Mew Pork
Htate College of Agriculture

At Cornell Anibersity
Sthaca, $2. B.

Library

Ke. University Library

SB 608.F8K

iO

ses of fruit-tree

219

mai

Cornell University

Library

The original of this book is in
the Cornell University Library.

There are no known copyright restrictions in
the United States on the use of the text.

http://www.archive.org/details/cu31924002844219

FRUIT-BLIGHTS

AND

DISEASES OF FRUIT-TREES.

INTERIM REPORT

BY

PROFESSOR T. KIRK, F.L.S.,

Of Wellington, New Zealand.

Reprinted by Permission of the Government
of New Zealand.

BRISBANE:
JAMES C. BEAL, GOVERNMENT PRINTER, WILLIAM STREET.

1886,

MEMORANDUM.

——

The ravages of noxious insects are such a serious drawback to
the profitable cultivation of the land in Queensland that any reliable
information as to their life-history and the remedial measures applic-
-able to any of them will, if promulgated among those concerned,
be of great value; especially when it is remembered that the literature
upon the subject is so much scattered as to be practically out of
the reach of the cultivator of the soil here. When the following
report reached me from its author, I was much impressed: with
the research which it displayed, and with the simple and intelligible
character of the remedies suggested or recommended; and having
been known for many years to take a warm interest in horticultural
industries, I ventured upon the liberty of inviting the attention of
the Queensland Government to Professor Kirk’s work, and of advis-
ing its reprint for distribution within this Colony. The report does
not profess to be exhaustive, nor is it the case that all the insects
treated are found here; but some of the pests dealt with are known
in almost every climate, while of others we have congeners with
habits so similar that the remedial measures described will be
equaily applicable to many of the vermin from which our orchards
and gardens suffer so much.

Lewis A. Bernays.

Brisbane, lst September, 1886.

Proresson Krex fo Tun Hon. Tae Minister or Lannps.

Wellington, 7th September, 1885.

Siz,

In compliance with your instructions received by me, when
in Christchurch, on the 27th February, I commenced ‘inquiries con-
cerning the various diseases of fruit-trees in the colony, and have now
the honour to enclose an interim report containing the results of my
inquiries, so far as I have been able to work up the material collected.

While I regret that the report is necessarily incomplete, I may
point out that, owing to the advanced period of the season when your
instructions were received, my researches were practically restricted
to the winter months; it was therefore impossible to ascertain the
life-history of many fruit-pests, or, in some cases, even to determine
their identity; while my stay in any one district was too brief
to allow of the work being performed in an exhaustive manner, more
especially as it was carried on conjointly with the important forest
work which had been placed in my hands.

T have satisfaction in stating generally that, although the ravages
of insect and fungoid pests have assumed such formidable dimensions
as to cause a serious diminution of the fruit-crop in several districts,
the trouble has, in nearly every instance, been the result of ignorance
of the nature of the evil itself, and of the best remedies to be applied
in each case. Even in the present imperfect state of our knowledge
the enemies of the fruit-grower may be kept within moderate bounds,
and, in most instances, completely eradicated ; so that there is nothing
in this direction to prevent fruit-cultivation from being placed ina
satisfactory position throughout the colony.

I have to express my thanks for the ready help and assistance
afforded me by fruit-growers and gardeners in all districts that I have
visited.

T have, &e.,

T. KIRK.
The Hon. The Minister of Lands.

FRUIT-BLIGHTS AND DISEASES OF FRUIT-
TREES IN NEW ZEALAND.

(INTERIM REPORT ON, BY T. KIRK, F.L.8.)

2-
-

INTRODUCTORY REMARKS.
EXTENT OF INJURY.

In the present stage of my inquiries it is not easy to form even an
approximate idea of the amount of injury effected amongst fruit trees
by disease, insects, and fungi. I can do little more than indicate in
general terms the chief causes of injury in each district.

As my work did not commence until I was on the point of leav-
ing the Canterbury District for the North, I have at present no
knowledge of the extent of injury effected in the southern districts.

In North Canterbury, so far as my observations went, the most
serious pests are scale-insects and American blight, which have caused
a vast amount of damage. Here, as elsewhere, the peach is almost
destroyed, and has ceased to be a profitable fruit. The pear suffers
from slug-leech.

In Westland, scale and American blight are, on the whole, less
destructive than in other places. The slug-leech, however, is very
troublesome ; and apprehensions were expressed with regard toa fly
which is said to attack the plum and kill the young wood; but I was
unable to obtain specimens of the insect.

Nelson and Marlborough have suffered more than any other
parts of the colony, and the results are of a more painful character
than elsewhere. Many settlers possessed of small holdings have
derived the chief portion of their income from fruit-trees; these have
become valueless, chiefly from scale and American blight. In most
cases the loss could have been prevented by a little timely attention,
as both scale and blight may be easily extirpated. The codlin-moth
has still further increased the injury; while the slug-leech has
diminished the yield of pears and plums by a heavy percentage, and is
increasing at such a rate that it is now attacking the walnut. The
vine is prevented from fruiting by mildew, while canker-worm and
other pests are still further reducing the yield of apricot, plum, apple,
and small fruits.

I was assured that the export of fruit from Nelson ports had
been diminished to a great extent, but was unable to procure parti-
culars. Bearing in mind that a large percentage of the fruit-crop of
Nelson is produced on small holdings, this diminution of the crop in

6

some cases, involves a considerable amount of privation. It is stated
that many settlers are leaving the district to procure work in other
localities.

At present I have but little knowledge of the blights of the
Wellington, Taranaki, and Hawke’s Bay Districts.

In the North Island the peach is everywhere decaying, but not-
withstanding the depressing effect produced by the general dying-out
of the tree, I believe its vigour may be restored, and that the most
important step in the way of restoration will be found indicated in
my .report. .

Apple-scale, so troublesome in the South Island, is almost
unknown in some districts in the North; although, from the way in
which some native scale-insects are attacking cultivated fruit-trees, it
will be necessary for growers to be very watchful in order to prevent
their trees from becoming badly infested.

Boring insects are more frequent in the northern districts than
elsewhere; all the ordinary cultivated fruit-trees are attacked, in
many cases with fatal results.

White-scale (Icerya purchasi) is a serious enemy to the orange-
grower, but may be destroyed with the greatest ease and at a trivial
cost.

The slug-leech is common, and causes serious loss yearly.
Foot-rot is of a more dangerous character, and less easy to deal
with.

The greatest scourge in the North is unquestionably root-fungus,
which may be found attacking fruit-trees, forest-trees, hedge-rows,
shrubs, and even grasses—from young plants in nursery-rows to
trees in full bearing—with the most destructive effects.

RESTRICTIVE MEASURES.

The importation of diseased or affected fruits should be strictly
rohibited. The orange-scale has been introduced with fruit from
Byditey: Apples infested with codlin-moth and the apple-scale are
occasionally imported. It forms no real objection to prohibition that
an insect or fungus may already be established here; since a change of
clmate often conduces to increased vigour, and the newcomer increases
with greater rapidity than its satablitied congener.

It is desirable that imported fruit-trees should be inspected on
landing, although there would be great difficulties in carrying out any
efficient system of inspection, owing to the number of ports of entry,
and the consequent cost of stationing a duly-qualified man at each.
The difficulties attending the inspection of affected fruit are but
slight ; in nearly all cases the presence of the insect may be easily
recognized. An officer of the Customs Department at each port
might easily acquire such a knowledge of scale or of codlin-moth, for
instance, as to be able to recognize affected fruit, and all fruit entered
at that port should be examined by him. But the examination of
living fruit-trees in order to detect the presence of minute fungi, or of

7

insect-ova, would require special knowledge and exceptional powers of
observation. The introduction of such a fungus as the “ black-knot,”’
ot California (Spheria morbosa), would be a serious aggravation of
the evils under which fruit-growers have to labour. danitian insects
of subterranean habits, as the currant-aphis, grape-louse, &c., might
be introduced on the roots of plants. It is stated that the grape-
louse of Australia attacks various kinds of plants; if this be correct,
it might be introduced into the colony any day, although the impor-
tation of the vine is strictly prohibited.

The appointment of inspectors, with power to order the destruction
of any affected trees, has been advocated, but no absolute necessity for
such a measure has been made out at present; and with the more
general diffusion of information about the diseases of plants it is
not probable that such need will arise.

The Codlin-Moth Act is strictly permissive, and at present has
not been adopted in a single district, although the insect is generally
distributed’ through the colony, and in some localities has materially
diminished the annual yield.

PREVENTION AND REMEDIES.

The climate of New Zealand is exceptionally favourable to the
rapid increase and vigorous growth of insects and plants introduced
from temperate countries. European insects and weeds, when intro-
duced, flourish with a vigour rarely exhibited in their native country,
and increase with greater rapidity. But this is not all: under the
new conditions induced by extensive cultivation the food-supply of
many native pests has been increased to an unlimited extent, so that
it is no matter for surprise that the grass-grub, lemon-tree-borer, and
several species of scale, are found in ever-increasing numbers, and give
good promise of excelling their imported allies in their powers of
destruction.

In former years fruit-cultivation was carried on under easier con-
ditions: few insects had been introduced, and indigenous kinds had
not discovered the more enticing food-supply afforded by introduced
fruit-trees. All this is changed: a tree is no sooner planted than it
is in danger of being attacked, and requires to be frequently inspected
‘in order that noxious insects and fungi may be destroyed on their first
appearance. The intending fruit-grower should consider this risk
before planting. Unless he determines beforehand that his trees shall
be kept clean at any cost, his anticipations of profit will be dis-
appointed, and his orchards will be a source of infection for the whole
country side. :

As a general rule, the old method of growing tall orchard trees,
with large spreading heads, will be found to place fruit-growers in
New Zealand at a disadvantage when compared with the plan of
growing dwarf trees occupying a smaller space. These have the
advantage of being more easily sheltered from the high winds which
visit most parts of the colony during the flowering season, and in

8

exposed situations often cause a serious diminution in the crop. ‘An
advantage of still greater moment is found in the increased facilities
afforded for detecting the first appearance of noxious insects, and for
the application of measures to insure their prompt extirpation. It is
difficult, if not impossible, to keep large-headed orchard trees free
from insect-pests; it is comparatively easy to keep trees 8 feet or
10 feet high in a clean condition, whatever mode of growth may be
adopted.

The difficulty of keeping free-growing varieties of apple worked
on blight-proof stocks in a dwarf condition may be obviated by double-
grafting, the stock to be first worked well above the ground with the
“ Paradise,” and that in its turn with the variety required for per-
manent fruiting.

Unless grown in the pyramidal form, fruit-trees should, as a
general rule, be kept open in the centre, so as to admit the greatest
possible amount of light. and air. Insects increase most rapidly in
proportion as they find shelter and protection on the trees which they
infest.

In old neglected apple-orchards, where the branches are allowed
to become interlaced and almost shut out the light of day, patches of
American blight may be seet with the cottony outgrowth three inches
in length. Ween shelter is abundant the natural enemies of the insect
have less chance of attacking it.

Prunings and thinnings from affected trees should be promptly
destroyed. ; insects and. fungi are often established in new localities by
neglect of this simple precaution.

Moss and lichen should not be allowed to grow on the trunks and
branches; grass and weeds should be eradicated from about the roots.
No useless-growth should be permitted, and everything calculated to
afford needless. shelter to insects should be removed.

The results of the application of insecticides should be carefully
watched, and the treatment promptly repeated, if found necessary.

In the majority of cases insects may be extirpated with but little
trouble on their first appearance; but if they are allowed to increase
until the entire orchard is affected, their extirpation will involve a
large expenditure of time and labour. Constant watchfulness against
insect-pests, and promptitude in meeting their attack, will be found
golden means for fruit-growers in New Zealand.

It seems advisable to offer a few general remarks upon the
remedies applicable to the chief classes of noxious insects, referring

for fuller particulars of treatment to the detailed account given under
each species. :

SCALE.

_ No insects are more easily destroyed than the apple-scale and its
allies with horny shields: the castor-oil mixture, recommended under
apple-scale, has never failed when properly applied. It is inexpensive,
easily applied, and harmless to vegetation, It should be used during

9

the winter or early spring months, before the commencement of
growth, and should be applied with a light hand. In excessive quanti-
ties it tends to retard growth, but does no permanent harm. _

In all respects I prefer castor-oil to kerosene as an insecticide : it
is equally destructive to insect-life, and does not injure the plant, as is
often the case with kerosene. For those who prefer kerosene emul-
sions, [ would recommend 1 |b. soft soap, dissolved in a gallon of boiling
water, with the addition of a pint of kerosene.

Insecticides consisting chiefly of oils should always be applied
lightly, as for the most part they cause injury to the superficial tissue
of the plant.

Mr. Weisenhavern, Mr. Budden, Mr. Hale, and other fruit-growers,
informed me that hundreds of fruit-trees had been recently killed in and
about Nelson by the use of kerosene, or kerosene and linseed-oil, to
destroy scale.

Waite Scare (Icerya).

Syringing or spraying with a garden-engine, with a solution of
caustic potash, 1 oz. to a let of water, is most effective; or the
castor-oil mixture will be found excellent. Emulsions of turpentine
and milk, or soapsuds applied with the syringe, would be of high value.

