| Insects in the family Evaniidae (Hymenoptera), also known as ensign wasps, are colorful, easily recognized, and frequently collected. The larvae develop as egg predators within the oothecae of cockroaches (Dictyoptera), and the family follows a largely tropical distribution. Despite myriad fascinating biological attributes (mimicry complexes, wing venation heterogeneity, unexplored biogeographical patterns) the systematics of these wasps has largely been neglected. The current classification is evaluated phylogenetically, using fragments of the mitochondrial 16S rRNA and cytochrome oxidase I genes and the nuclear 28S rRNA gene for 60 exemplar taxa. After alignment of the ribosomal RNA sequences to predicted secondary structure, relationships between genera are estimated using three methods: unweighted parsimony, six-parameter parsimony, and mixed model Bayesian analysis. Results indicate that most genera are monophyletic except for the clades represented by Zeuxevania + Parevania + Papatuka and Acanthinevania + Szepligetella + Evaniella, which require more data to resolve. The genera are keyed and four new extant genera are described: Decevania, Papatuka, Rothevania, and Vernevania. The species of the world, including all fossil taxa, are cataloged and reassigned to the updated and phylogenetically tested generic classification. Two new fossils from Lebanese amber (120--130 million years old) are described as new genera and species, and their morphological characteristics are discussed and compared to morphotypes exhibited by extant species. These fossils represent the oldest known ensign wasps and are used in combination with other known fossils as calibration points to estimate divergence times for Evaniidae and the major clades within therein. Results indicate that Evaniidae is 151.83 (+/-6.33) million years old, which corresponds to the age (based on fossils and published molecular data) at which cockroaches began encasing their eggs in a protein matrix (i.e., the ootheca). Current literature indicates that ensign wasps are the dominant predators of cockroach eggs and they have been coevolving with Dictyoptera for 150 million years. Egg case protection behaviors, for example depositing the egg case in a hostile environment (Nyctibora acaciana Roth) or retaining the egg case internally until hatch time (Blaberidae), likely evolved in response to egg predation by ensign wasps. |
