natural result of neglecting one of the insect factors. This plantation
is the government's chestnut orchard at Bell, Maryland, which was
planted for scientific purpose some years ago by Dr. Van Fleet. This
orchard of around one thousand trees contains numerous species and
varieties of chestnut, some of which bear fruit every year. The various
scientific projects carried on in this orchard in the past have all been
of such a nature that they called for no consideration of weevil
increase. Many nuts have been allowed to lie under the trees until the
weevil larvae issued and entered the soil. This has resulted in a
constant increase of weevils until infestation of the nuts became
practically one-hundred per cent. All nuts of the crop of 1922 were so
wormy that when planted they failed to germinate. Injury to the crop of
1923 seemed somewhat less severe, but its extent may be indicated by the
fact that 3080 nuts from this orchard which were kept by the speaker in
rearing jars yielded 11,085 worms. In the woods adjacent to the orchard
the native chestnut trees are disappearing on account of the blight, and
presumably weevils are on the decrease. Within the small area of the
orchard, however, the increase has been abnormal, due, as has been
indicated, to the peculiarly favorable and man-made conditions. If, from
the time the trees of the orchard began to bear, the investigations
being carried on had called for close gathering of the nuts at maturity
and the destruction of all the worms that issued from them, there is
little doubt that infestation would have been kept within reasonable
bounds. At present, after two years of attention to the collection of
ripening nuts, there is an apparent decrease in the number of weevils.
Strong emphasis should be placed upon the importance of gathering
chestnuts as soon as they are ripe and prevention of the worms from
reaching the soil. This is especially true of districts where woods
surrounding chestnut orchards do not contain bearing native chestnut
trees.
_The Nut Weevils_
Now that the subject of nut weevils has been introduced, let us consider
in more detail these grotesque, long-snouted insects whose larvae, or
grubs, play havoc with so many of our nuts. Most of us have had the
experience of gathering in autumn rich stores of our delicious native
chestnuts. But how often our anticipations of boiled and roasted feasts
have been blighted. We have found that the chestnuts were like the manna
which fed the children of Israel in the wilderness, "When we left of
them until the morning they bred worms and became foul." There are
numerous cases in this country where chestnuts in shipment have been
seized and condemned under the provisions of the Food and Drugs Act.
Usually the phraseology of the libel has been "because the shipment
consisted in part of filthy animal substances, to wit, worms, worm
excreta, worm-eaten chestnuts and decayed chestnuts." Altogether the
loss to chestnuts from weevil injury is beyond computation.
The beetles which are the parents of the familiar worms in chestnuts are
not commonly seen, or, if observed, they are not associated with the
disgusting inhabitants of the nut kernels. These beetles represent in
their structure a very interesting adaptation to a special end. The
mouth is located at the tip of an enormously long snout, or proboscis,
and the drill-like instrument is used for puncturing the thick covering
of various kinds of nuts so as to admit the egg into the kernel upon
which the young will feed. In some cases the mouth is situated at a
greater distance from the eyes and other head appendages than is the
anal extremity of the insect. There are in the northern part of this
country two species which attack chestnuts, one which attacks
hickory-nuts, one which attacks hazel-nuts and about a dozen which
attack acorns. And here may be mentioned an interesting peculiarity of
the feeding habit which is decidedly to the advantage of the nut-grower.
Each species adheres closely to its own food plant. The hickory-nut
weevil does not attack hazel-nuts nor the hazel-nut weevil hickory-nuts.
None of the acorn-infesting species will seek for food in the nuts of
chestnut, hickory or hazel. Once the chestnut weevils are absent in a
locality, there is no chance that oak trees will serve as a means of
spreading the weevils back into the locality. So closely confined are
these weevils to their particular food plants that many of them
distinguish between the different species of oak and will oviposit only
in certain kinds of acorns.
