PROCEEDINGS, 1917. 49 



cauliflower, beets, mangolds, potatoes, beans, apple, hydrangea, sweet pea, garden pea, 

 pigweed and numerous cultivated flowers. The chief damage is done by the second 

 brood, late in the season; whole fields of turnips are often destroyed and the adjacent 

 crops attacked. 



NATURAL ENEMIES. 



Dipterous and hymenopterous parasites were reared during this investigation but 

 at the time of writing have not been determined. 



ACKNOWLEDGEMENTS. 



The writer is indebted to Prof. W. H. Brittain for advice and assistance in his work, 

 also to Mr. L. G. Sanders who carried on the work at the laboratory alone for two 

 weeks at the later part of the season. 



THE FALL CANKER WORM 



(Alsophlla pometaria Harris) 



H. G. Payne. 



FOR THE PAST three years many parts of the Annapolis Valley have been visited 

 by severe outbreaks of the canker worm, resulting in the defoliation of many acres 

 of orchard. While the life history of this pest has been well known in a 

 general way for some time a more detailed study of the insect does not seem to have been 

 attempted. The following paper is an account of the studies made during the season of 

 1917. It should be noted that this season was unusually late, from eight to ten days 

 later than the average. 



THE EGG. 



The female moth usu'ally deposits her eggs on the young twigs of the tree, often in 

 exposed positions, but in cases of severe infestations the tree trunl s and larger branches 

 are utilized for this purpose. Egg deposition extended over a long period, from the 

 first of November well on to the end of the month when the severe frosts stopped the 

 emergence of the adults. On December the 24th and twenty-fifth there came a mild 

 period and many more moths emerged, oviposition being resumed. It is, therefore 

 quite conceivable that under certain weather conditions a considerable proportion of 

 the eggs might not be deposited until early spring. The eggs hatched in the spring from 

 the latter part of May to the middle of June, the maximum emergence being about the 

 end of the first week in June. 



Description. — The eggs are laid in a long narrow flat mass one layer deep, closely 

 contiguous. General color purplish gray to brown. Cylindrical in form; .56 mm. high, 

 .5 mm. in diameter. Chorion smooth and shining. Centre of cap finely and irregularly- 

 sculptured and indented in the middle; surrounding this sculptured portion a raised 

 chain-like ring of darker brown occurs. 



It may be noted here that the twenty specime is reared in this experiment all 

 emerged in the insectary from the first to the middle of November, wnile the notes on 

 the length of the egg laying period are from field observations. 



THE LARVA. 



The larva on emerging from the egg eats through the indented area of the cap, 

 increasing the size of the hole until it is large enough to permit escape. The young lar- 



