360 THE GARDENING WORLD. February 2, 1901. 
INTS FOR WMATEURS. 
INSECTS INJURIOUS TO GARDEN CROPS. 
Forwarned is forearmed, and the purpose of these 
notes is to put growers on the alert so as to take pre¬ 
cautionary or preventive measures against the insect 
pests that destroy our crops. 
Carrot Fly ( Psila Rosae ).—One of the worst of 
scourges is the Carrot Fly which, when once it 
obtains a footing in a garden, is very difficult to 
eradicate. The signs of its presence is speedily 
marked by the drooping of the young seedling 
Carrots. The female fly appears in early spring and 
lays her eggs just below the ground by the side of a 
Carrot. It is agreed by all who have studied the 
question that the eggs are laid below the ground, and 
as soon as the larvae hatch out from them, they 
enter the roots. They continue to bore up and 
down in the roots, and usually gnaw through the 
root, causing the young seedling to collapse. These 
larvae or maggots are whitish in colour, and about a 
quarter of an inch in length. Before pupating the 
larvae leave the root and go into the earth, and in a 
week or two change to the mature or imago state, 
that is, it becomes a fly. The last generation of the 
year, however, remains either in the roots or in the 
soil, in the pupa condition. When the agreeable 
spring weather comes, these pupae emerge as flies, 
and again start the life cycle of a new generation or 
brood, of which there are several during the 
summer. 
The means of prevention are comparatively few, 
and are not always very effective. So soon as the 
bed of seedlings show signs of failure, those that are 
affected must be pulled up and burned The Carrot 
beds should be lightly syringed with paraffin emul¬ 
sion from the time the young seedlings come through 
the ground. The emulsion should not be used 
stronger than at the rate of a wineglassful per 
gallon of water. The odour of the paraffin acts in 
warding off the female flies. In large Carrot fields a 
horse distributor would have to be used. It has also 
been, found of service to place well-pulverised coal 
ashes, sand, wood ashes, and peat moss impregnated 
with paraffin oil at the rate of 4 qrts. per cwt., into 
the drills before sowing the seeds. In badly infested 
gardens this method is really worth the trouble, 
Curtis recommends a gallon of spirit of tar to a 
barrowful of sand for this purpose. Sand or ashes 
impregnated with paraffin or carbonic acid may be 
scattered over the plants at singling time to keep the 
flies from them. If the flies can be prevented from 
layiDg eggs the crop can be saved. To prevent the 
egg laying, obnoxious substances such as soot and 
sand steeped in paraffin, &c., should be kept 
sprinkled about. 
The Onion Fly (Phorbia cepetorum, Meade ).— 
Another well known and persistent vegetable pest is 
the fly which makes its special attacks on Onions. 
In some seasons the damage done is much greater 
than at other times, but every year brings quite a 
number of complaints about this insect. Winter- 
sown Onions are noticed not to be so badly subjec¬ 
ted as those placed out in spring. Or if the seeds be 
sown in the open air in February the seedlings 
usually gain a sufficiently large size, and are stout 
enough to resist the preying of the larvae. Where 
Onions are raised indoors for planting outside they 
should be a good size and as hardy as possible before 
being set out. 
The fly appears about the middle of February in 
mild seasons, and lays from two to six or more eggs 
on the leaves of the young Onions. In a week’s 
time, if the weather is favourable, the larvae have 
hatched and are busy boring into the bulbs. The 
maggot stage continues for three weeks, or a little 
more, when the maggot becomes a pupa, and after a 
further period of three weeks the pupa emerges as a 
fly. Spraying and dusting as recommended for the 
Carrot fly also applies in this case. 
Kainit sown broadcast over the land may be used 
at the rate of 5 cwt. per acre, with advantage. The 
Kainit acts severely upon the larvae of the fly, and 
at the same time is very helpful to the Onions. 
Infested ground should be dressed with gas lime 
when the crop has been lifted. The lime may be used 
at the rate of 1 to 3 tons per acre, or 5 cwts. per 
rood, equal to 1 stone per perch or pole. Thus a 
good barrowload of fresh gas lime would suffice for 
a plot of two or three poles of land, square measure. 
