172 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
[ February 56 18S5. 
equal in appearance all over the deposit is partial, being thick over 
certain parts and absent from others, just as would happen by the protec¬ 
tion of leaves above. The honeydew is exactly like this, and such ihis is, 
I should say, for there is nothing to indicate anything to the contrary. It 
will be found, I suspect, that the Camellia in question has been near some 
insect-infected climber or taller plant. There is a fungus on the leaf—no 
doubt nourished by the ‘ glutinous matter ’—but it has nothing to do 
with the cause, and is only an after appearance.” 
A Cultivator’s Letter. —“Judging from the sample sent, and from 
the whole of the evidence before me, I am further convinced that the 
glutinous matter is the result of excreta from insects. I am returning the 
foliage sent by “ Borderer ” as well as some from a tree infested with 
scale ; the leaves selected are from the centre of the tree and directly 
under branches on which scale is established. The last two letters from 
‘ Borderer ’ confirm in a marked degree that the opinion I formed and 
gave a fortnight ago as the correct one. The mealy bugs on his|Tecoma— 
however limited the numbers may be—are sufficient to account for the 
gum on the foliage of his Camellias. I am not surprised that he has 
discovered fresh evidences of the glutinous matter on the pot plant he 
sponged. I should have been very much surprised had he not done so, 
for however carefully the operation was performed it would be next to an 
impossibility to eradicate every scale. I have on many occasions been 
surprised myself at the amount of excreta and the rapidity with which it 
was formed after the trees had been washed and cleaned. The same 
glutinous matter is deposited on any plant below where aphides is 
established, although in a less marked degree, unless the insects are very 
numerous. A Cattleya sponged only a few days ago has one leaf covered 
with a gummy substance, the same as that upon the Camellia leaves. 
What has caused it ? not internal influences, but yellow aphides—very 
few in number—on the young growth of a Dendrobium suspended above 
the plant upon the stage. The cause is external, not internal, and if the 
advice given is followed and the bug cleared from the Tecoma and scale 
from the plants, if any exist upon them, which, from “ Borderer’s ” own 
showing, is the case, the glutinous substance will also disappear.” 
l_The Camellia leaves sent by our correspondent with “ gum ” on 
them are exactly like those sent by “ Borderer.”] 
MRS. PINCE GRAPE. 
When I read Mr. Reid’s note on the above Grape (page 131) last 
issue, I thought his re'marks were not very clear. He says, “ This 
Grape when fully ripe should be kept in a low temperature, and should 
be shaded from the sun by means of brown paper to preserve the quality 
and colour of the fruit. No water should be spilt on the paths, or the 
fruit is sure to get bad and likely to drop from the stalk.” He also 
says, “ The temperature should be kept at 40°, as the above Grape will 
grow better at that heat than higher if the sun be entirely excluded.” I 
think most growers have sufficient knowledge to know that when Grapes 
are ripe a high temperature is not required ; and as to the shading of the 
fruit, the foliage should effect this, as all black Grapes require abundance 
of foliage to colour them well, and by the time the Vines lose their 
leaves there will be very little sun to produce any ill effects. As to water 
being spilt in the house, causing the fruit to go bad, it is not remark¬ 
able, as all Grapes are subject to this if dampness is allowed about them. 
If a temperature of 40° is suitable for growing this Grape surely a great 
error has been made in planting it in Muscat houses, which is usually the 
case, and I should like to know in what situation and position a house 
should stand so as to command a temperature of 40° during summer.— 
A. Anderson, Lea Wood. 
THE INSECT ENEMIES OE OUR GARDEN CROPS. 
THE TURNIP. 
Were they beings possessed of intelligence, sundry species of 
insects might rejoice that it has pleased man to cultivate the 
Turnip freely in fields and gardens, since they are thus provided 
with an agreeable food in its roots, leaves, or flowers, lacking 
which they must have subsisted upon other Crucifers if as 
attainable yet less attractive. Any measure of gratitude, however, 
the insects could hardly be expected to feel, since no sensible 
gardeners allow them to revel in peace, though in the case of 
several enemies of the Turnip all precautions taken and remedies 
used will fail during some seasons to bring up the crop to an 
average yield. And every year affords fresh proofs of the long- 
unobserved fact, that to keep insects under it is not sufficient to 
kill them or drive them away ; the cultivation of the plant must 
be pursued on the best methods, to ward off vegetable disease 
and to lessen the danger of insect attacks. 
