15 
stated, no trouble is experienced in using the mattresses after a cer- 
tain period, which period probably indicates the termination of the 
life of the mites infesting the straw. It therefore did not seem nec- 
essary to seek further for the primary cause of this eastern epidemic 
of dermatitis, the center of which seems to have been in and about 
Philadelphia. 
A WESTERN EPIDEMIC OF THE DERMATITIS. 
While the problem of the epidemic in the East was apparently 
solved, some of the wheat straw involved therein had come from 
Indiana, and during the last few years an outbreak of the jointworm 
(figs. 10 and 11) had been gathering force throughout Ohio, Indiana, 
and southern Illinois, 
until during the sum- 
mer of 1908 very seri- 
ous damages occur- 
red. Investigation 
of the insect during 
previous years had 
shown that the out- 
break really began 
in the more elevated 
portions of Virginia, 
in the upper Shenan- 
doah Valley, in West 
Virginia, and in east- 
ern Ohio, as early as 
1904, afterwards ad- 
vancing broadly to 
the westward. 
During the sum- 
mer of 1908 there 
came to the Bureau of Entomology from this section of the 
country a great number of complaints of serious skin trouble 
among people engaged in thrashing grain that had been stored 
for some time in barns, and in some localities it had become 
difficult to secure help to thrash under such conditions. Also the 
same disorder was encountered by those who used this straw for 
the purpose of filling bedticks, or as a substitute for felting under 
carpets, and in one case berry pickers had been attacked when such 
straw had been used as a mulch for berry plants. This straw came 
from a field that had been seriously damaged from jointworm attack 
in 1908. In one instance a carload of wheat straw was shipped to 
Pittsburg, Pa., and six men engaged in unloading it were attacked 
[Cir. 118] 
Fig. 10.—Effect of jointworm attack on wheat straw in field. Note 
enlargements and distortions. Reduced. (Original.) 
