insect identification. Finally, because of their complex life histories, lycaenoid butterflies are particularly vulnerable to habitat destruction and are disproportionately represented among endangered species (e.g., the Xerces Blue, Karner Blue and Mission Blue in the US, all symbols of conservation; the Large Blue in the UK; Brenton's Blue in South Africa; and Illidge's Blue in Australia). An understanding of factors that affect both extinction and diversification of these insects will have a clear application to ongoing conservation efforts.