“Concentrated lye”’ is strongly recommended by American culti-
vators as a remedy for scale. Its cost here would be 6d. or 7d. per
Ib. wholesale. It is applied with a syringe or garden-engine, in the
proportion of 1 Ib. of ie to a gallon of water; stronger solutions are
injurious to the tree.

It is said to contain about 8 per cent. of caustic potash, the
remainder consisting of carbonate of soda, with a small percentage of
caustic soda. ~

I am satisfied that equally good results may be obtained with
caustic potash alone, in the proportion of 14 oz. to a gallon of water,
at a cost of 1d. or 13d. at most.

CANKER-WORM AND OTHER SmaLL CATERPILLARS.

Syringing freely with weak solutions of caustic potash. Dusting
the trees with Paris-green has been found beneficial, but great care
should be taken in applying this remedy. Should it fall on a cut or
wound on the hand or elsewhere, the results might be of an unpleasant
character.

L&AF-APHIS.

Syringe freely with soapsuds or even with cold water. In most
cases this will be found sufficient to dislodge the insect, but with some
kinds it may be necessary to use a weak solution of caustic potash.

The aphides infesting fruit-trees in New Zealand appear to be
identical with European species.

10

SLUG-LEECH.

White hellebore powder has been found effective, but I believe
the caustic-potash solution would be even more beneficial.

LEAF-FUNGI.

I believe solutions of permanganate of potash would be found
effective with nearly all fungoid pests attacking the leaves. 1 hope to
carry out a series of experiments in this direction during the coming
spring. Dusting the leaves affected with fungi with sublimed
sulphur or with Goodhue’s mixture will be found productive of good
results.

Root-FuNnevs.

In addition to tar-water, I have to suggest the following experi-
ments with a view of eradicating this pest: (1.) Top-dressing of lime,
at the rate of 12 bushels to the acre, to be dug in and well mixed with
the soil. (2.) The same, with the addition of 1 1b. of sulphur to each
bushel of lime. (8.) Top-dressing of soot, at the rate of 10 bushels
to the acre. (4.) Top-dressing of salt, at the rate of 3 cwt. to the
acre, applied in the autumn.

Mr. Goodhue’s mixture applied in the dry state is destructive to
the chermes infesting pines, and to many other insects, as well as to
the black blight of the lemon. If prepared for market and placed
before the public in a convenient form, it would doubtless meet with
ready sale, as it is an insecticide of considerable value, and easy of
application.

es

With one important exception—the use of blight-resisting stocks
for the apple—the cultivation of plants possessing properties which
render them distasteful or even poisonous to certain insects, has not
received the attention it deserves, although it opens a field rich with
promise. A few instances may be mentioned here. The common
garden nasturium, planted amongst apples, and-allowed to ascend their
trunks, is a preservative against American blight ; white mustard sown
amongst turnips protects them from the attacks of wire-worm; the
beetle of the grass-grub, under certain conditions, feeds on the castor-
oil plant with suicidal results; the cabbage-aphis is repelled by the
tomato ; Isatis tinctoria, the ancient woad, protects root-crops from
attacks of the larve of various beetles; and itis stated that the common

flax (Zi usitatisstimum) grown amongst potatoes will avert the
attacks of the Colorado beetle.

Facts of this kind demonstrate one class of the advantages that

might be obtained from an experimental garden under competent
supervision.

11

THE CHIEF DISEASES OF FRUIT-TREES, ALSO THE MOST
PREVALENT FUNGOID AND INSECL BLIGHTS.

ROOT FUNGUS (Lycoperdon gemmatum).

This terrible pest may occasionally be met with in all parts of the
colony, most frequently in rather dry fern lands. It attacks fruit-trees
of every kind, but does not confine itself to trees ; ornamental shrubs,
gooseberries, currants, box-edging, strawberries, and other herbaceous
plants—even meadow-grass, rye-grass, and cocksfoot—are occasionally
attacked, while troublesome weeds, such as sheep-sorrel, wireweed, and
sow-thistle are not allowed to escape. Chains of hawthorn hedges,
pines, oaks, cypresses, and other forest-trees have been killed by its
ravages in the Waikato District. In the majority of instances, fruit-
trees are attacked just when coming into bearing, or when they have
been in bearing from two to four years, but trees from ten to fifteen
years’ growth-are not exempt. It is most capricious in the selection
of its victims; sometimes single trees in a hawthorn hedge are
attacked ; at others, two or three together; or every tree may be
killed for the distance of yards. In an orchard a single tree in a row
may be visited, or every second or third tree, or the pest may travel
the rows obliquely, or pass from one row to another in a most irregular
and erratic manner. It is not easy to form an estimate of the loss
occasioned by this destructive parasite: tree after tree, apparently
in vigorous health and bearing, is suddenly stricken, withers, and dies.
In the Hamilton and Cambridge Districts alone, the value of fruit-
trees destroyed by this pest during the last four years must be esti-
mated at not less than £4,000.*

Even the youngest trees are not exempt from attack ; although its
greatest ravages are effected amongst trees which are commencing to
yield the grower a fair return for his outlay, time, and labour. On
witnessing its effects in various localities in the Waikato, I was not
surprised to find that it was regarded by the settlers with greater
apprehension than any other disease to which fruit-trees are subject,
not excepting the peach-blight. The frequent and extensive gaps
caused by its ravages, and the certainty with which new plants are
attacked when replacements are made, may well dishearten the most
enthusiastic cultivator, and cause the gravest fears for the future.

The first indication of the attack of the parasite is afforded by
the leaves of the affected plant, which present a starved and drooping
appearance ; ultimately they become discoloured and fall; but there
is no external indication of the cause. On examining the roots they
appear flecked with delicate white cottony-looking threads, which
permeate the soil in all directions, and frequently form small matted
patches resembling the fine mould often seen on stone-fruits. Hach
thread consists of a delicate tube, and when a number of tubes become

* After this report was sent to press, I was informed by Mr. G. Edgecombe, Secretary to the
Waikato Horticultural Society, that the above sum does not by any means represent the value of
fruit-trees destroyed during the period stated.

12

matted together they form a kind of web or false tissue ; they never
coalesce by fusion of their walls so as to form a continuous tissue.
They present a similar appearance to mushroom-spawn, and. collectively
form the mycelium, or vegetative system of the fungus, and extract
their nourishment from the plant selected as their host. The mycelium
penetrates the woody portion of the root and produces effects of a
similar character to those developed by dry-rot (Merulius laerymans),
so that ultimately the stoutest roots may be crumbled to pieces
between the finger and the thumb; the bark of the collar decays, the
decay extends to the trunk, and the tree can be pulled out of the
ground with little more difficulty than a common stake.

The erratic manner in which the attacks of the fungus are made
may possibly be due to slight variations in the compactness of the
surface soil. In all probability the mycelium is able to penetrate soils
of a certain texture more easily than others.

In one garden all the plants, chiefly strawberries, within a large
irregular patch were first attacked; the mycelium had then attacked
the box-edging and worked below the surface of the walk to the
opposite side, where it attacked a number of fruit-trees in full bearing.

In some seasons the reproductive system of the fungus is not
developed ; its vegetative system may permeate spaces many square
yards in extent without a single perfect specimen making its appearance.
In other seasons the reproductive state is developed in great abundance
in certain localities, although in adjacent localities, in which the
subterranean state is equally plentiful, there may not be a single

reproductive specimen.

The reproductive system is terrestial, and makes its appearance
above the surface in the form of small spherical bodies, which break
through the soil singly or in clusters of from five to ten. At first
they are whitish, fleshy, and apparently homogeneous, but inless than
48 hours they assume the form of small puff-balls; the fleshy portion
is converted into countless millions of dark-brown spores, resembling
extremely fine snuff, and contained in a thin membranous spherical
envelope. At length the sphere exhibits a minute aperture at the
apex, and the spores escape in myriads, so that, in addition to the
indefinite underground extension by means of its vegetative system,
the germs of new individuals are distributed broadcast over extensive
districts by the lightest breath of air.

It is rarely found to attack trees growing in damp situations.
Although I was assured that instances of the kind were known, none
came under my observation. In the valuable orchard of Mr. Horn,
near Cambridge, not a single tree was attacked on the low ground, but
on a dry sloping bank many trees had been killed and others were
dying at the date of my visit.

Trees planted on fern-land are especially liable to be attacked by
this fungus. In most cases it will be found that fragments of the
underground stems of fern have been left in the soil, and when

‘18

partially decayed have been attacked by the fungus, which, finding a
suitable nidus, has speedily covered them with its white thread-like
tubes. These mycelial tubes spread through the soil with amazing
rapidity, attacking and destroying every plant that comes in their
way.

PREVENTION AND REMEDY.

When preparing the ground for planting care should be taken to
remove fern-stems and decaying wood as completely as possible.
Where lime can be procured the soil should be sparingly top-dressed
and the dressing turned in some time before planting. Soot-dressings
would also prove beneficial. The best remedy that I am able to suggest
for this pest would be the saturation of the ground with tar-water, and,
where the disease is not too far advanced, the free use of the pruning-
knife, cutting away all affected parts unsparingly, then applying a
light dressing of Stockholm tar mixed with clay to the wounds. So
far as I am aware, the only cultivator who has tested this remedy at
present is Mr. Reynolds, of Cambridge. I had the opportunity of
examining several trees in his orchard in which decay had commenced
at the base of the trunk, and found indications of the arrest of the
disease in each case; a new corky growth was forming at the edge of
the decayed bark, and the trees were assuming a more healthy
appearance.

Unless precautionary measures are taken, planting trees in places
where others have been killed by the fungus is simply fatal to the new
tree, which may be destroyed the first year. On this point the
experience of Mr. Reynolds is conclusive. After having repeatedly
replaced diseased trees without a single instance of success, although
the soil on the spot was exposed to the air during winter, he saturated
the ground with tar-water before planting, and met with complete
success inevery instance; in no case has a tree treated in this way
been attacked by the fungus so far. A single tree planted last year
without the previous application of tar-water to the soil was destroyed
by the fungus, while those protected by its application are untouched.
It is evident therefore that experiments in the application of tar and
tar-water may be carried on with the most hopeful prospects of good
results.

Pulverised sulphur, mixed with the light soil and worked in
amongst the roots, would prove of service, but is less easy of applica-
tion than tar-water, and would be more expensive. A top-dressing of
soot, or, still better, of soot witha little sulphur, turned in to a full spade’s
depth, would be attended with excellent results, as would the applica-
tion of weak-brine solutions. A light top-dressing of gas-lime would
also prove of value.

Although I have indentified root-fungus as Lycoperdon gemmatum
further observation may possibly show that mycelial states of other
fungi are mixed with it; but this would not affect the mode of
treatment.

14

APPLE.

AMERICAN BLIGHT (Schizoneura lanigera),

Unhappily this insect is too generally distributed throughout the
colony to need description. Its presence on an infected tree is at
once indicated by cottony-looking tufts or patches, which, if neglected,
increase in size, the cottony outgrowth often attaining a length of two
or three inches. The aphides vary somewhat in colour, but most
frequently are black or purplish-black, the young of a faint reddish
tinge; the cottony outgrowth is produced from their abdomen ; but
the process of development has not been fully made out.

From eggs hatched in the spring wingless insects are produced,
each of which becomes the mother of a colony, and may be termed the
“ queen aphis”’; she is viviparous, and able to produce several genera-
tions of insects without the intervention of the male. The young
insects are also viviparous, and, as they are able to commence the
work of reproduction when five days old, their rate of increase is
enormous. It is no exaggeration to say that a single queen may have
many billions of descendants even during her own short lifetime.
The sexless insects thus produced resemble the queen, but are of
smaller size and more oblong form; they are also of a brown or
purplish-brown colour, while the queen is nearly black. Viviparous
winged insects are occasionally produced, but they are certainly
infrequent in the colony. On the approach of winter perfect-sexed
insects are developed, which pair, and in a few days the female deposits
her eggs in a crevice of the bark and dies. The eges remain dormant
until the following spring, when new queens are developed.

The sexed individuals have no mouth-apparatus, and are unable
to take food, so that their existence is of brief duration. They are of
smaller size than their viviparous parent.

In the North Island there appears to be no absolute cessation
of the process of viviparous reproduction. Wingless insects are
certainly extruded during the winter months, although in reduced
numbers.

The woolly aphis is found in crevices of the bark, or at’ the forks
of branches, at the base of suckers, or even in the axils of the leaves.
In many cases the roots are attacked and large galls formed, which
vary from one to four inches in diameter.

The insect punctures the bark and pumps up the sap, which not
only weakens the tree but causes an excessive flow of sap to the
affected part, resulting in a diseased warty growth: the bark becomes
cracked, and exposes the tissue beneath to further attack, while a new
growth forms round the margin of the fissure, thus affording a larger
amount of shelter to the insect, and more copious supplies of food to
the ever-increasing colony, until at length stem and branches alike
are thickly studded with warty excrescences, partially clothed with the
white outgrowth so characteristic of American blight.

