INSECTS INJURIOUS TO BEANS AND PEAS 



289 



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

 be particularly destructive to beans, though affecting many 

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

 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, 



FIG. 247. The ash-gray blister-beetle FIG. 248. NuttalTs blister-beetle 



(Macrobasis unicolar 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.) 



poisons will be of little avail and mechanical measures must be 

 employed for their destruction. 

 Control. See page 271. 



The Bean-aphis * 



" Crowded together in clusters upon the top of the stalks 

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

 dahlia, and several other plants, may be found a small black plant- 

 louse with pale shanks, and a row of mealy white spots along each 

 side of the back." Fitch. 



This is an old European pest of the bean, where it is known 

 the black dolphin, collier, and black fly, and has sometimes 

 caused the entire destruction of a crop. In the United States 

 it probably occurs wherever beans are grown, having been reported 

 from New York, Illinois, Iowa, Minnesota and Colorado. The 

 species is probably best known as affecting various species of 



* Aphis rumicis Linn. Family Aphididce. 