Amongst the foes of the Turnip the fly must undoubtedly 
take the lead. It is an insect noted for its skipping rather than 
its flying propensities ; hence evidently the popular name should 
be Rea, not fly, though the species is neither flea nor fly, but a 
beetle. TVst it can fly as well as jump, showing activity princi¬ 
pally in warm bright weather. When the atmosphere is damp 
and heavy this insect is sluggish and little inclined for any 
movements. Under the common epithet of Turnip fly are in¬ 
cluded several species of Phyllotreta, the commonest of which is 
that called somewhat absurdly P. nemorum, for it has no par¬ 
ticular connection with woods or groves; indeed, one farmer 
reports that in his experience crops grown in shady places are 
likely to be exempt from its visits. This species has a broadish 
stripe of yellow upon the wing cases; another, with wing cases 
rather of a brassy hue, is that named P. concinna, which, having 
troths (to appearance) upon four of its six legs, has been styled 
the “ tooth-legged hop flea ” in some districts. The bluish- 
tinted P. undulata was another species that took an active part 
during 1881, when the crops suffered so severely from the 
destructive fly, that in more than twenty English counties a 
second or even a third sowing was necessary, and the loss in 
different ways amounted to hundreds of thousands. Scotland 
also sustained heavy losses, but Wales nearly escaped. 
In referring to this too familiar insect we shall avoid repeating 
facts that are to be read in most books on horticulture, and con¬ 
fine ourselves to such as are of recent observation, while also 
correcting any misapprehensions that may be current. The 
exact number of broods during the season is uncertain, varying 
from three to five or even six, but on the whole its life history is 
tolerably clear. Although this foe of the Turnip will eat both 
the rough and the smooth leaves of the plant, it is chiefly mis¬ 
chievous to seedlings, therefore the first or the second brood are 
to be specially guarded against. In a backward season it may 
happen that the first brood of the maggots subsist upon wild 
Crucifers, such as Charlock and Hedge Mustard, the beetles or 
flies from which devour the Turnip leaves when ready, and 
deposit eggs also to produce the next brood of maggots; and 
it must be always remembered that the maggot, which generally 
lives about a week, bui*rowing in the leaves, which it quits to 
enter the earth for pupation, is on the whole less hurtful to the 
Turnip than the fly, which by its persistent attacks succeeds in 
killing many young plants. At the end of the summer there is a 
hatch of the fly or beetle that does no harm then, but lays up in 
all sorts of hiding places in and near fields, waiting through the 
winter to begin operations upon the seedlings of spring. 
The association between this insect and several weeds which 
occur in all fields and by waysides, and which are much more 
abundant some years than they are in others, is a circumstance 
never to be forgotten. And we note in passing that it has been 
stated, as a small fact to the credit of the Turnip fly, that by its 
agency whole fields of Charlock which had been left neglected 
have been cleared of this undesired weed. Also a season when 
Charlock and its brethren are numerous (as this autumn, for 
instance, owing to the absence of frost) is likely to be followed 
by a bad year for the Turnip, a host of flies being fed up in the 
autumn. Careful removal of Charlock from all waste ground 
near Turnip fields may deprive the flies of the means of depositing 
eggs for the first brood of maggots if this is done early in the 
year. And that the flies conceal themselves in winter amongst 
stubble heaps, bunches of straw, and the like is certain, hence 
refuse of any kind that might shelter them during winter should 
be cleared away and burnt. 
It has been repeatedly noticed that a crop of Turnips raised 
off land that has laid fallow through the winter and kept free 
from weeds is seldom injured by the fly. Satisfactory results 
may also be looked for when the ground has been well manured 
some little time before sowing, say with superphosphate drilled 
in. A thorough preparation of the soil in spring as soon as the 
weather permits by the usual methods, works in the moisture that 
may have been received during the winter, and the growth of the 
young Turnips will thus be hastened, unless the season is un¬ 
favourable ; for while a cold spring checks them considerably, 
it is almost invariably the case that dry and mild weather about 
that time very much favours the increase of the fly. The fly is 
well known to be troublesome when Turnips are in succession to 
a green crop of the previous season, such as Yetches or Winter 
Oats ; and the gardener or farmer who desires to be forward in 
his operations is no gainer here, since the early-sown Turnips are 
the greatest sufferers. 
At the time of sowing many recommend that a small quantity 
of stimulating manure should be applied. Some prefer the artifi¬ 
cial to the farmyard manure, and judicious watering should follow, 
in gardens at least; in fields there will not always be facilities for 
this, but one watering, perhaps, with liquid manure might be 
managed. As to profuse sowing, which has been tried on the 
chance of the survival of the strongest plants in the crop, and their 
shielding each other to some extent, it has scarcely proved satis¬ 
factory enough to be generally recommended. From the certain 
preference the fly shows for white Turnip when it can be had, 
there is advantage in drilling some rows of it amongst Swedes or 
mixing the seeds ; while the partiality of the fly and its maggot 
for Charlock has suggested that Mustard seed be mingled with 
that of the Turnip, which will lessen the loss upon the latter 