Tt has been contended that the aphis attacking the root belongs
to another species, which has been described as Schizoneura pyri. I

15

have no evidence on this point, and, whatever may be the case in other
countries, it has ceased to be of direct practical interest to fruit-
growers in this colony, owing to the protective measures adopted of
late years. In fact, except in very old orchards, it is not easy to find
a, tree with the roots attacked by woolly aphis.

Some years ago attention was drawn to the fact that certain
varieties of the apple exhibited almost complete immunity from the
attacks of woolly aphis, and that their roots were invariably exempt.
This blight-resisting power was most strikingly exhibited by the
“Winter Majetin” and “Northern Spy,” which has led to these
varieties, with some others, being generally adopted as stocks for other
kinds, with the best results. Apples worked on these stocks are never
attacked at the roots, and the branches suffer but lightly when com-
pared with trees worked on the crab or on ordinary seedling stocks.

PREVENTION AND CURE.

The bark must be kept clear of moss, lichen, &c.; all loose bark
should be removed, and the central portion of the head should be kept
open by judicious pruning, so as to allow the freest circulation of air,
and afford the least amount of cover to the insect.

The most efficient remedy is castor-oil, containing about 2 oz.
wood-soot to the gallon; this mixture should be applied to the
affected parts with a paint-brush. In very bad cases it might be found
advisable to make a second application, but I have never known it to
fail when properly applied.

Mixtures of caustic potash, sulphur, and oil are excellent. The
following has been generally circulated under the instructions of the
Hon. the Minister of Lands: ‘Four pounds of sublimed sulphur in
an iron-pot, with enough water to stir conveniently while boiling for
twenty minutes; then add 11b. of caustic potash (Greenbank Com-
pany’s is the best), previously dissolved, and whilst still hot, and as
much colza or other vegetable oil as will make it like a thick paint.
Then, when warm, with a large paint-brush, daub it for about the
space of a foot round the butt of the stem of the tree. Rain will wash
it into the roots, and the oil will tend to preserve its strength for

ears.” ;
z Emulsions of kerosene and milk, or kerosene and soapsuds, are
employed in America. Diluted carbolic acid employed as a wash has
been highly recommended. Soft-soap, dissolved in boiling water, with
the addition of caustic potash and sulphur, forms an excellent remedy.
Sulphur and lime used as a whitewash; fish-oil; soft-soap dissolved
in boiling water with carbolic acid.

Many other remedies might be mentioned ; but, so far as my ex-
perience goes, nothing has proved superior to the mixture of castor-
oil and soot mentioned at the outset.

Syringing with soapsuds or other liquids has been often advised,
but no amount of syringing would be sufficient to clean a badly-
infected tree, as it would be impossible to force fluids into all the in-
numerable chinks and crevices of the diseased outgrowth. -

16

Trees may be protected from American blight and other aphides
by ee the common tall nasturtium (Tropeolum majus) at the root,
and allowing it to ascend the stem. I believe this to be a specific with
regard to the root.

CANKER-WORM (Ctenopseustis obliquana).

The larval state of this moth is becoming increasingly trouble-
some to apple-growers in the Nelson, Marlborough, and Auckland
Districts. At Cambridge it is termed the “ privet-moth,” but I could
not learn that it had been observed on that shrub.

The small green caterpillar feeds upon the leaves of the apple,
which.it glues together by its adhesive threads ; it is, however, most
injurious when it fastens a leaf to the side of the fruit, forming a
secure hiding-place from which to attack the epidermis of the apple at
its leisure. A considerable amount of injury has already been caused
by this insect, and, unless measures are taken to keep it in check, its
ravages may be expected to assume larger dimensions.

For a description of the insect and means of prevention, see under
“ Apricot.”

APPLE-SCALE (Mytilaspis pomorum).

At the present time this pest is causing serious loss inthe Nelson
and Canterbury Districts, where, in certain localities, it has led to a
diminution in the annual yield. It is, however, not uncommon in other
parts of the colony, and it is found to infest not only apples, but pears,
plums, hawthorn, and other trees.

In old neglected orchards the mussel-scale is sometimes so
abundant as to form a scurfy crust over the bark, the shells secreted
by the insects being in contact; usually, however, it is not so densely
packed. Badly-infested trees present a starved appearance; neither
leaves nor fruit attain their full development.

In the young state the insect is extremely minute, wingless, but
possessed of active locomotive powers; the body is oval, furnished
with three pairs of legs, a pair of antenne, a pair of eyes, and
curiously-modified mouth-organs adapted for suctorial purposes. The
locomotive stage rarely lasts more than a week, when the insect is
found to be attached to the epidermis by its suctorial beak, and its
metamorphoses commence. It casts off the first coat or pellicle, which
it has outgrown, and within two days of becoming stationary com-
mences the formation of its test or shield, which is composed of a
secretion produced by the spinnerets on the under surface of the
abdominal region, combined with the two coats or pellicles cast off by
the insect. The shield is attached to the bark by its margin, but does
not attain its full growth until after midsummer, requiring a period
of seven weeks for its completion, when the insect is found to have
attained its mature state, and to oceupy the greater portion of the
space protected by the shield, but without being directly attached to
it. Having no further use for organs of sight or locomotion, it has
thrown off its eyes, three pairs of legs, and its antennew, with ‘its cast-
off coat, and now resembles a minute grub. It commences to deposit

17

eggs, the process occupying about a fortnight, during which time the
insect has become reduced to less than one-third of its size at maturity,
and occupies the upper portion of the shell, the eggs filling the lower
portion. As a rule the eggs are not hatched until the following spring.
The male of this species has not been observed.

In America this insect is considered to cause a greater amount of
injury than any other, and I believe this to be true in the Nelson
District at the present time. ”

Although numerous remedies have been proposed, it must be
confessed that few have proved satisfactory in practice. Many of
them require the removal of the scale by rubbing or scraping, a process
involving the unnecessary expenditure of a large amount of time and
labour, as the insects can be destroyed and the trees kept in a clean
condition at a very small cost and with but little trouble.

Castor-oil, containing 2 02. of soot to the gallon, as recommended
for American blight, is thoroughly efficient under all conditions when
properly applied. :

At the School of Agriculture, Lincoln, several hawthorn plants
amongst the ornamental trees were so badly attacked by the apple-scale
that their bark was completely encrusted, their leaves shrivelled, became
discoloured, and fell away without reaching maturity. The bark was
lightly washed with the castor-oil mixture, applied with a paint-brush,
the result being a complete success: the scale fell away, the bark
assumed a healthy appearance, and new leaves were developed within
six weeks of the first application. As a matter of precaution a second
dressing was applied later in the season, and the trees remained in a
healthy state. In planting the experimental orchard a few trees just
received from the nurseries were found to be slightly infested with
scale and American blight; the parts affected were treated in the same
way, and, although the orchard is in a district where infested trees are
much too common, a careful examination in the early spring, and the
application of the wash to any branch on which scale or aphis had
effected a lodgment, was found sufficient to eradicate the pests with
very little trouble.

A mixture of kerosene and linseed oil has been recommended, and
without doubt would prove effectual; but, unfortunately, in practice,
it has been destructive to the tree Mr. Budden, Mr. Weisenhavern,
and other growers informed me that in Nelson numbers of young trees
had been killed by its application, and similar results have been ex-
perienced in other places.

Kerosene emulsions have many advocates, but in actual practice I
do not find that kerosene has the slightest advantage over castor-oil,
while its application to growing vegetable-tissue is certainly attended
with risk. The worst effect that I have seen attending the use of
castor-oil, when applied in excessive quantities, is the retardation of
of leaf-development for a few days.

Amongst other applications may be mentioned a mixture of soft-
soap and seal-oil ; covering with a thin wash of soft-soap and scraping
with a wooden knife; lime-water; tobacco-water and sulphur, applied

B

18

as awash; covering the affected parts with clay reduced to the con-
sistency of paint, with the addition of oil and sulphur, &c. At pre-
sent, however, I have not seen any preparation equal in value to the
simple mixture of castor-oil and soot.

GREEN APHIS (Aphis mali).

A green aphis, which is occasionally met with on apple-trees, ig
for the present identified with this species.

I have not met with any instance in which its presence has been
attended with serious results, although tie leaves of infested trees are
more or less curled backwards so as to afford shelter to the insect.

The green aphis may be readily destroyed by syringing with soap.
suds, or even with water, if ejected with sufficient force. —

Strong tobacco-water is an excellent wash for trees infested by
aphides. It is made by pouring a gallon of boiling water over four
ounces of tobacco and allowing it to stand for a few hours. A little
soft-soap dissolved in the infusion would be beneficial. — oat

Tobacco of sufficiently good quality to serve as an insecticide may
be grown in any part of New Zealand. :

In Europe and America several successive seasons may elapse
without any great amount of injury being effected by Aphis mali, but
in other seasons the insect becomes diffused with such rapidity that the
leaves and crop are destroyed.

CODLIN-MOTH (Carpocapsa pomonella).

This pest is increasing in many parts of the colony, but at present
is not generally distributed. It is most destructive in the provincial
districts of Canterbury, Marlborough, and Nelson, but is not confined
to them; it is known in Westland, Wellington, and in several parts
of the Auckland District. It was observed in the Auckland District
about twelve years ago, and in Nelson about eight. Instances of its
importation from Tasmania and California in affected fruit are
occasivnally reported, and in all probability have been of not un-
frequent occurrence.

The moth is about three-quarters of an inch across when its wings
are fully expanded, but the individuals vary in size to a considerable
extent; the wings are grey, with dark transverse lines and black
markings. ,

The eggs are deposited singly on the apex of the ovary when the
aryl is in flower, or on the crown of the young fruit at a later season;
the caterpillar is hatched in a few days and eats its way to the central
portion of the ovary, and at first does not attack the covering which
immediately protects the young seed; it extends its burrow until it
perforates the epidermis of the fruit, so that a somewhat tortuous
gallery is formed, admitting air freely and facilitating the discharge of
excreta. The caterpillar now returns to the core of the apple, pierces
the cartilaginous covering and gains access to the seeds (pips), upon
which it feeds until the apple falls, when it emerges from the fruit and
ascends the trunk of the tree, taking shelter in a crevice of the bark,

19

or beneath a tuft of lichen or moss, or below the junction of a branch
with the trunk, &c., having passed fully three weeks in the caterpillar-
stage. Having found a convenient resting-place it enters the chrysalis-
Stage, which in the early part of the season is of brief duration, the
moth emerging to deposit its eggs as already described, so that two or
even three generations may be developed in one season.

Caterpillars leaving the fruit late in the season remain in the
dormant stage during the winter, the perfect insect making its appear-
ance the following spring.

PREVENTION AND CURE,

All loose bark should be removed, moss or lichen should be
scraped off. Loose growth of every kind should be cut away so as to
afford the least possible amount of shelter for the caterpillar after it
oe the fruit, and expose it for a longer period to the attacks of

irds.

The period at which the insect may be most easily destroyed is
during the caterpillar-stage, when advantage may be taken of its habit
of ascending the trunk to capture large numbers. Bands of canvas,
calico, or even stout paper, three to five inches wide, are attached
round the stem in such a way that the upper. margin fits tightly all
round, while the lower margin is sufficiently loose to allow the
caterpillar to creep beneath it without difficulty; the insect readily
takes possession of the shelter afforded by the band, and, secreting a
light web, enters upon its dormant stage. The bands should be ex-
amined once a week and the caterpillar destroyed: usually several
insects will be found under each band.

Ropes of hay or straw, dipped in a mixture of tar and oil, and
laid-on the ground so as to surround the trunk without touching: it,
would doubtless prevent the caterpillar from gaining access to the tree,
but would do nothing towards destroying it.

All fallen fruit should be promptly collected and destroyed before
the caterpillars have time to emerge.

LEAF-CHAFER.

I was informed that a small brown beetle frequently attacked the
leaf of the apple in several districts during the early summer months,
and in the Waikato I saw large quantities of apples disfigured during
the early stages of growth, and often curiously warted or even
distorted, not improbably by the same beetle; but 1 was unable to
obtain specimens of the insect. i

In the North it was spoken of as the “ Maori bug,” but this name
is misleading, being commonly applied to the karamu, so well known
on account of the unpleasant odour which it emits when touched.

GRASS-GRUB (Odontria zealandica).
See under “Olive,” page 35

20

APPLE-BLOSSOM WEEVIL (Anthonomus pomorum).

At present this troublesome beetle has been noticed only in a
single locality—the experimental orchard at the School of Agriculture
Lincoln, where it was observed in November last that all the blossoms
on a single tree had been destroyed. In all probability it will prove
to be not infrequent, and in late seasons cause much injury if allowed
to remain unchecked.

The first indication of the attack of this insect is afforded by the
condition of the flower-buds, which often exhibit a healthy and
luxuriant appearance almost up to the point of full expansion, when
further development is arrested, the petals wither and become matted
together, and the prospect of fruit is entirely destroyed for the season.
On examination it is found that every flower-bud exhibits a minute
perforation, and that the stamens and pistils have been destroyed by a
minute white grub one-eighth of an inch in length.

