work at that time and also worked with the Farm Bureau people
in the counties where walnuts were grown fairly commonly. In many cases
these Persian walnuts were grown on fruit farms where they also have
apples and other fruits. So that in those cases it was not a difficult
problem to obtain control. We worked out a program whereby, say,
beginning about July the 20th to the 25th, at which time quite a few of
the flies would have emerged, if the orchardist, when he was going
through with his regular spray operation on his fruit trees, would give
his walnuts at least two applications at about two weeks intervals, he'd
cease to have a maggot problem. That pretty well solved it, as far as
they were concerned. But there were also these other plantings where
you'd have just a few trees, or possibly one tree in a back yard,
something of that sort, which is a little bit more difficult to control.

Dr. Glasgow and I found that on cherry maggot in the city, while a
material like lead arsenate is very effective in a commercial orchard,
it's very ineffective for just one little tree in your own back yard,
providing your neighbors have some trees and they don't spray them. The
reason is very obvious: the flies don't necessarily stay on the same
tree. They visit around from tree to tree, they feed on the surface of
the leaves or fruit. Therefore, it's possible for them to be over on
someone else's unsprayed tree and still come over and lay eggs in the
nuts of a sprayed walnut tree before being killed. So you can see that
such activity may create somewhat of a problem.

At any rate, the lead arsenate spray of three pounds to a hundred
gallons, with or without fungicides, has given good control in the past.
That No. 3 combination of lime sulphur and lead arsenate was used west
of Rochester here around Hilton where this grower had a commercial fruit
planting, but he also had a number of English walnuts. The year prior to
the time these trees were sprayed he had about 40 per cent of the nuts
infested, and the year these were sprayed the infestation dropped they
came down to about one percent. Notice the comment at the foot of the
table which states that the trees that were not treated the following
year went back up to 20 per cent of the nuts infested. There were about
20 per cent of the trees that had infestation. Of course, the flies
moved around enough that the trees became reinfested. It simply brings
out the point that unless you hav