CABBAGE PESTS 
Fig. 3. The Cabbage Maggot. 
Radish showing egg. 
winter also as adult flies, hibernating in 
sheltered nooks about the field and in 
outbuildings. As the warm days of spring 
advance, the flies emerge from _ their 
hibernating quarters and also from the 
pupal cases in the soil, and seek their 
host plants for the purpose of egg deposi- 
tion. The eggs are deposited close about 
the plant, the female fly working herself 
down below the surface, if the soil will 
permit, and placing the egg right against 
the plant root (see Fig. 3). The eggs are 
often placed above ground on leaves or 
developing buds. The eggs hatch in from 
four to ten days, depending on the tem- 
perature, and the young larvae commence 
at once to burrow into the tender plant 
(see Fig. 2). The maggots reach matur- 
ity in a month to six weeks, pupate and 
emerge soon after as adult flies. From 
Fig. 4. Cabbage Maggot Adult. 
—Photo by Essig. 
679 
this time on until late fall one may usu- 
ally find both larvae and pupae in the 
soil. As the season advances, a portion 
of the maggots assume an aerial habit. 
This is especially true in the fields when 
early cabbage has been harvested and 
where the stumps left standing have put 
out adventitious buds. The flies deposit 
eggs in these tender buds and the mag- 
gots burrow into the midribs of the leaves 
and into the core of the shoots. 
Control] Measures 
Possibly for no other group of insects 
will one find such a variety of remedial 
measures suggested as for the root mag- 
gots, nor more diverse results following 
their application. No single remedial 
measure will ordinarily afford satisfac- 
tory relief. Combinations of preventive 
and remedial measures are best. A single 
application of any solution will seldom 
suffice; hence the crop should be treated 
again when the effect of the previous 
treatment is diminished. 
Preventives 
Plowing of the infested fields as soon 
as the crop is removed will materially 
lessen next year’s brood. The soil should 
be turned to a depth of four inches or 
more. 
Destruction of Stumps.—The old stumps 
in the field or the refuse root crop in the 
soil should be destroyed. Such materials 
furnish ideal conditions for the develop- 
ment of this pest. 
Rotation of Crops.—Where conditions 
will permit, rotate the crops so that 
plants of the family Cruciferae occupy 
the same soil but a single season. The 
flies are weak fliers and do not as a usual 
thing travel far to their hosts. 
Screening Seed Beds.—Cabbage plants 
yet in the seed beds are often infested 
with this pest, and the maggots are car- 
ried with the plants when they are trans- 
ferred to the field. Mr. Schoene* has 
studied the value of screening cabbage 
seed beds and the following discussion 
is based on his bulletin on this subject. 
For early settings of cabbage, where the 
product usually brings a fancy price on 
* Schoene, W. J., New York Agricultural Ex- 
veriment Station, 1911, Bulletin 334. 