As soon as the buds are sufficiently developed for the white colour
of the petals to be distinguished, they are perforated by the female
insect, and an egg is deposited; the egg is hatched in about a week,
and the grub commences to destroy the essential parts of the flower ;
the petals wither and become matted together, and as soon as the
food-supply is exhausted the grub enters into the pupa-state, which is
passed in thé withered flower. The perfect weevil is developed from
the pupa in less than a month from the time at which the eggs were
deposited, and feeds on the leaves for the remainder of the season.
On the approach of winter it takes shelter under stones or in crevices
of the soil, or amongst loose bark and moss. The perfect female is less
than an eighth of aninch in length, and is furnished witha long curved
proboscis. She is reddish-brown in colour, with light patches behind
the head.

Eggs cease to be deposited as soon as the flowers are fully
expanded, so that the season during which this inconspicuous pest can
work mischief is of the briefest, but it is unfortunately sufficient to
enable it to destroy all prospect of a crop for the season. The
female, being wingless and passing the winter season at the foot of
the tree, may be prevented from ascending by tying narrow strips of
brown paper, saturated on the outside with tar mixed with a little fish-
oil, round the stem of the tree. These bands should be tightly
attached round the upper margin, and the oil should be sufficient to
prevent the tar from becoming ‘dry during the period necessary for the
expansion of the flowers.

Should the weevils not be observed until the buds are attacked,
syringe freely with a strong solution of caustic potash; this
will kill the grubs and prevent the development of newly-laid
eggs

As the period of flowering is necessarily prolonged by cloudy
weather, it follows that the insect has a longer period in which to
deposit its eggs, and therefore requires to be more closely
watched.

21

APRICOT.
SCALE.

The apricot is occasionally attacked by at least two species of bark-
scale, for which the best remedy is the mixture of cavtor-oil and soot,
with the addition of soapsuds.

For fuller particulars, see under “ Apple-scale, page 16 ante.

CANKER-WORM (Ctenopseustis obliquana).

The caterpillar of this moth is very injurious to the apricot,
feeding on the leaves, which it fastens together by viscid threads, and
attaches them to the ripening fruit, when it feeds upon the epidermis
and under-surface, rendering the affected apricots unfit for market.

I was informed that the caterpillar makes its first appearance in
December or January, and continues feeding for nearly three months
on the leaves of the apricot, apple, and plum, but doing the greatest
injury to the apricot. The caterpillar may be found in the orchard
as late as the middle of May. .

It has been mistaken for the European winter-moth (Geometra
brumata), but that species has not been found in New Zealand, and in
Europe attains its perfect state during the winter months, November
and December. The females have only abortive wings.

The caterpillar of the canker-worm moth is about three-quarters
of an inch in length, and of a pale-green tint, yellowish on the side,
head black or dark-brown. The moth is about five-eighths of an inch
long, with dull-brown wings, showing patches of a deeper tint. The
caterpillar enters the pupa-stage about May.

I have observed the insect in'the larval state only, and do not feel
absolutely certain as to the correctness of the identification, which is
based upon a solitary specimen of the moth, for which I am indebted
to Mr. P. Swanwick, of Picton.

Infested trees may be syringed with a weak solution of caustic
potash ; or fires of weeds, &c., may be made underneath the trees so as
to stupify the caterpillars or drive them away. Leaves spun together
by the threads of the insects should be removed as soon as observed,
care being taken to destroy the caterpillar.

A small spider destroys large numbers by depositing its eggs in
the body of the larvae.

The caterpillars of several moths are confused by fruit-growers
under the general term “ Canker-worm,” but the perfect state has only
been observed in the present instance.

CHERRY.
CHERRY-APHIS (Myzus cerast).
For treatment, see “‘ Apple-aphis,” page 18 ante.

SCALE.
For treatment, see “‘ Apple-scale,” page 16 ante,

22

SLUG-LEECH.
For description and treatment, see under “ Pear,” page 42.

RED SPIDER.
For description and treatment, see under “ Hop,” page 23.

CURRANT.
BORER (Zmona hirta.)

This troublesome insect is sometimes found infesting the currant,
occasionally in such excessive numbers as to cause death.

When the insects are not numerous, affected branches may be
cut off; but, when the trees are badly affected, they should be rooted
up and burned at once.

For a more complete account, see under “ Lemon,” page 26.

CATERPILLAR.

The larva of a small moth, not yet identified, feeds upon the
leaves of the currant Its habits are similar to those of the can ker-
worm of the apricot, to which reference may be made for treatment.
See page 21 ante.

GOOSEBERRY.

BORER (mona hirta).

The gooseberry as well as the currant is infested by this pest, and
its ravages are sometimes fatally destructive. Mr. A. T. Urquhart
informs me that trees which bore heavy crops last season are now
dead. The gooseberry and currant alike appear to have less power of
resistance than the lemon ; perhaps on account of their smaller size
and short period of duration.

For treatment, see under “ Lemon,” page 26.

SCALE,
Two species of scale-insects are found on the gooseberry, some-
times in large numbers.
For treatment, see under ‘‘ Apple-scale,” page 16 ante.

CATERPILLAR.

The gooseberry is also attacked by a caterpillar bearing a strong
resemblance to the species which infests the currant, but further infor-
mation is required before it can be identified.

It may be treated in a similar manner.

HOP.
RED SPIDER (Tetranychus telavius).

This minute spinning-mite is a troublesome pest not only to the
hop but to the apple and other fruit-trees in many parts of the colony.
I have observed it in ail the districts except Taranaki, Westland, and

23

Otago, and it would doubtless be found to occur in the first and last
if searched for.

Unless oceurring in large numbers it may easily’ pass unnoticed
by a casual observer. In the autumn months it forms dense reddish
or brownish patches on the stem and leaves, and as winter approaches
seeks the shelter of crevices, especially near the base of the plant. It
increases rapidly during periods of drought, but is rarely able to cause
serious injury in moist seasons. Its structure cannot be made out
without the assistance of a pocket-lens, when the minute speck is
found to consist of an oval body, differing from that of an insect in
having four pairs of legs, two pointing forwards and two backwards ;
it also has a suctorial mouth and a short pair of anteune. Plant¢
infested by this mite are characterised by curled, shrivelled leaves,
which assume a brown or rusty hue, changing to a dull yellow before
they fall. On examination the under-surface of the leaves is found to
be covered with a web, which affords shelter to the mite.

The eggs are thickly attached to the delicate threads of the web,
and only require about eight days before hatching, so that new colonies
are formed with great rapidity.

PREVENTION AND REMEDY.

Frequent syringing with cold water is sufficient to prevent this
troublesome pest from becoming estabiished. Dusting sulphur over
infested trees is an effectual remedy.

Mr. Goodhue’s preparation of sulphur and lime, used as a thin
liquid and applied with the syringe or garden-engine, is excellent and
inexpensive ; or the powder may be used, although it would be less
easy of application, and for this purpose less effective. A thin solution
of soft-soap containing sulphur might be used with advantage.
Sulphur and lime might be dusted over the surface of the ground at
the base of the stem.

In exceptionally bad cases it may be found advisable to wash the
trunk and main branches of affected fruit-trees with a thin solution of
soft-soap containing sulphur and lime.

In late dry seasons the hop suffers severely from the ravages of
this pest, the crop being deteriorated in, quality and diminished in
quantity.

The hop-aphis (Phorodon humuli) has not been observed in New
Zealand. :

LEMON, ORANGE, CITRON, ETC.
1. FOOT-ROT.

This disease is attended with more serious results than any to which
the lemon and citron are liable in this colony. The first mdication
is afforded by the leaves turning yellow and falling; in a short time
the branches are partially denuded, and, as the luxuriant growth of
young shoots is severely checked, the tree assumes a straggling habit.
At the same time the aifected tree usually produces flowers in pro-
fusion, and the flowers develop fruit, Although diseased, it may

24

continue in a fruit-bearing condition for several years, and even carry
heavy crops; but with the progress of the diseasé the fruit becomes
gradually reduced in size, and at length the power of maturation is
lost. In the last stage the tree becomes almost leafless, yet still
develops flowers, although the pollen is usually abortive, and the ©
ovaries do not become fertilized. It may linger in this condition for
several years. .

The disease commences with the decay of the minute fibrils of the
root ; the fibres are next affected, and the decay extends to the larger
arms ; the epidermis peals off in flakes or rots away, when the decay
spreads to the woody parts, and, after attacking the bark of the collar,
makes its appearance above ground, ascending the stem fora foot or
more, the decaying bark emitting a nauseous odour, and falling away
in pieces ; even before it falls, and while apparently sound, it may be
rubbed off by the fingers. The bark is sometimes attacked by fungi,
but their inroads are simply due to the progress of the disease, which
has prepared a suitable nidus for the parasite, and must not be mis-
taken for the cause.*

- If the decay of the bark is confined to one side of the stem the
plant may continue to produce fruit for years, but if the entire
circumference is affected, so that the outer layers of tissue are
destroyed, death speedily ensues.

Healthy trees produce masses of matted rootlets immediately
beneath the surface of the soil; every minute fibril being clothed with
root-hairs near the tip. In diseased trees the branches of the root are
almost naked; but few fibrils having escaped decay, and they are so
much affected as to be almost destitute of root hairs.

CausEs.

Foot-rot is chiefly caused by the rootlets penetrating into a cold
retentive subsoil; ‘deep planting; earthing-up, whether with wood-
ashes, stable-manure, or with earth; excessive manuring, &c.; in some
cases by excessive autumn pruning, leading to a late growth, and
consequent development of unripened wood. Young plants that have
been kept so long in pots as to become “ pot-bound” are peculiarly
liable to be attacked.

PREVENTION AND CURE.

Excessive autumn pruning, the application of manure late in the
season, or any cause tending to stimulate root-action shortly before
the approach of winter must be avoided, on account of the risk
attending a sudden arrest of growth.+

The degree to which remedial measures may fairly be expected to
prove successful must depend to some extent upon the stage of the
disease ; as a general rule, so long as decay has not encircled the stem,
recovery may be hoped for. The soil must be thoroughly drained,

*In this stage Ihave seen a trunk clothed on one side with a dense growth of Hirneola
polytricha, the fungus so much in demand amongst the Chinese.

tAt the Bay of Islands, in June last, oranges and lemons in active growth were severely cut by
frost, while trees which had completed the season’s growth were uninjured.

25

and, if of a retentive character, properly worked before replanting.
All unsound portions of the root must be cut away, and all traces of
decay removed; in cloudy weather the roots may be lefi partially
exposed for a few days; afterwards covered with leaf-mould or with
light alluvial soil. The decayed bark must be pared away in such a
manner as not to wound the sound portion more than can be avoided.
Frequent application of tar-water to the root and stem will be found
beneficial in all except extreme cases. A light top-dressing of lime
mixed with a little sulphur would probably prove of benefit.

This disease is most frequent among trees growing in cold sub-
soils; it is rare on open volcanic soils or where the trees have been
surface-planted. It attacks the lemon and citron more frequently
than the orange, and its effects upon the former are more severe than
upon the latter. The shaddock appears to be exempt from its attack,
but the lime sometimes suffers severely.

In some cases a gummy secretion is exuded by the affected parts
of the stem during the earlier stage of the disease, and ceasing with
the decay of the bark; this constitutes the disease termed “ lagrima,’’
but I am unable to draw a distinction between the two.

ROOT-FUNGUS.
See ante, page 10.

BLACK BLIGHT, OR LEMON SMUT (Capnodium australe, n. sp.).

TI have no hesitation in referring this fungus to Capnodiwm, but
am unable to identify it with any species of which I possess descrip-
tions ; itis therefore provisionaliy distinguished as Capnodium australe
for convenience of reference.

The fungus forms a black film on the surface of the leaves and
twigs, and usually develops short, erect, excessively-branched filaments
from one-tenth to one-quarter of an inch in length, sometimes in such
abundance as to form a velvety surface, but the general appearance of
trees clothed with this sooty-coloured parasite is simply disgusting.

The fungus acts injuriously by closing the orifices of the air-
passages, and preventing the direct action of light, so that the leaves
are unable to discharge their functions.

By some cultivators it is said to be the excreta of the large white
scale (Icerya purchasi); it is, however, a true fungus, although
frequently found growing on trees infected by scale, aphis, or other
homopterous insects. It certainly assumes its most luxuriant growth
on twigs or leaves coated with the boney-dew secreted by many of
these insects, but, so far as my observation serves, the connection is
not invariable.

Trees infested with scale and aphides are not always infested with
the fungus; and trees affected by the fungus are not invariably
attacked by Homoptera. ;

That it has no necessary vonnection with Icerya is apparent from
the fact that orange and lemon-trees were observed to be infested with
the parasite at least ten or twelve years before the introduction of
Icerya into the colony.

26 \

There is a curious similarity of growth between our plant and its
near relative, Antennaria scoriadea, a fungus also of a velvety, sooty
appearance, but of much larger size. Both plants are found on trees
infested by Homoptera, and both are found on trees apparently
destitute of these insects; the Antennaria is, however, found oceasion-
ally on bog mosses (Sphagnum), which, so far as I am aware, are never
infested by scale or aphides.

