January 16, 1897. 
315 
rHE GARDENING WOR 
and should be destroyed by frequent washings in 
winter, with strong solutions of soft soap and sulphur, 
lime water, etc. 
Everyone has seen the froth-like substance on 
plants, which, if examined, will be found to contain 
a small insect, Aphrophora spumaria, a plant bug or 
froth fly. These little creatures do considerable 
damage to choice plants, and should therefore be 
destroyed, the best means of which is hand picking. 
01 mealy bug, there are several species, the most 
destructive being Dactylopius adonidum. All who 
have had anything to do with stove plants will 
know how difficult it is to keep them free from this 
pest; but by patient perseverance, and a frequent use 
of the syringe, even the most persistent attacks may 
be got under. Scale of various kinds also trouble 
the gardener, a good wash for which consists of 
soft soap and sulphur, to which a little lime may be 
added, or the trees may be washed with any well- 
known insecticide. The second section includes the 
plant bugs, most of which do not damage our garden 
crops to any considerable extent. 
We next come to the most interesting order in the 
whole class of insects, namely the Lepidoptera or 
scale winged. Here we have insects of various 
sizes, from those with wings, when fully expanded, 
that do not reach for more than a quarter of an 
inch, to others of very large size. It is to this order 
that butterflies and moths belong. The habits of 
some of the species are very familiar to many of us ; 
there are others, however, whose earlier stages of 
existence have baffled even the most zealous 
entomologists. This order is divided into two 
sections, the Rhopalocera or Butterflies, and 
Heterocera or Moths. The first contains only a few 
species that do serious damage to the gardener, the 
worst of which is Pieris Brassicae or large Cabbage 
Butterfly. This is so well known that it needs no 
description, the diagram before us being a faithful 
illustration. To the gardener it is a terrible foe, for, 
being double brooded, it is on the wing during 
April and July, and the caterpillars may be found in 
June and August. The latter brood, however, is the 
more numerous in individuals, and therefore does 
the greater damage. It is only in the caterpillar 
state that these do us harm ; for then they are so 
voracious that in one day they will consume more 
than double their own weight of food. Hand picking 
is the best remedy. 
We next come to the second section, and here we 
shall find some of the prettiest, and at the same time 
most destructive, of all the enemies the gardener has 
to contend against. Who would have any idea that 
the delicate Clear Wing Sphinx Moth (by which the 
entomologist sets such store) played such havoc 
with our Currant bushes. There are about a dozen 
species of Trochilium, all of which feed on the pith 
of trees. T. tipuliformis is, perhaps, the best known 
to the gardener in this district, the larvae of which 
feed on the pith of the Red Currants. The perfect 
insect makes its appearance early in June, when the 
female deposits her eggs in the crevices of the bark. 
When the caterpillars are hatched they burrow into 
the centre, and feed on the pith till full grown. They 
then change into the pupa state, emerging in the 
following June. To rid the trees of these pests, 
when the foliage shows signs of drooping, the 
branches should be cut off. If these are opened the 
caterpillars will be found. The moth is a very 
pretty creature, and worth preserving. There are 
many others of the Sphinx tribe, but none do any 
serious damage to the fruit trees. 
There are, however, others of this extensive order 
to which may be traced much of the mischief done 
to our garden crops, they being amongst the most 
destructive of our fees. The Goat Moth, Cossus 
ligniperda, the larvae of which feed under the bark 
of the Elm, and other trees, sometimes does consider¬ 
able damage. It is in search of these that we so 
often hear the woodpecker tapping at the trees. On 
one occasion I took no less than 94 larvae of this 
moth from one tree. They had completely eaten the 
inner bark for the greater distance round the trunk, 
leaving a cavity. When they are so numerous, if 
left to themselves, they will soon kill the largest 
trees. The larvae should therefore be destroyed 
when they make their first appearance. 
The Ghost Moth, Hepialus Humuli.—In some 
districts the larvae of this species do considerable 
damage to the roots of various crops, especially the 
Carrot. People residing in the country may often 
have seen the perfect insect hovering over the 
meadows just at twilight. The male, which is about 
two and a half inches across the wing, is of a snow 
white colour ; hence the name Ghost Moth. The 
female is of a dull yellow, with irregular markings. 
The best of all preventives is deep cultivation ; for 
during the autumn when the larvae are at work they 
may be turned under at the lime of digging to a 
sufficient depth to prevent any harm being done, as 
they cannot live long at such a distance from the 
surface. 
The Wood Leopard, Zeuzera Aesculi.—The 
larvae of this, like that of the Goat Moth, feed on 
various trees, but, instead of being content with 
feeding between the two barks, they eat holes into 
the trunks They may, however, be destroyed in 
the same way as recommended for the Goat Moth 
caterpillars. 
The Buff Tip, Pygaera bucephala.—The larvae of 
this species feed gregariously on the leaves of various 
trees, sometimes doing considerable damage. They 
can easily be distinguished, as they clear everything 
before them. If the boughs are shaken they at once 
let themselves down by a thread, which, if broken, 
causes them to fall to the ground, when they may 
be destroyed. 
