Forest Insect and Disease Survey; Ontario, 1965 - NFIS

E, 15
Table 16
Summary of White-pine Weevil Attack on Eleven Strains of Scots Pine in German Township
Note: Growth rate . based on the average length of 10 representative leaders for each
strain.
Origin
of seed
No. of trees
examined in
1965
a verage
leader
growth
in inches
Per cent
of trees
attacked
Per cent of infested
leaders
Killed
Survived
Auvergne 60 6 23 78 22
Haute Loire 5
77
17 77 23
:Finland 83 5 11 11 89
South Finland 63 5 19 75 25
cevennes 126 5 39 61 39
Adirondack 92 7 0 0 0
East Baltic 172 9 25 23 77
Sweden 102 9 15 7 93
West Europe 162 10 15 58 42
Lower Austria 93 11 27 32 68
West Baltic 144 12 39 16 84
Balsam Shoot-boring Sawfly, Pleroneura borealis Felt
Population levels of this primitive sawfly were considerably reduced, however,
small numbers of trees were heavily infested at several points in the district
(Table 17).
Table 17
Summary of Balsam Shoot-boring Sawfly Counts in the cochrane District from 1963 to 1965
Note: Based on the examination of all buds on four branch tips from each of five trees
at each point.
Av.. ht. of
No. of shoots
Location sample trees examined Per cent of shoots infested
(township) in feet in 1965 19 3 19
Haggart 26 379 .5 4.4 0.0
Thorneloe 12 386 0.0 12.0 0.0
Calder 28 385 3.9 7.3 4.6
Timmins 26 389 1. 4.2 3.7
Pharand 21 376 4 11.1 2.8