THE EUROPEAN CORN BORER AND ITS CONTROL. 61 



provide humus so necessary to the maintenance of fertility and texture 

 in the soil. If this method is adopted, however, the infested plants 

 must be buried at least a foot in the soil, and the surface packed, if possible. 

 Experiments to date have indicated that this method of destroying in- 

 fested plants cannot be relied upon unless undertaken with great care. 



In ordinary plowing operations infested plants are only partially turned 

 under, and much of the plant remains are left on the surface of the ground. 

 This is not an effective method for destroying mfested plants. 



During the month of May, 1918, infested cornstalks were buried in the 

 soil to a depth of 6 inches, and in a manner resembhng the work of an 

 ordinary plow. The second generation larvse contained in these buried 

 stalks promptly made their way to the surface of the soil and entered 

 plant remnants in the vicinity. Different results might possibly have 

 been secured if the infested stalks had been buried in the fall and left in 

 the soil through the winter, and experiments were started durmg the fall 

 of 1918 to determine this point. 



Infested cornstalks, buried to a depth of 12 inches in October, 1918, 

 were dug up five weeks later and found to contain h^dng larva?. These 

 were still actively feeding, although the interior of each cornstalk was 

 soft and had begun to decay. 



If a method could be developed for plowing under infested plants in 

 order to destroy the larvse contained therein it would be very desirable 

 but in the present state of our knowledge concerning the matter this 

 practice cannot be recommended. 



Feeding of Infested Plants. 



The feeding of infested plants to hve stock is, from the economic view- 

 point, the best possible means for destrojang the larvse of the European 

 corn borer. The value of the stalks for fodder is not materially affected 

 by the presence of the insects, and, if properly carried out, this method 

 must result in the destruction of all insects within the infested plants. 

 This is particularly true in the instance of infested corn fodder. 



Shredding the corn fodder, or cutting it into small sections before 

 feeding, greatly reduces the chance that any of the contained larvse will 

 survive. Live stock rehsh corn fodder when fed in this form, and will 

 eat all parts of the plant. 



Ensilage, by ordinary methods, effectively destroys all larvse within 

 the fodder, as the insects cannot survive the conditions existing in the 

 silo. 



Composting Infested Plants. 



Whenever infested plants or parts of plants are placed in a compost or 

 manure pile and covered deeply, the resulting decay and fermentation 

 quickly result in the death of the larvse contained within the plants. 



It is a common practice on some farms to use corn fodder for bedding. 

 This corn fodder ultimately becomes mixed with the manure, and any 

 larvse present in the corn fodder do not survdve the treatment. 



