A revision and a phylogenetic analysis of the genera Zelomorpha Ashmead, 1900 and Hemichoma Enderlein, 1920 were conducted. Phylogenetic analyses used molecular and morphological data. A total of 39 sequences were obtained for COI (887 bases long) and 57 for 28S (1254 bases long). DNA sequences were aligned manually and also aligned with ClustalW (Thompson et al. 1997). Parsimony, Maximum Likelihood, and Bayesian approaches were applied to phylogenetic analyses with each gene region analyzed separately and in a combined analysis. The phylogenetic analysis analyses supported the monophyletic status of the genera Zelomorpha, as defined by Sharkey et al. (2006), and Hemichoma; they upholdseld the hypothesis that the the New World species formerly placed in Biroia belonged to Zelomorpha, and corroborated the synonomy ofgenus Dichelosus with Zelomorpha (Sarmiento and Sharkey, 2005). A total of 3,242 specimens of Hemichoma and Zelomorpha collected through the New World representing 113 species were examined. In addition to the 29 species of Zelomorpha described originally in diverse genera and now moved into the Zelomorpha, 74 new species are described. Seven new species are described for the genus Hemichoma for a total of 10 species. All species are fully redescribed. Fully illustrated keys to the species of Zelomorpha and Hemichoma are provided. The phylogenetic results based on maximum parsimony suggest that, despite the colorful nature of the sister group Hemichoma, species of Zelomorpha were nocturnal and became diurnal secondarily in one lineage. The change to diurnality is linked to a decrease in eye size, to an increase in body size, and to the emergence of colorful patterns. Palatability field tests using lizards as predators of Zelomorpha concinna, a common species with one of the more characteristic and bright color patterns, suggest that the coloration has a warning function and that this wasp is highly unpalatable. Evidence was found that the short ventrally curved ovipositor is an effective defensive structure. DISCLAIMER: The text of this dissertation does not constitute the publication of new species as defined by the International Code of Zoological Nomenclature. The newly estrablished species names in this work will be/have been recognized as valid upon their publication in a peer-reviewed journal.

Many Hymenoptera, with their painful stings and noxious chemical defenses, exhibit bright aposematic warning color patterns and are the most frequently mimicked group of organisms. Such aposematic color patterns are found in parasitic wasps of the Neotropical Compsobracon group (Braconidae). Many members of this group exhibit color patterns similar to several thousand other species of Braconidae, Ichneumonidae, sawflies, assassin bugs, flies, moths, and beetles. One hypothesis to explain this observation is that the members of the complex and their colors are generated by multiple cospeciation events resulting in the constituent genera having isomorphic phylogenetic trees. An alternative hypothesis is that the organisms have colonized existing color pattern niches independently and do not have topologically similar phylogenetic histories. In order to test the hypothesis that these patterns are the result of cospeciation events they will be described and mapped onto a phylogenetic tree. If clades are found to have isomorphic topologies; evidence will suggest cospeciation. However, if clades are not found to have similar topologies, evidence will suggest independent colonization of color pattern niches. / Graduation date: 2006