April 30, 1892. 
THE Gardening world. 
54? 
ENEMIES OF THE PLUM. 
The insect enemies of the Plum are fairly numerous, 
but few of them are confined to it in their depreda¬ 
tions. Some of them attack other fruit and forest 
trees, occasionally doing serious harm, while a few 
of them are injurious to plant life generally. Fortu¬ 
nately the worst class of them are not very widely 
distributed, and may be considered of local occur¬ 
rence, though with the extension of fruit culture 
they may become more troublesome. The fruit 
grower has all the more reason therefore to be on 
his guard, and exert himself in the reduction of their 
numbers, even if he cannot exterminate them. Under 
judicious management and when the conditions as to 
soil are fairly favourable, the Plum does not suffer 
much from the attacks of fungi ; and gumming can 
be avoided to some extent by a careful and proper 
use of the pruning knife. 
Fruit Destroyers. 
Red Grub of Plum ( Carpocapsa funebrana, T). —The 
parent moth lays its eggs on the young fruit early in 
June, and during July the grubs are hatched, and 
commence immediately to gnaw their way into the 
interior, feeding upon the fleshy parts particularly 
around the stone. Here they feed securely, and as 
the small hole they make on entering soon heals over 
or gets closed up, their presence is difficult to de¬ 
tect unless the fruit is cut open. The grub is of a 
dirty pale red with a black head, a few brownish 
markings on the next segment, and some fine hairs 
all over the body. Stainton says that the perfect 
moth is scarce, but that the grubs are frequent in 
Plum pies ! When full fed they leave the fruit either 
before or after the latter has fallen, and seek for a 
place of concealment in crevices of the bark, where 
they spin a cocoon and complete their transforma¬ 
tion, appearing in the perfect state next spring. The 
moth measures about 6 or 7 lines across the fore 
wings, which are pale grey, shaded with darker 
scales and having an eye-like spot near the hinder 
edge enclosing four dark lines. 
Remedies —Affected fruits ripen prematurely and 
drop. The trees, however, may be shaken to test 
the soundness of those that remain, and the whole of 
those that have dropped collected and burnt im¬ 
mediately, or deeply buried in the ground so as to 
effect the destruction of the grubs in them and pre¬ 
vent future attack. This should be done early and 
repeatedly during the month of August to ensure 
the destruction of as many grubs as possible. All 
loose bark should be removed and the crevices well 
scraped to destroy the cocoons if any, while the 
scrapings should be burnt. 
Plum Sawfly (Hoplocampa fulvicornis. King .).— 
This has also been known for some time in this 
country under the name of Tenthredo morio, Fab. 
The perfect female fly commences her mischievous 
work by laying an egg in the calyx of an expanding 
flower bud, and the grub hatching out in seven to 
ten days, eats its way into the young fruit where it 
subsists upon the kernel until it has eaten all it cares 
for, after which if not yet full fed, it proceeds to 
attack another. It is white or reddish-yellow with 
a brown head, and like the sawfly (Nematus Ribesii) 
of the Gooseberry and Currant it has six legs and 
fourteen prolegs. It is full fed in the course of four 
to six weeks, and by this time the injured Plum falls, 
when the creature leaves its feeding ground and 
burrows into the soil, where it spins a cocoon and 
remains in the caterpillar state till spring, when 
it completes its transformation and comes forth to 
attack the opening buds again. The perfect insect 
has four transparent wings, a black body and dusky 
yellow legs. 
Remedies. —The Plums attacked from having the 
kernel destroyed, do not attain full size, but drop 
prematurely with the contained grub or caterpillar. 
The trees may be shaken, and all the fruits that fall 
collected and burnt. As the affected ones may be 
detected by a wound on the top and that is either 
open or choked up with gummy material, or which 
has the remains of the flower still gummed to it, 
such fruits maybe gathered and burnt with the rest. 
By perseverance in destroying the fruits containing 
grubs, the pest can be kept under and future 
depredations prevented. 
Copper-coloured Weevil (Rhynchites cupreus, 
L .).—The perfect weevil feeds upon the young shoots 
and buds of various kinds of fruit trees during the 
month of June and even later ; but Plum trees and 
Cherries constitute its favourite food. The females 
pierce the young fruits and deposit an egg in each. 
