trees, the fall web-worm commonly feeds upon the foliage of nut trees,
especially hickories, causing considerable damage in the South. The
adult is a white moth, having a wing-spread of an inch or more,
appearing in midsummer and laying its egg-cluster on the under side of a
leaf. The young caterpillars make a nest at the end of a lateral branch
by drawing the leaves together with their webs. These nests usually
appear in July and August, though in Connecticut there is a partial
second brood and usually a few nests of the early brood may be found in
June. In the South there are two complete generations. When the larvae
have exhausted their food supply, they extend their nest by taking in
fresh leaves, but always feed inside the nest, differing in this respect
from the tent caterpillar which makes its nests here in May. When fully
grown the caterpillars are about one and one-fourth inches long, with
brown bodies covered with light brown hairs, and may be seen crawling
about seeking a place to pupate. They soon go into the ground where they
transform, the adults emerging the following year.
The best remedies are (1) clipping off and burning the nests when small,
and (2) spraying the foliage with arsenical poison.
THE WALNUT BUD MOTH.
_Acrobasis caryae_ Grote?
Inconspicuous nests containing small caterpillars are often found at the
ends of the new shoots of _Juglans regia_, seriously injuring them, and
sometimes killing the trees. One small tree two feet high was killed,
and thirty-five pupae were found in the nests at Dr. Morris' farm in
1912. The adult is a small gray moth with a wing expanse of about
three-fourths of an inch. There are three broods each season in
Connecticut, the larvae appearing about June 1, July 10 and August 18.
By spraying the foliage with lead arsenate (3 lbs. in 50 gals. water)
this insect can be controlled. One application should be made about June
1, followed by a second about July 10.
Though this insect is thought to be _Acrobasis caryae_ Grote, it is
often difficult to distinguish some of these species in this genus
without a knowledge of their food habits and seasonal life histories. We
possess such knowledge regarding this species which we have studied and
reared in Connecticut, but it is lacking in connection with adult
specimens in the United States National Museum labeled _caryae,_ which
superficially seemed identical with ours. Further study, therefore, may
prove this to be an undescribed species. There are other bud-worms
attacking nut trees, especially in the southern states, where they cause
considerable damage to pecans.
THE WALNUT WEEVIL OR CURCULIO.
_Conotrachelus juglandis_ LeC.
Probably the most serious enemy of _Juglans_, in Connecticut at least,
is the walnut weevil or curculio, _Conotrachelus juglandis_ LeC. The
larvae tunnel in the tender shoots, often ruining the new growth, and
they also infest the nuts. The adults feed upon the shoots and leaf
petioles. Observations on the different hosts indicate that _Juglans
cordiformis_ and _J. sieboldiana_ are preferred, and the most severely
injured, followed in order by _cinerea_, _regia_, _nigra_ and
_mandshurica_.
Though described as early as 1876, little was known about the life
history of this insect until the studies were made at the Station in
1912 by Mr. Kirk and the writer. Formerly it was supposed that this
insect attacked and injured only the nuts or fruit, and Dr. Morris in
1909 seems to be the first on record to observe the injury to the shoots
of _Juglans regia_. It was on the trees of Dr. Morris here in Stamford
and those of Mr. H. L. Champlain at Lyme that the life history studies
were made. There is but one brood each year, and the winter is passed in
the adult stage. The beetles appear the latter part of May and feed upon
the stems and leaf veins during the egg-laying period, which extends
from the last week in May up to August 1st. The eggs are laid in
irregular crescent-shaped punctures, similar to those of the plum
curculio, and hatch in from six to twelve days, depending upon the
weather.
From four to six weeks are necessary for the development of the larvae,
and when mature they go into the ground where they remain for about ten
days an inch or so beneath the surface. They then pupate, and from
sixteen to twenty days later the adult beetles emerge. They fly to the
trees and eat small holes chiefly at the base of the leaf petioles, but
must early go into winter quarters as they are seldom seen after the
first week in September.
This insect occurs throughout the Eastern United States, but seems to
cause more injury in Connecticut than has been noted elsewhere. The
remedy is to spray the new shoots and under side of the leaves about
June 1, with lead arsenate (6 lbs. of the paste in 50 gallons of water),
to kill the beetles when feeding on the leaf petioles.
THE NUT WEEVILS.
_Balaninus_ sp.
Several kinds of nuts are attacked and injured by long-beaked snout
beetles or weevils belonging to the genus _Balaninus_, the chestnut
probably being the most seriously damaged. All of them feed inside the
nuts or fruit during the larval stage, and the larvae are without legs.
