(Next slide.) This photograph is one that I wasn't sure I was going to get back in time for the meeting, but it is a Kodachrome of a pair of flies mating on an English walnut. This happened to occur on some of our own trees at the station, so that we are not immune from attack by this bug.
(Next slide.) That is a close-up of an egg puncture, just a very tiny little hole in the husk, and once in a while they lay an egg even on the surface. Those eggs are quite small, about a millimeter in length and about two-tenths of a millimeter in width, but the next slide will show you that what they normally do is to put them inside that puncture in groups. They vary quite a bit, but the average number of eggs is about 20 in each puncture. But that doesn't mean you won't have maybe four or five different punctures on a given nut, so you may end up with at least a hundred or more maggots in a shuck.
(Next slide.) And the next picture is a photograph of the same English walnut taken about six or seven days later, showing the young maggots that have just hatched out. What they will do, they will begin boring in, and they will just radiate out in all directions into the shuck. When they have gotten that far along, of course, there is no hope for control.
(Next slide.) This slide is one taken when the maggots were almost mature, showing the type of damage that you get.
(Next slide.) This is the resting stage, or the pupa, the one which spends the winter in the soil and from which the flies emerge in New York, at least in our section, beginning about July 15th and going through up until August 15th.
(Next slide.) The one at the top is normal fruit. I mentioned a while ago that this butternut curculio causes quite a bit of concern and also spoke about its being in terminals. If you look carefully you see a very definite hole here in the husk. That is where the adult punctured the husk. It may have been a feeding puncture first and later an egg was laid inside, and then you get the maggot or the grub of the curculio developing in there, so that superficially that discoloration looks very much like the walnut husk maggot. But in this case you may not find over one or two maggots in a nut. And the other difference is that these fruits which are attacked usually fall during July and August, whereas the ones that have maggots in, many of them stick right on the trees and don't come off at all.