All the different species resemble one another in both the adult and
larval stages. There is also a general similarity in their behavior. I
have recently discovered, however, a marked difference in the life
cycles of certain species. For example, the larger chestnut weevil and
the smaller chestnut weevil look alike, but they are decidedly unlike in
their development. The grubs of the larger weevil begin to leave the
nuts at about the time the nuts drop. They enter the soil to a depth of
several inches and fashion smooth-walled cells in which they remain
unchanged until the following summer. During June and July they
transform to pupae, and soon afterward to adults. In August they issue
from the ground and seek the trees where they collect around the burs
and begin to deposit eggs soon after the nut kernels start to form. This
life cycle is continued year after year. To forestall starvation of the
race in case of entire failure for a year of the chestnut crop, a few
individuals carry over the second winter in the ground and then issue as
beetles along with the one-year-old specimens. It is probable that a
small per cent of the insects may remain in the soil over three winters.
Thus does nature by unique arrangements safeguard the lives of even the
very small creatures.
The life cycle of the lesser weevil is quite different. The larvae of
this species leave the nuts somewhat later in the autumn than do those
of the larger weevil. Like them, they enter the ground and pass the
first winter unchanged. The grub stage is continued throughout the
summer, but late in autumn, after the beetles of the larger species have
been on the trees for some weeks and deposited most of their eggs, the
larvae of the smaller species transform to adults. Instead of coming
from the ground, however, they remain in their earthen cells throughout
the winter. The next spring, prior to the blooming of the
chestnut-trees, they emerge from the ground and soon thereafter collect
in large numbers on the male catkins of the chestnuts. At this time very
little feeding is done and the sex instinct does not manifest itself. As
the time approaches for the nuts to mature, however, the beetles begin
to feed and pair and soon thereafter to lay their eggs in the ripening
nuts. Most of the eggs are deposited directly into the nuts after the
burs begin to open. In the case of the larger weevils the beetles are
present only about three months of the year. Those of the lesser
species, however, are perpetually present, those of the younger
generation reaching the adult stage in the ground before those of the
previous generation have finished laying their eggs in the ripening
nuts. As with the larger species, a few of the smaller weevils carry as
larvae for several years to tide over possible failures of the chestnut
crop. The life cycle of the hickory-nut weevil is similar to that of the
larger chestnut-weevil, and that of the hazel-nut weevil is like that of
the lesser chestnut weevil. Both cycles are represented among the
acorn-infesting species.
Any intelligent warfare against the nut weevils calls for a knowledge of
these distinctive life histories. Thus, an abundance of maturing larvae
of the larger species this autumn will insure an abundance of beetles to
deposit eggs in the nuts next autumn. With the lesser weevil, however,
maturing larvae this autumn will not affect the number of beetles on the
trees the succeeding autumn but will provide beetles for the crop two
years hence. Large numbers of beetles of the lesser species may be
destroyed by collecting them from the blossoms of chestnut, but, at that
season of the year there are no beetles of the larger species abroad.
These weevils are to be made the subject of a bulletin by the Bureau of
Entomology in the near future, in which it is hoped to go more fully
into a discussion of control measures.
_Walnut Husk Maggot_
Although none of the weevils of the group just discussed attacks
walnuts, the fruit of this tree has a serious enemy in the walnut husk
maggot. This insect is most familiar in the form of multitudes of
dirty-white maggots inhabiting the blackened, slimy husk of ripening
walnuts. Originally, the black walnut furnished the favorite food of
this insect, although the husk of butternuts was sometimes attacked.
More recently the pest has turned its attention to the Persian walnuts
which are fruiting in many places in the east. The watery, dark-colored
pulp into which the husk of the nut is converted when the maggots begin
to feed penetrates the shell of the nut and injures the kernel by
staining it and imparting a strong flavor. The operation of hulling is
also made doubly disagreeable, the nut coming out of the husk discolored
and dirty.
These maggots hatch from eggs inserted into the husk of nuts by a
light-colored fly about the size of our common housefly. Although easily
overlooked, these flies may be seen on the nuts at almost any time in
August and September. They have strong ovipositors with which they
puncture the surface of nuts and insert into the openings masses of
white eggs from which the maggots hatch.
As to the control of this pest, the speaker obtained very promising
results in spraying Persian walnut trees belonging to our friend, J. G.
Rush, at West Willow, Pa., with a solution of 1-1/2 pounds of lead
arsenate to 50 gallons of water with 10 pounds of glucose sugar added to
impart a sweet taste. The flies were observed feeding on the sweet
coating given to the leaves and the nuts that ripened later were
comparatively free from maggots. It was obvious that the flies died from
the poison before depositing many eggs in the nuts.
