DISEASES AND INSECT ENEMIES OF SMALL FRUITS
Nature is very impartial. It is evidently her intention that we shall
enjoy all the fruits for which we are willing to pay her price, in
work, care, or skill, but she seems equally bent on supplying the
hateful white grub with strawberry roots, and currant worms with
succulent foliage. Indeed, it might even appear that she had a leaning
toward her small children, no matter how pestiferous they are. At any
rate, under the present order of things, lordly man is often their
servant, and they reap the reward of his labors.
Did not Nature stumble a little when man fell? She manages to keep on
the right side of the poets and painters, for it would seem that they
see her only when in moods that are smiling, serious, or grand. The
scientist, too, she beguiles, by showing under the microscope how
exquisitely she has fashioned some little embodiment of evil that may
be the terror of a province, or the scourge of a continent. While the
learned man is explaining how wonderfully its minute organs are formed,
for mastication, assimilation, procreation, etc., practical people, who
have their bread to earn, are impatiently wishing that the whole genus
was under their heels, confident that the organs would become still
more minute.
The horticulturist should be cast in heroic mold, for he not only must
bear his part in the fight with moral wrong, like other men, but must
also cope with vegetable and insect evil. Weeds, bugs, worms, what
hateful little vices many of them seem in nature! I do not wish to be
thought indiscriminate. Many insects are harmless and beautiful; and,
if harmless, no one can object if they are not pretty. Not a few are
very useful, as, for instance, the little parasite of the cabbage worm.
There is need of a general and unremitting crusade against our insect
enemies; but it should be a discriminating war, for it is downright
cruelty to kill a harmless creature, however small. Still, there are
many pests that, like certain forms of evil, will destroy if not
destroyed; and they have brought disaster and financial ruin to
multitudes.
Mark Tapley hit upon the true philosophy of life, and it is usually
possible to take a cheerful view of everything; such a view I suggest
to the reader, in regard to the pests of the garden that often lead us
into sympathy with the man who wished that there was "a form of sound
words in the Prayer-Book which might be used in cases of great
provocation." Under the present order of things, skills, industry, and
prompt, vigilant action are rewarded. Humanity's besetting sin is
laziness; but weeds and insects for months together make this vice
wellnigh impossible, save to those who are so unfortunate as to live on
the industry of others. Therefore, though our fruits often suffer, men
are developed, and made more patient, energetic, resolute,
persevering--in brief, more manly. Put the average man into a garden
where there were no vegetable diseases, insects, and weeds to cope
with, and he himself would become a weed. Moreover, it would seem that
in those regions where Nature hinders men as much as she helps them,
they are all the better for their difficulties, and their gardens also.
Such skill and energy are developed that not only are the horticultural
enemies vanquished, but they are often made the means of a richer and a
fuller success.
In a valuable paper read before the New Jersey State Horticultural
Society, and recently published in the "American Entomologist," Mr. A.
S. Fuller makes the following useful suggestions:
"Insects and diseases are frequently so closely united, or so dependent
upon each other, that the naturalist often finds it difficult to
determine to which the fruit grower should attribute his losses. Some
species of insects attack only diseased or dead plants; others only the
living and healthy. If a plant shows signs of failing, we are inclined
to speak of it as being diseased, whether the failure is caused by a
lack of some element in the soil, attacks of parasitic fungi, or
noxious insects. The loss is the same in the end, whether from one or
all of these enemies combined.
"There are two practical methods of combating insect enemies and
diseases of plants; one is to so carefully cultivate and stimulate the
growth of the plants that they may possess the power of resisting
attack; the other is to make war directly upon them by artificial
means. Of course, the first method is most applicable or practicable
against the more minute species, such as the plant-lice, rust, smut,
and mildew. I do not recommend forcing plants to extremes, in order to
enable them to resist their enemies, as this might work an irreparable
injury; but the condition to be aimed at should be a healthy, vigorous
growth; for anything beyond this is more the sign of weakness than
strength.
"The half-starved, overworked and uncared-for horse is sure, sooner or
later, to become the prey of various kinds of internal and external
parasites, which are thrown off, or successfully resisted in their
attacks, by the healthy, vigorous, and well-fed animal; and the same
principle holds good all through the animal and vegetable
kingdoms--whether the subject be a man, horse, sturdy oak, or delicate
strawberry plant. Not that all diseases are due to loss of vigor
through starvation and neglect; but that a large number of them are is
well known."
