DEPARTMENT OF THE INTERIOR. BULLETIN OF THE UNITED STATES GEOLOGICAL AND GEOGRAPHICAL SURVEY OF THE TERRITORIES. VOLUME V. 1879. NUMBER 1. Art. 1.-Notes on the Aphididæ of the United States, with descriptions of species occurring West of the Mississippi. By Chas. V. Riley and J. Monell. PART I. BIOLOGICAL NOTES ON THE PEMPHIGINE, WITH DESCRIPTIONS OF NEW SPECIES.-C. V. RILEY, Ph. D. The object of the present paper is to set forth some interesting biological facts relating to the gall-making Pemphiginæ,* and which were presented in abstract at the late meeting of the American Association for the Advancement of Science. These facts have a special interest just at this time on account of the close relationship between the insects of the sub-family in question and the notorious Grape-vine Phylloxera (Phylloxera castatrix). The life-history and agamic multiplication of the Plant-lice (Aphidida) have always excited the interest of entomologists, and even of anatomists and embryologists not especially given to the study of insects. The lifehistory, however, of the gall-making species belonging to the Pemphigina has baffled the skill of observers more than that of any other group. All of the older writers, in treating of the different gall-producing Pemphigina of Europe, have invariably failed to trace the life-history of any of the species after the winged females leave the galls, and, with few exceptions, have erroneously inferred that the direct issue from the winged females hibernates somewhere. The most recent production on the subject is a paper published the present year in Cassel, Germany, by Dr. H. F. Kessler, on the life-history of the gall-making Plant-lice *This term is used in the sub-family sense, in accordance with most common usage, and not in the tribal sense, as employed by Buckton in his Monograph of British Aphides, 1875. Bull. v, 1-1 |