Pests of Specific Crops

Pest Description
Pear Trellis Rust (Gymnosporangium fuscum): Orangered
spots with black centres appear on leaves in
June-July. By late August, the spots thicken and
spores emerge in spiky tufts from the lower leaf
surface. Fruit and twig infections may occur on
trees with large numbers of leaf infections. Juniper
is the alternate host. Spores from juniper must reinfect
pears each year, although in some cases
repeating infections can occur from twig cankers.
The disease is common in the Lower Mainland,
but not in the Interior. A Domestic Movement
Certificate is needed to transport pear nursery
stock out of the Lower Mainland. See British
Columbia Plant Protection Regulations, Chapter 2.
Scab (Venturia pirina): See under MALUS.
Insects and Mites:
Pear Leaf Blister Mite and Pear Rust Mite (Eriophyes
pyri and Epitrimerus pyri): Almost microscopic,
white, worm-like mites produce blistering and
russeting on leaves and fruit. The mite is within
the blisters and is difficult to control during the
growing season. Best control is achieved with a
dormant spray.
Pear Psylla (Psylla pyricola): Adults are green to
brown and overwinter on the trees or on the
ground and become active in March. Eggs are
laid in spring before buds open during
blossoming. Nymphs invade buds and feed on
developing leaves and flowers. Later they
move to leaves and live in honeydew drops.
Summer eggs are laid on leaves. Three to five
generations occur per season. Leaves blacken
with sooty mould and fall off.
Not known to be a pest in Coastal nurseries.
More common in Interior orchards.
Pear Sawfly (Caliroa cerasi): Adult is a shiny, black fly
with four wings. Black slug-like larvae
skeletonize leaves in summer.
Chemical Control
(rate per 100 L water; or per
unit area if indicated)
NOVA 40W: 34 g
Repeat at 14-day intervals. No
more than 6 applications per
year.
CAPTAN 80 WDG: 120 g; do
not use Captan on ‘Anjou’.
EQUAL 65W: 3.25 kg/ha; do
not use in the Interior where
resistance is common.
FERBAM 76 WDG: 200 g
INSPIRE: 292 mL/ha
KUMULUS DF: 400-750 g
LIME SULPHUR: 125 mL
MAESTRO 80DF: 3.75 kg/ha;
do not use on ‘Anjou’.
SULPHUR: See labels.
Cultural Management
Do not plant ornamental
pears as landscape trees in
the Lower Mainland. Avoid
planting pear trees within 30
m of susceptible junipers.
Pick off infected pear leaves
as you see them. The leaves
and fungus will die quickly if
removed in mid-summer.
In addition to the control
measures used for apple scab,
pear scab control also
requires measures to reduce
overwintering on twigs.
Prune out severely infected
twigs during dormant season.
Apply dormant or delayeddormant
lime sulphur.
European canker can infect
through scab lesions on
twigs.
See General Insect and Mite Management: Mites, Chapter 11.
AGRI-MEK 1.9% EC: 20-40 mL + 0.25% PARAFFINIC SPRAY OIL
DIAZINON 50WSP: 150 g + 1 L of HORTICULTURAL OIL
DYNO-MITE or SANMITE: 28.4 g
KUMULUS DF: 200 g
True dormant stage only:
LANDSCAPE OIL: 3 L
LIME SULPHUR 23%: 10 L
ACTARA 25 WG: 315-385 g/ha
AGRI-MEK 1.9% EC: 20-40 mL + 0.25% PARAFFINIC SPRAY OIL
DECIS 5 EC: 6.8-11.8 mL
DIAZINON 50EC or 50WSP: 100 mL or 100 g
IMIDAN 50-WP: 3.75 kg/ha
INSECTICIDAL SOAP 47% or 50.5%: 2 L
MALATHION 500 E: 125-250 mL
POUNCE 384 EC: 17.5-35 mL. Use the low rate to control
overwintering adults prior to bloom.
RIPCORD 400 EC: 7.5 mL
SEVIN T&O: 230-350 mL
True dormant stage only:
LANDSCAPE OIL: 2 L
SUPERIOR 70 OIL: 2 L
Treat when damage is first noticed in spring and again in July-
August. See General Insect and Mite Management: Sawflies,
Chapter 11.
Nursery Production Guide Pests of Specific Crops • 35