The Lackey Moth, Clisiocampa neustria.—The 
larvae of this moth are very pretty creatures. They, 
however, do considerable damage to the Apple 
trees. Like the preceding they live in companies, 
and if frightened at once let themselves down by 
means of a thread, when they may be destroyed. 
The larvae of the Figure-of-eight Moth, Diloba 
caeruleocephala, also do considerable damage to the 
foliage of the Apple and other fruit trees. They 
may be got rid of in the same way as before des¬ 
cribed. None of these, however, are to be com¬ 
pared to those of the smaller species in their work of 
devastation, such, for example, as the Codlin Moth 
Carpocapsa pomonella. The larvae of this moth 
cause what are called worm eaten Apples, which, 
falling before they are ripe, will, if examined, be 
found to contain a small hole from which the cater¬ 
pillar has emerged. The moth lays her eggs in the 
eye of the Apple when it is very small. When 
hatched, the caterpillar eats its way into the pulp, 
and when fully grown, attacks the core, causing the 
fruit to fall to the ground, many of the finest speci¬ 
mens being thus destroyed. All fruit that has fallen 
should be picked up as soon as possible, not that this 
will materially lessen their number, for most of the 
larvae will have escaped to find a convenient place 
to spin their cocoons. Some, however, may still be 
left, and these will be destroyed. The stems of the 
trees should also be besmeared with some sticky 
substance to prevent the caterpillars from crawling 
up them again. 
When the larvae of the small Ermine Moth, 
Hyponomeuta padella attack the trees severely, hand 
picking is the best remedy, as they feed in com¬ 
panies under a web, and are therefore difficult to reach 
with any insecticide. 
The Winter Moth, Cheimatobia brumata, which 
does such damage to the foliage of our orchard 
trees, ought not to be given any quarter. Every 
means should be employed to rid the country of this 
pest. Many are the modes adopted, but none seem 
to be effectual. So numerous are the larvae in some 
seasons that they destroy everything before them. 
As a means for their destruction the ground beneath 
the trees should be dug soon after the caterpillars 
have gone to the earth to spin up their cocoon ; and 
any system that will prevent the wingless females from 
creeping up the stems of the trees, should be 
adopted. 
The Mottled Umber Moth, Hybernia defoliaria is 
also another very destructive little creature, and 
should be treated in the same manner as recom¬ 
mended for the preceding. 
Magpie Moth, Abraxas grossulariata.—This moth 
is widely distributed, being found from the north of 
Scotland to the south of England, the caterpillar 
feeding on the Gooseberry, the Currant, and various 
other plants. The larvae of this are often mistaken 
for those of the Saw-fly. In some parts of the 
country the species is very common ; but I have 
never experienced any difficulty in keeping the 
larvae under, as they are never so numerous as those 
of the Saw-fly. 
Dart Moths, Agrotis segetum and Agrotis ex- 
clamationis.—The eggs of these are laid early in 
the summer close to the roots of small plants, and 
when the caterpillars are hatched they feed on the 
D. 
plants near the surface, but as they get older they go 
deeper into the soil, only coming up to feed at night. 
They burrow into Turnips, sometimes as many as a 
dozen being found in one root. 
Yellow Underwiog, Triphaena Pronuba.—This 
moth, like the preceding, feeds near the surface on 
various plants, often doing considerable damage to 
young Cabbage and Lettuce plants, also to Straw¬ 
berries. 
-- 
FUMIGATING WITH HYDROCYANIC 
ACID GAS. 
The practical utility of this gas for greenhouse 
work is no longer a matter of experiment. A good 
Orthesia insignis.—Male. 
and novel method was recently used in fumigating 
30,000 coleus cuttings infested with the white-tailed 
mealy bug (Orthesia insignis). The cuttings, as 
they were brought from the stock plants in the 
parks, were placed in trays before trimming up. The 
trays were provided with wire-mesh bottoms, so as 
to allow a thorough diffusion of the gas. They 
were then placed in a box one above the other, 
and the top fastened down as nearly airtight as 
possible, so that no gas could escape. After this a 
small dish, containing equal parts of water and corn* 
mercial sulphuric acid was placed under the trays 
through the small door, provided for the purpose, 
and then potassium cyanide (98 per cent, pure) was 
added at the rate of 1-10 gm. per cubic foot of 
space and the door quickly closed. The cuttings 
were allowed to remain exposed to the gas for 
twenty minutes. They were then removed, trimmed 
up, and placed in the cutting bed. Treating the 
cuttings in this way cleaned them completely. 
Orthesia insignis.—Female. 
The gas has also been successfully used in fumi¬ 
gating Violet cuttings to kill black aphis. In one 
case 10,000 cuttings in sand were treated. All the 
insects were killed and no injury resulted to the 
plants. We have used the gas with marked success 
in fumigating Violets in flower. The work has been 
done in three houses, two of which are each 12 by 
60 feet and the other 20 by 50. No injury whatever 
has resulted to the plants, while fully 95 per cent, of 
the black aphides were killed. The advantages and 