_Twig Girdlers_
During the past two seasons the speaker has made special studies of
several species of beetles which cut or girdle young hickory trees, or
the branches of larger trees, causing the severed part to break off or
die. Not fewer than four distinct species of beetles in the east have
this habit. Three of the insects do their damage in the larval stage.
One of these, _Elaphidion villosum_, has been called the twig-pruner. It
is a well known species and its work in pruning the branches of hickory
and various other trees has often been referred to. The other two
species which sever the wood in their larval stage are _Pseudobidion
unicolor_ and _Agrilus arcuatus_. Thus far, these two have no common
names. In certain localities they are proving to be very troublesome to
both young and bearing trees. In one block of a nursery in Virginia I
estimated that the Agrilus larvae had ruined one-hundred dollars worth
of young hickory trees. Fortunately, the adult of this species feeds
freely on hickory foliage and can be killed readily under nursery
conditions by spraying with arsenical poisons.
The fourth girdler referred to is our familiar hickory twig-girdler,
_Oncideres cingulatus_. In this case the adult insect cuts a ring-like
furrow around the wood and the portion above dies. The purpose of the
girdle is to provide dead wood in which the young may feed. After the
girdle is made, a process which occupies several hours, and, sometimes
several days, the eggs are laid in the bark above. In central West
Virginia and northward the grubs which hatch from these eggs require two
years in which to reach maturity. In the vicinity of Richmond and
southward, however, the larvae mature in one year. This more rapid
development in the south probably accounts in part for the recent
serious outbreak of this insect in Virginia and the Carolinas.
Each female beetle is capable of girdling several twigs. One female of
about a dozen kept in confinement last autumn made eleven girdles and
deposited 55 eggs. Several of the beetles continued their interesting
operations until after several snows and severe frosts had occurred.
The twig girdler in the beetle stage feeds rather freely on the bark of
twigs. Enough of the surface is eaten to justify the belief that the
beetles may be killed by spraying with arsenical poisons. This treatment
is being tested at the present time. In the cases of all these insects
which sever the branches the wood is killed for the safety and comfort
of the insect as it undergoes further development above the severed
point. There is a period of at least several weeks in each case after
the twig dies during which the insect in one stage or another remains in
it to complete its growth. This affords an opportunity to gather the
twigs and burn them with the assurance that the insects are being
destroyed thereby.
At least some progress has been made in discovering the habits and the
methods of controlling these and various other insects that may be
expected to give nut growers in the north more or less trouble. The
remedies that can be offered at the present time are not in all cases
entirely satisfactory. There is much yet to be learned, but there are
control measures within the reach of most of the nut growers which are
well worth consideration and adoption.
THE SECRETARY: Dr. Zimmerman, will you read to us now?
DR. ZIMMERMAN: Perhaps some of the members will not be so glad to hear
what I have to say, but I feel that there is a need for something along
the line I will refer to.
DEVELOPING A NUT INDUSTRY IN THE NORTHEAST
BY DR. G. A. ZIMMERMAN, PENNSYLVANIA
We have all heard of the pecan. No doubt most of us have traveled
through the South at some time or other and have entertained a wish for
a pecan grove. A personal friend of mine, a minister, told me recently
that the only time he was ever tempted to invest in a commercial
proposition was when a real estate agent laid a picture of a pecan grove
before him. I had entertained the thought that some day I might possess
an orchard. Therefore, a couple of winters ago, when I found it
necessary to go south for my health, I silently hoped I could kill two
birds with one stone, by getting some undeveloped land and starting a
pecan grove, which at the same time would keep me in the open air and
give me exercise. Consequently, my eyes were always open and I was on
the constant lookout for pecans. After miles of travel they appeared.
They were very interesting and I went into the subject pretty
thoroughly. I was informed that no cheap land was available any more
that was desirable for pecans. I am not so sure of that. I was also
informed that most of the people who had planted groves had made a
mistake, that the pecan business was just beginning under new ideas, and
that most of the work would have to be done over. From the amount of
trees that are being top-worked I am inclined to believe this is true.
