CARROT APHIS OR GREEN FLY. 
17 
great part of rotting vegetable matter, appears to attract tlie flies to 
lay, and the maggots from the eggs go on thence to the root. This 
appears to be the case, judging by the notes sent in by our own 
agriculturists during the last few years ; also by continental observa¬ 
tions. 
Where there is fresh manure there are three points to bring attack : 
the smell to attract the flies, and the damp soft material for shelter, 
and food, as far as we see, for the young maggot. 
It may be submitted whether in field cultivation of Cabbage a good 
dressing of lime given directly after the plants are put in would not 
be very serviceable. The plants are often merely carelessly set up in 
the hole, and a dab given on each side by the dibber, so that the root 
and the manure are both much exposed. If instead the workers were 
obliged to put in the plant properly, and a handful of lime was then 
thrown round each, there would not be nearly so much smelling 
surface exposed to attack, and the lime would give a surface thoroughly 
obnoxious to the Fly, as the maggots could not live in it. 
It will be observed from the notes that dressings of gas-lime before¬ 
hand, or of lime, superphosphate, or anything suited to push on 
growth, but at the same time, as well turned by Mr. Glenny, “ to 
make circumstances disagreeable to the flies,” are what we want, and 
it would be very serviceable if in addition we had notes of how far 
watering manure in the heap with a weak solution of carbolic acid acts 
to prevent the heap being the head-quarters of maggots. 
A watering of one part of carbolic acid in 100 or 200 parts of water, 
given once a fortnight to the outside of the heap,—say three times,— 
would cost little, and would not injure the manure, and might be 
exceeding likely to keep off Fly laying. 
CARROT 
■ Carrot Aphis or Green Fly. A. papaveris , Fab ; ? Aphis carota , 
Koch. (A. subterranea, Walker). 
The following observations refer to attack of Carrot Green Fly on 
plants weakened by previous insect injury, mentioned on p. 18. 
Mr. J. Speir notes, with regard to his Carrots at Newton Farm, 
near Glasgow, that “ about the time the ‘ worm ’ (maggot of the Rust 
Fly) had exhausted itself, Green Fly began on the leaves, also on 
the west side, where the crop was weakened by the worms, and it 
gradually spread over the whole plot, reducing the leafage by at least 
an average of one-half. 
