Copyright
William Salisbury.

Hints addressed to proprietors of orchards, and to growers of fruit in general, comprising observations on the present state of the apple trees, in the cider countries. Made in a tour during the last summer. Also the natural history of the Aphis lanata or American blight, and other insects destructi online

. (page 3 of 9)
Online LibraryWilliam SalisburyHints addressed to proprietors of orchards, and to growers of fruit in general, comprising observations on the present state of the apple trees, in the cider countries. Made in a tour during the last summer. Also the natural history of the Aphis lanata or American blight, and other insects destructi → online text (page 3 of 9)
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ticularly such as are injurious to fruit and
other trees in this country.

Of injuries arising to fruit-trees from
insects of various kinds, w-e have many
examples, and we are far, \'ery far from
having a perfect knowledge of their
nature. However, we know that some
species of them appear only in certain
seasons when the weather is very favours-
able for their hatching and existence.
As we are so much at a loss in these
c 6



36



points, we have much to regret that
the science of entomology is not more
cultivated, as many facts would be ascer-
tained, leading to conclusions that might
ultimately enable us to destroy or retard
the baneful progress of these natural
enemies to plants ; and it ought not to
be forgotten that an acqziaintance toith our
common nojvious insects is a subject of
as mitch interest to the grower qfjhdt-
Irees, and ought to be as intimately con-
nected in this branch of husbandry ^ as
the necessary knowledge qfcojm and cattle
is to farmers in general.

The aphis or small green fly which is
so common in the spring of the year, and
which produces the honey-dew, is to be
destroyed by burning tobacco or any
strong scented leaves or rubbish under
the trees, or by sprinkling them with
water in which tobacco has been infused,
and although this may appear to be a
work of much labour when the trees are
large ; yet in young trees it will repay
the trouble.

But the most destructive insect we know



57

is the white bug, described by a foreign na-
turahst under the name of apliis lanata, or
American blight which has found means,
within a few years, of extending itself
all over the kingdom, and is every season
gaining ground. Various are tiic opinions
respecting this insect, both as to its nature
as well as its production. I have long con-
sidered it to be the same insect that has
of late years infested the poplars and the
larch, and have lately been borne out
in my opinion, as it has left the a])ple-trees
and begun to make ravages on the plum,
and also on a species of the ranunculus
which libund growing close to somea})ple-
trees in the neighbourhood of Worcester.
As I have for some years past paid parti-
cular attention to this insect I shall give a
detail of its history as it has occurred to
me, which may probably stimulate some
person to discover a remedy for its dread-
ful ravages. It docs not appear to hatch at
any particular season, but all the while
the weather is open it continues its work
of reproduction ; the eggs (which are ex-
tremely minute, and must be observed



with the as'^istaiice of the microscope)
are laid amongst the white cotton-Hke sub-
stance in which the insect is enveloped,
and which it also deposits on the
bark of tlie trees. I liave from good
authority heard it was brought to this
country by the refugees from France, in
the reign of Louis XIV., when a colony
of these people settled at Paddington,
and there it was first observed to begin its
depredations on the apple trees: I am led
to think that it is a native of a warmer
climate than ours, from the circumstance
that the living insects as v/ell as the eggs
remaining on the branches of tlie trees are
frequently killed by the action of frost,
which was the case in the winter of
1813, a season in which I had them con-
tinually imder my notice, and I trust that
it has afforded me an o})portunity of
giving the world a cheap mode of destroy-
ing them, or at least of retarding their
progress.

I am, in some measure, warranted in my
belief that the insect in question was in-
troduced from France, as an old French



39

gardener who worked in my garden seve-
ral years ago stated that he was well ac-
quainted v.ith tlie bug as lie termed it,
since his childhood, and that it had been
the destruction of man}' fruits, not apples
in particular, in the neighbourhood of
Montpelier, where he was [)rouglit up.
He also suggested that tlie frost of our
severe winters migiit be the means of
killing it, from its being, in his opinion,
originally a native of a warmer climate :
this caused me to pay attention to its ha-
bits, and I soon found that in the cold of
our winters it usually disappeared, al-
though there was the appearance of some
of it among the cracks in the bark, but
not so much as in the summer weather.
I therefore had recourse to scraping the
outer bark and washing the trees over
with soap suds, and solutions of lime, soot,
and sul])]mr ; and although from the above
treatment, or the operation of the brush,
they were in great measure killed or their
progress lessened, yet I was mortified
greatly to find that every spring they were
quickly renewed.



