jan. 5,1934 The European Corn Borer versus the Corn Earworm 69 
CONCLUSIONS 
The evidence presented in this paper shows that the com earworm 
and the European com borer may exist in harmony in the same host 
plants. 
In each of the two examinations made 100 per cent of the ears were 
found infested by one or the other species. Both species were present 
in 71 per cent of the ears in the first case and in 82 per* cent in the 
second case. The European com borer infested 88 per cent of the 
ears in the first instance and 96 per cent in the second. Larvae of the 
com earworm were found in 83 per cent of the ears in the first count 
and in 86 per cent in the second count. 
Injury resulting from the feeding of larvae of these two species was 
found on October 14, 1921, to be a destruction of 10.5 per cent of the 
total grain on 100 ears and on October 20, 1921, 18.9 per cent of the 
total grain on 50 ears. It should be observed at this point that this 
injury was to fully developed kernels and not to any that had failed to 
develop because of injury by the European corn borer to other parts 
of the plants. It was found that on the last-mentioned date the com 
earworm was responsible for 60 per cent of the total damage, or 11.18 
per cent of actual grain destruction, while 40 per cent of the total damage, 
or 7.72 per cent of actual grain destruction, was inflicted by the European 
com borer. These figures show the total injury caused by the com 
earworm, but do not show the whole damage by the European com 
borer, such as undeveloped kernels and feeding by the latter species 
after the com earworm has become full grown and deserted the ears. 
Since it has been shown that these two species may exist in com, each 
feeding independently of the other, and each contributing a share to 
the total injury, it appears that, should the European com borer ever 
reach the great corn-producing area in which severe losses occur through 
feeding of -com earworm larvae, the total damage resulting from the 
injury by both species would probably lead to an appreciable decrease 
in the yield of grain. 
