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 have a pretty good-sized planting, you are going to have to spray pretty thoroughly in order to get control, and also, if you only have one or two trees and you have a lot of surrounding shrubbery and a lot of trees, it would be very wise to also spray those, unless they are plums or peaches, which are quite susceptible to arsenical injury. But most things would stand the arsenate of lead, and it would be very desirable, wherever you can, to spray surrounding trees and shrubs close to the walnuts themselves, and in so doing you would get pretty effective control. It is quite possible to use this control method and obtain over 80 per cent reduction in infestation.