THE EUROPEAN CORN BORER AND ITS CONTROL. 23 



been observed m only one field, and in this instance the celery was growinp; 

 adjacent to a very badly infested field of sweet corn. This corn was 

 inhabited by so rcany Jarvse that the food supply was apparently exhausted, 

 and the larvae were attracted to the green succulent stems of the celery 

 plants. Several were commonly found in each of the outside stems, but 

 none were found in the stems near the center of the plant. 



Similar circumstances to those which resulted in this infestation may 

 be expected to occur from time to time, as celery is frequently grown 

 adjacent to or between the rows of corn plantings. 



Celery may be considered an important economic food plant of the 

 European corn borer because of the possibility that plants containing 

 infested stems may be shipped outside the infested area. 



SivifiS Chard. 

 The stalk and midrib of the leaves of Swiss chard plants were fre- 

 quently found infested by the borer under the same circumstances and 

 with the same result as has been recorded in the instance of celery. The 

 injury to Swiss chard, however, was observed in a number of fields in 

 widely separated localities. The green stalks and leaves of this plant 

 are commonly shipped from town to town and must be considered as 

 sources of danger. 



Beans. 

 The pods, immature beans and interior of the vines of bean plants 

 were found infested by larvae of the European corn borer in several fields. 

 This generally occurred in instances where several crops were planted 

 together, and the bean plants served to accommodate the overflow larvae 

 from other food plants. The infestation was always foimd to be very 

 light in character. Under exceptional circumstances the bean plant may 

 become important economically' as a host of the borer because of the 

 possibility that larvae of the species might be transported within the 

 immature pods of string beans. 



Potatoes and Tomatoes. 

 In badly infested areas the larger larvae of the European corn borer 

 may occasionally be found tunneling the stems of potatoes and tomatoes. 

 Not more than a single larva has ever been observed within a plant, and 

 the injury, so far as observed, is very slight and not at all important 

 commercially. 



Beets and Spinach. 

 Larvae of the European corn borer are infrequently found tunneling 

 within the leaf stems of beets and spinach during the early fall. This 

 type of injury may be of economic importance because of the possi- 

 bility that infested plants may be transported for use as greens. 



