81 
on the trees. Destruction of windfalls and midsummer plowing" 
liave the disadvantage that they lock the stable door after one of the 
Iiorses, at least, is stolen, since they can at most prevent only in- 
juries by the new brood of curculios appearing after midsummer. 
In the absence of poison sprays, an orchard freed of curculios in 
midsummer — if this is possible — by plowing and harrowing, would 
be liable to invasion and serious injury later in the season by insects 
entering it from outside, and would also be exposed to injuries in 
the spring and early summer of the" following year. With these 
facts in mind, I undertook, in 1904, a field experiment in southern 
Illinois intended to test the practical value of an arsenical poison 
directed immediately against the plum-curculio, with the under- 
standing that similar experiments were to be carried on by the Hor- 
ticultural Department of the State Experiment Station in another 
part of the state. My experiment was placed in charge of my field 
assistant, Mr. E. P. Taylor, and this report is based on his field 
notes and specimens. 
The farm selected, after an examination of some twenty-five 
fruit farms in southern Illinois, contained three small orchards ag- 
gregating eighteen acres. It was situated two miles south of Car- 
bondale, in Jackson county. These orchards were chosen partly 
because of the considerable crop which they bore — an unusual thing 
that year — and also because the separation of the varieties with 
which they were planted, enabled us to make, in most cases, check 
and experimental plots of the same variety. 
Woods 
Pasture 
ORCH'Dl NO. Z 
ORCHARD 
NO. 3 
Site amo surrouwdimgs of experimental ORCMAPOS 
