Wednesday, December 16, 2009: 9:47 AM
Room 102, First Floor (Convention Center)
The sheer number of species in hyperdiverse taxa poses logistical problems for taxonomy. To break large groups into more workable subsets, systematists often rely on distinctions based on arbitrary sets of characters, especially in cases where the underlying evolutionary relationships in the group are poorly understood. In the present study we explore the phylogenetic patterns of taxonomically useful diagnostic characters in Heterospilus, a hyperdiverse braconid genus that normally attacks stem-boring beetles. We employ character codings and a multi-locus molecular phylogeny from an ongoing revisionary study of Costa Rican Heterospilus, a fauna containing several hundred mostly undescribed species. 4kb of sequence data from 100 wasps produce a well resolved tree. Taxonomically diagnostic characters show considerable variation in phylogenetic signal. We infer Heterospilus to be paraphyletic- and some related genera to be polyphyletic- mostly the result of secondary losses of the assortment of synapomorphies and sympleisiomorphies that have defined the genus. For recent divergences, genetic data largely concur with morphological species delimitations and show promise for associating previously unlinked males and females.