482 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 14 



All this refers to com as ordinarily grown. Late com is often so 

 seriously injured as to be worthless. 



As to sugar cane, this crop grows till fall, and beginning about Sep- 

 tember the damage increases rapidly. It is estimated that the average 

 loss is about 16% of the crop, though it is sometimes as high as 33%. 



There is also an injury to young corn and cane plants, the larvae 

 entering the stalks at the surface of the ground or a little below and 

 killing the plants. 



From the literature, it would seem, that the European com borer 

 may do much more damage. Caflrey (1) writes: "The larvae or 

 borers of the European com borer tunnel through all parts of the com 

 plant except the fibrous roots. They even feed within the midrib and 

 upon the surface of the leaf blades. They cause their m^ost serious 

 damage, however, by their work in the stalks and the ears, which they 

 partially or totally destroy. Generally, they enter the stalk at its 

 upper end near the base of the tassel, and at first tunnel upward. This 

 damage so weakens the tassel stalk that it breaks over before the tassel 

 matures, resulting in loss of pollen and the lack of normal grain formation 

 on the ears. . . . Field counts in badly infested areas have shown 

 as many as 60% of the tassels broken over in this manner." 



More recently, Felt (5) writes: "Generally speaking a 30 percent, 

 stalk infestation is necessary to produce marked commercial injury though 

 in some fields with a 10 percent, stalk infestation as high as five percent, 

 of the ears of sweet com were affected and judging from conditions in 

 other single brooded areas, a 90 percent, stalk infestation of field com 

 by no means implies the destruction of the entire crop, though it does 

 involve serious damage. There has been in New York State no very 

 serious losses due to the actual work of the European Com Borer though 

 the 30 percent, to 40 percent, stalk infestation in the more seriously 

 infested areas suggests a probability of increased injury and possibly 

 an approximation to the great dam.age caused in certain Canadian areas." 



Food Plants Other than Corn 



The sugar cane species is unlike the European com borer in that it 

 does not attack various w^eeds, though it does breed in Johnson grass 

 and other large grasses. On a sugar plantation both com and sugar 

 cane are grown. The stalks of planted cane undoubtedly supply many 

 moths for the infestation of both com and sugar cane, as it has been 

 found that the moths can emerge from one half inch of packed soil. 

 In the case of both insects, moths come from a source other than com. 



