It is our thought that if DIELDRIN was applied to the surface of the soil that many of the larvae would be killed upon entering the soil or would be killed at some later time when the adults emerge.
Dr. C. L. Fluke at the University of Wisconsin has been working for the past several years with DIELDRIN applied as an orchard spray for the control of plum curculio. In Dr. Fluke's work he applied the DIELDRIN to the orchard floor or cover. He has had some very promising results. Dr. Fluke has used two application rates, namely, six pounds and three pounds of DIELDRIN per acre. Since he obtained a high degree of control at the three pound level, it would seem worthwhile to investigate the possibilities of applying even a lower rate, say one and a half pounds per acre. In Dr. Fluke's work he applied the DIELDRIN to the soil in the orchard using a DIELDRIN emulsifiable concentrate containing one and a half pounds per gallon.
DIELDRIN is now available impregnated on a 30-60 mesh attapulgus clay. Such formulations are now available containing 5%, 10%, and 15% DIELDRIN. The DIELDRIN granules would appear to have certain advantages over liquid sprays where the grove has considerable ground cover. A high percentage of the insecticide is retained by the cover and does not reach the soil. The 30-60 mesh granules have the advantage of penetrating even the densest cover and their application results in a maximum deposit of the insecticide on the soil surface.
Groves or orchards under cultivation can be sprayed or treated with the granules. In either case it is advisable to disc the insecticide into the soil following application.
The granules are free flowing and can be applied quite readily with any fertilizer or distributor.
Without any field experience to go by it would seem that a 5% 30-60 mesh DIELDRIN granule formulation would be most convenient to use. By using a 5% DIELDRIN granule material you would obtain a dosage of 1-1/2 pound of actual DIELDRIN per acre by applying 30 pounds of granules per acre. Likewise, 60 pounds of the granules per acre would give a dosage of 3 pound of DIELDRIN. On the basis of work done with DIELDRIN for the control of the Japanese beetle, 3 pounds of DIELDRIN per acre will control this insect for more than 5 years. While it is not safe to assume that we could expect the same results in the case of the Hickory weevil, it does give us something to go by."
It seems likely that the foregoing will create some interest and that by the time of the next annual meeting we should have the results from the use of DIELDRIN to control the Hickory weevil.
MR. PAPE: It is my thought now if we could get a little discussion here concerning what some of you have been doing to control this pest, we might get somewhere, or at least get enough suggestions or get enough parties interested to carry on some experiments in different parts of the country.
MR. SILVIS: What company makes Dieldrin?
MR. PAPE: Julius Hyman Company is the one that sent the most literature and Shell Corporation local agents handle it. Also in Indiana the Farm Bureau Cooperative store handles it. The cost in small quantities is two pounds for 85 cents.