INSECTS INJURIOUS TO CLOVER AND ALFALFA 209 



of grass lands while the adults are numerous are the Bureau of 

 Entomology recommendations for control.* 



When leafhoppers are unusually numerous and destructive 

 they may be captured in enormous numbers by the use of a 

 hopperdozer or hopperette, constructed along the same lines as 

 those used for grasshoppers. 



Miscellaneous Insects of Clover and Alfalfa 



In addition to the insects already discussed there are many 

 others which attack these crops, either occasionally or regularly. 

 Among these should be mentioned the grasshoppers, a complete 

 discussion of which will be found in Chapter VII, the pea-louse, 



FIG. 174. The alfalfa caterpillar: full-grown larva. Enlarged about three 

 diameters. (After Wildermuth, 1. c.) 



which is fully discussed in Chapter XV, and the blister beetles, 

 also discussed in Chapter XV and the one following and in Chap- 

 ter VII. Besides these there are several species of caterpillars 

 found in greater or less abundance in clover and alfalfa at all 

 times. These include the following: 



The Alfalfa Caterpillar f which is the larva of one of our 

 most common yellow butterflies always associated with clover 

 fields and so familiar to all as to need no description. The larva 

 is green in color and similar to the common cabbage worm, dif- 

 fering in the possession of a light stripe on each side through 

 which runs a bright red line. The insects seem to hibernate in 

 all stages and there are two or more broods. 



Damage to the crops is usually not severe in any one place 

 but evenly distributed and aggregates more than would be sup- 



* See Farmers' Bulletin 737, U. S. Dept. Agr. 



t Eurymus eurytheme Boisd. Family Pieridae. See V. L. Wildermuth, 

 U. S. Dept. Agr. Bulletin 124. 



