Hoverflies of the subfamily Microdontinae have a reputation for causing confusion. The adult flies differ so much from other hoverflies that according to some they should be placed in a family of their own. Their diversity in shape and size is astonishing: from large, furry-haired species and convincing wasp-mimics to tiny, unsightly creatures, easily mistaken for something uninteresting. This paper introduces a new generic classification of the Microdontinae. A key to all 43 genera, 7 subgenera and some species groups is presented. All 552 available species names are classified into (sub)genera and species groups. The resulting classification comprises 454 valid species and 98 synonyms, of which 17 valid names and three synonyms are left unplaced. A total number of 26 new species are described, 267 new combinations of species and genera are proposed. The paper concludes with a discussion on diagnostic characters of Microdontinae.

The growing field of conservation biology has placed a new value on cataloging the Earth's living creatures, even as many of them face extinction. In the first systematic revision of the Chrysidid wasp family since 1889, the authors present a worldwide overview of this colorful group. Some 3,000 valid species have been named and are arranged in 84 genera and four sub-families. This comprehensive treatment presents a reclassification of the generic and higher taxa. It also includes a summary of previously published information, indicated problems in need of further study, and detailed synonomic species lists for each genus. Discussions for each tribe and sub-family include ancestral characteristics, phylogenetically important characters and a corresponding cladogram, keys to genera, and relationships among taxa.