STRAWBERRIES
We all have seen these principles verified. In the Great American
strawberry, I think, we have an example of feebleness resulting from
over-stimulation. The Wilson Seedling, that, in the local vernacular,
is sometimes said to be "running out," is, in contrast, the consequence
of starvation, neglect, and long-continued propagation from poor, mixed
stock. Feebleness can scarcely be called a disease, and yet it is best
counteracted by the tonic treatment suggested by Mr. Fuller.
In loose, light soils, the Aphis, or Green Fly, often penetrates to the
roots of strawberry plants in immense numbers, and they suck away life
or vitality. The tonic of wood-ashes scattered over the rows will
usually destroy the pests. Refuse from the tobacco-factory is also
recommended.
I think that wood-ashes and bone-dust are excellent preventives of
burning or sun-scalding. They give the plants such vigor that they are
able to resist sudden or great climatic changes, from heat to cold, or
from drought to moisture.
Many varieties are enfeebled by their disposition to run profusely.
Kerr's Prolific, for example, will speedily sod the ground with small,
puny plants, whose foliage will burn so badly that the fruit can
scarcely mature. Set out these small plants, and give the tonic
treatment of cutting off all runners, and large, bushy stools, with
vigorous foliage and superb fruit, will result. Indeed, next to
fertilizers and moisture, there is nothing that so enhances the vigor
and productiveness of a plant as clipping the runners as fast as they
appear. The uncurbed habit of running depletes almost like disease; and
but few varieties will make large fruit buds and runners at the same
time.
In close, wet weather the fruit and leaf stalks will sometimes suffer
from mildew; and occasionally a microscopic fungus, known as the
strawberry brand, will attack the foliage. I have also seen, in a few
instances, a disease that resembled the curl-leaf in raspberries. The
plants were dwarfed, foliage wrinkled and rusty, and fruit misshapen,
like small, gnarly apples. In all such instances I believe in tonic
treatment, of wood-ashes, bone-dust, guano, and fertilizers of like
nature, used with care. Plants do not need over-doses or over-feeding
any more than we do ourselves. When a few plants are diseased, I
believe in rigorously rooting them out and burning them. If a field is
affected, as soon as possible turn the plants under, and renovate the
land with clover, buckwheat, a light dressing of lime, and thorough
exposure to the air, light, and frost. By such methods, and a wise
selection of fertilizers, I believe that strawberries can be raised on
the same ground for centuries. My plants have always been exceptionally
free from all kinds of disease or rust, and I attribute it to the
liberal use of wood-ashes.
But there is one enemy that inspires me with fear and unmingled
disgust. It is the type of a certain phase of character in society most
difficult to deal with, and which the mantle of charity is rarely broad
enough to cover--the stupidly and stolidly malignant, who have just
sense enough to do a great deal of mischief, and to keep it hidden
until too late for remedy. Science has dignified the detestable thing
with a sonorous name, as usual--the _Lachnosterna Fusca_, already
referred to. It does not deserve even its name in the common
vernacular--White Grub; for its white is of a dingy hue, and its head
dark, like its deeds. Has it a redeeming trait? "Give the de'il his
due," says the proverb. The best I can say of the white grub is that
crows, and an odorous animal I forbear to name, are very fond of it,
This fact, I think, is its sole virtue, its one entry on the credit
side; but there is a long, dark score against it. Of its havoc on the
lawn and farm I will not speak, since it is sufficient for our purposes
to state that it is the strawberry's worst foe.
The best method of circumventing the "varmint" is to learn its ways;
and therefore I shall outline its history, beginning at a period in its
being when stupidity predominates over its evil-that is, when it is the
May beetle or June bug, that blunders and bumps around in utter
disregard of itself and every one else. In this stage it is like the
awkward village loafer, quiet by day, but active and obtrusive in the
early evening. It dislikes honest sunshine, but is attracted by
artificial light, at which it precipitates itself with the same lack of
sense and reason that marks the loafer's gravitation toward a lighted
groggery. Moreover, in the beetle phase, it is sure to appear at the
most inopportune times and unsuitable places, creating the inevitable
commotion which the blunder and tactless are born to make. As it whisks
aimlessly around, it may hit the clergyman's nose in the most pathetic
sentence of his sermon, or drop into the soprano's mouth at the supreme
climax of her trill. Satan himself could scarcely produce a more
complete absence of devotion than is often caused by these brainless
creatures.
