88 Farmers’ Bulletin 1294. 
The practice of plowing down infested material in the fall must 
be regarded as only an aid, or “ finishing touch,” to other repressive 
or clean- up measures. In ‘ordinary farm plowing operations, con- 
siderable quantities of plant remnants are left on the surface of the 
soil, or are only partially buried. It is possible, however, under favor- 
able conditions, by exercising proper care, to cover the infested mate- 
rial sufliciently to cause the destruction of many of the contained 
borers. Any loose plant material left on the surface of the soil should 
be raked into piles and burned. 
Spring plowing has not proved effective, apparently because the 
borers become active before the soil is in condition for plowing in 
the spring, and if plowed under at this time, many of them make 
their way ‘to the sur face, even when buried under several inches 
of soil. 
When necessary to plow down fields of standing cornstalks, it is 
advisable to run a stalk cutter over the field before plowing in order 
to roll down the stalks and cut them into sections. 
PROTECTING GREENHOUSE PLANTS. 
Good results have been secured in protecting chrysanthemums and 
other susceptible plants grown in greenhouses by screening all doors, 
ventilators, and other openings in such a manner as to prevent the 
moths from entering the greenhouse. These screens should be put 
on during the early spring "(about May 15), and left in position until 
the late fall (about November 15). Screen cloth, cheesecloth, and 
similar materials are suitable for this purpose. 
This method is not effective where the plants are allowed to 
become partly grown in infested fields during the summer and are 
subsequently moved into the greenhouse in the fall to complete their 
growth. 
Cornstalks, corncobs, large weed stems, and similar plant rem- 
nants which are likely to contain the borer should be removed from 
manure or compost which is intended for use in the greenhouse. 
METHODS RECOMMENDED IN MARKET GARDENS. 
ABANDONMENT OF SUSCEPTIBLE CROPS. 
Several crops commonly grown on market-garden farms in eastern 
Massachusetts are favorite host plants of the European corn borer, 
and furnish food for large numbers of caterpillars of the first gen- 
eration. The resulting moths deposit eggs on later crops and thus 
produce a second veneration of borers in such crops. Sweet corn, 
which is very susceptible to infestation by the borer within the very 
heavily infested area in Massachusetts, might profitably be aban- 
doned ‘on-market-garden farms, except as a trap crop to be disposed 
‘of before July 25. Rhubarb is.also attractive to the corn borer, so 
that it would be advisable to abandon the growing of this crop in 
badly infested fields, especially where other less susceptible crops 
may be grown with equal profit. Beet plants are a favorite host 
for the corn borer, but where these are grown in the early season and 
sold as bunch beets, or as greens, they are not in the field long enough 
