10 BULLETIN 221, U. S. DEPARTMENT OF AGRICULTURE. 



their rubbish and trash for boiler fuel and thus destroy a great number 

 of the beetles. 



Ordinarily the beetles attack a field of corn when it is very young 

 and destroy it before the farmer becomes aware of their presence. 

 No remedy has been found that can be recommended in combating 

 them after they enter the cornfield. If the crop is so badly dam- 

 aged as to be worthless it can be replanted with safety from damage 

 by this insect about one month after the regular planting time. 

 Within a few days after they have killed out the first planting they 

 will leave the field, thus making it safe to replant. 



From all the writer has been able to observe or learn the beetles 

 leave their hibernating quarters in early spring, depositing their eggs 

 about young corn plants as soon as these are available for their pur- 

 pose. It would also appear that the season of oviposition is prolonged 

 and that it is these overwintering beetles that feed upon and destroy 

 the corn plants while thus engaged. This would lead to the some- 

 what anomalous assumption that the parent beetle under stress of 

 hunger destroys the food plant of the larvae, which if true would 

 account for the very erratic occurrence of the outbreaks of this pest. 



As an additional suggestion, the fact that the beetles appear and 

 disappear with considerable regularity from south to north, taken 

 together with the fact that corn planted three or four weeks after 

 the usual planting season has escaped attack of the beetle, would 

 indicate that something might be gained by delaying corn planting 

 in localities where beetles have been injurious the previous year. 



Mr. E. H. Gibson, in his experimental work with this species in the 

 vicinity of Charleston, Mo., during late April and early May, 1915, 

 reports having found that, after repeated trials under varying con- 

 ditions, carried out with check experiments, the beetles can be readily 

 destroyed by a poisoned-bran bait, consisting of 25 pounds of wheat 

 bran, 1 pound of Paris green, 1 gallon of low-grade molasses, and 

 the juices of 3 oranges, with enough water to bring the mixture to a 

 stiff dough. The best success in the use of this poisoned bait was 

 obtained when applied in the late afternoon. It would seem that 

 this measure might be an extremely practical one if applied to the 

 restricted areas from which the beetles frequently spread, the bait 

 being scattered lightly on the ground among the plants where the 

 beetles are at work. 