It has been suggested that, as the fungus is almost invariably
connected with the occurrence of scale or aphis, it is superfluous to
treat it as a separate pest ; if the insect be destroyed the fungus will
cease to exist. While fully admitting the frequency of the association,
T am unable to give full assent to this view. I find instances in which
the fungus is not directly associated with insects, and have seen trees
sparingly attacked by scale, but having the leaves so excessively
infested with fungus that it was not easy to see in what way the small
quantity of honey-dew secreted by the insects could have caused the
excessive abundance of the plant. Another point is worthy of con-
sideration : even should it be proved that the fungus can only originate
upon leaves covered with honey-dew, it does not necessarily follow
that it is unable to maintain its existence without continuous supplies
of the secretion.

The closely allied Antennaria, to which reference has already been
made, sometimes starts into existence on plants growing under the
shade of trees infested by scale insects, and consequently exposed to
the drip of falling honey-dew, but it has been known to exist long
after the removal of the overshadowing trees, and consequently of the
insect-secretion also.

Oranges or lemons picked from trees affected by fungus should
be carefully wiped before being packed for transit by sea. This pre-
caution is of some importance, as the warm damp atmosphere of a
steamer’s hold would facilitate the germination of the fungus-spores,
and the fruit might arrive at its destination in an unsaleable condition,

The fungus may be destroyed by dusting the affected leaves with
sulphur, or with a mixture of sulphur and lime, either of which would
also be found beneficial in assisting to dislodge insect-pests also.

LEMON-TREE BORER (mona hirta).

All citraceous trees are subject to the attacks of boring insects)
and in some districts receive excessive injuries from these pests.
Occasionally the stem and main branches may be found completely
riddled, the injuries sometimes extending below the surface of the
ground, and resulting in the death of the tree.

My observations on the insect were exclusively restricted to its
larval condition, the only state which I was able to obtain during the
months of June and July, although numbers of affected trees were
examined. For its identification I am indebted to A. T. Urquhart,
Esq., of the Karaka, who has recently (27th August) forwarded
specimens in the pupa-state, one of which was sufficiently developed to

27

enable him to identify. it as the mona hirta of Captain Broun’s
“Manual of the New Zealand Coleoptera.” He informs me that he
has observed the beetle for several years in connection with the fer-
tilization of the Yucca, but its identity with the lemon-tree borer has
not hitherto been suspected.

In trees affected by the borer a few of the young branchlets pre-
sent a withered appearance, the bark for an inch or more below the
tip shrivels and turns brown, the leaves fall, and in a short time the
twig breaks; at the point of fracture a few grains of wood-dust ma;
be discovered, and on splitting the branchlet longitudinally below the
fracture a small gallery will be found excavated in a downward direc-
tion, and containing the larval insect ensconced at or near its lower
extremity.

The perfect female insect punctures the branchlet a short distance
below the apex and deposits an egg; on being hatched the grub com-
mences to bore its way downwards, taking advantage of the central
pith. On reaching the base of the twig it continues its excavations
into the branch, at the same time increasing the diameter of its gallery,
and at intervals forming shallow expansions to the right and left. At
length it reaches a stout branch, or possibly the main stem, when it
bores through the bark, and after a longer or shorter periud enters upon
its quiescent stage, the exact duration of which has not been ascertained.

The largest specimens of the larval state that have come under my
notice are about an inch and a quarter in length, and of a yellowish-
white colour. The segments are thirteen in number, somewhat keeled
or ridged; the mouth is small and slightly sunk in the head. Each of
the three thoracic segments carries a pair of minute pointed feet
turned outwards, and all the segments are more or less clothed with
short, rigid, scattered hairs.

The galleries vary greatly in length; the longest that I was able
to trace uninterruptedly was under two feet, the average being from
nine to fifteen inches; the greatest diameter was three-eighths of an
inch. I was assured by one or two observers that the grub invariably
makes its way to the main stem; this view, however, cannot be main-
tained, as the apertures by which the beetle makes its exit may
frequently be observed on the branches. The sudden increase in the
diameter of the gallery as the borer passes from the branchlet into the
adjacent branch is very striking; it is often marked by a small pellet
of curved woody fibres, such as may be found near the shallow lateral
expansions already mentioned. In rare instances the gallery is driven
upwards, and the larva has the power of moving along its gallery either
upwards or downwards with some degree of rapidity, the movements
being doubiless facilitated by the short stiff hairs which are scattered
over the segments.

The perfect insect isfrom five- to seven-eighths of an inch in
length, with a narrow body; the head is partially clothed with yellow
hairs; antenne as long as the body, eleven-jointed, the terminal joints
hairy ; body cylindrical or slightly flattened ; wing-cases reddish brown,
somewhat truncate, i

28

The duration of the larval and pupa states has not been ascertained
at present. In all probability eggs are deposited from December to
April, and require but a short time for hatching ; the grub certainly
remains in the trunk through the winter season, not emerging before
September at the earliest, but whether it remains there more than one
season can only be ascertained by further observation. Mr. Urquhart,
under date the 16th August, states, “Some galleries end in an enlarge-
ment or chamber communicating externally with a small breathing-hole.”
This would indicate that boring operations in these cases were not
completed, although many insects had attained the pupa-stage. It is
probable that the lemon is infested by more than one species of borer.
Two instances have come under my notice in which the gallery was
driven transversely nearly through the branch, and the woody tissue
excavated from each side without interfering with the bark, so that a
shallow circular chamber was formed about three-quarters of an inch
in diameter and one-tenth of: an inch in height, but the insect escaped
observation. A branch injured in this way is broken even by light
winds.

PREVENTION AND CURE.

In all probability the most efficient way of meeting the inroads of
this pest will be by preventing the deposition of eggs, but at present
the perfect beetle and its habits are quite unknown, so that further
observation is necessary. :

All wounds should, as far as possible, be covered with a thin film
of tar or some other substance calculated to prevent the deposition of
eggs. Branches attacked by the insect should be at once removed and
destroyed, care being taken to cut below the extremity of the
burrow.

Probing the galleries with a fine-pointed wire and perforating the
larvee would be found effective, and might easily be carried out when
the insects are few in number. Mr. Campbell, manager to W. J.
Hurst, Esq, M.H.R., Hurstmere, injects soft-soap dissolved in
boiling water containing a little carbolic acid into the galleries by
means of a syringe with a fine nozzle. He informed me that this
mixture dissolved the larve, so that the outflow presented a milky
pearance: A weak solution of caustic potash would prove equall
effective. Possibly the perfect insects might be captured by suspend-
ing pots containing treacle or treacle and honey amongst the branches,
or even by smearing treacle on loose cloths.

Trees extensively infested by borer present a somewhat straggly
appearance, the branches being broken and partially denuded of leaves ;
still fruit is produced in abundance until the energy of the tree is
exhausted. The least amount of harm 1s caused when the boring is
confined to the centre of a stout branch or the main stem, the greatest
when the excavations are made immediately beneath the bark. When
ne renin are numerous branches are continually broken off by
the wind.

29

WHITE SCALE (Leerya purchasi).

This unwelcome intruder was first observed by Dr. Purehas on
kangaroo acacia, in the cemetery gully, Auckland, in 1876, and the
female insect was described by Mr. W. M. Maskell in 1878 as Icerya
purchasi, It was supposed to have been introduced with wattle from
Australia; but it is not a native of that continent, and in all proba-
bility has come to our shores with imported citrads from the Fiji
Islands or California. Unhappily it is now found infesting citraceous
plants from the Bay of Islands to Nelson. In some localities it is
plentiful on wattles; less frequent on furze, manuka, &c.; more
rarely still it may be found on the apple, plum, and peach ; but I have
never seen it in quantity on either. It usually occurs in seattered or
linear masses on the twigs and small branches of the lemon, citron,
&c., and on the under surface of leaves. Not infrequently it forms
superficial patches, covering two or three square inches on the trunk.

The mature female insect is fully one-quarter of an inch in length.
In the young state it is of a reddish-brown colour, and is furnished
with a pair of short antenne, a pair of eyes, a short beak adapted for
piercing the epidermis of plants and extracting their juices, and three
pairs of short legs. In this state it is oval in shape, and exhibits a
certain amount of activity; in a few days the reddish-brown colour is
obscured by aflexuous, cottony outgrowth, and the oval shape is partially

_lost. Minute tufts of black hairs are arranged along the lower margin
of the body. The insect becomes attached to the epidermis by its
suctorial beak and loses the power of locomotion. It now forms its
nest between the abdomen and the surface of the twig in such a way
that the abdomen is gradually elevated and the space beneath pro-
portionally enlarged for the reception of eggs, which are deposited to
the number of fifty or more, and are hatched in a few days. I have
not seen the male insect, but have been assured that it is not uncommon
in the spring, and exhibits considerable activity, the slightest movement
of a branch being sufficient to start a number of them on the wing.

Trees attacked by white scale present a most unattractive appear-
ance; but, unless suffering from foot-rot, borer, or other plagues, do
not appear to become so much exhausted as might be expected from the
vast numbers of the insect. No instances of fatal results from its
ravages have come under my notice.

PREVENTION AND CURE.

Young trees should be carefully examined before planting, in order
to remove any scale that may have attacked them; dipping them in a
solution of caustic potash and sulphur would be an excellent safeguard.
After planting, the trees should be frequently inspected, so that the
first appearance of the pest may be detected, and prompt measures
taken for its destruction. In this way it may be prevented from
establishing itself at but little cost. Should the orchard become
thoroughly infected, the extirpation of the insect would involve a con-
siderable expenditure of time and labour. All affected branches should
be promptly destroyed.

30

The most effective means of destroying this pest is to syringe freely
with a solution of caustic potash. After the publication of my memo-
randum on the diseases of lemons, this remedy was tried by Mr. B.
Dawson, gardener to S. Morrin, Esq., of Remuera, with the best results,
and will, I am satisfied, prove satisfactory in all cases. It will rarely
need more than a second application. é

Washing the affected parts with boiling water is one of the most
effective remedies that can be adopted, but is scarcely applicable on a
large scale, and is altogether inapplicable to young shoots during the
period of active growth. Syringing or washing the tree with a thin
solution of soft-soap, painting the affected parts with castor-oil contain-
ing a small quantity of soot, would be found of the greatest value.

Mr. Maskell has kindly drawn my attention to kerosene made into
an emulsion with soapsuds, which in America is considered the best
remedy for scale of all kinds. I have elsewhere stated my reasons for
preferring castor-oil to kerosene as an insecticide.

All preparations containing oil must be applied to citraceous plants
with the greatest care and with alight hand. Castor-oil is an insecticide
of great value, and, properly applied, is not injurious to vegetable tissue.
I am, however, confident that, on account of its thorough efficiency,
cleanliness, and the ease with which it can be applied, weak solutions
of caustic potash will supersede all other applications recommended
for the destruction of Icerya, which, owing to its rapid increase, must
be looked upon as one of the most dangerous enemies which the
emon-grower has to encounter.

LEAF-SCALE

OLIVE-SCALE (Lecanium oleae).
ORANGE-SCALE (Lecanium hesperidum).
SANDALWOOD-SCALE (Diaspis santali).

In addition to the soft-bodied white scale (Icerya purchas?),
citraceous trees are infested by several scale-insects, more or less
protected by tests or shields, beneath which they live, and which are
attached to the epidermis of the plant by their margins, in a similar
manner to the apple-scale already described. The most common of
these are the species whose names are given above. Their chief char-
acteristics maybe briefly stated.

The orange-scale is found on the twigs and on both surfaces of
the leaves. It is oval in outline, and about one-fifth of an inch in
length. The shield is dark-brown and somewhat rugose. It is
sometimes termed the tortoise-scale, and is found also on holly,
Portugal laurel, and other trees. ;

The olive-scale forms minute brown or blackish cushion-like
bodies on the twigs and leaves. It is very common on citraceous
trees, but especially on the mandari orange, of which it sometimes
takes complete possession. Like the precéding, it is naturalised in
New Zealand, and is commonly called “black scale.” It is also
found on the plum and other cultivated fruit-trees, as well as on
several native plants.

31

The sandalwood-scale is found on the native maire (Fusanus
cunninghamit), but appears to be extending its attacks to cultivated
trees, aud, amongst others, to citraceous trees. It is much smaller
than either of the preceding, and is chiefly confined to the twigs and
branches, on which it forms a scurfy crust.

The injury effected by these pests cannot be compared with that
caused by the white scale. Unfortunately they are increasing rapidly,
and, unless kept in check, may cause as great .a loss amongst oranges
and lemons as their near ally, the mussel-scale, causes amongst apples.

The castor-oil and soot mixture, recommended for the apple-scale,
will be found equally effective in destroying the hard scale infesting
the orange.

Syringing with a solution of caustic potash and sulphur would
prove of great benefit, but less effectual than the above.

ORANGE-APHIS.

At present I am unable to identify the species which infests the
orange and lemon. -

In some seasons it attacks the young shoots in myriads. At a
short distance the leaves on the upper portion of the branches appear '
to be suffering from black blight, which, however, is rarely to be
seen on young leaves, its attacks being mostly confined to those fully
developed.