As both the methods of attack and the life history are similar for all
species, they will be considered here in a group. For the sake of
distinguishing them, however, their names are mentioned.
Larger Chestnut weevil, _Balaninus proboscideus_ Fabr.
Lesser Chestnut weevil, _B. rectus_ Say.
Hickory nut or Pecan weevil, _B. caryae_ Horn.
Hazelnut weevil, _B. obtusus_ Blanch.
Common acorn weevil, _B. quercus_ Horn.
Mottled acorn weevil, _B. nasicus_ Say.
Straight-snouted acorn weevil, _B. orthorhynchus_ Chittn.
Sooty acorn weevil, _B. baculi_ Chittn.
Confused acorn weevil, _B. confusor_ Ham.
Spotted acorn weevil, _B. pardalus_ Chittn.
All of these weevils pass the winter in the ground in the larval stage,
transforming to pupae about three weeks before the adult beetles emerge,
which varies from June, when they are usually few and scattering, to
September, when they have become abundant. Thus there is a single brood
each year, and the larval period lasts from three to five weeks in the
nuts and some ten months in the ground, from two to eight inches below
the surface.
The control of these weevils is difficult, and ordinary methods such as
spraying are not effective. In fact little can be done other than
destroying the weeviled nuts, which may be fed to hogs. When first
gathered the nuts may be fumigated with carbon disulphide. About two
fluid ounces of the liquid should be used for each bushel of nuts and
placed in a shallow dish on top of the nuts, which should be enclosed in
a tight box or barrel. The period of fumigation should be from 12 to 24
hours. Where nuts are not to be used for seed they may be thrown into
boiling water for about five minutes--just long enough to kill the
weevils. The nuts are then dried and sold. Most of the weeviled nuts
will rise to the surface and may be discarded, but this test is not
absolute and cannot be depended on to distinguish the sound from the
weeviled nuts.
HICKORY BARK BEETLE OR BARK BORER.
_Scolytus quadrispinosus_ Say.
Outbreaks of the hickory bark borer occur periodically throughout the
northeastern United States, and during the past five years many hickory
trees in this vicinity have died.
The adult is a small black beetle appearing in May and June, which eats
holes in the axils of the leaf stems causing them to fall early--usually
in July and August. Brood galleries are then made longitudinally just
under the bark of the trunk by the female, and a row of eggs is placed
along either side of this brood chamber. On hatching the grubs, which
are at first very small, tunnel at right angles to the central chamber,
each making its own separate gallery. These galleries never meet or
cross each other, but must necessarily diverge toward their extremities
as they become larger. The effect of this is to girdle the tree which
soon dies. The larvae pass the winter under the bark, finish their
development in the spring, pupate, and the adults emerge in May and June
from small round holes about the size of bird shot.
For control measures, Dr. Hopkins advises examining the trees during the
fall and marking all dead and dying trees within an area of several
square miles. Then between October 1 and May 1, cut all such trees and
dispose of the infested portion to destroy the insects before the adults
emerge.
Many forms of treatment have been devised and recommended by tree
doctors for the control of this insect. Some of them may be worth
trying; most are of doubtful value, and some are absolutely injurious to
the trees. On July 3, 1914, some affected hickory trees on the Station
grounds were sprayed heavily with powdered lead arsenate, 4 lbs. in 50
gallons of water, to which one pint of "Black Leaf No. 40" was added.
Two days later many dead beetles were found on the tar walks under the
trees, and a few were observed each day up until about the middle of
August. Most of the trees treated, however, had been so badly injured by
the insect that they were removed. Since then this insect has caused
little damage on the grounds, though a few hickory trees still remain.
In 1901 an outbreak of the hickory bark beetle caused the death of 110
trees on the Hillhouse place in New Haven; then the destructive work of
the insect ceased and the few remaining hickory trees are still standing
and in fairly good condition. I mention these instances to show that
nature's control methods through parasites and natural enemies is far
more effective with certain pests than any which man has yet devised. Of
course, we hope that in the future man will make better progress along
this line.
THE PAINTED HICKORY BORER.
_Cyllene pictus_ Drury.
There are several borers attacking the wood of the trunk of the hickory,
but one of the commonest is the painted hickory borer. It also
occasionally attacks black walnut, butternut, mulberry and osage orange.
