1925] Efficiency of Birds in Destroying Larvae of Corn Borer 45 
90 per cent of the overwintering larvae have been removed from 
the stalks. 
Experiments where infested cornstalks were placed in rep- 
resentative localities in the infested area of New England in the 
fall of 1922 and 1923 were examined the following spring in each 
case, before larvae had become active. These experiments were 
for the purpose of determining whether or not the habit of 
feeding on larvae of this insect was general. The experiments 
examined in the spring of 1923 showed that of 18 localities the 
cornstalks of which were recovered in good condition, birds had 
fed extensively on larvae contained in the cornstalks of 5 locali- 
ties, the proportion of larvae credited to such feeding ranging 
from 12 percent to 84 per cent, and averaging 61 per cent for 
these 5 localities and 17 per cent for the whole 18 experiments. 
Examined in the spring of 1924 showed that of 47 local- 
ities the cornstalks of which were recovered in good 
condition, birds had fed extensively on the larvae contained in 
the cornstalks of 16 localities, the extent of such feeding ranging 
from 19 percent to 78.5 per cent. The average proportion of 
larvae taken from these 16 localities was 54 per cent and the 
average of larvae taken from the whole number of 47 localities 
was 19 per cent. The feeding, which was mostly the work of 
woodpeckers, was found to be over a much more extended area 
in the spring of 1924 than in the spring of 1923. 
Feeding by woodpeckers on the larvae of this insect over- 
wintering in sunflower, ( Helianthus annuus L.), Princesplume 
(Polygonum orientate L.), Polygonum sp., and cocklebur (Xan- 
thium spp.) have also been found in experiments and in barnyard 
grass (Echinochloa crusgalli L.) and cocklebur ( Xanthium spp.) 
in the field. 
The importance of the feeding by birds on overwintering 
larvae of this insect at the present time, taking the infested area 
in New England as a whole, is not great, but in small areas the 
importance of their feeding must be considerable, since these 
small areas are often very heavily infested. The important 
point at present is that birds are finding the overwintering larvae 
of the corn borer, that they are feeding on them, and that such 
feeding seems to be on the increase. 