But I didn't kill the two birds with one stone. I did not attempt to
build up a pecan grove, but instead I came back with the idea firmly
impressed that we have a better proposition for the future right here,
that we have right here in the North the building material in the
shagbark hickory and the black walnut for a nut industry that will rival
or even surpass the enviable position the pecan holds today. Was I
correct or was I wrong? A second trip last winter has served only to
imbed that idea into a firm conviction.
What ground have I for drawing this conclusion? Some of you, my friends,
may disagree with me in some of my remarks, and no doubt insist that I
am uninformed. Perhaps I am, but I am giving my convictions
nevertheless, and I ask you to withhold judgment for twenty years before
deciding against me.
Why has the pecan forged to the front as it has? Because the pecan is a
good food, easily available, of pleasant taste and presents a fine
appearance. From a commercial standpoint, after 20 years or more on the
pecan, there is only one really desirable variety available, namely the
Schley, and the fact that it readily sold last fall for 80 cents per
pound wholesale, while the choice of the other varieties brought 60 and
65 cents per pound, bears me out in this. I am not referring to the
greater productivity and other qualities of some of the other varieties.
Many of them are tolerated for various reasons.
How about the shagbark in the North? It is my belief that we do not have
at present a shagbark that will anything like meet the pecan of the
South, yet the consensus of opinion of the people I know who have eaten
both, decides in favor of the shagbark. The quality of a very ordinary
shagbark is better than the best of pecans. What then, is lacking? Size,
shape, thinness of shell, cracking qualities, color, everything but
flavor is lacking in most shagbarks. Don't misunderstand me. I am not
condemning what we have, for I believe that if as many years are spent
by as many people in finding or developing a shagbark, we will have one
that will surpass the pecan. But as the matter stands I am constrained
to say that I do not know of a really good nut today that will stand the
test of building an industry that will compete with the pecan. We must
find or develop a couple of really good nuts that will compete, nuts
that are large, smooth, shell thin enough to crack with the fingers, a
white kernel that is plump and easily extracted. I do not believe that
any thick shell nut will ever meet the favor it should or become
extremely popular. The Weiker, one of our best, is of good size, looks
fairly well, but the shell is thick and it is poorly filled. It will
never fill the place for a real industry, and yet they sell for a good
money-making price today.
If we build our groves after this standard we will be in the same place
in a few years that many of the pecan growers are now, namely, with a
lot of trees on hand that must be top-worked later on. But they are the
best we have and, like the old adage that it is better to love and lose
than not to love at all, it is better to go ahead with these than not to
go at all.
How about the black walnut? This nut will come to the front and be
popular for baking purposes and candy-making, for it is the only one
that holds its flavor after heating. But its competition will be against
the thin-shelled English walnut. It will not be extremely popular until
we get one with a shell equally thin. At present we do not have one.
How then can we anticipate a great future industry after meting out this
doleful outlook? Are we going to discard everything we have and start
again? By no means. The price of nuts, even of the ordinary class, is
sufficient even now to well repay any man for his effort, if producing
them on a large scale, and what must be done is to encourage more people
to become interested.
If we could arrange to have nice exhibits of named varieties of nuts at
the various county fairs, and have someone there to explain them, a good
deal of interest could be created. I frequently see native nuts
displayed, but not named varieties.
I shall not refer to the hazel, chestnut, pecan nor butternut, all of
which I believe can be developed into a more or less successful industry
but only repeat in closing that I am convinced, after pretty thorough
investigation, that the shagbark hickory and the black walnut can be
developed into an industry in the Northeast in a much shorter time than
it has taken to develop the pecan, to a point that will equal or surpass
the enviable position that nut holds today. But, and let me impress this
point, we must develop a few new and better nuts to do it. On account of
the colder climate, which goes for the developing of fine flavor in all
products, I do not believe the pecan will ever equal the shagbark in
quality. This is our great natural advantage.
DR. MORRIS: I accept all of the statements by Dr. Zimmerman with one
exception. The pecan is tremendously prolific and so productive that
there are records of 30 bushels to a tree. I do not know that any of the
shagbarks or shellbark hybrids ever will rival that in production. From
the marketman's point of view production is of prime importance. In this
the pecan out-rivals the black walnut.
TRANSPLANTING NUT TREES
_Willard G. Bixby, Baldwin, N. Y._
When I set out the first nut trees which now are growing at my place at
Baldwin, I was very particular to follow the best advice obtainable.