In hickory especially the larval tunnels are often found in the wood
when trees are felled. There is probably one brood annually and the
winter passed in the pupa stage, though it may possibly hibernate as a
larva. Its life history is not fully understood. It is a common
occurrence in Connecticut, and specimens are sent me every year, for the
adult beetles to emerge in March from firewood in the house or cellar
and crawl about seeking a chance to escape. The housewife fears that a
terrible household pest has descended upon her, and with fear and
trembling invokes the aid of the Agricultural Station.
The beetles appear outside in April and May, and probably oviposit soon
afterward. They are about three-fourths of an inch in length and are
black, prettily marked with golden yellow.
The insect can be controlled only by the old arduous methods of digging
out, and injecting carbon disulphide into the burrows.
Several other long-horned beetles are borers in the hickory and other
nut trees. Then, too, the leopard moth, _zeuzera pyrina_ Linn., and the
carpenter worm, _Prionoxystus robiniae_ Peck, may be found occasionally
in most any kind of tree.
The chestnut tree (if it has thus far escaped the blight or bark
disease) may show small, deep tunnels into the wood of trunk and
branch, made by the chestnut timber worm, _Lymexylon sericeum_ Harr.
Slow-growing woodland trees are more apt to show these galleries than
trees of rapid growth standing in the open.
There are a number of tussock moths, sawflies, beetles, etc., which feed
on the leaves of nut trees. Spraying with lead arsenate will prevent
damage. There are also many sucking insects attacking them, such as the
hickory gall aphis, and several species found on the leaves. Some of
these may be controlled by spraying with a contact insecticide such as
nicotine solution or kerosene emulsion.
In the Southern States, pecan trees are attached by some of these
insects which I have mentioned; there are also many more which cannot
even be mentioned in the time allotted to this paper. Information may be
obtained regarding them, by any one interested, and for this purpose I
have appended a short list of publications.
LITERATURE.
Britton, W. E., and Kirk, H. B. The Life History of the Walnut Weevil or
Curculio. Report Conn. Agr. Expt. Station for 1912, page 240.
Brooks, Fred E. Snout Beetles That Injure Nuts. Bull. 128, West Virginia
Agr. Expt. Sta., Morgantown, W. Va., 1910.
Chittenden, F. H. The Nut Weevils, Circular 99, Bureau of Entomology, U.
S. Dept. of Agr., Washington, D. C., 1908.
Felt, E. P. Insects Affecting Park and Woodland Trees. Memoir No. 8, N.
Y. State Museum, Albany, N. Y. 2 vols., 1905, 1906.
Gossard, H. A. Insects of the Pecan, Bull. 79, Fla. Agr. Expt. Station,
Gainesville, Fla., 1905.
Herrick, G. W. Insects Injurious to Pecans, Bull. 86, Miss. Agr. Expt.
Station, Agricultural College, Miss., 1904.
Hopkins, A. D. The Dying Hickory Trees. Circular 144, Bureau of
Entomology, U. S. Dept. of Agr., Washington, D. C., 1912.
Kirk, H. B. The Walnut Bud Moth. Report Conn. Agr. Expt. Station for
1912, page 253.
* * * * *
A MEMBER: Early in the spring I noticed something on the
hickory trees swollen and bright red in color, so that the trees were
conspicuous from a distance. Later insects emerged which appeared to be
these little gnats that fly in swarms.
DR. BRITTON: From the description I am not able to say what it
was, but it was probably one of those gall flies, a great many species
of which exist and which attack all kinds of plants. They do not, as a
rule, cause very serious damage, and I can not suggest any particular
remedy. Did it interfere with the growth of the tree?
A MEMBER: I noticed what seemed to be the same insect on the
grape vines.
DR. MORRIS: I would call attention to one pest that is very
destructive to hazels; unless watched closely it will produce serious
injury. That is the larvae of two of the sawflies. Dr. Britton was
unable to determine off-hand the species of the specimens I sent him,
but you may know the sawfly larvae by their habit of collecting in a row
like soldiers around the edge of the leaf and when the branch is
disturbed, their heads and tails stand up. These sawfly larvae need
looking after and can be killed by spraying. They usually collect on two
or three leaves at a time.
I would like to ask about a bud worm that attacks the leaf of the
hickory near the axil, sometimes very extensively, but not very
injuriously. At the same time it makes deformities. Colonies of this
insect select certain trees, for instance, the Taylor tree that you saw
yesterday is infected with this particular bud larva. The base of a
petiole becomes enlarged two or three times, and you will find one white
worm at the bottom. This colony is confined to this one tree, and the
very next tree adjoining the Taylor has its branches interwining, but is
not bothered at all, so far as I can determine.