40



My surprise however was soon lessened,
when on examining the roots of the apple-
trees I found there existed a progeny,
which in all probability served every
season to renew the stock, and I therefoi'e
turned my attention to this point which
led me to the following expedient. I
took ofifi during the frost, the branches of
apple trees on which there had been great
abundance of the insect, and found, by the
use of the magnifier, that the eggs were
discoloured and incapable, to all appear-
ance, of producing young. At the same
time I searched the roots of the same
trees, and there I found not only eggs but
Jiving insects, and had them moving
under the lens in a few minutes after be-
ing taken into a warm room.

In order to illustrate this fact I had a
drawing made of the roots with the insect
attached to it, as I have considered it of
considerable moment to give as perfect an
account of it as my labours have afforded
opportunity. I have had it engraved, and
by reference to the plates the following
states of this destructive insect will be
seen:



11

Plate 1. No. 1, is a branch of an
apple-tree with the appearance it makes
when the insect is feeding on it.

No. 2. is a piece of the root of an
apple-tree with the aphis feeding on it in
a similar manner.

No. 3. is the aphis magnified and
the egg, as it appears among the down
in which the insect is enveloped, when
the weather occasions it to take shelter.

No. 4>. is the insect more highly mag-
nified.

No. 5. is an aphis that has acquired
wings ; these are by no means so plentiful
as those without. I regret that I cannot
speak with certainty, if this is a different
sex, or whether it acquires the wings from
age, which is supposed to be the case with
other species of aphis. In investigating the
common green fly, which are so frequent
on green house plants, and on rose trees
inthe spring of the year, we perceive some
which are oviparous and others that are
viviparous. This circumstance was, I
believe, first noticed by Mr. Curtis, and
it, in some degree, accounts for their mul-



42



tiplyinginthe aslonisliiiig way which it ap-
pears to do; and we observe that, in the
later stages ofexistence, many of these in-
sects become winged in a similar manner.
I notice this circumstance merely as 1
hope some persons whose time may per-
mit them, may be able to carry the
examination of these animalculae so far
as to give us a much more perfect idea
of their nature than we have at pre-
sent. There is no subject that demands
investigation more than this, and nothing
would produce more benefit to this coun-
try, and probably the world at large, than
proper encouragement being held out to
personsto make the necessary experiments,
and to publish the results arising there-
from. If the growth of fruit, or the
produce of cyder, is of any moment to us
as a country, it is necessary that atten-
tion should be immediately paid to this
subject, or the result will most inevit-
ably be, the destruction of apple trees al-
together ; and as the insect is beginning
to attack otlier kinds of fruit-trees, it is
not inu'easonable to suppose that the mis-
chief mav not end with that loss alone.



4S



Having thus discovered its subterra-
neous habitation, I had recourse to tlie
following expedient: while the frost was
in the grountl, and the snow lay on the sur-
face, I caused a necessary-house to be
emptied, and its contents taken in a soft
state, and spread regularly over the
ground, in quantity sufficient, as my men
beheved, to kill all the apple trees. When
the thaw came the whole was of course
washed down to the roots, and ever since
I have had the satisfaction of finding
the trees perfectly clear from the insect
and growing most luxuriantly ; and to
this hour all that are left unsold remain
healthy. From the success of the above
experiment, I should recommend that
the trees be continually cleaned so far as
relates to the branches, and that the roots
be made as bare as possible in tlic win-
ter season, and a dressing of the above
or a similar material applied to the roots,
and I have little doubt of its success in
curtailing the evil to a certain degree,
although it may probably be the destruc-
tion of some of the trees, vet if we can



4i



by any means lessen the ravages of this
destructive monster, we ought not to con-
sider this loss as material.

That we have other insects which infest
our fruit-trees, and diseases of different
kinds is certain ; and whoever has had
opportunity of visiting the cyder coun-
ties, cannot help having observed the
general decay of the fruit-trees, which
appears equally to affect the young and
old, with very few exceptions, a circum-
stance so much to be regretted, that it
ought most seriously to engage our atten-
tion.

