MR. WEBER: Will this spore powder kill other kinds of grubs that are in the sod?
DR. ADAMS: Not to any practical extent. It does not control the grubs of the "June bugs," or brown June beetles, or what are called "white grubs."
MR. LOWERRE: Would the DDT kill the parasitic wasps?
DR. ADAMS: Turf treated with chlordane or DDT is grub-proofed and is not of any use to the flying parasites as a place to lay eggs, or for bacteria to multiply. So we don't want to put chemicals on top of biological control plots. For instance, on an average home property I would treat the front lawn, the more valuable piece, with chemicals so that it would be 100% grub-proofed to protect the turf and to take that much turf out of beetle production. Then on the back lawns or grassy fields adjoining, I would apply at least a half-pound of this milky disease material, and in that way provide a complete treatment; the parasites can be added on some large public turf area nearby. And don't think you are going to stamp the Japanese beetle out just by spraying all the adult beetles you see each summer on the cultivated plants, because there are lots more on the shade trees, weeds and vines.
A new book, "The Insect Enemies of Eastern Forests," contains a great deal of information on the insects feeding on nut trees. Unfortunately, it isn't indexed to crops, so you can't look up "walnut" and find what insects bother you. You have to know what the insect is, and you will find it with its insect family. That is U. S. Department of Agriculture Miscellaneous Publication 657, by George E. Craighead. Price $2.50, from the Superintendent of Documents, Washington, D. C.
MR. CORSAN: What in the world has become of the black walnut caterpillar, that big, black fellow with the grey hairs?
DR. ADAMS: Maybe they are at a low point in a cycle. Mr. Bernath will show you a few of them.
MR. CORSAN: He might show me a few of them, but I have been pestered with them for years, and this year I haven't got any.
DR. ADAMS: I suppose natural conditions have taken care of them for a while, but they will come back again.
(Applause.)