have made towards this discussion.

In New York State we have in our official list of insects about 30
species of fruit flies that are catalogued, but only about five of these
can be classified as of economic importance. Two of these occur on the
cherries, both sweets and sours, and are called the cherry maggots.
Another one on apples, known as apple maggot, and a related form on
blueberry. And then, of course, the walnut husk maggot, and one other
which occasionally occurs on currants, but this one, of course, is of
less importance than the others.

The fruit industry, of course, in New York is quite large, both apples
and cherries, so that there is a considerable problem there as far as
control is concerned. The growers spend thousands of dollars every year
in combatting the various species of fruit flies. The interesting thing
in this connection is that throughout the last 25 years with which I am
familiar with the cherry fruit flies--in fact, that was one of the first
projects I worked on in cooperation with Dr. Hugh Glasgow when I came to
the Experiment Station in 1925--the control measures which we developed
in 1925 to 1927 are essentially the ones which we are still using today;
that is, for the most part. There have been various attempts to change
the control program through the introduction of these newer
insecticides, and some progress has been made, but in every case they
have been wrought with some difficulties. At the present time the
official state recommendations for the control of apple maggot and
cherry maggot still include the use of arsenate of lead under some
conditions. I mention that at this point because it is of some
significance in the overall control. I am going to discuss that later
on.

As far as the host plants and distribution of the walnut husk maggot is
concerned, according to the original description which was published
almost a hundred years ago, it was listed as occurring in and to the
Middle States. That is a little bit indefinite, but at least it occurs
all over the Eastern United States and as far west as Kansas. Then the
one which occurs in California, which has since been called _Rhagoletis
completus_ (?) looks very similar to the one that we have here, but
there are slight taxonomic differences, so at least it is considered a
different species. At any rate, it is very similar to the one we have
here, and this whole group of fruit flies that we have been talking
about have a l