Insects in the Garden 329 
5 days. The young maggots feed on or within the roots, 
but when fully grown they usually leave the plants and 
burrow out into the soil, where they change to the pupal 
or dormant stage. During the summer months, the 
pupa lies dormant only from 12 to 18 days, and then the 
adult flies appear. Thus, several broods are produced 
ina season. The pupe that are formed in the autumn 
live over winter in the ground. The following methods 
are used in the control of the radish maggot : 
(1) Protection by covering. Beds of radishes or cab- 
bage plants grown in cold frames, or outdoor beds of 
these plants, may be protected from the flies by piacing 
over them a board frame covered with cheesecloth. 
(2) Prevention of egg laying. It is believed by some 
that the flies will not lay their eggs in soil upon which a 
little kerosene has been sprinkled. To apply the kero- 
sene, pour a cupful of it over a pail of dry sand, mix well, 
and scatter the sand over the soil about the plants. 
(3) Disks of tarred paper. Cabbage plants may be 
protected by covering the earth about the roots of the 
plant with disks of tarred paper about 4 inches in diam- 
eter. These should be fitted closely about the stem of 
the plant when it is placed in the field. 
(4) Killing the maggots in the soil. The maggots that are 
in the soil may be killed by pouring kerosene emulsion or 
corrosive sublimate solution (1 part of corrosive sublimate 
to 1000 parts of water) over the bed or row until it soaks 
down into the soil about the main roots of young plants. 
Another effective solution, which may be used in the 
same manner, is made as follows: mix a pint of crude 
carbolic acid ina gallon of hot water, then add a bar of 
