PESTS AND DISEASES. 
89 
opposite side of the shoot to escape observation, and as soon 
as all is quiet again it will start in a fresh spot, and re-cover 
itself with froth. If allowed to remain long on the plants, the 
larvae will cripple the shoots considerably ; therefore, take 
prompt steps for their removal. In some seasons they are 
very partial to outdoor chrysanthemums, and dozens of frothy 
lumps will be seen on the shoots. 
Remedies. — The most effective mode of eradication is to 
grasp the larva between the finger and thumb, and crush it. 
To make sure of seizing it, blow off the froth first. If you do 
not care to do it with your fingers, remove the larva with an 
aphis brush. Syringing with one of the liquid insecticides 
recommended for aphides will be beneficial also. 
Greenfly. — See Aphides. 
Leaf-=mining Maggot. — The larvae of the Mar- 
guerite Leaf-mining Fly (Phytomyza afifinis) frequently do con- 
siderable injury to the leaves of the chrysanthemum by boring 
small channels between the two surfaces. The maggots feed 
on the soft tissues, cause blisters and whitish zig-zag tunnels to 
form on the surface. When very numerous, the functions of 
the leaves are seriously disorganised, and the health of the 
plant badly affected. The fly is like the Common House Fly 
in shape, and of a dark slaty black or ash colour. It 
measures one-fifth of an inch in the spread ofits wing, and 
about one-twelfth of an inch in length. The flies appear in 
May and June and deposit their eggs, by means of an 
ovipositor, in the cuticle of the leaf. When fully grown the 
maggots do not quit the leaves, but form chestnut-brown 
coloured pupae in the mines, and eventually emerge therefrom 
as perfect flies. 
Remedies. — When the maggots are seen in the leaves it is 
useless applying insecticides, as anything powerful enough to 
reach them would at the same time kill the leaves. The only 
remedy in such a case is either to pinch off and burn the 
infested leaf, or to crush the maggot between the finger 
and thumb in the leaf, or to pick out each grub with the 
point of a penknife or darning needle. As a preventive, 
syringing the foliage frequently during May and June, 
when the flies are on the wing, with a paraffin solution 
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