BLISTER BEETLES IN KANSAS. 23 



During these experiments Paris green has, except in one instance, 

 killed the beetles in less time than zinc arsenite. Its killing time has 

 been consistently shorter throughout than lead arsenate in quantities 

 that it is practicable to apply. The results from Bordeaux mixture 

 do not justify its use in this connection. Of the beetles poisoned 

 during these experiments very few remained in sight. Most of them 

 were to be found among the bases of the stems or under clods about 

 the base of the plant. 



IvEPELLENTS. 



To determine what substances possess the greatest repellent prop- 

 erties, part of a cluster of beet plants Avas sprayed with Paris 

 green, part with Bordeaux mixture, part with fish-oil soap, part with 

 nicotine sulphate, and the remainder with; water. A large screen 

 cage was then set over the beets and about TO beetles introduced. 

 They scattered over the plants indiscriminately, but none fed on^tihe^ 

 ones treated with Paris green and Bordeaux. A little foliage was 

 eaten from the plants treated with nicotine sulphate and soap. The 

 beets sprayed with water were defoliated. 



Contact Insecticides. 



Lime-sulphur in strengths up to 30 per Cent did not produce satis- 

 factory results. The weaker solutions had no effect on the beetles 

 and the stronger ones stunted the beets. 



Whale-oil soap, 1 pound to 2 gallons of water, killed beetles that 

 could be thoroughly wet, but injured both sugar beets and potatoes 

 on which the applications were made. No other contact insecti- 

 cides were tested. 



CONTROL MEASURES IN INFESTED FIELDS. 



On June 23. 1913, blister beetles attacked a half-acre field of 

 sugar beets at the Garden City branch of the Kansas Experiment 

 Station. Most of them were the small-spotted blister beetle {Epi- 

 cauta metadata) , but the outbreak included a few of a large gray 

 blister beetle or spotless blister beetle (Macrobasis immaeulata) . The 

 little four-leaved plants had been stripped to the midribs over most 

 of the field, and on the remainder the beetles were feeding. They 

 were also crossing the road into a patch of Irish potatoes. 



The beets where the beetles were feeding were sprayed with 1 

 pound of lead arsenate in 9 gallons of water. Part of the potatoes 

 were sprayed with 1 pound of zinc arsenite in 32 gallons of water, 

 part with 1 pound of Paris green and some lime in 40 gallons of 

 water, and the remainder left as a check. The beets were so small 

 and so badly eaten before being sprayed that they never recovered. 