This colony habit is also true of the hickory nut weevil--the hickory
weevil makes the Taylor tree a colony house, whereas I haven't found a
single weevil in nuts of the adjoining hickory tree that has its
branches interwining.
That colony habit is, perhaps, a weak point with the weevil, and it may
enable us to eradicate them by concentrating our attention upon their
colony trees.
One point in regard to the chestnut weevil. When our chestnuts began to
die here, I supposed that the chestnut weevils would immediately turn to
my chinquapins for comfort. Weevils attack the chinquapins so
extensively in the South that Mr. Littlepage said chinquapins would not
be acceptable to Dr. Kellogg because they furnished so much animal diet.
(Laughter). Curiously enough, the chestnut weevils did not go to my
chinquapins. These chinquapins bear full crops, heavy crops, and one
will almost never find a chestnut weevil in the nuts. I have found now
and then a little weevil, about half a dozen altogether, that attacks
the involucre at its point of attachment to the chinquapin. This looks
like the chestnut weevil, but perhaps, only according to my eye, very
much as all Chinamen look alike to one who has never seen them before.
The matter of carbon disulphide for the painted hickory borer. I have
used that apparently successfully, but I didn't tunnel through six feet
of hickory tree afterward to see whether the borers were dead or not. It
is a successful treatment for apple borers. I have no trouble with the
apple borers now. I simply clean off the entrance of the hole, the
"sawdust," and then with a little putty spread out with my hand make a
sort of putty shelf below the hole, then I squirt in a few drops of
carbon disulphide with a syringe, turn up the putty and leave it
adhering to the bark, closing the hole. You can do that very quickly,
and it spares a good deal of perspiring and backache.
The black walnut. On one of my black walnut trees there is a serious
pest, a very little worm which infests the involucre. The black walnuts
of this tree fall early. I found that same worm last year also extending
to the Asiatic walnuts, so that a great many Japanese walnuts fell early
as the black walnuts fall, as a result of this little worm's working in
large numbers within the involucre. I sent some specimens to New Haven
for the species to be observed. This will be a very serious matter if it
is going to involve the English walnuts as it does on Long Island. I
have found the same thing, apparently, on Long Island in the black
walnut, in the English walnut, and in the pecan. It causes a serious
drop of these nuts at Dana's Island, near Glen Cove, Long Island.
THE EXTENT OF THE HARDY NUT TREE NURSERY BUSINESS.
R. T. OLCOTT, NEW YORK.
For obvious reasons this subject may well be considered as constituting
a gauge of commercial nut culture in the North; it is therefore of much
more importance than the mere title would suggest. If there is merit in
all that has been preached regarding the planting of budded and grafted
trees instead of seedlings; and if it is still true, as we have long
observed, that the propagation of named varieties of nut trees, and
especially of hardy nut trees, is successful almost solely in the hands
of experts, the progress of commercial nut culture in the northern
states rests largely in the hands of the nurserymen. We may even go
further and assert that it rests for the present mainly in the hands of
a few nurserymen who have persistently studied the problems pertaining
to the taming of a denizen of the forest, and have persevered with
experiments in the face of repeated failure; for, as editor of the
_American Nurseryman_, I am in a position to state that with a few
exceptions nurserymen generally have not attempted to prepare to supply
a demand for hardy, northern-grown, improved nursery nut trees. Seedling
walnuts and hickories have been procurable for years from nurseries all
over the country, as is shown by nursery catalogue listings; and at
least two concerns--one at Lockport, N. Y., and another at Rochester, N.
Y.,--have advertised nut tree seedlings extensively, despite the
universal nursery practice of budding or grafting or layering
practically all other kinds of trees and plants offered for sale as
nursery stock--simply because it is not easy to propagate nut trees, and
these nurserymen would take advantage of the growing demand for nut
orchards.
Within established nut circles all this is commonly known. It was my
purpose in referring to these conditions to direct the attention of
those not posted to what has been done by a half dozen or more
conscientious nursery concerns in an endeavor to supply material of
quality for the starting of nut orchards or the planting of isolated
trees in response to the arguments set forth in behalf of nut culture.
