LAWSON : KANSAS CICADELLID^. 2i) 



freezes, and snows of winter, regardless of whether hiberna- 

 tion occurs in the egg, nymphal or adult stage. Actual ex- 

 perimentation with extremes of heat and cold, controlling also 

 tl^e moisture conditions, should give us interesting and per- 

 haps very instructive data as to just what part climatic con- 

 ditions do play in the control of such insects. 