The colour of the insect is brownish-black. Winged males and
females may be found associated with wingless females in June and
July, as well as during the autumn months. It is most destructive
during the early spring and the late autumn, but may be found at all
periods of the year.

It is readily destroyed by syringing with soapsuds, tobacco-water,
or with soft-soap dissolved in hot water, or the leaves may be dusted
with lime or sulphur. Heavy rain will often clean trees badly infested
with aphides.

PHASMIDS (Bacillus hookeri). (Acanthoderus spiniger.)

The “ walking-stick ” insect occasionally attacks the young shoots
of citraceous plants, and when numerous effect a considerable amount
of injury in a short time.

‘Affected trees may be freely dusted with lime or sulphur, or
syringed with soapsuds, &c. 42

CICADA, Etc. (Cicada cingulata).

The cicada frequently injures the smaller branches by forming a
longitudinal groove on the surface, and depositing its eggs at the base.
Its habits have not been fully observed, but, in all probability, the
larve descend to the ground and attack the roots of certain plants,
not necessarily of the orange itself. This can only be ascertained by
further observation. ;

At present its injurious effects appear to be restricted to the
wounds caused by the female previous to the deposition of eggs, and
which often lead to the injured branch being broken by the wind.

32

Crickets are also said to cause injury to the roots by gnawing
the epidermis, but no instance of this kind came under my observation.
The larve may readily attack the roots of oranges amongst other
plants. In their perfect state crickets may be destroyed by mixing
a small quantity of phosphoruswith flour, and placing it in their haunts.
The larval state may be treated in the same way as the grass-grub
(see “ Olive’).

The New Zealand mantis is also stated to be injurious; but
nothing is certainly known about it at present, and the insect itself is
comparatively rare.

CATERPILLARS.

The larve of several small moths are frequently found feeding on
the young leaves, but at present none of them are known in the perfect
state so as to allow of their identification. Their ravages are seldom
of a serious character; but any great increase in their numbers would
be attended with a corresponding increase in the amount of injury
effected by them.

Syringing with strong tobacco-water, or with a solution of caustic
potash containing sulphur, may be applied where necessary.

GRASS-GRUB (Odontria zealandia).

The grass-grub attacks the roots of citraceous trees as well as
others, and when in large numbers causes a considerable amount of
injury in a brief period. The larve feed upon the root-fibrils and
epidermis of the more tender portions of the root, so that the tree is
unable to procure a proper amount of nourishment, its growth is
arrested, and it is unable to mature fruit. ‘The perfect insect has not
been observed to attack the foliage, as in the apple.

For a more complete account of this insect and for remedies, see
under “ Olive.”

THRIP.

These minute insects may sometimes be found on neglected trees
in vast numbers, especially when the trees are growing in dark damp
situations. Careful pruning and the removal of all superfluous growth
from the centre of the tree will do much towards preventing their
attacks. Frequent syringing with a powerful syringe or garden-engine
will usually be found sufficient to drive them away. Where they have
been established for any length of time, it may be advisable to add a
weak solution of caustic potash with sulphur.

WOOD-LICE.

These well-known pests are occasionally troublesome to the
orange-grower, but their ravages are rarely of a serious character.
They are usually found at the base of the trunk or in the forks of
branches. Saturating the soil at the base of the trunk with a thin
solution of lime and sulphur will be found beneficial, or Goodhue’s
powder may be dusted over their habitat.

33

LICHEN.

_, rhe trunks and branches of neglected trees are sometimes covered
with a strong growth of lichen (chiefly Ramalina fastigiata, &c.),
which is most troublesome when the trees are growing in a hard or
unbroken subsoil.

When this is the case every effort should be made to improve the
quality of the soil, and to facilitate vigorous growth. The bark
should be scraped and the lichen removed. Amongst other evil
effects, epiphytic growths on the bark afford shelter to noxious insects.

SNAIL (Helix aspersa.)

This introduced mollusc is a dangerous enemy to all kinds of
citraceous plants, and is frequently found infesting the trees in large
numbers. During the winter season snails collect in large masses in
the forks of branches, &c.; sometimes as many as from thirty to fifty
may be found together. The eggs are laid in masses from fifty to
eighty on or immediately beneath the surface of the soil, or under
bark or wood lying on the grouud.

Snails feed on the epidermis of the young branches and leaves,
causing the growth to be checked; they are especially fond of the
young fruit, and reduce its value for market by disfiguring it to a
great extent. The eggs and shells may be easily collected by hand,
and will form a welcome addition to the food-supply of poultry, &c.

Citraceous trees, especially the small-leaved oranges, if neglected,
are liable to decay of the branches, sometimes to a considerable
extent: the leaves fall, the branch turns brown and decays. This is
sometimes considered a special form of disease, and termed “ die-back.’’
It is, however, simply caused by neglect of pruning, especially when
the trees are planted too close together; it is rarely seen in trees
which receive proper attention. -

The minute mite which causes the disease known as “ orange-
rust ” has not been observed in the colony, so far as I am aware.

ON THE BEST STOCKS FOR ORANGES, LEMONS, ETC.

Orange-growers in New Zealand are not generally alive to the
importance of selecting suitable stocks, and of planting only budded
or grafted trees. In many cases stocks are completely discarded, the
plants being either raised from seed or propagated by layers. When
a stock is called into requisition, the lemon is usually selected on
account of its rapid growth and early fruiting. It is, however, the
least durable of all, on account of its liability to foot-rot and other
diseases ; so that it is no matter for surprise to find its general adoption
is everywhere leading to considerable loss and disappointment.

It is not unfrequently asserted that the climate of Auckland is
unsuitable for the production of oranges of good quality. I am con-
vinced that this statement derives its chief support from the inferior
quality of most of the fruit produced by trees raised from seed. It

c

34

is most unwise to rely upon seedling trees producing fruit equal to
that of the parent. “Rarely one may be found equal or even superior,
but the great majority will prove of but low quality All cultivated
fruits exhibit a strong tendency to revert to their original state, and
when of arboreal habit can only be kept of good quality and true to
their kind by working scions from proved varieties on suitable stocks.
The bitter orange (Citrus bigaradia) is unquestionably the best
stock for general use, but it has the disadvantage of being of slow
growth.
Under these circumstances it may prove advantageous to test
the value of the indigenous Australian species as stocks for the
ordinary cultivated kinds. Citrus-australis is a strong-growing species,
attaining the height of thirty feet; it is a native of Queensland. CO.
australasica is found in Queensland and New South Wales, extending
to the Clarence and Richmond Rivers. It will probably prove the
hardier of the two. In all probability, there would be but little diffi-
culty in procuring seeds or young plants of either.
The followmg species of Citrus are generally recognised by those
botanists who have paid attention to the genus :—
1. C. medica, Lin. The Citron.
2. C. limonum, Risso. The Lemon.
var., lumia. The Sweet Lemon.
5 var., acida. The Lime.
#5 var., limetta. The Sweet Lime.
3. C. aurantium, Lin. The Sweet Orange.
= var., nobilis. The Mandarin Orange.
4. C. bigaradia, Risso. The Seville Orange.
3 var., bergamia. The Bergamot Orange.
5. ©. decwmana, Willd. The Shaddock.
6. OC. australis, Planch. Native Orange of Australia.
7. O. australasica, F. Muell. Native Orange of Australia.
All the forms placed as varieties are considered distinct species by
some authors.

MULBERRY.

So far as I am aware, the mulberry is attacked only by a single
insect capable of inflicting injuries of a serious character, a species of
borer, which excavates galleriesin the young shoots and branches, causing
the affected tree to present a scrubby appearance, owing to the partial
arrest of growth. The injuries were observed in July ; at present, I
have been unable to secure specimens of the insect in any stage.

OLIVE.
SCALE (Lecanium oleae).

The olive is frequently attacked by the black-scale, which forms
Sere bodies on the twigs and leaves, sometimes in great pro-
usion.

35

_ The castor-oil and soot mixture recommended for apple-seale will
extirpate the pest with but little trouble. Syringing with dissolved
soft-soap containing a little lime and sulphur would be attended with
excellent results.

GRASS GRUB (Odontria zealandia).

The roots of the olive as well as other fruit-trees are liable to the
attacks of the grass-grub, which, although usually feeding upon the
roots of grasses, has of late years developed a voracious taste for all
kinds of roots, so that in localities where it is numerous very few
trees escape its attacks.

In the apple the roots are but rarely attacked ; the foliage, how-
ever, is largely eaten by the perfect insect. On the other hand, the
perfect insect rarely attacks the olive, but the larve often cause serious
injury to the roots, especially in the case of young plants.

In the extensive olive-plantations of Dr. Campbell, at One-Tree
Hill, I noticed numerous young trees attacked by the grub, and on
examination found the finer portions of the roots had been eaten away,
and the trees injured to such an extent that the growth had been
arrested ; the leaves were of a yellowish tint, and presented a miser-
able, starved appearance. In all respects they afforded a strong con-
trast with hundreds of trees in the same plantation, planted at the
same time, and exhibiting a most luxuriant growth.

The life-history of the grass-grub has been recently made out,
and may be briefly stated here. In its perfect state the insect is a
small dark-brown beetle, about half an inch in length; the head is
often dotted, and the wing-cases are marked by four smooth longitu-
dinal lines, with or without a row of minute dots on each side. The
legs are yellowish-brown, with three large teeth in the middle joint of
the foremost. It makes its first appearance in Canterbury about the
commencement of November, but most likely a few days earlier in the
North; and may be met with until the close of January, sometimes in
countless numbers, and in this state feeds on the leaves of apple,
peach, plum, mulberry, vine, and many other trees. It especially
affects untrimmed furze-hedges in the month of November, but late in
the season the furze is abandoned for other plants, probably owing to
the increasing firmness of the epidermis. It rarely makes its appear-
ance until the shades of evening are fairly advanced, and is of quick
but not lofty flight. During the day-time it becomes inactive, usually
hiding amongst the loose soil at the base of trees or large herbs, but
not restricting itself to situations of this kind. As a general rule, it
commences to deposit its eggs about the third week in November,
most frequently at the base of the stems of grasses or other plants,
but sometimes amongst the loose svil on the surface of a sloping bank,
or beneath loose litter or oF farm-yard manure, &c.

I have not observed the larval or grub state earlier than the
second week in December, at which date specimens may occasionally
be found less than one-eighth of an inch in length. When it has
attained its full size it is from five-eighths to three-quarters of an inch
in length, with a hard, yellowish-brown head, one pair of short

36

antenne, and three pairs of legs; its segments are thirteen in number,
and partially clothed with scattered rigid hairs. In this state it is a
voracious feeder, and lives on the delicate fibrils of the roots of
grasses and other plants. As its voracity continues unimpaired for
ten or eleven months at least, it is obvious that its ravages must be of
a serious character.

The time during which the insect remains in the pupa-stage,
although liable to considerable variation, is very short, often not
exceeding a fortnight. Further observation, however, is required with
regard to this point, as the duration of the pupa-stage is likely to be
affected by the food-supply.

In many instances the insect remains in the larval condition for
two years, and there is good reason to believe that it may occasionally
remain three years in this state. Whenever its larval existence is
thus protracted the grub is found at a greater depth than usual, and
is of slightly larger dimensions.

Although the grub is never hatched before the middle of
December, the effects of its ravages may be observed about the third
week in January. The injured grass presents a flaccid appearance, at
first confined to single roots or small patches, which increase in number
and extent daily. The herbage turns black, shrivels, and dies away, 80
that by the close of February the once-flourishing pasture is disfigured
by a series of unsightly barren patches, often connected to a greater
or less extent.

Lawns suffer severely from its ravages, the grass being killed for
spaces extending over many square yards, and the surface more or less
broken up. :

In the Te Anau District I found a compact sward of mixed native
and European grasses, the roots of which had been completely
destroyed, but owing to the dense growth the culms had become so
matted that large sheets were blown about by the wind, leaving the
ground quite bare. The destruction was more complete than if it had
been effected by rabbits.

When the roots of trees are affected by the grub the leaves turn
brown or yellow, the tips of the branches droop, and ultimately fall
away. Young plants die from exhaustion ; older plants are better able
to endure the attack, and after a longer or shorter period'of prostra-
tion often recover; but the season’s growth is lost, and in the case of
fruit trees the crop is prevented from reaching maturity.

Cryptomeria elegans seems especially liable to attack when young ;
the strongest growing pines are not exempt, as Pinus insignis, Araucaria
imbricata, Cupressus towrnefoltii, C. macrocarpa ; the sycamore, oak,
ash, and other deciduous trees are subject to the attacks of this
voracious. pest, and it is now showing an undue partiality for the roots
of the strawberry.

In the larval state the insects may be destroyed by watering the
ground with a solution of caustic potash, the efficiency of which would
doubtless be increased by the addition of sulphur. “This would per-
haps be rather costly for general application to grass lands, but the

37

cost would be trivial for the preservation of valuable fruit-trees, and
would not prevent its application on the first indications of the
ravages of the insect on lawns.

Nitrate of soda has been applied as a top-dressing on grass-lands,
at the rate of from 13 ewt. to 2 ewt. to the acre, but Ido not know
with what results.

