Although a relatively small family (comprising approximately 270 world species), the Blephariceridae (net-winged midges) have been long recognized as having special potential significance to general studies of dipteran phylogeny and zoogeography because of their antiquity and very limited vagility. Their actual consideration in such studies has been restricted, however, because the faunas of major regions still remain untreated systematically, a failing largely due to the slight recognition afforded these midges by entomologists. They tend not to be taken except by dipterists and stream biologists with a special interest in them.
The present work will salve this dearth of knowledge for the Nearctic Region, bringing together for the first time all available data on the 25 presently known North American species. Because collecting in the last few years has turned up only two cryptic new species, the likelihood of major new discoveries seems small. Yet much basic taxonomic work is still necessary, particularly with the eastern Blepharicera tenuipes group, to clarify the integrity and interrelationships of the species and to fill gaps in distributions. A great need is also apparent for morphometric and ecological studies on all the species.