e 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.

I am sorry to say I don't have any information on these newer materials,
like DDT, methoxychlor and parathion. You have probably read about all
of those in the magazines. Some of the men in our department have done
quite a bit of work with these insecticides on the apple maggot in the
Hudson Valley and in Western New York and they find, as I mentioned
earlier, while it's possible to obtain control of apple maggot, say,
with DDT, it requires much more frequent application. In that case, if
any of you are orchardists or follow the apple-growing insect problems
at all, the first application of the walnut maggot spray should go on at
about the time the last cover spray for the coddling moth goes on for
the first brood. That sounds a little involved, but from the calendar
point of view it would be about July 25th in Central or Western New
York. Normally, with us here the cherries are being harvested by about
July 15th, sometimes a little earlier, but at any rate, that's the time
the flies usually begin to emerge.

We have what we call a pre-oviposition period of about two weeks, during
which time the flies are not laying any eggs in the shucks and are
moving around feeding. Of course, that is the time you have to get this
spray material on, before they have punctured the nuts and deposited
eggs inside.

I think, unless there are questions, that's all I have to say.

A MEMBER: You recommend No. 3 to be used?

DR. GAMBRELL: Lead arsenate at 3 lbs./100 gallons and 2 gal. of lime
sulphur would be an effective insecticide-fungicide mixture. I have used
both the wettable sulphur and lime sulphur, as shown here, without any
injury to foliage. Sometimes, as you know, if it's real hot, like today,
sulphur could cause you a lot of foliage injury. Dr. MacDaniels will
certa