158 minnp:sota bill bugs. 



( Ainl)rosia si).), cabbaLiC lettuce and bean were not touched. S. .ccae 

 \\\\\ at least refuse mammotli red clover; alsace clo\er, and ragweed. 



Methods of Control — (Mainly for S. venatus). 



Exce])t in rare instances, attacks from billbugs are confined 

 exclusively to ri\er-bottoms and lake shore lands when a field of 

 corn and possibly wheat, oats or timoth}- is ]danted beside a field 

 of the yellow nutgrass or where all or a jiortion of the yellow nut- 

 grass is "turned over." 



In Illinois, where ^". l^an'iiliis exists, timothy appears to be a 

 ver\- dangerous crop to ]:)lant, but so far as observed, S. z'ciiatits and 

 -V. rjcac do very little if any damage. 



Fall and spring- plowing does not appear to control either 

 species for two reasons ; first, from a practical jjoint of view it would 

 be next to im])ossible to destroy all of the sedge, unless a ^■ery 

 thorough method of summer fallowing- was carried out. Th.is 

 would mean a year lost in time and money, especially so on ri\er 

 bottom land, which is subject to partial losses by high water; and 

 second, from preliminary experiments wdiere two adults of 5^. Tenatus 

 were placed at the bottom of and inside of a two-inch glass 

 tube with difierent heights of field placed on top of them. When 

 two. three, and four inches of soil was placed on top of the l)eetles, 

 they all reached the surface in three, four, and seven days, respect- 

 ively. In another lot, where two, two and one-half, and three and 

 one-half inches of wet, compact soil was used, the beetles reached 

 the surface in approximately three to ten days. It was discovered 

 that with this wet soil, thev would come to the top and go back 

 down again. 



On July 10, 1*U3, when the experiment was again tried, four 

 specimens of 6^. x'cnatiis were placed at the bottom of a tube one 

 inch in diameter, having fourteen inches of damp 1)Ut not wet field 

 soil in it. ( )n ]n\\ 18. or eighteen days after, one adult reached 

 the surface, but for two and one-half days this adult remained a 

 half inch below the surface ])efore coming to the top. ( )n July 

 22 another adult reached the surface and on August 2 the third 

 reached the top, but it was not until August 3 that the last billbug 

 made its escape, in a total i)eriod of twenty-four days. To be 

 conclusive, similar experiments should be tried under field condi- 

 tions ; however, the hint given is that late sjiring plowing might 

 prolong the period of emergence, provided the adults liibernate near 

 or on the surface; otherwise spring plowing would i)robably be a 

 detriment. 



