INSECTS INJURIOUS TO BEANS AND PEAS 



317 



Fig. 230. The beetles attack this and other legumes in immense 

 swarms, riddling the forest in a few days if not checked, and 

 appear from the middle of June to the middle of July. 



Nuttall's Blister-beetle.* This species occurs from the Miss- 

 issippi west to the Rockies, through the region of the Missouri 

 Valley, and north to the Northwest Territories, where it seems to 

 be particularly destructive to beams, though affecting many 

 garden vegetables. The life history is not known, but is probably 



FIG. 230 The ash-gray blister-beetle FIG. 231. Nuttall's blister-beetle 



(Macrobasis unicolm Kby.) : female (Cantharis nuttalli) Say: female 



beetle at right, twice natural size; beetle, enlarged one-third. (After 



male antenna at left, greatly en- Chittenden, U. S. Dept. Agr.) 

 larged. (After Chittenden, U. S. 

 Dept. Agr.) 



similar to that of other species, as the beetles appear about July 1st. 

 in years following severe outbreaks of grasshoppers. Owing to 

 the rapidity with which this species works and the large numbers, 

 poisons will be of little avail and mechanical measures must be 

 employed for their destruction. 

 Control. See page 302. 



The Bean-aphis f 



" Crowded together in clusters upon the top of the stalks 

 and under side of the leaves of the English bean, the puppy 

 dahlia, and several other plants, a small black plant-louse with 



* Cantharis mittatti Say. 



t Aphis rumicis Linn. Family Aphididce. 



