In northwestern Ontario, as reported last year, the area 

 sprayed in 1968 had a surviving population of budworm in 

 the core area near Burchell Lake, and at French Lake in the 

 northeast corner of Fort Frances Forest District. These areas 

 were re-sprayed in 1969 (see section on control). In addi- 

 tion, a new area of infestation of about 4,000 acres was dis- 

 covered south of Northern Light Lake near the Minnesota 

 border. It is believed that this new infestation may be asso- 

 ciated with the widespread infestation in Minnesota. 



In northeastern Ontario, the rpost important of many 

 widely scattered infested areas was a block of almost 2,000 

 square miles, north and northeast of the Town of Chapleau. 

 Because there was not any hope of justifying aerial spraying 

 to prevent the development of infestations throughout the 

 vast area of northeastern Ontario, largely because of the 

 cost/benefit relationships resulting from low over-all balsam 

 and white spruce values, the area is being studied from the 

 standpoint of future spraying to keep strategic areas of trees 

 alive and green. Some selective spraying may be necessary 

 in 1970 to prevent serious damage to valuable stands which 

 will have had three years of feeding by the budworm. Fore- 

 casts are for expanded and intensified infestations in 1970. 



In southeastern Ontario, the spruce budworm caused 

 noticeable defoliation of white spruce and balsam trees 

 throughout many areas of the Ottawa Valley, in total almost 

 1,200 square miles. One of the areas infested is a portion of 

 the Larose Forest, southeast of Ottawa, containing several 

 hundred acres of valuable white spruce stands. Because of 

 the extent of defoliation already present, this area is being 

 studied for possible spraying in 1970. 



Epidemics of the jack-pine budworm occur frequently in 

 northwestern Ontario, but fortunately the insect has not 

 had a history of causing serious damage to commercial 

 stands of jack pine in that area. In 1969, the current infesta- 

 tion in the northwest declined to an insignificant level. In- 

 festations in the east are much less frequent, but the current 

 epidemic in central and eastern Ontario is perhaps the most 

 severe on record. In view of forecasts for continuing high 

 populations during 1969, some spraying was necessary to 

 avoid serious damage and mortality of jack-pine stands. 

 Except in the areas sprayed, continuing high populations 

 are forecast for 1970, particularly in the French River-Lake 

 Nipissing area, and in the Lake Traverse area of Pembroke 

 Forest District. 



The forest tent caterpillar continued to defoliate stands 

 of poplars west and north of the Town of Fort Frances, 

 covering an area of more than 400 square miles. The infesta- 

 tion along the southern portion of Sault Ste. Marie Forest 



District declined to an area of 200 square miles, and this in- 

 festation is expected to die-out in 1970. 



The European pine sawfly did not add significantly to the 

 main body of its range in southern Ontario, the eastern 

 boundary being a line roughly from Midland to Kingston. 

 The insect also occurs on Manitoulin Island, and on orna- 

 mental plantings in the Cities of Sault Ste. Marie, North Bay 

 and Ottawa. 



The saddled prominent is a native insect which in the 

 past has rarely occurred in serious outbreaks in Ontario. 

 The current series of outbreaks in sugar maple stands in 

 many areas of southern Ontario, the most severe on record 

 here, were described in some detail in last year's report. 

 For the most part, infestations in Lake Huron Forest District 

 declined, and remained about the same in Lake Simcoe 

 Forest District, while new small infestations appeared in the 

 southern part of Lindsay Forest District, and the large in- 

 festation (900 square miles) in Parry Sound Forest District 

 spread westward and northward but declined along the 

 eastern boundary. This insect is subject to effective natural 

 enemies, including parasites, diseases and predators, and 

 therefore outbreaks usually do not persist for more than 

 two or three years in any locality. 



The Dutch elm disease, as noted last year, is now well 

 established as far north as Sudbury and Sault Ste. Marie, and 

 further spread northward, where elm trees are widely scat- 

 tered in the forest, will be slow. Consequently, there was no 

 significant change in the geographic range of Dutch elm 

 disease in 1969, but where it does occur the trees were 

 killed at an accelerated rate. 



During 1969, there was no change in the status of two 

 relatively new disease problems — the annosus root rot and 

 the scleroderris canker. 



Extensive damage of an uncommon type occurred in 

 late August when a wind storm caused a massive blowdown 

 north of the Town of Hearst. The blowdown swath was 10 

 miles wide and about 65 miles long. Progress is being made 

 in salvaging the timber. 



CONTROL OPERATIONS 



As mentioned in the 1968 report, a residual population of 

 spruce budworm remained in the core area of the large 

 Burchell Lake - Shebandowan outbreak sprayed in June, 

 1968. In 1969, a block of 22,000 acres was sprayed with feni- 

 trothion, about 8,400 acres of which received two applica- 

 tions, each at 5.7 oz. per acre, and the remainder received 

 one application. The 5,000-acre infestation at French Lake 

 was also sprayed twice at the 5.7 oz. rate. The sprays were 

 fully effective in bringing the persistent infestations under 



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