BLISTER BEI:TLES 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 consistentl}^ 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 feAv 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. 



Repellents. 



To determine AA'hat substances possess the greatest repellent prop- 

 erties, part of a cluster of beet plants was 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 70 beetles introduced. 

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

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

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

 beets sprayed Avitli water Avere defoliated. 



Contact IxsKCTicmES. 



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 Avater, killed beetles that 

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

 on Avhich the a2)p]ications were made. Xo othei- contact insecti- 

 cides Avere 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 Avere the small-si)otted blister beetle {Epi- 

 cauta imiculata) , but the outbreak included a feAv of a large gray 

 blister beetle or spotless blister beetle {Macrohas-ls immaculata) . The 

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

 of the field, and on the remain(kn- the beetles Avere feeding. They 

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



The beets where the beetles Avere feeding Avere sprayed Avith 1 

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

 were sprayed Avith 1 pound of /inc arsenite in 32 gallons of Avater, 

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

 Avater, and the remainder left as a check. The beets Avere so small 

 and so badly eaten before being sj)rayed that they never recovered. 