Because quiet by day, they are not out of mischief, as defoliated trees
often prove. As midsummer approaches, they die off; but never until
each female beetle has put into the ground about two hundred eggs,
which never fail to hatch. The first year, the grubs are little, and,
while they do all the harm they can, the small roots they destroy are
not seriously missed by the plants. The second year, their ability
keeps pace with their disposition, and they occasionally destroy
strawberries by the acre. More often, certain patches of a field or
garden are infested, and sometimes will be kept bare of plants in spite
of all one can do. Too often, the presence of the grub is learned only
after the mischief is complete. You may have petted a strawberry plant
for a year, and after it has developed into noble proportions, and
awakened the best expectations from its load of immature fruit, you
will, perhaps, find it wilting some morning. You then learn, for the
first time, that this insidious enemy has been at work for days, and
that not a root is left. An inch or two beneath the dying plant, the
grub lies gorged and quiet in the early morning; but if undisturbed it
soon seeks the next-best plant it can find, and it is so voracious that
it is hard to compute the number it can destroy throughout the long
season in which it works.
Having made its full growth in the spring of the third year, this grub
passes into the chrysalis state, and in May or June comes out a perfect
insect or beetle. It is "one, two, three, and out."
While there are beetles every year, there is, in every locality, a
special crop every third year; in other words, if we observe beetles in
great numbers during the coming May and June, we may expect them again
in like quantities three years after; and every second year from such
super-abundance they will be very destructive in all those fields
throughout the locality wherein the eggs were laid.
REMEDIES
When once our soil is full of them, scarcely any remedy is possible
that year. Surface applications that would kill the grubs would also
kill the plants. Where they are few and scattering, they can be dug out
and killed. Sometimes boys are paid so much a pint. When seeing a
wilting plant, it would scarcely be human nature not to dig out the
pest and grind it under our heel. Prevention of the evil is usually our
best hope. Mr. Downing writes to me: "I believe that if you would use
refuse salt three or four years in succession, at the rate of five or
six bushels to the acre, the grubs would not trouble you much. Salt
will not kill the full-grown larvae, but those in a very young state."
The reader will remember a statement in Mr. Hale's letter on commercial
fertilizers confirmatory of this view.
Experiments in this direction should be carefully made, since, in one
instance that I am aware of, a fruit grower remarked, "I do not know
whether the salt killed the grubs, but I know it killed my plants." It
is my purpose, however, to try this agent very thoroughly. There is
danger of our being misled in our estimate of the value of remedies,
from forgetfulness of the habits of the insect. We find our ground full
of larvae one year, and apply some cure or preventive. The following
spring, the larvae become beetles and fly away, and, even if they fill
the same ground with eggs again, the grubs are too small to be noticed
that year; and therefore we may claim that our remedy is effectual,
when there may have been no effect from it whatever.
One of the best preventives is to keep the soil under cultivation, for
this beetle rarely lays its eggs in loose soil, preferring old meadows
and moist, loamy, sodded land; the larvae are equally fond of grass
roots. This is one of the reasons why a year or two of cultivation must
often precede the planting of strawberries. When this fruit is grown in
matted beds, they afford as attractive a place for the deposit of eggs
as grass land; and this is another fact in favor of the narrow-row
system and thorough cultivation.
Mr. Caywood, a nurseryman, says that he has prevented the approach of
the grub by mixing a teaspoonful of sulphur in the soil just beneath a
plant, when setting it out. Mr. Peter B. Mead recommends the pomace of
the castor bean spread on the surface around the plants. I have never
tried these preventives. One thing certainly might be done;
exterminating war might be waged on the beetles. In the morning they
are sluggish and easily caught; and in the evening we can treat them as
whiskey venders do the loafers--burn them up. "Every female beetle
killed heads off 200 grubs." If one could discover a complete remedy
for this pest, he would deserve a statue in bronze. Mr. Fuller had a
domesticated crow that would eat a hundred of these grubs daily. "When
domesticated," he adds, "the crow forgets the tricks of his wild
nature, and, not being a timid bird, he is not frightened by hoe or
spade, but when the earth is turned over, is generally there to see and
do his duty."
