DDT Dust versus Butternut Curculio
I was prompted to write this note by reading Mr. S. H. Graham's article entitled "An Experiment with DDT" appearing on page 101 of the 1945 annual report, in which he states that the butternut curculio did not survive DDT powder.
In the past four or five years the butternut curculio (identified as such by Prof. Conklin of the University of N. H.) has all but ruined my Crath Persian walnuts and heartnuts, so, acting on the basis of Mr. Graham's experiment, I had my trees dusted early in the morning when the dew was on the leaves, using a 10% DDT powder, the first time about May 30 and again two weeks later, and I am happy to say that this dusting has been very effective. I have been unable to find any sign of curculio injury this year, although I have seen it nearby on some native butternut trees.
My Gellatly heartnut was riddled by the curculio last year. This year, when the dusting was done, this tree was overlooked, so I undertook to dust it myself, and not realizing that the Niagara duster which I used was set in the closed position, I dusted the tree with considerable effort. In spite of the small amount of dust that came out, it proved sufficient to keep the curculios away or else to kill them so that there is no sign of any damage at this writing.