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

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3.2.15 Fall Webworm, Hyphantria cunea (Drury):- Populations of this
webworm were slightly higher than in 1962 and caused moderate to
severe defoliation of individual alder, green ash, elm, balsam poplar,
birch, willow and chokecherry at scattered points in the eastern part
of the District. Feeding was confined mainly to the smaller reproduction
trees. The stink bug, Podisus modestus Dail., was observed
feeding on larvae in the Moose Lake area.
White birch was moderately defoliated in the Agassiz Forest
Reserve north of No. 4 Highway. Moderate to severe defoliation occurred
on occasional alder clumps in the McMunn -East Braintree area and
near White Lake in the Whiteshell Forest Reserve; on willow in the
Birch Lake area; and on balsam poplar, green ash, elm, and chokecherry
north of Moose Lake in the Northwest Angle Forest Reserve.
3.2.16 Western Tent Caterpillar, Malacosoma pluviale (Dyar):-
Slightly higher populations of this tent caterpillar were found on
chokecherry, pincherry, trembling aspen, birch and alder. Light to
moderate feeding on chokecherry was noted at Big Whiteshell Lake,
near the Whiteshell River along the Central Whiteshell Road and at
Bird Lake, Crowduck Lake, and Gods Lake. Pincherry was light to
moderately defoliated at Wallace and Long lakes. An occasional snail
trembling aspen was moderately defoliated just north of Caribou Lake,
and young birch at Black Lake. Alder was lightly attacked near Bird
Lake.
3.2.17 Yellow necked Caterpillar, Datana ministra (Drury):- This
caterpillar was collected from birch, burak, willow and elm. Light
infestations were noted on birch at Crowduck Lake; on willow north of
Pine Falls and at Dawson Cabin, and on elm in the Northwest Angle
Forest Reserve. Moderate infestations were recorded on birch in the
Falcon Lake West Hawk Lake area; on willow at Black Lake; and on bur
oak at the Whiteshell River along the Central Whiteshell Road, at the
junction of -No. 4 Highway and the Central Whiteshell Road, and mile
south of St. Malo.
3.2.18 Birch Skeletonizer, Bucculatrix canadensisella Cham.:- This
skeletonizer caused light damage to the foliage of birch at Otter Falls
in the Whiteshell Forest Reserve and at Big Stone Lake in northern
Manitoba. Higher populations were detected 9 miles north of Pine Falls,
where light to moderate skeletonizing was observed on several trees
(Fig. 8).