A fruit grower writes to Professor C. V. Riley: "I inclose specimens of
a terrible pest on my strawberry vines. The leaves are almost entirely
destroyed. I must fight them some way, or else give up the fruit
entirely," etc. In a letter to the "New York Tribune," Professor Riley
replied:
"The insect referred to is the Strawberry Worm (_Emphytus maculatus_),
the larva of a saw-fly, which is of quite frequent occurrence in the
West. I quote the following account of it from my Ninth Report:
"'Early in the spring numerous flies may be seen hanging to and flying
about the vines in fields which have been previously affected. They are
dull and inactive in the cool of the morning and evening, and at these
hours are seldom noticed. They are of a pitchy black color, with two
rows of large, transverse, dull, whitish spots upon the abdomen. The
female, with the saw-like instrument peculiar to the insects of this
family, deposits her eggs, by a most curious and interesting process,
in the stems of the plants, clinging the while to the hairy substance
by which these stems are covered.
"'The eggs are white, opaque, and 0.03 of an inch long, and may be
readily perceived upon splitting the stalk, though the outside orifice
at which they were introduced is scarcely visible. They soon increase
somewhat in bulk, causing a swelling of the stalk, and hatch in two
weeks--more or less, according to the temperature; and during the early
part of May the worms attract attention by the innumerable small holes
they make in the leaves. Their colors are dirty yellow and gray-green,
and when not feeding, they rest on the under side of the leaf, curled
up in a spiral manner, the tail occupying the centre, and fall to the
ground at the slightest disturbance. After changing their skin four
times they become fully grown, when they measure about three-fourths of
an inch.
"'At this season they descend into the ground, and form a weak cocoon
of earth, the inside being made smooth by a sort of gum. In this they
soon change to pupae, from which are produced a second breed of flies
by the end of June and beginning of July. Under the influence of July
weather, the whole process of egg depositing, etc., is rapidly
repeated, and the second brood of worms descend into the earth during
the fore part of August, and form their cocoons; in which they remain
in the caterpillar state through the fall, winter, and early spring
months, till the middle of April following, when they become pupae and
flies again, as related.
"'The remedy is the same as that employed against the currant worm,
which belongs to the same family. It consists of white hellebore, used
either in powder or liquid.'"
I think that tobacco dust or a strong decoction from the stems would
prove effective, also.
I have never had any experience with this worm, but have read of
instances in which fields had been entirely cleared of the pest by
young chickens and turkeys.
The common little flea-beetle has often caused great injury to my
recently planted beds. I once paid nearly $100 for a new, high-priced
variety, and before I was aware of it every plant had been devoured.
They rarely injure large, fully matured plants, but are often very
destructive to those recently planted, especially if set during the
summer. You can not catch them; for, as your hand approaches a leaf on
which they cluster, they scatter with a sudden bound, and are at once
lost to view, so nearly do they resemble the color of the ground.
Slight dustings of dry wood-ashes impede their feeding somewhat; but I
think we must cope with this insect as we do with the Colorado or
potato beetle. It must be poisoned. Paris green, of course, will finish
them speedily, but such a deadly poison must be used with great care,
and if there is any green or ripe fruit on the vines, not used at all.
Hellebore, London purple, tobacco dust, may destroy them; and when
little chickens can be employed, they are a sure remedy.
"Black eyes," or the receptacle turning black, is caused by light
frosts, to which the open flowers are very susceptible. If one's
strawberry bed were in bloom, and there was a prospect of a frosty
night, I think the blossoms could be saved by covering the bed with
four or five inches of straw or hay, and raking it off again as soon as
the temperature rose sufficiently high in the morning.
Without doubt, new diseases and enemies to the strawberry will be
developed in the future, and as they come we must experiment till we
find some means of mastering them.
