THE ALFALFA CATEKPILLAR. 29 



keys likewise feed there are few Eurymus to be found, and consequently no 

 damage. * * * I also observed several chickens feeding upon Eurymus 

 larvse. 



From these observations it is seen that chickens may be utilized 

 in small fields to keep down the numbers of alfalfa caterpillars, and 

 that turkeys, because of their roving nature, can be used to advantage 

 in larger fields. Mr. Charles Springer, of Cimarron, N. Mex., in- 

 forms the writer that he hires a boy to herd an immense flock of 

 turkeys on the range, so that they may feed upon the grasshoppers 

 destroying the grama grass and other range grasses (see PL I, fig. 

 2, p. 4). It seems that the same method could be employed in out- 

 breaks of the alfalfa caterpillar. 1 There is always a good demand for 

 fattened turkeys, and with the cheap labor of a Mexican boy for 

 herding the turkeys, if this additional expense is really necessary, the 

 caterpillars could be kept within bounds at a very small cost per acre, 

 or possibly even at a profit. 



OTHER ENEMIES. 



Quite a few observations have been made upon the food habits of 

 toads. These batrachians have been found to feed upon both adults 

 and larvse of Eurymus, as many as 45 adults and 1 larva having been 

 found in a single stomach on one occasion, while on another 15 

 Eurymus larvae were found, besides 4 of Heliothis, 3 geometrids, 

 3 larvse not classified, a cricket, and the remains of a few beetles. 

 As toads are quite numerous throughout the alfalfa fields of the Salt 

 River Valley, they must exert a considerable influence toward the 

 suppression of outbreaks of the alfalfa caterpillar. 



THE CONTROL OF THE ALFALFA CATERPILLAR. 



PASTURING VERSUS HAYING. 



It was first noted by the writer in 1910, during his early study of 

 the subject, that fields in pasture are never troubled as much by the 

 alfalfa caterpillar as are haying fields. Since then this has been 

 clearly verified, not only by the writer but by others connected with 

 the work. On July 14, 1913, Mr. R, N. Wilson makes the following 

 note, which bears out this statement: 



Many of the fields about El Centro have been cut recently and so show 

 nothing now as to Eurymus conditions. Many are also being pastured, and 

 in these the caterpillar attack is slight. In some fields which have not been 

 either pastured or cut the damage is considerable. 



There are several factors which explain this. At first it was 

 thought to be owing entirely to the lack of bloom for the butter- 



1 Of course care should be exercised not to allow the turkeys in the alfalfa after it has 

 become too high and rank, nor should too great a number be used in any one field, as in 

 such cases the alfalfa might be badly trampled. 