They then cut partly or wholly through the fruit 
stalk, and the Plum sooner or latter falls with the 
contained egg or grub. The latter feeds upon the 
fruit till full grown, when it buries itself in the soil 
and passing into the pupa state remains there till the 
following June. The perfect weevil is 2 to 2J lines 
long, and is of a dark bronzy or brassy hue above 
and brassy black beneath. The wing cases are 
striated and of a bronzy or brassy hue. The head 
is produced into a long decurved, slender snout, and 
the antennae are clubbed but straight. The feet are 
black. This species is pretty widely distributed over 
England, but is only moderately common in some 
localities. It is, however, plentiful and very destruc¬ 
tive upon the Continent. 
Remedies. —While the perfect insects are busy upon 
the trees in June a cloth may be spread on the ground 
and the trees sharply shaken to make the weevils 
fall. In the case of wall trees a light birch broom 
may be lightly switched along the branches without 
injuring the foliage, and the weevils, if any are 
present, will drop, when they may be collected and 
destroyed. All fallen fruits should be promptly 
collected and destroyed from time to time, before the 
grubs have time to become full fed and escape. 
Where they prove troublesome they may be kept in 
check by the above methods where there are no 
hedges to harbour them. 
Leaf Destroyers 
Plum Aphis (Aphis Pruni, Reaumur). —The Plum is 
very liable to have its young unfolding leaves greatly- 
injured by this Aphis during the months of May and 
June. The insect under favourable conditions mul¬ 
tiplies with amazing rapidity, and owing to the irri¬ 
tation set up by so many beaks sucking the juices, the 
leaves become revolute at the sides, or wrinkled 
and blistered forming ample shelter for the Aphides. 
The leaves also assume a greenish-yellow or 
sometimes red hue, and the pores on their 
under surface get choked up by the sticky 
excrement and mealy exudations from the 
filthy pest. The wingless, young - producing 
females are pale or dark olive-green, with three 
darker stripes on the back, brown eyes, and antennae. 
The winged, young-producing female is olive-green, 
with head, shoulders, and a large blotch on the abdo¬ 
men black. The antennae shanks and feet are also 
black. The large, pale wings have brown veins. If 
the Aphides are allowed to get thoroughly established 
on a tree, the young shoots as well as the leaves are 
irreparably injured and the tree crippled. 
Remedies. —Various washes consisting of solutions 
of soft soap, tobacco water, sulphur, decoctions of 
quassia-chips, and ammoniacal liquor, either separ¬ 
ately or in mixture, are used by different cultivators 
for destroying green-fly. It is well to use soft-soap 
as a basis, especially in this case where the Aphides 
are protected by a mealy covering, as the soap 
causes any poisons that may be applied to adhere to 
the insects, while it serves to cleanse the foliage. 
In the case of wall trees where the pest is noticed 
before the colonies get numerous, a dusting of to¬ 
bacco powder while the foliage is wet, will often be 
sufficient to stay their ravages. 
A solution of one p >und of soft soap in eight gal¬ 
lons of water would be rendered much more efficient 
by boiling one pound of flour of sulphur in it. An¬ 
other receipt would consist of five pounds of soft 
soap to twenty-five or thirty gallons of water to 
which is added the juice made from one ounce of 
strong shag tobacco. A decoction of quassia may be 
used by boiling a quarter pound of quassia-chips in a 
gallon of water, and adding a quarter pound of soft 
soap after the decoction is cold. The quassia-chips 
may be put in a bag while being boiled to save the 
trouble of having to strain the liquid. Gas-water or 
ammoniacal liquor may be used at the rate of one 
gallon to five or ten of water according to its strength, 
but as it varies greatly in this respect the trees 
should be washed with clean water two or three 
hours afterwards, especially where the foliage is 
young and tender. If the trees are tall, or when 
several of them are to be treated, a garden engine 
would be the best instrument to apply the insecti¬ 
cides as well as for washing the trees afterwards. 
Clean water applied with force would wash down 
many of the Aphides and be conducive to the health 
of the trees. 
Clear-wing Plum Aphis (Hyaloptcris Pruni , Fabr.). 