RASPBERRIES AND BLACKBERRIES
These two fruits are so near akin that they are subject to the attacks
of the same diseases and enemies. The most fatal scourge of red
raspberries that I have seen is what is called at Marlboro' the
curl-leaf; and, if unchecked, it will eventually banish the famous
Hudson River Antwerp from cultivation. As yet, no remedy has been found
for it that I am aware of. I believe it to be contagious, and would
advise that the plants be dug out and burned immediately, and that
plantations of strong, healthy plants be made on new land that has
never been in raspberries. I also suggest the free use of wood-ashes
and well-decayed compost. As far as my experience goes, this disease is
confined to foreign varieties, and almost wholly, as yet, to the
Antwerps.
Mr. Fuller, in the paper already named, describes a disease among
blackberries that resembles the raspberry curl-leaf so closely that it
may be identical, and spring from the same cause.
"Some ten years ago, the cultivators of the blackberry in various parts
of New Jersey noticed that the ends of the young, growing canes, in
summer, would occasionally curl, twist about, and often assume a
singular, fasciated form, resulting in an entire check to their growth.
The leaves on these infested shoots did not die and fall off, but
merely curled up, sometimes assuming a deeper green than the healthy
leaves on the same stalk. At the approach of winter, the infested
leaves remained firmly attached to the diseased stems; and all through
the cold weather, and far into the spring, these leaf-laden and
diseased stems were a conspicuous object in many of the blackberry
plantations of this State.
"If the infested shoots are examined in summer, thousands of minute
insects, of a pale yellow color, and covered with a powdery exudation,
will be found sucking the juices of the succulent stem and leaves,
causing the crimping, curling, and twisting of these parts as described.
"This parasite resembles somewhat an ordinary greenfly (_Aphis_) or
plant louse; but, according to the observations of Professor Riley, it
belongs to the closely allied Flea-lice family (_Psyllidae_),
distinguished from the plant-lice by a different veining of the wings,
and by the antennae being knobbed at the tip, like those of the
butterfly, the knob usually terminating in two bristles. These insects
jump as briskly as a flea, from which characteristic they derive their
scientific name. The particular species in question was called by
Professor Riley the 'Bramble-Flea-louse (_Psylla rubi_ [Footnote: "It
can not be distinguished from _Psylla tripunctata_, Fitch (Catalogue of
Homoptera, etc.), and, what is most singular, the same species is very
common on pine-trees all over the eastern part of the continent, from
Florida to Canada."]),' in the American Entomologist (Vol. I., p. 225).
It has increased rapidly during the past half-dozen years or more, and
unless fruit-growers make a more vigorous fight than they have yet
done, it will soon get the mastery of many blackberry plantations. The
only practical method as yet discovered for checking the ravages of
this insect is to cut off the ends of the infested canes and burn them.
This operation should always be performed either in the morning or
during cool, wet weather, else many of the insects will escape; and at
all times the severed shoots should be immediately dropped into bags,
and in them carried to the place where they are to be burned, and there
emptied into the fire. If every one having blackberry bushes in their
gardens would practice this method of destruction, this pest would soon
cease to do much harm."
There are species of borers and gall insects that attack these two
fruits, but as yet they have not become formidable. All infested canes
should be cut out and burned with their contents, or else the pests may
so increase as to cause much injury.
The larvae of the _Selandria rubi_, an insect nearly related to the
imported currant worm, and known as the raspberry saw-fly, is
destructive in some regions. It is semi-transparent, and so like the
foliage in color that it could scarcely be detected, did not the
ragged, perforated leaves indicate both its presence and its mischief.
This worm measures half an inch in length, when fully developed. It has
two black eyes, like spots, upon a green head, and usually a slightly
fuzzy body. The remedies recommended are the same as those used against
the currant worm. I have had no experience with this pest.
The Orange-rust (_Uredo rubrum_) is one of the worst of foes to both
the blackberry and raspberry--the _Rubus occidentalis_, or black-cap
family, suffering the most, usually. I have seen fields of the Early
Wilson and Kittatinny blackberries in New Jersey that presented a
melancholy appearance. It is believed to be very contagious, and it can
be spread by both trimmer and pickers. Mr. Chas. A. Green, of Monroe
County, N. Y., writes: "The end plant of a row in my garden was
affected, and I let it remain, as an experiment. In three years, nearly
every plant in the row was more or less diseased. We have tried picking
the leaves and cutting back the canes, without relief, and have found
that the only safe method is to dig out and destroy all affected plants
without delay." Mr. Fuller says that "application of lime, salt, or
some similar substance, may check the disease; but I know of no remedy
except that of rooting up every affected plant, and burning it." Mr.
