Pests of Specific Crops

Pest Description
Phytophthora Root Rot and Shoot Blight
(Phytophthora spp.): Death of seedlings;
browning and flagging of lower branches on
older trees; stunting and sunken cankers on
stems or on trunk just above soil line. There is
swelling above the canker and wood is stained
brown under the bark, unlike Grovesiella. Trees
are usually affected within 3-4 years of
planting and often in pockets or groups.
Rusts:
Fir-Fern Rust (Urediniopsis spp.)
Fir-Bracken Rust (Urediniopsis spp.)
Fir-Fireweed Rust (Pucciniastrum spp.)
Fir-Blueberry Rust (Pucciniastrum spp.)
Fir-Willow Rust (Melampsora sp.)
Fir-Broom Rust (Melampsorella spp.)
White or yellow, cylindrical fungal structures
called “aecia” appear on the underside of
needles. Alternate hosts (fern, fireweed-
Epilobium spp. and willow) have yellow leaf
spots. Severe infestations can cause needle
drop, growth loss or death of trees.
Scleroderris Canker (Gremmeniella abietina): Does
not occur in BC. Causes shoot blight and
cankers on pines and balsam fir in Eastern
Canada.
Chemical Control
(rate per 100 L water; or per
unit area if indicated)
See General Disease Management:
Root Rots Caused by Phytophthora
and Pythium, Chapter 9.
Cultural
Management
Do not plant Abies spp. on
poorly drained soils.
Remove alternate hosts
within 300 m of fir. Cool,
moist spring weather
promotes infections.
Seedling Blight (Sirococcus conigenus): See under PICEA - SPRUCE and General Disease Management: Sirococcus Blight,
Chapter 9.
Insects:
Balsam Gall Midge (Paradiplosis tumifex): The adult
midge appears when fir buds are developing.
The female lays eggs in the opening buds. The
larva feeds at the base of a needle, initiating the
growth of gall tissue that will eventually enclose
the larva. Galls are formed on current season
needles. Infested needles yellow and abscise in
the fall. The larvae overwinter in the soil.
Balsam Woolly Adelgid (Adelges piceae): Branches
and tips become swollen, which results in a
“bird-claw” appearance. White woolly masses
appear on bark. Most severe damage on Fraser
and alpine fir.
ACER - MAPLE
Diseases:
Anthracnose (Kabatiella apocrypta and Discula spp.
(Apiognomonia)): Brown to white irregular
blotches appear on the leaves. Twigs dieback.
The causal fungus overwinters on twig cankers
from which spores are splashed when hit by
rain or irrigation water.
MOVENTO 240 SC: 585 mL/ha
BANNER MAXX: 28 mL
Apply every 14 days. Do not
apply more than 4 times per year.
All Abies must be grown
under permit. See British
Columbia Plant Protection
Regulations, Chapter 2.
Remove dead and damaged
twigs and those with visible
cankers to reduce inoculum.
Minimize sprinkler irrigation
or schedule applications so
the foliage has opportunity
to dry off quickly. Rake and
burn fallen leaves.
2 • Pests of Specific Crops Nursery Production Guide