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belt has come from these shipments. Any one knowing of such ship- 
ments having been made in the last two or three years should notify the 
Natural History Survey, Urbana, Ill., of fields where such shipments 
have been planted, and should keep a sharp lookout for the borer in their 
vicinity, or more particularly in the neighborhood of places where such 
corn may have been shelled, if there is any likelihood that all the cobs have 
not been burned, as the borers would probably be transported inside 
the cobs. Careful examinations have already been made in the vicinity 
of all canning factories where such corn was known to have been re- 
ceived, but so far no trace of the insect has been found in Illinois. 
MEANS oF CONTROL. 
At present no very effective means of controlling this insect are 
known. In fact, the only way by which‘its numbers may be appreciably 
reduced is by burning the plants in which it passes the winter. This is 
a very expensive operation, as the borers are found in the stems of prac- 
tically all weeds, large grasses, and cultivated crops remaining on the 
ground after harvest, all of which must be completely burned up. This 
method of control was put to a thorough test in. the infested areas in 
New York and Massachusetts last year, with the result that the 
cost of clearing ordinary corn-stubble fields or land used for general 
truck crops was from $25 to $50 or moré per acre. More extensive ex- 
perimental work along this line is being done with improved machinery 
in Massachusetts this season (1919), and it is hoped to reduce materially 
the expense of this method of control. No adequate summer measures 
have been worked out. Spraying of food plants with arsenicals, while 
it affords some measure of control, does not kill a sufficiently large per- 
centage of the borers to make it worth while. 
NaTIvE BorERS CLOSELY RESEMBLING THE 
EuROPEAN CORN-BORER 
There are several related species which closely resemble the Euro- 
pean corn-borer, both in the appearance of all stages of the insects and 
in their work. The most abundant of these is commonly known as the 
smartweed-borer (P. obumbratilis), which is found very commonly in 
smartweed throughout the entire state. The life history of this insect 
is approximately the same as that of the European corn-borer, there 
being two generations, the moths appearing in May and again the latter 
part of July, and the insect passing the winter as a full-grown larva in 
the stems of its food plants. Until the last two or three years, this in- 
sect was not generally known to infest corn, but investigations made 
during the past year have shown that it frequently winters in the corn 
plant. A single specimen was found in gréen corn growing in a very 
large patch of smartweed about July 1, 1919. This specimen, however, ~ 
had evidently gone to the corn from a newly mown patch of smartweeds, 
