CONTRIBUTION TO THE KNOWLEDGE OF TOXOPTERA 
GRAMINUM IN THE SOUTH 
By Philip Buginbill, Entomological Assistant, and A. H. BEYER, Scientific Assistant, 
Cereal and Forage Insect Investigations , Bureau of Entomology , United States De¬ 
partment of Agriculture 
INTRODUCTION 
_ i 
Although the spring grain aphis (Toxopfera graminum Rondani) has 
been treated fully in a bulletin 1 issued at a comparatively recent date 
by the United States Bureau of Entomology, the life-history studies 
mentioned therein were conducted primarily in the North, where sexual 
forms appear and the viviparous ones die off annually in the fall of the 
year. Comparatively little was known at the time of that publication 
of the life history of the species in the South, especially in the Southeast. 
Consequently the establishment of a field station at Columbia, S. C., 
afforded the senior writer a good opportunity to make a study of the 
insect in that section of the United States. This study was begun in the 
spring of 1913, continued through the year 1914, and to the spring of 
1915. Its purpose was to ascertain whether or not Toxoptera graminum 
in that latitude breeds viviparously throughout the year, and, if so, 
(a) fot how long a period it breeds in this manner, (b) whether or not 
the strain becomes weaker as it gets older, and (c) whether or not sexual 
forms are produced. 
In addition to this study a number of molting experiments were con¬ 
ducted during the spring and summer months of 1914 in order that the 
variations in the duration of instars as caused primarily by temperature 
conditions might be learned. 
During the year 1914 the senior writer was assisted in conducting the 
experiments by the junior writer, and during the former's absence in the 
fall of that year the latter took charge of the work. 
METHOD OF PROCEDURE 
The breeding of series of generations began in March, 1913, with an 
individual taken from the field. The first-born of this individual was 
isolated as was the first-born of this and each succeeding generation in 
this series. A careful record was made of their progeny and of the 
length of life of the individuals constituting the generations. Similarly, 
a specimen and a record were kept of the last-bom of the individual 
collected, and of the last-bom of every succeeding generation originating 
in this series. The series collectively will be known in this paper as the 
“A” series. 
1 Webster, F. M. f and P hillip s. W. J. the spring grain aphis or “green bug.” U. S. Dept. Agr. 
Bur. Ent. Bui. no, 153 p., 9 pi., 48 fig,, 5 diagr. 1912. 
Journal of Agricultural Research, 
Washington, D. C. 
oe 
Vol. XIV, No. a 
July 8,1918 
Key No. K-68 
(97) 
