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Table 2.--Average weevil attack on the top and bottom 25% of families at the Little Benson and Clearwater test sites.
Families were ranked by average heights at various ages.
Test age
Comparative Trials
Little Benson test Clearwater test
Top Bot. Diff. Top Bot. Diff.
Initial ht. 15.5 18.2 2.7 28.7 40.8 12.1
3-year ht. 14.4 18.6 4.2 26.3 41.4 15.1
6-year ht. 10.4 19.7 9.3 22.4 43.8 21.4
10-year ht. 7.6 21.8 14.2 17.5 47.6 30.1
In 1992 another pilot project plantation was evaluated for weevil damage. This plantation was established in 1976 to
compare the relative performance of native British Columbian spruces with those originating from eastern Canada. Eastern
spruces up to now perform well in B.C., and we are planning to incorporate some eastern material into our breeding program.
This plantation is a replicated complete block design with 15 blocks, 10-tree row plots in each block from each of 21
families. There are 9 families from eastern Canada (ENA) and 12 families from B.C. (four each from East Kootenay (EK),
Prince George (PG), and Prince Rupert (PR)).
Results indicate that eastern white spruce is very resistant to the white pine weevil. Of the 1,220 eastern trees, only
67 were damaged by weevil, whereas 379 native spruces were damaged out of a total of 1,665 (Table 3). Interestingly, 25 of
the 67 individuals damaged were progenies of the same parent. These results are very significant in light of the fact that these
trees also grow and survive extremely well.
Table 3.--Weevil attack differences among families of different geographic origin.
Parents Number of trees
Source Number Alive Attacked Percent
ENA 9 1,220 67 5.5
EK 4 545 154 28.3
PG 4 562 85 15.1
PR 4 558 140 25.1
BC Total 12 1,665 379 22.8
Further proof of the resistance is demonstrated by the eastern North American white spruce clones (about 75 clones)
located in our breeding arboreta at the Kalamalka Forestry Centre. These clones are surrounded by native B.C. clones that
are heavily attacked by weevil yet eastern clones are almost void of attacks. It is not possible to treat these data using
statistical procedures due to the small number of ramets per clone (4), but there is no doubt about the trend.
DISCUSSION
Based on our observations, we must review weevil behavior on interior spruce. It has been postulated that in Sitka
spruce, white pine weevil preferentially attacked the most vigorous, longest, and thickest leaders (VanderSar and Borden
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