Forest Insects and Diseases 



Forest insect and disease problems in Ontario are shared co-operatively with 

 the Forest Entomology and Pathology Branch of the Canadian Department of 

 Forestry. The Province is responsible for initiating and conducting all control 

 operations on lands under its jurisdiction, and the federal government conducts 

 the surveys and research work on which control decisions are based. 



SURVEYS 



Each year, this Department participates to a large extent in the Ontario 

 portion of the Canada-wide Forest Insect and Disease Survey of the Federal 

 Department of Forestry. Detailed information concerning the occurrence and dis- 

 tribution of specific forest insects and diseases is contained in the Annual Report 

 of the Forest Insect and Disease Survey. 



The outbreak of spruce budworm in northwestern Ontario showed distinct 

 indications of weakening and declined in over-all area to about 5,500 square miles. 

 Within this area, there was a marked decline in the extent of severe defoliation. 

 The infestation is now confined to the eastern two-thirds of the Fort Frances 

 District and the adjacent south-west corner of the Port Arthur District. The 

 infestation of spruce budworm which had persisted in the southern part of the 

 Geraldton District for 10 years virtually disappeared in 1962. Only small pockets 

 of light infestation remain. 



In addition, three widely scattered small pockets of medium-intensity spruce 

 budworm infestation occurred in the Lake Simcoe and Tweed Districts of southern 

 Ontario. 



Most public interest was centered on the developing outbreak of the forest 

 tent caterpillar, although this insect in Ontario is not serious from the economic 

 standpoint. The caterpillar occurs in cyclic epidemics an average of every 10 to 

 12 years, and the current outbreak in Ontario is the eastern end of the over-all 

 epidemic which extends across the forested areas of the Prairies to the Rocky 

 Mountains. In 1962 the largest continuous block of infestation, affecting aspen 

 stands primarily, occurred in the Kenora and Sioux Lookout Districts over an area 

 in excess of 15,000 square miles. Several scattered small patches of infestation 

 occurred throughout northwestern Ontario, and in the Sudbury, North Bay, Pem- 

 broke and Parry Sound Districts in eastern Ontario. 



Larch sawfly populations across northern Ontario as a whole declined still 

 further in 1962 to the point of causing insignificant damage to tamarack trees. 

 Scattered small pockets of medium to heavy infestation persisted in the Geraldton, 

 Kapuskasing, Cochrane, Swastika, Sault Ste. Marie and Sudbury Districts. Moderate 

 to heavy infestations in several tamarack stands and European larch plantations 

 were reported from all of the most southerly row of districts across southern 

 Ontario, but were particularly noticeable in the Lake Simcoe, Lindsay and Tweed 

 Districts. 



The European pine sawfly in Scots and red pine plantations continued to 

 sxtend its range eastward in southern Ontario by an average distance of about 

 four miles. The most noteworthy eastern advance was along the north shore of 

 Lake Ontario, and in this vicinity has now reached Newcastle. The whole eastern 

 boundary of the infestation now extends roughly from Penetanguishene southerly 

 to Barrie and King City, and easterly to Orono and Newcastle. The insect is also 

 well established at two spot infestations farther to the east near Vernonville and 

 at Belleville. 



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