My subject lies at the very base of the formation of this association;
for was it not with the idea of directing into safe channels interest
which might be aroused in nut culture that the pioneers of the industry
in the North organized and convened repeatedly to select and propagate
and recommend certain varieties? As the result of years of concentrated
effort selections have been made and varieties have been named--and to
some extent recommended--throughout the northern states. Now and for
some time past the public has had opportunity to purchase and plant
carefully grown budded and grafted true-to-name nursery nut trees of
varieties having in the parent trees exceptional characteristics deemed
sufficient to warrant propagation and dissemination. I need not go into
the matter of years of patient effort on the part of a few nurserymen
and of a few investigators who entered the lists solely for the love of
Nature's developments.
This, in brief, is the rise of the hardy nut tree nursery business. Now,
what of its extent? There are upwards of two thousand propagating
nurserymen in the country, but those who have made a specialty of
hardy, northern-grown nut trees are few. They include the Vincennes
Nurseries, W. C. Reed & Son, Vincennes, Ind.; the Indiana Nurseries, J.
Ford Wilkinson, Rockport, Ind.; the McCoy Nut Nurseries, R. L. McCoy,
president, Evansville and Lake, Ind.; the Maryland Nurseries, T. P.
Littlepage, Bowie, Md.; J. F. Jones, Lancaster, Pa,; J. G. Rush, West
Willow, Pa.; C. K. Sober, Lewisburg, Pa., and some in the northwest.
As showing the extent of the business, Mr. Reed, of Vincennes, reports
demand for nut trees increasing. He had to return orders unfilled last
spring. His nurseries have 3,000 to 4,000 Persian walnut trees and about
the same number of pecan trees for fall sales; also about 1,000 grafted
black walnut trees. There are growing in the Vincennes nurseries ready
for budding and grafting 50,000 black walnut seedlings and 50,000 pecan
seedlings. Mr. Reed said recently: "Owing to the extreme difficulty of
propagating nut trees in the North, I think the demand will keep up with
the supply."
Mr. Jones sold last year about 8,000 nut trees which went to points all
over the country; not many to California, or to the far South; a good
many to New Jersey, New York, Maryland, Virginia, West Virginia,
Pennsylvania, Ohio, Indiana, Illinois, Missouri, etc. The largest order
was for 600 trees. A number of orders were for 100 to 300 trees. New
Jersey leads in planting, he finds, with Virginia a close second, in
large orders. In small orders, Pennsylvania leads with him.
Mr. McCoy has done a great deal of experimenting with grafts and he is
still at it. He has 40 acres mostly under nut tree cultivation, and has
a considerable number of trees for sale.
Anyone who has seen the handsome nut tree catalogue issued by Mr.
Littlepage, of the Maryland Nurseries, must have been impressed with the
great care taken to produce the attractive trees and nuts there
depicted. These nurseries have been recently established and not a great
number of trees have yet been offered for sale, but Mr. Littlepage has
150,000 seedling nut trees in his nurseries for propagating purposes.
Mr. Sober's nurseries are devoted almost entirely to the cultivation of
chestnut trees. Mr. Rush's specialty is the Persian walnut. Mr.
Wilkinson naturally specializes in Indiana pecan trees. At Rochester, N.
Y., James S. McGlennon and Conrad Vollertsen have produced interesting
results with filberts imported some years ago from Germany. They have
five-year-old bushes bearing; these have proved hardy in every way and
they have no blight. The nuts compare favorably with the best of the
imported kinds. Nursery stock will soon be ready in quantity, and they
now have 500 plants suitable for transplanting.
Filbert and walnut are the only nut trees grown commercially to any
extent in the nurseries of the northwest. A few almond and chestnut
trees are grown there, but the demand for them is very light. J. B.
Pilkington, Portland, Ore., a well-known grower of a general line of
nursery stock, advertises French, Japanese and Italian chestnut trees
and the American Sweet. Filberts are being produced to a considerable
extent. At present the nurseries cannot supply the demand for filbert
plants, owing to the limited number of mother plants in the northwest.
Practically all the nurseries have Barcelona and Du Chilly for sale, and
a number have the Avelines. From one nursery or another De Alger,
Kentish Cob and a few other varieties can be had. Persian walnuts are
grown on a larger scale. Groner & McClure, Hillsboro, Ore., are the
largest exclusive walnut nurserymen in the northwest. They produce close
to 6,000 grafted trees annually. These sell at 90c. to $1.00 per tree in
lots of 100. The Oregon Nursery Company, Orenco, Ore., produce a large
number of both grafted and seedling walnut trees, asking up to $2.00 per
tree for grafted and 35 to 50c. for seedlings. Many of the smaller
nurseries procure their nut trees from California nurseries. Each year
the proportion of seedlings planted is less. Franquette is the popular
variety that is propagated.