24 



BULLETIiNT 967, U. S. DEPARTAIEIS'T OF AGEICULTUEE. 



The sprayed potatoes were only slightly injured by the beetles, but 

 the unsprayed ones were defoliated (fig. 22). 



On July 5 a small patch of potatoes, grown by Dr. CO. Town- 

 send of the Bureau of Plant Industry for experimental purposes, was 

 attacked by blister beetles of several species. The potatoes were 

 being sprayed with Bordeaux mixture, so Paris green was added 

 thereto for part of the patch and zinc arsenite for another portion. 

 The potatoes designed to be left as a check on the Bordeaux treat- 

 ment were sprayed with Paris green alone. These potatoes suffered 



Fig. 22. — Field of potatoes attacked by blister beetles ; strip through middle left un- 

 sprayed. Sprayed on left and on extreme right. (Photo by Lill, Bureau of Plant 

 Industry. ) 



very little during the attack. Another invasion occurred three 

 weeks later, at which time the potatoes were all sprayed with Paris 

 green, 1 pound to 25 gallons of Bordeaux where the latter was used, 

 and the same strength alone on the remainder. Xo damage resulted 

 from the second attack. 



Three acres of sugar beets belonging to Mr. D. A. Sheaks, of 

 Garden City, Kans., were attacked by blister beetles that gathered 

 in one edge of the field, most of them being large beetles {Mao''ohasis 

 immaculata) . On July 26 about half of the field, including the in- 

 fested portion, was sprayed with li pounds of Paris green and some 

 stone lime in 50 gallons of water. The beetles ceased their injury on 

 the sprayed portion of the field, those that escaped collecting on 

 beets on the unsprayed area. Xot more than 25 per cent of them 

 were killed. 



On July 28 blister beetles from a freshly cut field of alfalfa 

 gathered in a one-acre field of beets. About one-third of the patch 