Downing recommends the same course. It is one of those evils that
should be stamped out at once. If a plantation were generally affected
with this yellow symbol of contagion, it would be well to destroy all
the plants, and, obtaining new, healthful stock from a distance, start
again on different grounds. Should the snowy tree-cricket become very
abundant, it might cause much injury, chiefly by cutting off the
leaves, as the ordinary cut-worm serves the stem of a young plant.
CURRANTS AND GOOSEBERRIES
We have not only imported our best currants from Europe, but also their
worst enemies. The most formidable of these is popularly known as the
currant worm. Robert Thompson, the English authority, thus describes
it: "The magpie moth (_Abraxas grossulariata_) deposits its eggs upon
the foliage, and from them is hatched a slightly hairy cream-colored
caterpillar, spotted with black, and marked with orange along the
sides, and which forms a loop in walking. It feeds upon the leaves,
devouring all but the petiole, and often entirely defoliating both
gooseberry and currant bushes. It changes into a pupa in May or June,
and in about three weeks afterward, the perfect insect makes its
appearance." Very naturally, this currant worm made its debut near
Rochester, N. Y., a great fruit centre, receiving annually large
importations of plants. Its first appearance was in 1857.
In England, the caterpillar of the _Phalaena vanaria_, a similar
insect, is often destructive. Whether it has appeared among us yet, I
am not informed. They fight it abroad as they do the ordinary worm.
The gooseberry and currant saw-fly (_Nematus ribesii_), another
pestiferous foreigner, has made its appearance in some localities.
We have, besides, a native saw-fly (_Pristiphera grossulariae_), which
resembles its European congener, and emulates it in mischief. The larva
of this fly feeds upon both, the currant and the gooseberry, but
prefers the latter.
Nature is liberal, and has given us, in addition, a native gooseberry
span-worm, the larva of a small moth. These several worms, unchecked,
would soon render the culture of the currant and gooseberry impossible
in the regions where they abounded; and, at first, horticulturists were
almost in despair, for the pests seemed proof against the usual
insecticides and means of destruction. It was eventually discovered
that powdered white hellebore was a specific remedy. Usually, it is
applied unmixed with other substances; and pains should be taken to get
a genuine article, or else it will not destroy the worms.
Mr. H. T. Jones, of Rochester, recommends the following:
"To one pailful of wood-ashes, add one quart each of white hellebore
and flowers of sulphur; mix thoroughly; apply by sifting on the bushes
while the dew is on them. I used nothing else on my plantation of over
two acres last season, and want nothing better; but it must be used
_daily_ as long as any worms are seen."
I have heard that, if applied in a liquid form, a heaping
table-spoonful of hellebore to a gallon of water is a good proportion.
At the meeting of the New Jersey Historical Society, it was stated by
good authorities, as the result of actual experience, that tobacco-dust
would kill the worms as readily as hellebore. I hope this is true,
since the latter is expensive when applied on a large scale, and the
tobacco-dust can be bought at from two dollars to three dollars per
barrel. I shall try it next year.
I also quote the following from a recent editorial by Mr. Fuller, in
the New York "Weekly Sun:"
"White hellebore has long been considered one of the most efficacious
of all poisons for the imported currant worm, but a New Jersey
fruit-grower of considerable experience informed us not long ago that
he had found strong tobacco water quite as good as the hellebore, and
it was also soon washed off by heavy rains, whereby the fruit was not
rendered unfit for use, as when other and more virulent poisons are
employed. To make a strong solution, put a half-bushel or bushel of
tobacco stems, or even the leaves, into a cask or barrel, and press
down and hold in place with a stone or other weight; then pour on hot
water enough to cover the tobacco, and leave it for a few days to
steep. After steeping, the cask may be filled up with warm or cold
water, and the solution is ready for use. If a half-pound or pound of
crude potash is added, or a quart or two of soft soap is stirred in,
the solution will be much improved, especially in its destructive
properties. After using the first liquid, the barrels may be filled
again with water, and left to steep a few days longer than the first
time, or some fresh tobacco may be added, to give the solution the
required strength. Tobacco water is certainly a cheap insecticide, and
will frequently be found quite as efficacious as those that are more
costly and troublesome to apply."