It is much to be lamented, in this
age of science, that most authors who
have treated on the subject of insects,
have published works more calculated
for furthering the scientific views of the
learned, than to inform the ignorant;
so that I scarcely know of any English
author who has considered it worth his
notice to give so much of the minor his-
tory of the subject as relates the par-
ticulars of their production, existence,
and the subsequent changes through



45



which tliGsc wonderful creatures pass
during their hfe-time.

As somewhat of this knowledge is ne-
cessary before we can at all speculate in
destroying the noxious kinds of insects, or
afford protection to others that are useful,
I shall devote a page or two for the pur-
pose of describing the history of the
propagation of some of our most common
kinds.

In the butterfly kind, the different
sexes are as distinct as in the ordinary
course of animal nature, but these in-
sects differ from most other parts of the
creation, by the metamorphoses they un-
dergo, and which consist in a change of
structure which is observed during their
progress to maturity.

The egg contains the rudiments of the
insect, and from it is produced the larva,
or caterpillar, which, in many instances
casts its coat as it increases in size;
at each of which changes it assumes a
different colour and form. In this state
it is like to w hat the poet says of the
boasting lord of the creation ; " its first



46



** great ruling passion is to eat," being so
extremely voracious of its food ; that this
is the only operation it performs, and in
many instances its destructive powers are
truly alarming, a fact, it is presumed, not
unknown to many of my readers. In the
caterpillar state it exists for a consider-
able time, and its season of existence
varies in different kinds, and also as to the
food which it is destined to eat. Thus,
the silk-worm is hatched from the egg in
the month of April, at the season when
the mulberry puts forth its first leaves,
which are the natural food of this useful
creature*, and its continuance in the ca-

* I am aware that those of my readers who have
bred these insects for amusement, will say, that the
larva is generally hatched before the mulberry is in
leaf. This fact I am acquainted with, but it should
be considered, that neither the insect or the mul-
berry are natives of our climate, which causes
a difference not existing in Italy. It should be
moreover remarked, that in Switzerland the breed-
ers of the silkworms keep the eggs back from hatch-
ing by placing them out of the influence of the sun,
till the food is grown, holding it a certain maxim,
that giving them lettuce or any other food, as is
practised here, makes them sickly.



terj)illaror larva state, is till the mouth of
July, during the first luxuriant growth of
the tree. It then changes into a pupa
which is Inirder and more dry than the
caterpillar ; in this state it is confined in a
narrow compass, and becomes surrounded
by a kind of web termed a chrysalis, that
issues from its mouth, and which on being
wound oft' is the raw silk, but in some
other species it is surrounded by a hard
impervious coat, scarcely to be penetrated
by tlie sharpest instrument, or to be acted
on by the most corrosive liquid. When
the insect has escaped from this state of
torpidity, in which it lies for different
periods*, it becomes the perfect fly, and
is then fit to fulfil the principal functions
to which all nature is devoted, the re-
production of the species.

* One extraordinary circumstance attending this
race of creatures is the length of time some of the
species will remain alivein the pupastate; I released
one from a chrysalis this last summer, which had been
fixed to a wooden label in the Botanic (iarden, and
had been paijited over for eiglit years. There is a



48



Although an enumeration of all the
different kinds that infest plants at dif-
ferent periods is more than the limits
of this work will admit, yet, these in-
stances may serve so far to give an idea
of their nature, that persons who feel in-
terested may employ such means for
counteracting these great evils, as may
appear most likely to answer the pur-
pose.

It should be observed, that in general
each kind of insect has its particular food,

small kind of grasshopper described by naturalists
as coming regularly once in seventeen 3'ears, and
is called Tettigonia Septendecem from that circum
stance. But a more extraordinary account is pub-
lished by Mr. Marsham, in the Transactions of the
Linnsean Society of London, of an insect which was
known to have existed in a deal board that had been
converted into a writing desk in Guildhall. The length
of time it had been enclosed therein was uncertain,
but it was a known fact that it must have been there
upwards of forty years. It is moreover a curious cir-
cumstance, that its kind has never been noticed in
this country before, and that it is a native of China,
but is also sometimes found in Norway, and from
the latter country it is probable the timber in which
it was enclosed, was imported.



