l be glad to mail a copy to anyone who requests it.

As stated before we have found that the butternut curculio is a very bad
pest with the Persian walnuts, also heartnuts and butternuts. It does
not injure the black walnut at all. There are also several other insects
which feed on the Persian walnut, most of these chewing insects that
simply injure the foliage more or less severely. Last winter I was
advised by Dr. Dean of our experiment station staff, to try benzene
hexachloride (hexachlorocyclohexane) for control of the curculio. He
stated that in California they have found out that the Persian walnut is
quite susceptible to arsenical injury when a spray containing arsenate
of lead is used on it. Also tests so far indicate that D.D.T. is not
very effective against the apple and plum curculio, therefore not likely
to be effective against the butternut curculio. So last spring we
secured a supply of benzene hexachloride. Just as we were about to spray
the trees I discovered a swarm of orange colored insects with black wing
covers, feeding on them. So I checked the compatibility chart in the
February issue of the American Fruit Grower and found that benzene
hexachloride and D.D.T. were compatible when used together in the spray
mixture. I thought it would be well to use a double barreled dose. So we
made up a spray of four pounds of benzene hexachloride, four pounds of
D.D.T., 50% wettable powder, and 6 pounds of wettable sulfur to 100
gallons of water. This first spray showed a slight burning of the
leaves, which I suspected was due to the sulfur. We omitted sulfur from
the later sprays and did not note any more burning. We put on three
sprays at about two week intervals and a fourth spray about the middle
of July. The result of these sprays appears to be excellent. I have
found only one nut showing any insect injury and this one was only
slightly injured, whereas last summer we lost a considerable percentage
of the nuts from curculio injury. A day or two after applying the first
spray, I wanted to secure a specimen of the orange-colored insects with
black wing covers, but I could not find a single specimen.

We did not apply our first spray quite soon enough and curculio larvae
had already invaded a few of the terminals. The first spray should be
applied about as soon as the leaf buds separate and quite likely should
be followed by the second spray in about a week, as new growth is very
rapid at this time and the scan