May 25, 1907. 
THE GARDENING WORLD. 
355 
Tf?e Opion pig. (Anthomyia ccpannn). 
Signs of Attack.—Eradication.—Prevention. 
"N 
The ravages caused by this loathsome 
■rest in some seasons is really appalling. 
)ne distinct cause of a great deal of their 
lepredations is ignorance on the part of 
nany who grow this crop to recognise its 
presence in the bed till too late. This 
The Onion Fly; A, the grub;B, the 
-pupa; C, the perfect fly. 
hen allows of the fly to properly mature 
and escape, thereby rapidly increasing 
since there are several generations during 
1 year. 
The flies lay their eggs from May on- 
vards during the summer, depositing them 
in the Onions at the base of the leaves 
ind just above ground. Provided the 
veather is favourable these hatch out in a 
reek, and at once commence to feed on 
:he Onion, by boring their way through 
:he bulb or swelling part, passing from 
one plant to another. 
The maggots are of a dirty white colour, 
tbout % inch long, pointed at the end, with 
n blunt tail. These remain in the larvae 
■tate, feeding on the Onions for about a 
ortnight, when they pass into the chrysalis 
>tage, generally leaving the Onion and 
mtering the soil for the purpose. In this 
stage they are hardlv of the same length 
is the larvae, and of a brown colour. They 
hus remain for nearly three weeks, when 
hev come forth a perfect winged insect. 
These also lay eggs, which in turn pro- 
luce maggots, etc.; hence will be seen the 
tecessity of dealing at once with all 
ittacks. 
Signs of Attack. —The indications by 
vhich its presence becomes known are the 
turning yellow of the first leaves, which 
ater turn white; or the drooping over of 
he same on to the ground, even though 
freen, whilst the others are flabby to the 
ouch instead of being crisp or firm. The 
rork of the maggots causes the bulb part 
0 decay and often give off a most unplea- 
ant odour. When pulled it will be found 
he plant parts easily. Apart from these 
adications it is quite possible to discover 
and see the eggs six or eight in number 
on the Onions before they become hatched, 
if the latter are examined early and well. 
This takes time, therefore seldom done, or 
the results would be less disastrous. 
Eradication.- There should be no de¬ 
lay, but upon the first sign of attack to 
apply measures with a view to check the 
spread, and if possible destroy those in 
existence. The following can be recom¬ 
mended. To lift each infested plant to¬ 
gether with a quantity of the surrounding 
soil and destroy by burning. To im¬ 
mediately water the bed with a solution of 
paraffin, soft soap, and water, 2 ozs. of 
soap, 1 wineglassful of paraffin to each 
gallon of boiling water, the whole well 
churned to get the oil well mixed with the 
water, use when cold. This is properly 
termed paraffin emulsion. 
An application of salt and soot scattered 
thinly over the beds and hoed lightly in 
afterwards helps to destroy the maggots. 
One peck of each well mixed is sufficient 
for 80 to 100 square yards. Soot and 
lime may also be used instead of the 
former, if desired, 2 pecks of lime and one 
of soot to the same quantity of ground. 
2. Grubs of the Onion Fly in the Onion 
bulb. 
Prevention. — In all cases this is better 
than cure, and should be particularly em¬ 
ployed in regard to this pest, the chief 
being to avoid again cropping infested 
ground for one or two seasons; to deeply 
dig the ground in autumn (trenching pre¬ 
ferable) and giving a good dressing with 
gas lime, failing which ordinary lime, this 
to destroy the pupae, in which state the 
flies spend the winter, usually in the soil. 
Make use of the soot and lime mixture 
both previous to sowing the seed and after 
the latter are up in the form of top-dres¬ 
sing. Frequent waterings with the paraffin 
emulsion after the plants are up is also a 
good preventive. The better the condi¬ 
tion of the ground and greater encourage¬ 
ment given to the plants to grow and 
make headway whilst young the more 
favourable becomes their chance of escape 
from attack. 
Reference to Sketches. — Fig. 1. The 
three stages of the fly; A., larva; B., 
pupa; C., perfect insect (magnified). Fig. 
2. Onion plant being attacked by the 
larva or maggot. Fig. 3. Plant show¬ 
ing signs of attack, also maggots within 
the bulb. Geo. D. Rowles. 
The Temple Flower Show. 
The great annual spring flower show of 
the Royal Horticultural Society takes 
place in the Inner Temple Gardens, Lon¬ 
don, on May 28th and the two following 
days, and given fine weather this im¬ 
portant horticultural event is likely to draw 
larger crowds of sightseers than ever, 
whilst the space available for exhibitors 
will probably, if that Ire possible, have to 
be augmented. The show will be open on 
May 28th from 12.30 to 7 p.m., the price of 
admission to the public being 7s. 6d. ; on 
the 29th from 9 a. nr. to 7 p.m., admission 
2s. 6d. ; and on the 30th from 9 a.m. to 
6 p.m., admission is. Fellows of the 
society are admitted free on showing their 
tickets of membership. Lieutenant 
Charles Godfrey’s Military Band will play 
on the lawn each day. 
-- 
A Chat About 
Herbaceous 
N „ , Borders. 
Every gardener, whether amateur or pro¬ 
fessional, can admire a well furnished her¬ 
baceous border. Whether it is for cut 
flowers, long season of flowering, or for 
garden decoration, no other plants will 
yield more satisfactory results. However 
bright the flower beds may be, the border 
is in the running, and during wet spells 
the washed-out appearance is not nearly so 
pronounced as in the beds. 
The ideal flower border is one facing 
south-west at the foot of an old wall. 
Flowers are earlier, and are produced 
g. Pupae of the Onion Fly projecting out of 
the bulb. 
