Forest Insect and Disease Survey; Ontario, 1965 - NFIS

C7
occurred in the city of North Bay and in adjacent urban areas in Widdifield and West
Ferris townships.(see photograph)
Cocoon dissections were made at four locations to determine the degree of
parasitism and disease within the infestation. Normally, the degree of parasitism
tends to increase in relation to the duration of the infestation. However, for
unknown reasons, records in 1964 and 1965 show the opposite trend (Table 7).
TABLE 7
ummary of Forest Tent Caterpillar Cocoon Dissections at Four Points
in the North Bay District in 1964 and 1965
Note: Based on the examination of 100 cocoons at each point.
Per cent Per cent Per cent
Per cent cocoons cocoons unsuccess. Per cent
Location emergence parasitized diseased emergence predation
township l6 16. 1964 196 l6 1 6 l964 l6 1964 l965
Martland 24 49 76 41 0 9 0 1 0 0
Caldwell 20 57 69 41 7 2 3 0 1 0
Kirkpatrick 41 47 55 41 0 9 3 2 1 1
MacPherson 71 65 27 28 0 7 2 0 0 0
Defoliation forecasts for 1966 are based on egg band surveys made inside and on
the fringe of 1965 infestations (Table 8). The reliability of these forecasts may
be influenced by temperature extremes which in some instances affect egg development
or cause mortality of immature larvae.
TABLE 8
Summary of Forest Tent Caterpillar Egg Band Counts and Defoliation
Forecasts for 1966 in the North Bay District
Location Av. no. of egg bands per Defoliation forecast
township tree, 4-6 in. d.b.h. for 1966
Badgerow 42
Severe
Loudon 96 "
East Ferris 17
n
Bastedo 2
Light
Widdifield 2
Crerar 1 "
Beaucage '6
Severe
Bonfield 1
Light
Dana 0
•••
Phelps 0