1916 ENTOMOLOGICAL SOCIETY. 93 



That he understood the nature of this reaction may Ijc deduced from his statement 

 that the plant is compeJled to furnish a defonnity that serves to nourish the 

 deposited eggs of the insect. He must have observed the producers very closely, 

 as he gives a detailed account of the curious ovipositor of the Cynipidae, and 

 mentions, also, the stalked character of their eggs. He further discovered that 

 the galls are not left to the undisputed possession of the producers, but are in- 

 habited by other insects. He seems to have grasped fully the importance, not only 

 of a close study of the host i)lant, l)ut also of the habits and structure of the 

 insect parasite. 



Malpighi has recorded a number of reflections concerning the biological re- 

 lation between ])lant and insect in gall formation. His theory summarized in 

 brief is that a poison, introduced at the time of oviposition, breaks down the sub- 

 stances of the cell sap, and diverts the currents of its transference into wrong 

 channels, thus producing malformation by causing the growth energies of the plant 

 to be wrongly directed. 



Particularly interesting to us, as students of insect life, is the fact that the 

 founder of the science of cecidology, realized the importance of the entomological 

 viewpoint of the subject. 



The President : As the writer of this paper is not present and as its his- 

 torical nature rather frees it from any discussion, we will proceed to the next paper 

 by Mr. Strickland on *' The Army Cutworm in Southern Alberta." 



THE AEMY CUTWORM IZvT SOUTHERN ALBERTA. 



E. H. Strickland, Extomological Branch, Department of Agriculture, 



Ottawa. 



The Army Cutworm (Eu.voa aia-iliaris) is new to Canada as a field pest, 

 though it is a native species of the Western Provinces. Fletcher recorded it in 

 1903 as injurious to gardens in Regina and Calgary, but apart from this report 

 the insect has not been described as one of any economic importance in Canada. 

 Since 1898 it has been a frequently recurring field pest in Montana, where it was 

 given its popular name. 



In 1915 an extensive outbreak of this insect occurred in Alberta, and covered 

 a territory of about 3,000 square miles. The resulting study of the insect from an 

 economic standpoint brought to light several interesting features in its life-history 

 and habits. 



The eggs are laid in September and October, mainly upon weedy fields. We 

 were unable to find eggs in the field, but in all the experiments in which we re- 

 produced natural conditions in so far as we were able the eggs were laid in the 

 soil — near, but never actually ui)on, vegetation. This suggests, therefore, that even 

 though the eggs of this specit\-^ may be found on vegetation the majority of them 

 are laid in the soil. We believe that this will be found to be true of several other 

 cutworms which are described as laying their eggs exclusively on vegetation. 



The eggs hatch in the autumn, and the young larvae hibernate in the soil. 

 Soon after the frost is out of the ground in the spring they come to the surface and 

 feed upon the weeds. When the cutworms are numerous they soon destroy all of 

 the weeds upon the fields where they hatched and have passed the winter. Then, 

 like the Armv-worm, thev move off more or less in a body in search of inore food. 



