Annual District Reports: Forest Insect and Disease Survey ... - NFIS

3.2.3 Balsam-fir Sawfly, Neodiprion abietis complex:- Populations
were widely distributed throughout (Fig. 4). Light defoliation of
balsam fir and of white and black spruce, was recorded in patches from
Caddy Lake in the Whiteshell Forest Reserve north to Big Stone Lake,
and at Otter Falls, Manigotogan, and near Hazel Creek. Similar patches
occurred near the Marchand Headquarters in the Sandilands Forest
Reserve and throughout the Northwest Angle Forest Reserve. Light
defoliation also occurred on black spruce only at Dogskin, Family, and
Elliot lakes and moderate defoliation occurred on balsam fir at Sasaginnigak
Lake.
The most serious defoliation (up to 75 percent) occurred on
black spruce at several locations in southeastern Manitoba. One of
these was an area about l miles long and * mile wide along the
periphery of a large black spruce swamp west of the Contour Fire
Tower in the S.E. 1/4 of sec. 25, tp. 10, rge. 10, E.P.mer. A second
one was located within some 3D square miles that extended along both
sides of the Trans-Canada Highway from the western boundary of the
Sandilands Forest Reserve eastward about 6 miles in townships 7 and 8,
rge. 9, E.P.mer. A third affected most of the west half of see. 28,
tp. 1, rge. 12, E.P.mer. The fourth and fifth areas occurred west of
Menisino; south of the Morden-Sprague highway, the former affected an
area about 2 miles long and 1 mile wide, and north of the highway the
latter affected an area about 3 miles long and 1 mile wide. The sixth
and final one extended south from a point about 1 mile south of Woodridge
for about 7 1/2 miles to No. 12 Highway in a 1 to 1 mile wide band mainly
in townships 2 and 3, ranges 10 and 11, E.P.mer.
3.2.4 Yellow-headed Spruce Sawfly, Pikonema alaskensis (Roh.) .
Populations remained low and defoliation ranged from a trace to light
at widely scattered points. White spruce was lightly attacked at the
Whiteshell River on the Central Whiteshell Road, Crowduck, Bird,
Wallace, Manigotogan, Gem, Black, and Viking lakes, and black spruce
at Sasaginnigak, Gunisao and Big Stone lakes. In most cases defoliation
was confined to a few twigs per branch. Light to moderate defoliation
occurred on an occasional small white spruce from the Pinawa Channel
to Pointe du Bois, at Crowduck and Falcon lakes and along No. 4 Highway
at the Manitoba-Ontario boundary and on black spruce immediately
north of Pine Falls.
3.2.5 Black-headed Budworm, Acleris variana Fern:. This budworm
was commonly found throughout, but little serious defoliation occurred
(Fig. 5). Low populations occurred on white spruce at Caddy Lake,
along the Central Whiteshell Road at the Whiteshell River, near
Victoria Beach, and at Bird, Wallace, Long, Siderock, Gem, Sasaginnigak,
Dogskin, Family, Moar, Weaver and Molson lakes; on black spruce north
of Pine Falls, Wallace, Gem, Aikens, Sasaginnigak, Dogskin, Family, Black,
Moar, Charron, Gods, Stevenson, Weaver and Gunisao lakes; and on balsam
fir at Crowduck, Manigotogan, Hoar, Molson, and Eardley lakes. Higher
populations were recorded on white spruce at Eardley Lake, but only
light defoliation occurred.