DISTRIBUTION OF THE EUROPEAN ELM SCALE 
• ALBERT HARTZELL 
On May^ 27, 1919, an American elm on the Iowa State College 
grounds at Ames was found to be infested with European elm 
scale (Gossyparia spuria). Since the above date several other 
Iowa records have been added to our list and a considerable 
amount of information has been obtained regarding the distribu- 
tion of this species in the United States and Canada through cor- 
respondence with. State Entomologists, the U. S. Bureau of Ento- 
mology and Agricultural Experiment Station workers in states 
in which scale was thought likely to occur. 
The European elm scale was introduced into the United States 
from Europe in the latter half of the nineteenth century. The 
exact date will probably never be known. It was first brought 
to the attention of the United States Department of Agriculture^ 
by Mr. Charles Fremd of Rye, New York, in June, 1884, who 
complained that the elms in his nursery were badly infested with 
a bark louse. The insect in question was finally determined in 
1889 from material sent in by Mr. J. G. Jack of . Cambridge, 
Massachusetts. The spread of the species was rapid as was point- 
ed out in 1897 by Lintner^ in his 12th report, representing six 
states and the District of Columbia, including such widely scat- 
tered records as Palo Alto, California, Carson City, Nevada, East 
Lansing, Michigan and Burlington, Vermont; and it was known 
to occur along the Hudson from New York City to Troy. Since 
that time the spread of the insect along the main lines of travel 
has progressed until now it is found in twenty-seven states, the 
District of Columbia and the Provinces of Ontario and Quebec. 
That infested nursery stock is a contributing factor of great 
importance in the dissemination of this pest is shown by a study 
of the accompanying map. Long Island, the Hudson and Mohawk 
Valleys in the east and the Union Pacific Railway and its branches 
in the west constitute the main thoroughfare of dissemination. 
Gossyparia spuria is a native of Europe where it has been known 
to science for over a century, and has been reported from England, 
ijour. Ec. Ent., Vol. 12, No. 4, p. 351 (1919). 
2 Howard, L- O., Ins. Life, Vol. 2, p. 35 (1889). 
sLintner, J. A., 12 Rep. Ins. N. Y., p. 294 (1897). 
