16 
by some skin eruption, and the horses used in hauling this straw after 
it was unloaded also suffered from what was seemingly the same 
disorder. Perhaps the following from a correspondent of the Bureau 
of Entomology, residing in southern Ohio, will give a fair idea of the 
situation on many farms in that section of the country: 
About four years ago a parasite was found when thrashing wheat out of barns. It 
seemed to affect the victims almost as soon as they got into the mow. Themen began to 
scratch themselves, generally on the 
neck and on the arms (inside) opposite 
the elbow, and on the body, back and 
front. The parasites raised welts such 
as you describe and spread as you in- 
dicate. They have spread to such an 
extent that farm hands dread them 
and will not change work with neigh- 
bors unless they thrash in the field. 
Here of late they are found in wheat 
straw in the barns, especially if baled. 
Last week a farmer brought me baled 
wheat straw that seemed to be alive 
with them. They attacked every one 
that went into the barn, and one of my 
horses that was perspiring from effects 
of a drive was simply covered with 
little knots or swollen places and bit 
and rubbed himself continually. I 
had to have the straw hauled out and 
burned and the barn disinfected. The 
farmer stated that they were so thick in 
the shed that contained the straw that 
he had to keep all stock out of the shed. 
Many other similar letters 
from towns in Ohio were re- 
ceived by Doctor Schamberg, 
particularly from Zanesville, 
Columbus, Vincent, Springfield, 
etc., where the affection is 
popularly believed to be due to 
Fic. 11.—Female Isosoma in act of depositing egg in ‘“chiggers.”’ A physician from 
stem. About life size. (Author’s illustration.) the last-named town stated that 
in the fall of 1908 during harvest and thrashing time he saw in Wash- 
inzton County some 87 cases of the disease in question. It affected 
the harvesters and thrashers. This spring he observed 38 cases from 
contact with straw ticks refilled with straw of last fall’s crop. The 
disease is said to have been more prevalent last year (1908) than ever 
before. Information has come from Columbus, Ohio, that potters 
who used straw for packing crockery ware have been so badly attacked 
at times that the entire force of packers has been off duty. Many 
[Cir. 118] 
