Abstract
The chorionic architecture, including the general and fine structure, of the eggshell of the microtype egg of the tachinid Euexorista futilis (Osten Sacken) is described. It is about 220 μm long, flattened dorso-ventrally, and has distinct dorsal and ventral chorions, each of which is differently structured. The surface features of the microtype eggs of an additional 20 tachinid species are described, and the usefulness of these features in taxonomic decisions is discussed. Three new combinations are used: Allophorocera arator (Aldrich), Cyzenis browni (Curran), and Eufrontina mitis (Curran).