Every assistance and encouragement should be 
given to the young crop so as to get the bulbs over 
the period at which they are susceptible and liable 
to the greatest damage. When once the tunic of 
the bulb is tough and the bulbs large the maggots 
have not the same destructive effect upon them. 
The Celery Fly ( Tephritis Onopordinis).—The 
Celery fly is often enough found in gardens, but 
happily it does not do much harm beyond disfigur¬ 
ing the appearance of the leaves. Parsnips are also 
subject to attacks by this insect. When the Celery 
plants are early attacked they make little headway 
and become stunted. The fly is on the wing in the 
balmy days of April, and the female fly soon pro¬ 
ceeds to lay her eggs on the upper surfaces of the 
leaves. Many eggs are laid, and these hatch out in 
less than a week. The larvae bore into the tissues 
and mine about in the same manner as the Com¬ 
posite leaf-miner does in the leaves of Marguerites, 
Cinerarias, and Chrysanthemums. 
The pupae usually remain in the soil after the 
Celery has been been taken up, so that besides deep 
digging (which can be practised with effect where 
the soil is good) the land should be dressed with gas- 
lime, as recommended in the case of the Onion and 
Carrot infestations. Still, the lime has little effect 
on these pupae with their leathery, protective coat. 
If the attack is not very severe a good deal can be 
done by crushing the maggots, that is, the larvae, 
when they are in the leaves. Badly infested leaves 
and stems should be taken off and burned. Thistles 
are also infested by Tephritis Onopordinis, so that 
they ought to be cut down or kept under suppression 
if Celery plants are in the neighbourhood. The 
plants should be encouraged to active and vigorous 
growth, because then the harm the larvae do is 
much less apparent. Spraying the plants with the 
paraffin emulsion acts very well. A carbolic acid 
solution made in the proportion of one pint of car¬ 
bolic acid and half a pound of soft soap to ten 
gallons of water has proved effective. 
The Stem Eelworm ( Tylenchus devastatrix ).—Dur¬ 
ing recent years we bave heard and seen a great deal 
of the mischief done by this species of eelworm. 
Wheat, Oats, Clover, Hops, Onions, and Cucumbers 
appear to be the principal sufferers, and until 
recently at least the mischief appeared to be extend¬ 
ing. The habits of the creature prevent the culti¬ 
vator from being able to reach and kill it without at 
the same time harming the plant. The full-grown 
eelworm is about the 25th of an inch in length, and 
in shape it generally resembles a tiny eel. Eggs, larvae, 
and fully grown eelworms are sometimes found in the 
same piece of stem or root. The larva undergoes 
several changes or moults before it becomes a per¬ 
fect eelworm. In its various stages, and particularly 
in its perfect form, the eelworm lives entirely on 
vegetable tissue. When these tissues either decay or 
dry up the larvae fall or escape to tb.e soil, where it 
has been seemingly well proved that they can 
resume animation and activity after a period of two 
and three years in a perfectly dry condition. 
It is a knowledge of this fact that makes their 
extermination so difficult and their distribu¬ 
tion seem so easy. Boiling hot water, cold¬ 
ness, want of food, and other antidotes have 
certainly had an effect when applied against them. 
From the nature of the infestation the eelworms can 
only be "comeat” by applications through the 
roots. If the plants are maintained in vigorous 
growth a great deal of the harm is overcome. 
Nitrate of soda and sulphite of ammonia are re- 
commendable from the point of view of growth 
production. For Onions or Cucumbers a few 
ounces per square yard of sulphate of iron, sulphate 
of potash, and nitrate of soda mixed together should 
be applied to the soil to be watered in. Phenyle 
applied in the form of a solution to the roots has 
had as satisfactory results as any of the applications 
tried in the case of Cucumbers. Infested plants are 
much better to be burned at once, after which all 
the soil should be cleared out, and the house (in the 
case of Cucumbers) thoroughly washed and syringed 
with boiling water. 
Work for the Present.—So soon as a few days 
of open sunny weather come to bless our land the 
horticulturists will be among the busiest of men. 
