Forest Insect and Disease Survey; Ontario, 1965 - NFIS

D 29
Birch Skeletonizer, Bucculatrix canadensisella Chamb.
The outbreak of the birch skeletonizer which was widespread in 1963 and 1964
declined in extent in 1965. Pockets of heavy infestation were observed in Peters
and Cosens townships along Highway 101 and in Benton Township near the Wakami. River.
Understory birch was most seriously defoliated at these locations. Medium infestations
occurred on white birch stands in Leeson and Brackin townships near Misnaibi
Lake.
Larch Casebearer, Coleophora laricella .)
Numbers of this casebearer increased in 1965. In Chapleau Township a count of
12.5 larvae per 18 inch branch tip in one stand of mature tamarack was the highest
recorded in recent years.
The parasite Agathis pumila (Ratz.) killed 31 per cent of the larvae in a
sample from this area. The insect occurred in small numbers in Hoey Township and
northeast of Little Wakami Lake in Township 10A.
A Scolytid Beetle of Jack Pine, Conophthorus sp.
High numbers of this twig borer occurred in 1963 but declined sharply in 1964.
A further reduction in numbers was evident in 1965 (Table 5).
TABLE 5
Summary of Damage by Conophthorus sp. on Jack Pine Trees
in the Chapleau District from 1963 to 1965
Location
(township)
Av. height
in feet
Total no. of dama:ed shoots on ten trees
196 1964 1965
Panet 17 56 37 5
28 16 81 19 13
11B 21 161 14 0
12F 17 243 27 2
Halsey 16 251 37 8
11G 15 - 20 0
American Poplar Leaf Beetle, Gonioctena americana (Schaeff.)
Little change in numbers was observed. The favoured host was trembling aspen
reproduction adjacent to mature stands. Moderate defoliation occurred at the north
end of D'Arcy Lake in D'Arcy Township and eight foot reproduction on a silty lowlying
clearing in Borden Township was completely defoliated by this gregarious
feeder.
Occasionally reproduction in well-stocked mature stands of trembling aspen
supported high numbers of larvae but damage was confined to suppressed growth.
Aspen Blotch Miner, Lithocolletis salicifoliella Chamb.
Heavy infestations of aspen blotch miner have persisted on trembling aspen