The grub may be destroyed by mixing soot or sulphur with the
soil, or by soaking it with soapsuds, or by pressure on the surface.
Ploughing and harrowing are effectual on a large scale, as the grub is
singularly impatient of any disturbance of the surface soil.

Mr. R. C. Barstow, of Epsom, informs me that after feeding on
the leaves of the castor-oil plant the beetles are seized with a peculiar
stupor, and on hot days die in large numbers, but during cloudy
weather they are, unfortunately, apt to recover.

In many places the beetles may be collected by the bushel, on
shaking the branches of a tree and laying a sheet underneath.

THE RINGER.

At Takapuna I found two olive-trees with the leaders and upper
branches either dead or dying. On examining the stems I discovered
that a ring of bark, a quarter of an inch in width, had been eaten
away by an insect, at the height of about 5 feet from the ground, and
several branches rather lower on the stem had been treated in the same
way ; the process being practically identical with that which would be
adopted by a-woodman who might wish to kill a tree without falling.

The largest stem was 5 inches in diameter; the branches varied
from three-quarters of an inch upwards; all the branches were desti-
tute of leaves, and the bark was shrivelled and partly discoloured ; the
upper portions of the leaders were in the same hopeless condition, but
from their larger dimensions they were able to protract the period re-
quired for their exhaustion, and still carried a few discoloured leaves
on the twigs nearest the seat of injury.

A perforation on the upper side of each ring marked the entrance
to the gallery, which was found to be driven transversely until it
reached the pith, when it descended for about an inch. No trace of
an insect was found except in one burrow, where the shell of a grub
was observed, apparently hardened by some secretion of the wood,
which had rendered it so extremely brittle that it fell to pieces on
being touched with a knife.

T regret my inability to add to the unsatisfactory statement given
above, as it is evident that the olive-grower will have to deal with a
dangerous enemy should the unknown insect become widely diffused.
It appears to have been recently introduced into the colony, as its opera-
tions are so singular in their character, and at the same time so fatal in
their results, thatit is scarcely possible for them to have escaped notice.

Tn two instances the insect appears to have been unable to carry
the furrow round the trunk on an even place, the termination being
from three to six-eighths of an inch above the commencement, so that
the groove assumed a spiral direction,

38

It is probable that the female insect punctures the bark and de-
posits a single egg in the sapwood, after which she proceeds to “ ring
the stem in the manner already described. The limited dimensions of
the burrow, which in no case exceeded an inch in length, militates
against the idea that the ringing is performed in order to provide a
supply of dead wood for the food of the unborn larve, unless the
grubs forsake the burrows and pass a portion of their existence on
dead twigs before entering upon the pupa-stage; but there is no
evidence to support this conjecture. .

In all probability the insect to which I have given the name of
the “‘ringer’’ will prove to be a beetle belonging to the Cerambycide,
but its position can only be determined by examination in an advanced
stage.

OLIVE-STOCKS.

Four species of olive are indigenous to New Zealand; they are
commonly called maire, and afford valuable timber. One of thése,
Olea apetala, is also found in Norfolk Island, where it is known as
ironwood.

The other species, O. Cunninghamit, O. lanceolata, and O. montana,
might be profitably utilised as stocks for the cultivated kinds. It is
desirable that experiments should be made in this direction.

In all probability O. lanceolata will prove to be the most valuable
for this purpose.

PEACH.

PEACH-BLIGHT.

The peach is liable to the attacks of numerous fungoid and insect-
enemies capable of effecting a serious diminution in the yield, and of
exhausting the energies of the tree; but the total amount of injury
caused by these unwelcome parasites during a long series of years
would be but trifling when compared with the wholesale destruction
that has overtaken the peach throughout the colony, and to which the
term “ peach-blight’’ is generally applied. Thousands of acres of
peach orchards and plantations in the North Island have been
destroyed—the grand peach-groves of the Maoris in the Hokianga,
Kaipara, Waikato, Napier, and Wanganui Districts are things of the
past, and the peach itself, once the most common fruit in the colony,
has now become the rarest. It is no exaggeration to say that, by the
destruction of the peach, the value of the yearly food-supply of the
colony has been diminished to the extent of several thousands of
‘pounds.

The first symptoms of peach-blight are usually exhibited after
cold winds during the flowering season and before the full develop-
ment of the leaves. The ovaries swell until the young fruits attain
the size of a large pea, when a sudden arrest of growth takes place
and they drop from the trees, in many cases not even a solitary fruit
being -left. The leaves also fall away without attaining their full
development. Ator before this time orange-coloured dots or punctures,

39

doubtless of a fungoid nature, are formed upon the young twigs, and
In some instances become confluent, ultimately leading to the disinte-
gration of the bark, followed by an exudation of gum at the affected
parts. The buds decay and become infested with thrip or other insects
to a greater or less extent, the bark becomes shrivelled, and the
affected shoot dies. As a general rule, the lowest branches are affected
before the upper. Sometimes the tree is killed by the first attack, but
usually, on the approach of autumn, new leaves are produced towards
the tips of the young shoots. Although in many cases the new leaves
are attacked by a fungus, the plant seems in a fair way for recovery,
but in the following spring the same sequence of incidents occurs, and
sooner or later the tree dies.

All the symptoms enumerated afford evidence that the constitu-
tion of the plant has become weakened ; the vital processes are not
properly performed, so that the plant is not only unable to endure
sudden changes of temperature, but is more liable to the attacks of
fungi and insects, while it has less power to resist them.

Amongst the facts which might be adduced in support of this
view the following may be selected: (1) The simultaneous appear-
rance of the decay in various parts of the colony, its rapid extension,
and uniform results. (2) The similarity of results exhibited in other
countries where the peach has received similar treatment. (8) Trees
are destroyed at all periods of growth, from seedlings a few inches in
height to trees in full bearing. (4) No external conditions can
insure safety. Trees in sheltered positions suffer in the same manner
as those fully exposed, although in some instances a sheltered position
appears to retard the progress of exhaustion. On the other hand,
trees grown in sheltered positions are speedily exhausted when the
shelter is removed. (5) If the demand upon the vital energies of an
affected tree is reduced by removing a portion of the branches, the
remaining branches usually exhibit an improved appearance, although
of a temporary character. (6) If a tree be headed down when first
seen to be affected, luxuriant and apparently healthy branches are
speedily given off from the stump, but this also is only temporary ; the
te signs of weakness are usually exhibited the following spring, if not
before.

This weakening of the vital energies of the plant has been mainly
effected by growing peaches on their own roots, and is to be seen in
all countries where such a course has been followed. This is notably
the case with the old Maori peach-groves, where one generation of
trees after another has grown up from seed; and the same may be
said of the cultivated trees in the orchards and gardens of the settlers.
All the peach-trees in the colony have been either raised from seed or
have been worked on peach-stocks. ,

The first step in the work of renewal will be the selection of a
suitable stock, and this we find in the mussel-plum, the stock in-
variably adopted by English nurserymen, who have to carry on the
cultivation of the peach under far more unfavourable climatic con-
ditions than prevail with us.

40

It is advisable that the new stocks should be worked with buds
taken from sound healthy -trees. Trees of one year’s growth from
the bud could be purchased in England at £5 per hundred, so
that afew hundreds might easily be imported with a quantity of
stocks. The dying trees might be cleared away at once, and a new
start made on a satisfactory basis.

Trees worked on the mussel would be more hardy, better able
to résist adverse influences, while their productive power would be
increased rather than diminished. They would not be exempt from
the occasional attacks of curl and other fungi, nor from the numerous
insect-pests that infect the peach, and they would still be subject to
sudden changes of temperature during the flowering season ; but I do
not hesitate to express my belief, whatever may yet be discovered with
regard to the decay of the peach, that the adoption of the mussel-
stock would once more allow of its profitable cultivation. Whatever-
new facts may be brought to light by a careful examination of the
phenomena to be observed in the spring, the adoption of a new stock
lies at the base of all remedial measures.

In an Auckland nursery I observed two healthy trees—the only
trees absolutely healthy there; all the young stock, even the seedlings
still in the seed-beds, being badly affected. The two healthy speci-
mens were worked on mussel-stocks.

Three varieties of peach are stated by some to be “ blight-proof”’ :
the Comet, Solway, and Early Rivers. This statement, however, must
be received with some qualification, as I have seen the first and second
ina dying state, and feel very doubtful about the third. Had the
assertion been confirmed it might have been worth while to have
double-budded the mussel, using one of these varieties for the first
working.

Affected trees have been headed down and successfully worked
with certain varieties of plums when the decay has not been too far
advanced; time is required to prove the permanence of the scion.
Should present expectations be realised we shall have one of the most
striking instances of the influence of the scion upon the stock that has
yet been brought forward. I am assured, however, that some varieties
of plums do not succeed under such conditions.

._ One instance in which the process of exhaustion appeared to be
retarded by remedial measures came under my notice at the Bay of
Islands. Mr. Goodhue, nurseryman, of Taumarere, washes or syringes
all his fruit-trees during the winter season with a mixture of lime,
sulphur, and carbolic acid in the following proportions: 2 gallons
unslaked lime, 1]b. sulphur, 3 lb. Calvert’s carbolic acid powder.
Sufficient water is put upon the lime to slake it; the sulphur and
carbolic acid are added and thorough] incorporated. 1t can either
be used dry as a fine powder to dust affectad trees, or by the addition
of water can be made into a wash of any required consistency, Mr.
Goodhue’s fruit-trees were remarkably free from insect pests; in
every case the bark was bright and clean, and the trees generally were
ma vigorous state of growth. All his peaches, however, showed

41

unmistakable evidence of gradual decay, although he informed me
they had greatly improved since he commenced his treatment; the
bark looked fresh and was less shrivelled than usual, but the presence
of dead shoots, with occasional gummy exudation, told its own tale.
Unquestionably the application of the wash had proved beneficial in
destroying allinsects, and thus lessening the strain upon the vital
energies of the plant.

CURL OR BLISTER (Taphria deformans).

This well-known pest is a troublesome enemy to the peach-grower,
and is one of the first parasites to make its appearance on trees
affected by peach-blight. Although commonly considered to be
caused by insects, it is in reality a fungus of very simple structure,
but remarkable for its effect upon the leaves, which are curiously
contorted and curled, often presenting the appearance of being
covered with whitish blisters. The fungus consists of a thin layer of
cells developed on the surface of the leaf and containing sporidia,
which cause the leaves to look as if they were dusted with flour.

The best remedy is to dust the leaves with sulphur. Mr.
Goodhue’s mixture would, doubtless, prove beneficial.

Other species of fungi are found on the leaves of the peach, but
at present little is known about them.

PEACH-APHIS (Aphis amygdali.)

Two or more species of aphis are found on the peach, but the form
most frequently observed appears to be identical with the common
peach-aphis of Europe. The aphis frequently occurs on the peach in
great abundance, and accelerates the process of exhaustion caused by
peach-blight, of which it is not unfrequently said to be the cause.

For treatment, see under “‘ Orange-aphis,” page 31, ante.

- THRIP.
See under “‘ Lemon,” page 32, ante.
CATERPILLAR.
The caterpillars of several small moths feed upon the leaves of the

peach, but at present sufficient information has not been obtained to
allow of their identification.

For treatment, see under “ Lemon,” page 382, ante.

SCALE.

The apple-scale is occasionally seen on the peach, but only in
districts where it is generally distributed. In Auckland the native
gandalwood-scale is attacking the peach amongst other fruit-trees.

The castor-oil mixture, as recommended for apple-scale, will prove
equally efficacious with the scale-insects found on the peach.

BORER.

The peach is occasionally attacked by a boring insect, but at
present the insect itself has not been observed during any stage of its
existence.

42

PEAR.
SLUG-LEECH. PEAR-SLUG. (Selandria cerasi).

In its larval state this sawfly is terribly destructive to the pear,
plum, cherry, and hawthorn ; it may occasionally be found on the peach,
apricot, and walnut, but rarely in sufficient quantity to cause much
injury, although itis certainly becoming more frequent on the walnut,
and occurring in larger numbers.

The slug makes its earliest appearance on the leaves soon after
midsummer, but in some localities it may be as late as March ;
usually it occurs in vast numbers, several slugs being found ona
single leaf. hee :

The leaves are speedily devoured, and the fruit falls without
ripening. In favourable seasons trees in a robust condition some-
times produce a second crop of leaves, but these never attain their
full size although they remain on the tree long past the usual time.
The attack is repeated in following seasons, and after presenting a
miserable appearance for some time the plant dies.

The eggs of the sawfly are deposited on the upper surface of the
leaf, and the slugs make their appearance in a few days, but require a
month to, attain their full size; they are blackish-green in colour,
rather more than half-an-inch in length, and consist of thirteen
segments, the thoracic segment being the largest, and the abdominal
segments gradually decreasing in size so that the larve present a
clavate appearance. Jt is covered with a viscid slime, and emits a
most unpleasant odour. Two rudimentary feet are carried on each of
the three thoracic segments, and two sucker-feet on each of the
abdominal segments except the first and the tail, so that the slug is
twenty-footed. In about a month’s time the slug assumes the
appearance of a buff caterpillar, and soon afterwards descends to the
ground, where it enters the soil.and forms a small cocoon, in which it
passes the dormant stage of its existence.

