XIV INTRODUCTION 



North. It is the "alfalfa worm" of Kansas and Nebraska and 

 elsewhere it is simply called the army worm. Its technical 

 name is Laphygma frugiperda. 



It will thus be seen from the examples cited that the popular 

 name of an insect has frequently little bearing on its identity. 

 The scientific name must be determined. 



A frequent source of injury to plants is due to contiguous 

 growers who raise the same, or similar crops, for different pur- 

 poses, c. g., some may raise cucumbers for pickling, and in 

 the immediate vicinity others grow melons for fruit, so that 

 pickle-growers pick their crops while quite young, and the 

 fruit-growers when older. This means that after the pickle- 

 grower has stopped pickling, numerous vines remain, and the 

 insects scatter from them to melon fields. 



