19 



The value of a knowledge of etfective temperatures is well illustrated 

 in the case of the Hessian fly, and if we had more exact data of this 

 character concerning many of our pests it is not improbable that 

 valuable suggestions in their control would result. The paucity of 

 exact knowledge on some of these points with so common a species as 

 the cotton bollworm was brought to my attention recently in the 

 course of an attempt to determine the number of generations of this 

 species throughout the United States and Canada. Insects of such 

 wide distribution ofl'er exceptional opportunities for studying the 

 laws of temperature limitations and other factors of the greatest 

 interest and probable value. On such problems cooperation must 

 necessarily be secured. The desirability of this has often been the 

 occasion of remark in the proceedings of this Association and else- 

 where, but its accomplishment appears no nearer realization than 

 during the early daj'S of the society. 



Recent j^ears have witnessed an important change of sentiment with 

 regard to insect legislation, and its extent at the present day may 

 iloubtless be held as proof of its recognized value. However this may 

 be, the fact remains that, with few exceptions, the various States 

 have adopted laws which have for their end the restriction of one or 

 more species and, in numerous instances, the enforced control of pests 

 already established. 



A recent cc^nsus of legislation in the United States bearing on the 

 control of insect pests shows that of the forty-eight States and Terri- 

 tories the following only are yet without operative laws, and some of 

 these have bills in preparation for passage at coming legislative 

 assemblies: Arizona, Florida, Kansas, Xebraska, Nevada, New Mex- 

 ico, Oklahoma, South Dakota, Texas, Vermont, and Wyoming. The 

 following insects are mentioned as coming under the operation of 

 various laws, and in many cases provision is made for the designation 

 of other species which at any time it may be judged desirable to quar- 

 antine or whose control should be enforced. 



PHYTOl'TID-E. 



Pear blister mite (EriopJiycs pyri Pat>renst. ). 



ORTHOPTEUA. 



Grasshoppers (MclannpUis -sprctiis Tlios. ; J/, atlaids Riley; .1/. bivittatits Say, 

 etc.). 



HE.MIPTERA. 



San .Jose scale (AxpiJiotus pcrniciosns Coiust). 

 Cherry scale {Aspidiotu-'i forbcsi Johns.). 

 European fruit-scale (Aspidiotus ostrewfoniii-^ Curt.), 

 (ireedy scale (Aspidiotus rapax Conist. ). 

 Walnut scale {Aspidiotus jiujlanf^-reuia' Com'ni.). 



