Excerpt from Revision of the Tachinidae of America North of Mexico: A Family of Parasitic Two-Winged Insects Sir I have the honor to submit for publication the seventh of the technical series of bulletins of this Division. It has been prepared by Mr. D. W. Coquillett, of the office force, and consists of a revision of the species of the parasitic ies belonging to the family Tachinidaa, which occur in the United States and Canada. The desirability of such a revision of these economically important ies has been apparent to all workers in economic as well as systematic entomology for many years. They are among the most important enemies of many of our most injurious insects, and their characters are so obscure that workers have had the greatest difficulty in separating one species from another, and the result is that the literature of economic entomology in par ticular contains many wrong determinations and absolute misstate ments based upon such erroneous names. During the last eighteen years many species of Tachinidze have been reared at this office from injurious insects which were being studied. It has been heretofore impossible to record the results of these rearings, on account of the confusion which existed in this family, and in its original conception this study of the group was undertaken in order to enable us to record the results of this biologic work. The records are now given in the shape of two tables - one of parasites and hosts and the other of hosts and parasites - and a glance at these tables will be instantly couvin cing as to the important and beneficial role which these insects play. With the clear and systematic diagnoses of the genera and species which. Mr. Coquillett has prepared, any economic entomologist should be able to determine just what species of Tachina ies are assisting him in his work against injurious insects. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works."