22 THE REPORT OF THE ■ No. 36 



Table Showing Percentage Infestation of Various Grasses and Mortality 

 Among the Cephus Larvae. 

 Winter Rye. 



Sown in 1920 tout not out; 21 per cent, of stems not infested. 



Larvae matured 19 



'Larvae dead SI 



Volunteer crop among other grasses; 19 per cent, of stems not infested. 



Larvae matured 11 



Larvae dead; cause unknown 78 



Larvae parasitized 11 



Brome Grass (B. Enermis.) 



Collected in August; 12 per cent, of stems not infested. 



Larvse mature 23 



Larvae dead, cause unknown 37 



Larvae 'parasitized 40' 



Collected in October; 14 per cent, of stems not infested. 



Larvae mature 8 



Larvae dead, cause unknown ; 44 



Larvae parasitized 48 



Collected in late October; 13 per cent, of stems not infested. 



Larvae mature 2 



Larvae dead, cause unknown 44 



Larvae parasitized 54 



Agropyron tenerum 



Collected in October; 32 per cent, of stems not infested. 



Larvae mature 42 



Larvae dead, cause unknown 20 



Larvae parasitized 38 



Agropyron richardsonii 



Collected in August, 24 per cent of stems not infested. 



Larvae mature 40 



Larvae dead, cause unknown 19 



Larvae parasitized 41 



Collected in October; 21 per cent, of stems not infested. 



Larvae mature 32 



Larvae dead, cause unknown 7 



Larvae parasitized 61 



Lyme grass (E. canadensis.) 



Collected in August; 24 per cent, of stems not infested. 



Larvae mature 30 



Larvae dead, cause unknown 34 



Larvae parasitized 36 



Collected in October; 16 per cent, of stems not infested. 



Larvae mature 26 



Larvae dead, cause unknown : 37 



Larvae parasitized 37 



The above tables are compiled from the examination of several hundred 

 stems in each instance. 



THE EUROPEAN CORN' BORER (Pyrausta nubilalis Hubn.) : 

 LIFE HISTORY IN ONTARIO. 



H. G. Crawford, Entomological Branch, Ottawa, and 

 G. J. .Spencer, Ontario Agricultural College, Guelph, Ont.* 

 The apology for presenting so incomplete a study rests upon the fact that 

 this is a recently introduced and already widely distributed insect, spreading with 

 great rapidity and capable of doing very serious damage. ConsequeDtly, its re- 

 action to Canadian conditions where it has demonstrated its ability to increase 

 over 300 per cent, in a single year, and where its presence results in severe 

 damage to our corn crop, cannot but be of interest and value. 



* A joint progress report of the life history studies carried on at the laboratories 

 t the Dominion and Ontario Departments of Agriculture in the season of 1921.. 



