The Zygoptera, or Damsel-flies, of Illinois

Abstract

It is with a view to clearing up some of the obscure features of the classification and lessening the labor of determination that nymphs and adults, including both sexes, have been considered together and tables prepared for the separation of both. All obtainable biological data have been added for the sake of completeness; but it is fully realized that the data given here are incomplete, and can only be made complete after many years of diligent study. Nymphs of several species which are apparently new have been reared in the course of the study and are described herein for the first time. Some of the remaining species which doubtless occur in Illinois but which have not been collected by the writer, have been obtained through the courtesy of various people, and the list has been completed as far as possible in this way.