TABLE OF CONTENTS 



PAGE 



Theory of Toxicity C. W. Woodworth 509 



A New Mixture for Controlling Wood-boring Insects, Sodium Arsenate-kero- 



sene Emulsion F. C. Craighead 513 



Is otes on Ichneumon loetus H. H. Knight 514 



Some Notes on the Western Twelve-spotted and the Western Striped Cucum- 

 ber Beetle R. A. Sell 515 



Leptinotarsa decemlineaia W, C. Elli^ 520 



Experiments in the Control of the Poplar and Willow Borer, Cryptorhynchm 



lapathi Robert. Matheson 522 



Estimating the Number of Grasshoppers E. D. Ball 525 



Some Developments in Grasshopper Control F. M. Webster 527 



Some Studies on the Snowy Tree-cricket with Reference to an Apple Bark Dis- 

 ease P. /. Parrott, W, C. Gloyer and B, B. Fulton 535 



A New Species of Gonatocerus (Mymarid^e) Parasitic on the Eggs of Idiocerus 



(B3i;hoscopid8e) Feeding on Poplar M. D. Leonard and C. R. Crosby 541 



The Poisonous Effects of the Rose Chafer upon Chickens G. H. Lamson 547 



Scientific Notes 549 



Editorial 555 



Current Notes 556 



