202 
IOWA ACADEMY OF SCIENCE Voi.. XXVIII, 1921 
France, Germany, Bohemia and Italy. It appears to be quite 
generally distributed throughout the Continent. Its distribution 
in the United States is closely correlated with the distribution of 
Ulmus fulva and U. americana, its more common hosts. Roughly 
speaking, the red elm (^Ulmus fulva) occurs from the 100th mer- 
idian eastward and southward to Texas and Florida. The Amer- 
ican elm has approximately the same distribution except that in 
western Canada it extends northward to within half a degree of 
the southern boundary of Alaska. 'West of the 100th meridian 
the elms do not normally occur and the spread of the scale beyond 
the Rocky Mountains has been due no doubt to infested nursery 
stock. 
Fig. 31. Map showing the distribution of the European Elm Scale {Gossyparia 
spUria). Curved dotted line represents the limits of Ulmus fulva. Curved solid line 
represents the limits of Ulmus americana. Area in which the scale has been reported 
from many localities represented in solid black. The information regarding the dis- 
tribution of U. fulva and U. americanus furnished through the courtesy of Dr. E. N. 
Transeau. 
The distribution of the European elm scale is represented by 
the accompanying map (Fig. 31) on which are noted over 100 
locality records. There are three regions of general distribution : 
(a) the New England States and Middle Atlantic States, includ- 
ing the Provinces of Ontario and Quebec; (b) the Central States; 
and (c) California. The New England States and Middle At- 
lantic States form a region in which the scale is present in great- 
est abundance. Practically all the records in this region come 
from the territory between the Potomac and St. Lawrence rivers 
and include more than half the locality records in this list. In 
