University Studies 



Vol. X APRIL ipio No. 2 



THE APHIDIDAE OF NEBRASKA 



BY THOMAS ALBERT WILLIAMS 



The present paper is being published posthumously, having 

 been presented to the University of Nebraska in 1891 by Mr. 

 Williams as a thesis to fulfil part of the requirements of a minor 

 in entomology for the degree of master of arts, and remaining 

 still unpublished at the time of his death, which occurred Decem- 

 ber 23, 1900. It was expected at the time of presentation that 

 the thesis would be published at an early date and, while engaged 

 in completing it, Mr. Williams prepared as Special Bulletin No. 

 1 of the Department of Entomology, University of Nebraska, a 

 preliminary " Host-Plant List of North American Aphididae," in 

 which he included not only a complete summary of the previously 

 recorded food plants of our aphid fauna but also all of his orig- 

 inal personal observations, which course necessitated the use of 

 his manuscript names of new species. This list was published 

 July 8, 1891. While such publication would hardly be expected 

 to establish priority, these names are somewhat different from 

 the ordinary nomina nuda in the fact that they referred to insects 

 found feeding upon definite and frequently characteristic host- 

 plants, and moreover the complete specific descriptions were at 

 the time all prepared and reposing in manuscript form in the 

 archives of the University of Nebraska. The recent intensive 

 study of the Aphididae which is being carried on by several 

 specialists in this country has made it very desirable that Mr. 

 Williams' names be substantiated by the publication of his de- 



Unwersity Studies, Vol. X, No. 2, April 1910. 



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