Two broods are produced during the summer in the northern
parts of the colony, and probably in some parts of the South also.

An opinion prevails that the attacks of this insect are decreasing
in severity, and that it makes its appearance later in the season than
formerly. I believe a change is taking place in the date ofits first

appearance, but I have seen no evidence to warrant the conclusion that
its numbers are diminishing.

REMEDIES.

It is not diffici.1t to destroy the slug, although a little perseverance
is often required to effectually clear the tree.

The most popular remedy at this time is an infusion of white
hellebore, made by pouring a gallon of boiling water over one ounce of
the powdered herb, and allowing it to stand until cold, when another
gallon of water should be added. The infusion may be used at once.
It should be applied with a syringe or garden-engine. A weak
solution of caustic potash would be even more efficacious.

43

Dusting the trees with quick-lime, or even with common road-dust
or wood ashes, on a wet morning, has been found sufficient to clear
badly-infested trees. Even dry sand has been used with advantage,
notwithstanding its weight. Mr. Goodhue’s dry powder would be
excellent.

_ In many cases it will be found necessary to repeat the application
at intervals of ten days, in order to destroy any larve as fast as they
are hatched.

PEAR-SCALE.
(1) Mytilaspis pomorum.
(2) Aspidiotus camellia.
(83) Diaspis santali.

The first of the scale-insects enumerated above is frequentl
found on the pear, often in great abundance; the second, althengh
like the first, of European origin, is only met with occasionally. The
last is of native origin, and is unhappily becoming frequent on many
of our fruit-trees.

I have seen newspaper paragraphs stating that the oyster-scale
is troublesome on pear-trees in the colony, but I have seen no
specimens. In all probability the camellia-scale, which is of occasional
occurrence on pear-trees, has been mistaken for it.

For treatment, see under “ Apple-scale,” page 16, ante.

FIRE-BLIGHT (Restelia cancellata?). *

At Whangerei, the Bay of Islands, and other places, pears are
attacked by what is termed “ fire-blight,” which destroys the tree in a
longer or shorter period. Some varieties are more subject to attack
than others, notably the Summer Bon-chrétien, which in the North
appears to be dying out from this cause.

Unfortunately i was unable to gather much information respect-
ing fire-blight, as my examination of affected trees did not begin
until the last week in May, when the leaves had all fallen. Its first
indication is said to be the appearance of black blotches on the leaves ;
these increase in dimensions until the greater portion of the leaf-
surface is discoloured (my informants differed as to the presence or
absence of blisters): at length the leaves fall, the fruit shrivels, and
cankerous patches are formed upon the bark. The disease spreads
with great rapidity, and is most severe when the trees are growing in
a cold damp subsoil. Further observation is necessary before the pest
can be identified with certainty or remedial measures suggested.
But little doubt, however, can be entertained as to the injury being
eaused by a fungus, which will, in all probability, prove to be a well-
known European species (Restelia cancellata). ot ;

Affected trees may be headed down and grafted with some variety
capable of resisting the attacks of the fungus. In two cases I was
assured that this course had been followed with success, the Summer
Bon-chrétien having been replaced by Williams’s Bon-chrétien with
the most satisfactory results.

44,

PLUM.

SLUG-LEECH.
See under “ Pear,” page 42, ante.

SCALE.

As with other fruit-trees, two or three species of scale-insects
are found upon the plum.
For treatment, see under “ Apple-scale,” page 16, ante.

BORER.

Tn the northern districts the plum is attacked by a boring insect,
which often causes the decay of the upper portions of the branches.
At present the insect has not been obtained in any stage.

APHIS (Aphis prum). ;
This species is sometimes abundant on the under-surfaces of the
leaves, which are often curled, and afford copious skelter to the insect.
Its ravages are often of a serious character.
For treatment, see under “ Apple-aphis,” page 18, ante.

STRAWBERRY.
GRASS-GRUB (Odontria zealandia).

This voracious pest is yearly becoming a more serious enemy to the
strawberry-grower. It feeds on the roots, and speedily impairs the
vigour of the plant, so that growth is checked, the plant becomes
stunted in appearance, and is unable to mature fruit.

For description and treatment, see under “ Olive,’ page 35, ante.

VINE.
VINE-MILDEW (£rysiphe, sp.).

This troublesome fungus is more generally known under the name
of Oidium Tuckeri, but fungologists are now agreed that it is simply an
obscure state of some species of Erysiphe, producing secondary spores.
It forms patches of delicate white mould on the leaves and stem, the
mycelial threads being of extreme tenuity, and giving off erect
filaments, which develope minute spores (conidiospores) by a process
of transverse division.

The most approved remedy is sublimed sulphur, dusted freely
over the affected parts. In all probability washing the affected leaves

with a solution of pernuieninke of potash—say, 2 oz. to a gallon
of water—would be found even more effective.

VINE-LOUSE (Phylloxera vastatriz).

The occurrence of this much dreaded pest in the colony was
recorded by Mr. J. A. Pond in the Auckland. newspapers of May last.
On my arrival in that city I visited Mr. Pond’s laboratory, and was

45

courteously permitted to examine specimens of the insect mounted for
the microscope, and found that it differed from the typical Phyllowera
vastatri¢ in some particulars, notably in the length of the rostrum in
the larval forms.

The doubts which then arose in my mind with regard to the
correctness of the identification have been strengthened by a close
examination, of the specimens sent by Mr. Pond to the Colonial
Museum. Therefore, while fully assenting to the correctness of the
generic identification, I must for the present hold the identity of
the Auckland insect with the vine-louse of Europe and America “not
proven.” ;

It may be worth while to state the history of the affected vines,
so far as I have been able to ascertain it. About four years ago
Mr. Isaacs, of Remuera, erected a vinery, and instructed his gardener,
Mr. H. Allen, to preparea border, and to order certain vines from Britain.
The border was prepared by Mr. Allen, who is an intelligent
gardener, and bears a hah reputation as a vipe-grower. The plants
were supplied by a well-known firm of nurserymen in Scotland, who
obtained one or two special varieties from an eminent vine-grower in
England. They were planted in a Wardian case, and shipped by way
of Melbourne, where they were detained for a short time, pending
transhipment, but I could not learn that the case was opened until its
arrived in Auckland. In the meantime Mr. Allen had left the service
of Mr. Isaacs, and the vines were planted by his successor, but appear
to have been sickly almost from the first, the growth being weak and
miserable, and the plants, as I was informed, infested with mealy bug and
other pests. This continued until May last, when specimens of the roots
were submitted to Mr. Pond, who discovered phyllorera upon them.
Acting upon Mr. Pond’s advice, Mr. Isaacs had the vines destroyed,
the vinery washed and fumigated, and the soil in which the vines were

own burned, in order to extirpate the pest. It is, however, matter
for regret that specimens of the roots and leaves of the affected
parts were not preserved in spirit or glycerine for satisfactory
reference.

On visiting the vinery it was evident that the work of destruction
had been efficiently performed. I was unable to procure a scrap of leaf
or root to ascertain the extent of the affection. The gardener in
charge informed me that he did not enter the service of Mr. Isaacs
until some time after the vines had been planted, and that he found
them in a dirty condition, laden with insects. The remedies
which he applied were uniformly without effect. On examining the
roots, many of the fibres were covered with small galls, and the greater
portion of the roots appeared to be powdered with a fine white dust
something like flour. He did not observe any galls on the leaves.
In some places the roots extended beyond the border into the clay sub-
soil, and were perfectly clean. On the other hand, fibres given off
inside the house were badly infested. Weeds or other plants growing
on or about the border were not affected in any way, their roots being

perfectly clean.

46

Perhaps the most satisfactory feature of the case is that, although
the insect must have been introduced nearly four years ago, it does
not appear to have spread. Although I examined the roots of numerous
vines in Remuera and other places, no instance of its occurrence came
under my notice, nor could I hear of any one who had seen it. Mr.
Allen informed me that he had some rooted cuttings taken from the
waste prunings of the affected vines last year, and invited me to
examine them in his garden, which I did, but was unable to observe
any trace. of the insect. Sowe of these cuttings forwarded to
Wellington, and kept in soil in a ‘warm room, have remained perfectly
clean up to this date.

Now, it is extremely difficult to imagine that typical Phylloxera
vastatriz could have remained for between three and four years with-
out having spread to vines in adjacent gardens and vineries. Such an
occurrence could only be explained by the non-development of winged
forms during that period—a phenomenon at variance with all that is
known of its life-history.

Life-history of Phylloxera vastatriz.—This remarkable aphidian
insect exhibits two series of forms—one infesting the roots of vines,
the other the leaves and stem. They have been distinguished by
Professor Riley as Radicicola and Gallicola respectively. Both series
exhibit a wide diversity of form, and the larve vary in appearance
with each successive moult. More than twenty different forms were
drawn and described by M. Lichtenstein in 1876. In Europe the
subterranean form effects the greater amount of injury; in America
the aerial forms are most dreaded. The winged aerial female is
developed from atrue egg deposited the previous autumn, and is about
0070 of an inch in length, flask-shaped, and contains numerous
pseudova; the suctorial beak is about one-fourth the length of the
body. She becomes the mother of the colony, and punctures the leaf
in such a way as to cause an increased flow of sap to the wounded
parts, resulting in an unhealthy growth, which forms a gall completely
surrounding the insect; in this gall she deposits many hundreds of
ege-like bodies during the summer months. After the larve have
developed they descend to the roots in such vast numbers as to give
the fibres the appearance of having been dusted with flour. The bark
of the root decays and falls away, while small knots or galls are formed
on the fibres. The affected vines at this stage present an unhealthy,
stunted appearance. The wingless subterranean female is only 0:026
of an inch in length, and her body contains but few eggs. She produces
five or six generations, so that larve of various sizes and different
forms are found on the same root. Shortly after midsummer many of
her progeny develop wings and ascend to the surface, when they
migrate to other districts, where they produce true males and females,
the latter being more numerous than theformer. In thiscondition they
are about 0°120 of an inch in length; each contains a single egg, about
0°015 of an inch long, which will give rise to the true male or female,
the egg from which the last is developed being larger than that which

47

ives rise to the male. Pseudova capable of producing true males and

emales may, however, be produced by wingless forms also. The true
male is smaller than the female; both alike are destitute of a mouth,
and exist for reproductive purposes alone. Both male and female are
wingless. On the fourth day after the female is hatched she deposits
a single egg in the crevice of the bark, where it remains during the
winter. The winged forms are unable to cross extensive plains or
seas, but the true ovum retains its vitality for a considerable period,
and may readily be transported. The subterranean larval forms may
el be carried from one country to another on the roots of infested
plants.

The phylloxera found at Remuera differs from the typical P.
vastatrix in the greater length of the suctorial beak of the larval forms,
in which it is much longer than the body, and presents a singular appear-
ance. In the great length of the rostrum it resembles a subterranean
form of the well-known American blight-aphis, Schizoneura lanigera, but,
so far as I am aware, no similar state has been recorded amongst the
numerous changes of form assumed by the typical grape-louse, although
it has received a greater amount of attention and given rise to a more
extensive literature than any other insect.

No satisfactory remedy for the attacks of the vine-iouse has yet
been discovered. Flooding the affected vineyards has proved beneficial,
but a remedy of this kind can only be applied in special situations.
An open phial containing two ounces of carbon disulphide, placed
amongst the roots of the infested vines has produced good results, but
must be handled carefully, as the vapour is poisonous.

Most of the remedies proposed, as sulpho-carbonate of potassium,
arseniate of copper, &c., are dangerous to human beings, and must be
used. with the greatest caution.

In the case of a vinery, or a few isolated vines out of doors, being
attacked by phylloxera, the insect could be destroyed by saturating the
soil with a solution of caustic potash and sulphur. The cost would be
much less than the value of the fruiting vines, to say nothing of the
expense attending their destruction, the formation of a new border,
replanting, and total loss of the crop for two or three years. But, so
long as the importation of vines is prohibited, there is but little danger
of the vine-louse reaching the shores of the colony. Even should an
importation take place, the insect may be prevented from spreading
by the prompt adoption of destructive measures. It was first observed
in the British Islands in 1863, and since that year both aerial and
subterranean forms have been seen in several localities in England and
Scotland, but no difficulty has been found in extirpating the insect.
The climate of New Zealand would doubtless prove more conducive
to its rapid increase.

It is still a matter of dispute whether the typical form of the
grape-louse has been observed in Australia, where it is said that
the insect infesting the vines also destroys maize, peas, and other
plants.

48

WALNUT.
SCALE.
One or two species of scale-insects are found upon the walnut,

but at present do not appear to have caused serious injury, although
they are evidently increasing.

For treatment, see under “ Apple,”’ page 16, ante.

ra

LEECH-SLUG.

This pest is increasing on the walnut year by year, and unless
checked will be found to prodtice serious results.
For treatment, see under “ Pear,” page 42, ante.

|. KIRK.

By Authority: Jamzs C. Brat, Government Printer, William street , Brisbane.