Forest Insect and Disease Survey; Ontario, 1965 - NFIS

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TABLE 13
Survival of Phyllocolpa sp. in Leaf-folds of Balsam Poplar
in the Kapuskasing District in 1965
Note: Samples were collected from mid-July to mid-August at different locations
and are list chronologically.
Location
(township)
Total no.
of folds
examined
Eggs
unhatched
Eggs
parasitized
Per cent of fold
No feeding
scars
with
Feeding
scars but
no larvae
Feeding
scars and No
larvae egg
Nansen 60 1.7 16.7 15.0 18.3 40.0 8.3
Gurney 55 1.8 7.3 14.6 30.9 38,2 7.3
Torrance 58 3.4 304 0.0 - 25.9 65.5 1.7
#138 59 0.0 10.1 5.1 35.6 30.5 3.4
Fauquier 24 0.0 0.0 4.2 62.5 25.0 0.0
Nine doubtful folds were recorded in the sample from #138 Township and two from
Fauquier Township.
A Leaf-folding Sawfly on Trembling Aspen, Phyllocolpa sp.
A marked increase in population levels of this leaf-folding sawfly occurred
in the district in 1965. Heavy infestations were recorded in Rogers Township and
in Township #138. The light infestation that occurred in McCoig Township in 1964
increased to medium intensity in 1965 and medium infestations also developed in
Nansen and Studholme townships. Light infestations were recorded in the townships
of Burrell, Clavet, Parnell and Williamson. Small numbers were found in the remainder
of the district.
The results of quantitative sampling shown in Table 14 reveals an increase in
population levels at all six sample locations.
TABLE 14
Summary of Leaf-folding Sawfly Counts Based on the Examination of 100 Leaves
Taken at Random From Three Trembling Aspen Trees at Each Location
Total no. of leaves
Location Av. height infested Total no, of folds per 100 leaves
(township) in feet 1964 165 1964 19q
Gill 12 1 5 1 8
Wicksteed 9 0 9 0 12
Gurney 15 0 3 0 3
O'Brien 12 4 9 4 11
Parnell 12 1 8 1 9
Torrance 10 1 2 1 2