49



and they are often named by naturalists
from the plant on which they feed. As the
papilio urtica^, or tortoise-shell butterfly,
is never found on any plant but the sting-
ing nettle ; there are others which feed
only on two different plants as the phalaena
verbasci, water-betony moth, which will
eat either the mullein or water-betony,
but these are comparatively scarce to
the former, and much less common than
either is tlie brown-tail moth*, which
in the summer of 1783, committed so
much mischief on all the trees and herb-
age near London, that the whole coun-
try was very much alarmed : inasmuch
as advertisements, paragraphs, letters, &c.
almost without number were published,
and which spread great consternation
about the country. Some idea of their
number may be calculated from the fol-
lowing account, which I shall extract from
a history of this caterpillar, which was at
that time published by mypartner, the late
Mr. William Curtis : " In many of the pa-

* Bombyx phaeorhea.
D



50



" rishes near London, subscriptions have
" been opened, and the poor people em-
" ployed to cut off the webs at one shilling
" per bushel, which have been burnt un-
** der the inspection of tlie churchwar-
" dens, overseers, or beadle of tlie parish ;
" at the first onset of this business, fbur-
" score bushels, as I was most credibly
" informed, were collected in one day, in
" the parish of Clapham.*'*

It should be observed, that this gentle-
man was induced to publish his account of
this moth, to appeasethe minds of the peo-
ple. Some of the writers of that day hav-
ing asserted that "they were the usual pre-
*» sage of the plague," others, *'that their
" numbers were great enough to render
" the air pestilential, and that they would
** mangle and destroy every kind of vege-
" tation, and starvethe cattle in the fields.**
It was no wonder therefore, from these

* This insect forms a web which is attached to
the leaves of the trees, and to which it always re-
tires at night or in wet weather. Taking the
branches of the trees with the web and insect,
would certainly appear to be the readiest mode of
destroying it.



51



alarming accounts, " That almost every
" one ignorant of their history, were under
" the greatest apprehensions concerning
" them, so much so that even prayers were
" offered in some churches to deliver us
*' from the apprehended approaching ca-
" lamity."

" The caterpillar of the brown-tail moth
*' is not so limited a feeder as some, nor
*' so general a one as others. Its whole
*' economy however shews it is designed to
" feed on trees and shrubs on Avhich alone
*• it is ever found. These afford it a sup-
" port for its web, which is an habitation
** in many respects essential to its exist-
" ence, and with which herbaceous plants
" of lower growth cannot supply it."

The following facts will serve to corro-
borate what is here advanced. They are
found on the

Hawthorn most plentifully,

Oak the same.

Elm very plentifully,

Most fruit trees the same.

Blackthorn plentifully,

Rose trees the same,
D 2



52



Bramble the same,

On the willow and poplar scarce.

None have been noticed on the
Elder,
Walnut,
Ash,
Fir, or
Herbaceous plants.

Thus it appears that the mischiefs these
caterpillars are capable of occasioning, is
to rob particular trees and shrubs, and
thereby retard the growth of their foliage
and blossoms.

" With respect to fruit trees, the in-
" juries they sustain are most serious,
** as in destroying the blossoms as yet in
" the bud, they also destroy the fruit in
" embryo, the oxvners of orchards and
" standard fruit trees have therefore great
** reason to be alarmed."

Mr. Curtis also predicted, that although
it had been uncommonly numerous for
the last two seasons, it might be several
years before the like occurred again ; and
his predictions have been perfectly fulfil.



5S



led, for only once or twice since has it
made its appearance in this country in any
quantity. But we are at a loss to guess
how it can occur, that for " many years
" we do not see these creatures, and all at
*' once we have them so plentiful that
" their numbers become thus truly alarm-
" ing." A gentleman of Ciielsea, has in-
formed me, that he once took a nest of
moths and bred them, that some of the
eggs came the first year, some the second,
and others of the same nest did not hatch
till the third season. Now if the eggs of
insects are preserved thus for three years,
a chrysalis for seven, and a living insect
makes its appearance from a deal board,
where it must have lain upwards of forty
years, why should we fix any limits to the
period of their vitality in any of their dor-
mant stages of existence. We must there-
fore rest contented with such objects
as we can see, and be thankful to al-
mighty Providence, for the use of them
during our transitory residence in this life,
the secrets of nature's operations are some
of them too deep for human foresight.