What this was is to be found in Bulletin No. 5, published by the
association, pages 8 and 9, under Planting Directions. I will not take
time here to read them but will refer those interested to that
publication.
Much that is to be found there is unquestionably the best practice that
we know today. The importance of preventing the roots from drying out,
digging holes of sufficient size and filling with good top soil, firming
the soil well about the roots, severely cutting back after planting and
staking newly set trees if they are of appreciable size above ground,
are of the utmost importance and should be emphasized, but others of
these directions have been modified in my practice and I will relate the
unfortunate experiences which caused these changes to be made.
From the start there has been trouble in transplanting hickories,
difficulties with other trees being small in comparison. Out of a number
of fine looking little grafted hickories set out in the fall or spring
some would be sure to die. They mostly came from Mr. Jones, who, as a
rule, has furnished the finest looking hickories that I have received,
and were finely packed and seemingly ought to have lived, but only part
of them did. After losing a number out of one lot, I watched the lot
purchased next year with particular care. Three out of a lot of six,
which had put out leaves well in the spring, by the middle of July began
to show signs of distress, the edges of the leaves beginning to turn
brown which the year previous had been the beginning of the end. I knew
what had happened the year previous, felt that the trees would die if
something was not done, and did something. That something was to dig
about six quarts of chicken manure and two trowels of nitrate of soda
around the three trees that looked sick and saw that they were watered
plentifully till a heavy rain came. At first nothing was noticed, but
after a while the brown disappeared on the leaves that were only
slightly brown, while in other cases new leaves put out and finally a
second growth of shoots, very small to be sure, but the trees had been
saved. This was diametrically opposed to previous practice of putting no
manure or strong fertilizer in holes when planting the trees, but the
result was so satisfactory that I have continued to dig in about 1/4 of
a wheelbarrow of well rotted stable manure around each tree when
planting and two trowels of nitrate of soda in May when the growth
should start in the spring.
The above treatment seemed almost entirely to solve the difficulties of
transplanting and for about two years practically no hickories were
lost. Twenty-four Hales trees, 10 years from grafting brought here from
Monticello, Florida, all lived through the first year and 23 of them
through the second and now seemingly have a long life ahead of them.
Inasmuch as Mr. Jones expressed his doubts as to how successful this
experiment would be I regarded it as somewhat of a triumph. On the other
hand out of the finest looking lot of young Iowa hickories grafted a
year ago this spring and shipped in the fall and set out just as
carefully as I knew how, with well rotted stable manure in the holes and
seemingly having every prospect of a long life before them, all have
died now, excepting four, two of which I am making desperate efforts to
save.
The reason for this failure has not yet been proved, but I have an idea
what it is. With two exceptions the stocks were not large, unusually
small in fact, and the growth of the grafts was small, but, except for
their small size of stock and graft they were fine looking little
hickories as one often sees. The two that are in good condition today
were bitternuts on bitternut stocks and both the stocks and grafts were
notably larger than others. One of these bitternuts by the way, is
bearing this year. Evidently there was not as much vitality stored in
the smaller trees as in the larger ones. I am inclined to believe that
the real trouble was because the grafts, excepting the bitternuts, had
not become sufficiently established before having to stand the shock of
digging, shipping and transplanting. I have noticed in experiments made
to determine the adaptability of a number of species of hickory as
stocks that it was not unusual to find that a graft would do reasonably
well the first summer and die the second. If this happens occasionally
when hickories have not been transplanted it is undoubtedly very much
more likely to happen when they are transplanted. I have had practically
no losses in transplanting hickories when the graft had grown two
seasons before being transplanted. The safe plan, then, would seem to be
to let a graft grow two seasons before transplanting. Unfortunately
this will add to the cost of grafted hickories which even now are so
expensive to produce that almost no nurserymen grow them.
Another one of the commonly accepted principles that I do not now follow
is that of not planting trees any deeper than they grew in the nursery.
I prefer to plant them a little deeper, say two inches or so. I do not
recall losing any trees seemingly from this slightly deeper planting,
while I did lose a considerable number of seedlings last year that were
inadvertently planted two inches or so too shallow.