The ground will be forked and surface worked to 
obtain a deep tilth in preparation for the early 
plantings and the sowings. All work of a laying out 
nature, that is, the renovation or altering of grounds, 
should be brought well up, and should be kept under 
hand. Planting may go on for a long time yet, but 
in all these operations do not allow the current 
cultural work to be neglected.— Beacon. 
Correspondence. 
Questions asked by amateurs on any subject pertaining 
to gardens or gardening will be answered on this page. 
A nyone may give additional or more explanatory answers 
to questions that have already appeared. Those who desire 
their communications to appear on this page should write 
" Amateurs' Page " on the top of their letters. 
Treatment of Calanthes after Flowering. — 
L.S., Berwick-. After the flower spikes have been 
removed from evergreen Calanthes, the pseudo bulbs 
are encouraged by reasonable feeding and attention 
to dewing, watering, shading and ventilating them, 
to develop to as large a size and to be as well 
ripened as possible. Mere size would be ruinous, 
as indeed it would be with any class of bulbs what¬ 
soever, if they were unripened. All flowering bulbs 
beside being sound and well developed, should be 
thoroughly matured by the end of the growing 
season and then flowers may be expected. Weak 
liquid manure should be applied twice a week at the 
least. A span-roofed house and a temperature of 6o° 
up to 70° will answer their demands. They must 
be kept cleau. Stock for Christmas and mid-winter 
flowering should be potted (single bulbs) about the 
beginning of April, or from then till the end of that 
month. The deciduous Calanthes like C Veitchii, 
C. vestita and others require a thorough rest after 
flowering. 
General Climate of Natal.— J. S.: In the low 
lands tne climate is only suited for Zulus, and others 
of the Kaffir tribe, as well as the Indian coolies 
who have been introduced to the sugar fields ia that 
country. Europeans find the climate very agieeable 
in the altitudes of about 4,000 ft. and 5,000 ft. 
above sea-level. All the European fruits including 
open-air Oranges and Vines can be grown. Fruit 
culture is indeed, becoming a great industry there. 
Millions of all sorts of fruit trees have and are being 
planted. The native labour is somewhat scarce, or 
at least* the Kaffirs do not care to exert themselves. 
The seasons are just the opposite to ours, July being 
mid-winter in South Africa. For fine or six months 
the temperature ranges between 6o° and 70° in the 
highlands. 
Improving Grass Lands.— L. R. N. : We doubt 
if aoycbiog better than a nice top-dressing of finely 
sifted rich soil having wood-ashes and well rotted 
dung incorporated with it, could be used in your 
case. When soils are very light or are much 
exhausted, a solid top-dressing exerts a far better 
effect than merely dusting the surface with chemical 
fertilisers or soot. Still it is getting late to bethink¬ 
ing of such an operation so that the soil will have to 
be very fine indeed. It can be brushed in if the 
rains are not capable of washing the soil down to 
the roots. 
A Selection of Pot Herbs.—R Ingram: Almost 
any nurseryman’s seed catalogue will furnish a com¬ 
plete list of herbs for flavouring and other purposes. 
Such herbaceous perennial herbs as Mint, and Hore- 
hound, can be planted in March, or can be raised 
from seeds like any of those that are named below. 
All herbs for flavouring purposes are best when 
used green, and when they have to be dried this 
should be done as slowly as possible. The bunches 
must be kept well aired, else they may turn mouldy. 
The following are the more popular pot herbs:— 
Angelica, Bush Basil, and Sweet Basil; Chervil, 
Fennel, Horehound, Hyssop, Lavender, Marjoram, 
Rosemary, Rue, Sage, Thyme, and Wormwood. All 
of these can be raised from seeds and gome of the 
shrubby sorts like Lavender, Rosemary, and Sage, 
from slips or by layering. 
The Pomegranate. -L. F .: The Pomegranate 
does not succeed in this country as a fruiting plant 
though in dry warm summers it does flower even out 
of doors, but it requires the protection of a wall. 
Can Montbretia crocosmiflora and Gaillardia 
maxima be included in a collection of hardy 
herbaceous plants for competition ? — W. Y. B.,Edin 
Yes. Gaillardia maxima or rather G. grandiflora 
maxima is a variety of the perennial species G. 