D S



54



We must observe that wliilst we read in
nature's book, every page affords instruc-
tion ; the iirst ordination as given by the
great Creator, " increase and multiply"
aided by nature's first impelling instinct,
self preservation, is fully exemplified in
every lesson, and as men and rational
beings we should always bear in view the
determination as expressed, " By the
" sweat of thy brow shalt thou, &c. &c."
And should know that it is expected of us,
to use our utmost endeavours to curtail
the superfluities of nature's works, and
render those things committed to our
care as perfect as our intellect and indus-
try will admit.

I shall endeavour to illustrate the above
facts, by giving the history of some of our
most noxious insects.



oo



PapILIO CliATJE.GJ'



THE BLACK VEINED BUITEIIFLY.



THE caterpillar of this butterfly, is
one of the most destructive to fruit
trees that we have, and in particuhu* to
the apples, despoiling them of their fo-
liage early in the spring : we have men-
tioned the brown-tail moth whose ravages
are dreadful, but we have the satisfaction
of knowing, that it does not frequently
come in such great numbers, as it has
not made its appearance, in any alarming
degree, since Mr. Curtis wrote its history,
now thirty-four years since.

It would be fortunate for us, and for
our fruit trees, was the same fact to ap-
ply to the one in question, for although
we do not see it so very powerful, yet

*D 'i



56



it nevertheless commits great destruction
every s])ring, and not only to the apple-
trees but other kinds of fruits. As my
object in writing its history is intended to
shew to persons not acquainted with this
subject, its mode of living and producing
its offspring, I trust I shall be held ex-
cused if I descend to particulars that may
to some persons be already known.

The female deposits its eggs between
the interstices of the bark, and as near
to the ends of the branches as she can
find convenient, and more generally on
old trees where there is plenty of moss,
&c. to shelter the young as soon as they
are hatched, than on younger ones. The
eggs are coated with a strong mucus,
of more power than the finest glue,
as being quite impervious to moisture,
which serves to stick the eggs firmly to
the branch, those become moreover so
hard, that neither the birds nor other ani-
mals can destroy them, and in this state,
we have instances of their remaining
without losing their vitality for several
years, until a favourable opportunity of



57

their being brought into existence ar-
rives, when there is plenty of food for
them. The young ones are small on their
being first hatched, but as we observed
before, they begin the work of destruc-
tion by marshalling themselves on the
young leaves of the trees, eating off the
epidermis, and destroying it altogether as
they advance. As long as they are in their
first skins they remain together, and are of
a deep black colour, but when they arrive
at about one-third of an inch in length,
they begin to change their skins, this
is done at three different times, which
I shall describe. When the time ap-
proaches in which they put off tlieir first
skin, they spin a web together, on which
they sit fast and remain quite motionless,
after which their heads are observed to
swell, and the old skin, w^hich is now be-
come too narrow, bursts, after whicli the
caterpillar a]}pears something larger, its
head and the })oints of its hairs are pale,
but in a few minutes change to a dark
colour, nearly black ; after this they begin
to look abroad for food ; the other chansr-
D 5



58

ing of" the skin is similar to this, and is
attended with great pain to them, and in
which they often are observed to die.
Afiter the third and last changing the
caterpillar comes to perfection, at which
time it is beautiful to appearance.

Fig. 6. shews a fidl grown caterpillar
of the largest kind afiter the last chang-
ing, nearly two inches and a half long ;
they are not all of this length, especially
if they have not had sufficient fresh
food.

I shall now describe this full grown
caterpillar more fully : A caterpillar con-
sists in general of the head, neck, and
body. The head is, as in most species of
this class, prominent and heart-shaped,
divided in the middle downwards, so
that it forms a triangle towards the
mouth; from the mouth are two points
going out, which some call the man-
dibles. The head as well as the neck are
covered with many yellow protuberances
which render these parts somewhat shin-
ing. Tiie body consists often segments,
besides the last terminal part. On the
5



59

neck, as well as on these points are eight
pair of legs in the following disjiosition ;
three pair of pointed fore legs on the neck
and the two first segments, then follow
two segments without legs, the next four
segments have each of them a pair of
obtuse ones, which are commonly called


1 3 5 6 7 8 9

Online LibraryWilliam SalisburyHints addressed to proprietors of orchards, and to growers of fruit in general, comprising observations on the present state of the apple trees, in the cider countries. Made in a tour during the last summer. Also the natural history of the Aphis lanata or American blight, and other insects destructi → online text (page 3 of 9)