A gentleman from Erie, Pa., writes to me that he has used this remedy
for years, with complete success.
Mr. J. McK. Beattie, of Pictou, Nova Scotia, has written to me of a
still simpler method:
"I notice in the April number of 'Scribner's Monthly' that you intend
to use tobacco-dust to destroy the currant worms. It will prove
effectual; but as I can give you a far more simple plan, I take the
liberty of writing. It is one which I have proved for the past seven
years, and never have known it to fail wherever tried.
"After digging about my bushes, and manuring in the spring, I cover the
earth around the bushes with tobacco stems, and place a handful in the
middle of the bush, and the work is done for the season. I found that
when using the dust I had to renew it after every heavy rain, whereas
the stems did not need renewing, unless it was a very wet season, and
then, if any worms appeared, a handful of fresh stems scattered through
the bushes made them disappear.
"The stems have several advantages: they are cheaper than dust; they
serve as a mulch to keep the ground off the fruit; and when dug in
about the bush, they make an excellent manure. I think if you once gave
them a fair trial you would never be tempted to try any other method.
"Last year stems were very scarce here, and I could not get enough to
mulch all my bushes, so I only put a generous handful in the centre of
a good many bushes, and they were not troubled; but I would not like to
recommend that plan until I experimented further."
For the past two years the worm has attacked my bushes savagely; but,
as I am very fond of currants, and relish white, powdered sugar more
than hellebore, I fought the pests successfully by hand-picking. I kept
a boy, at moderate wages, whose business it was to kill insects and
worms. He had a lively time of it occasionally, for Nature sometimes
appeared to take sides with the pests.
The cautious use of lime and salt around and under the bushes might
prove beneficial, since the worm descends into the soil before changing
into a pupa.
The current and gooseberry are also infested with several species of
plant-lice. A gentleman whose bushes were attacked by lice and the
currant worm at the same time, wrote to the "Country Gentleman" that he
destroyed both by a strong decoction of white hellebore, applied from a
fine rose-sprinkling can. The bushes were turned back and forth, so as
to get the solution on the under side of the leaves. The writer
concludes:
"The decoction of hellebore must be strong to be effectual. I make it
as follows: To a gallon of boiling water add a tablespoonful of
pulverized hellebore. After standing fifteen or twenty minutes, add
three gallons of common soapsuds. When cool, apply with a sprinkler, I
do not know that there is any virtue in the soapsuds, excepting it
makes the solution stick to the leaves."
There are three species of currant borers with unpronounceable names.
Their presence is shown by yellow foliage and withering fruit in
summer, and by brown, shrivelled branches in winter. Cutting out and
burning is the only remedy. Usually, a vigorous bush will outgrow the
attacks of this enemy; and good cultivation gives vigor, and also
disturbs and brings to the surface the worms that have entered the soil
to undergo their transformation. From first to last, tonic treatment
supplements and renders more effective our direct efforts to destroy
diseases and enemies.
Most earnestly would I urge caution in using all virulent poisons like
Paris green, London purple, hellebore, etc.
Whenever it is possible to substitute a less poisonous substance, do so
by all means. Some good people regard tobacco as the bane of banes; but
to many it does not cause the feeling of repugnance and fear inspired
by hellebore and more poisonous insecticides. Let all such articles be
kept under lock and key; and one person should have charge of their
use, and be held responsible for them. Moreover, any watering-can used
with Paris green and like substances should be marked with the word
_Poison_, in large letters. If insecticides are used in the form of a
powder, great care should be exercised to keep it from falling on other
vegetation or fruit that might be eaten by man or beast. I have known
of pigs and horses dying from eating herbage on which Paris green had
blown from a potato field. London purple, which, as a cheaper and
equally effective article, is taking the place of Paris green, must be
used with the same caution, since it is a compound of arsenic, and
equally poisonous.
It is my wish and intention to experiment carefully with the various
means and methods of coping with the diseases and enemies of small
fruits, and to give this chapter frequent revisions.