— The trees are rendered even more filthy and 
disgusting by this Aphis than by that previously 
named, during June, July and August. The insects 
crowd under the leaves in myriads, completely cover¬ 
ing the surface, and presenting a bluish white 
appearance owing to the mealy exudations with 
which they are invested. The leaves also become 
more or less curled and greatly injured. The wing¬ 
less , young-producing female is narrowly oblong, 
pale glaucous green with a broad median deep green 
line, and hoary with mealy or powdery matter The 
eyes are brownish-red, and the feet black, all the 
rest being pale green or colourless. The upcurved 
tail is dagger shaped. The winged form correspond¬ 
ing to the above is also pale green, with a deep green 
median interrupted line and some spots of the same 
hue near the sides. The head is circumscribed by 
a brown line, and there is another on the neck, 
while the shoulders and antennae are deep brown or 
black. The wings are long and hyaline or almost 
colourless, a fact to which the generic name refers. 
Remedies. — The washes mentioned above, and in 
which soft soap is the predominant ingredient, 
should be used against this filthy insect. 
Hop Aphis [Pliorodon Humuli, Schrank, var.Malaheb 
Fonsc.). —This variety of the Hop Aphis sometimes 
infests Plum trees during May and June. The 
wingless young-producing female is ellipsoid, much 
narrowed to the head, and bright green or yellowish 
green, with the base of the antennae green and the 
rest as well as the feet deep brown or black. The 
variety differs from the type in being larger and in 
the tubercles on the front of the head being much 
shorter. The winged form corresponding to the 
above is of a brighter green than the type with the 
head, antennae, shanks and feet black. The legs are 
short in both forms. 
Remedy. —The second of the above recipes 
mentioned under Aphis Pruni would serve to destroy 
or keep the enemy in check. 
The Winter Moth (Cheimatobia brumata) and 
the Black Vine Weevil (Otiorhynchus tenebricosus) 
feed upon the young leaves and buds; the Woeberian 
Tortrix (Semasia Woeberiana), and the Plum Bark 
Weevil (Magdalinus Pruni) sometimes injure the 
bark and cambium layer by making galleries under¬ 
neath them, but generally in old and already more 
or less unhealthy trees ; and the larvae or grubs of 
the May Bug or Cock Chafer (Melolontha vulgaris) 
occasionally eat the roots. — J. F. 
-—i-- 
DOUBLE CHINESE 
PRIMULAS. 
With reference to the culture of the old double¬ 
white Chinese Primulas, referred to by "Visitor ’’ at 
p. 433 of your issue for March 12th, I may say now 
that most of them are going out of bloom, no time 
should be lost in preparing the plants for propaga¬ 
tion. I prefer keeping them indoors if possible, in¬ 
stead of adopting the usual practice of transferring 
them to a frame, as just now is the time that they want 
attention the neglect of which so often leads to disap¬ 
pointment. To obtain good strong plants you must 
have good cuttings, and by keeping them in a house, 
and looking after their wants, there will be no 
scarcity of them. 
Double Primulas must either be propagated by 
cuttings or by division, and the latter method is the 
easiest. Remove the old leaf stalks at the base of 
the growths and earth up the stems as far as the 
lower leaf stalks with a mixture of leaf-soil and sharp 
sand, pressing it firmly about the stems. Never let 
the plants get dry, and they will soon throw out new 
roots. When well rooted they must be divided, each 
crown separately, and be potted off into good loam, 
leaf-soil, and sharp sand, and be kept close in a frame 
until well established, when more air must be given. 
As soon as the roots reach the side of the pot, 
give them another shift into larger pots, using a-com- 
post of two parts of leaf-soil, and one each of turfy- 
loam and old cow-manure with a little sand, and the 
pots should be well drained. Many growers err on 
the side of over-potting, which is a great mistake, as 
if over potted the leaf-growth will too greatly pre¬ 
ponderate over the production of flowers. Of course 
plants grown in comparatively small pots will want 
feeding, and liquid cow-manure with a little guano 
added will be found an excellent stimulant.— H. 
Dyer, Messrs. Jefferies &■ Son's Nursery, Cirencester. 
