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

2.2.10 Fall Cankerworm, Alsophila pometaria (Harr.):- Populations of
this defoliator increased notably and several new infestations were
reported in both urban and rural areas. Severe defoliation of Manitoba
maple, white elm, green ash and basswood occurred in Kildonan Park and
on Fraser's Point in the City of Winnipeg, and light to moderate infestations
were common throughout the remainder of the Metropolitan area.
Similar conditions were reported along the Red River Valley from Emerson
north to Winnipeg, and west from. Lockport and Selkirk to Warren.
The most extensive infestation occurred in Edwards Municipality
(Lyleton) in southwestern Manitoba. Field plantings of Manitoba maple,
white elm, green ash and Manchurian elm were almost completely stripped
of foliage in sections 7 to 9, 17 to 29, and 30 to 36 in township 1,
range 28, W.P.mer., and in sections 1 to 5 and 6 to 11 in township 2,
range 28, W.P.mer. In addition, light defoliation occurred in other
shelterbelt and field plantings up to two miles on the outside of the main
infestation area, and moderate defoliation was recorded in a windbreak
of white elm at Dalney, approximately ten miles to the east.
2.2.11 Boxelder Twig Borer, Proteoteras willingana Kft.:- Light populations
of twig borers were recorded in practically all Manitoba shelterbelts
examined. Larval counts at three permanent sampling points in southwestern
Manitoba (which are shown in Table 2) showed a slight increase in numbers
in some areas.
TABLE 2
Boxelder Twig Borer Population Counts
Southwestern Manitoba-1963
(based on examination of four branches 36 inches long from
each crown level of five trees at each, sample point)
No. of twigs examined and twig borer
Av. Av. Av.
Populations b Crown Level
Location ht. crown crown LOWER MID UPPER
(ft.) depth width No. No. No. No. No. No.
(ft.) (ft.) of of of of of of twigs borers twigs borers
Souris 25.0 19.0 11.0 359 10 411 9 359 8
Holland 25.0 20.0 12.0 322 8 318 8 338 6
Sidney 5.0 21.0 13.0 352 5 303 12 338 9
2.2.12 American Aspen Beetle, Gonioctena americana (Schaeff.):-
Collections of this leaf eating beetle were taken at widely scattered
points throughout both the Interlake section and southwestern Manitoba.
The most notable damage occurred at Mile 80 along the Gypsumville-Grand
Rapids Highway where relatively high beetle populations caused moderate