Notes on Apple Insects
Oriental fruit moth
Identification
Adult oriental fruit moths (OFM) are small, dark grey moths, 8-10 mm
long, with wavy, light grey bands. Adult females lay eggs on leaves and
fruit. Mature larvae have brown head capsules, three pairs of legs and
distinct pink bodies. OFM larvae look very similar to codling moth (CM)
larvae except they have an anal comb, which can be seen under a microscope.
OFM larvae attack the terminals and fruit of apples. Frass is present
on the terminal and infested shoots wilt. Fruits damaged by CM and OFM
have similar symptoms and can be difficult to diagnose correctly. Both
CM and OFM larvae burrow into the apple and leave dark frass or fecal
matter at the entry point. OFM larvae most commonly enter fruitlets via
the calyx. Late season OFM damage is often difficult to detect and infested
apples can make their way through a packing line unnoticed.
Period of activity
The OFM overwinters as a mature larva in tree bark and orchard debris.
Other sources of infestation include fruit baskets, bins and packing barns.
OFM adults begin to emerge in late April and this pest continues to be
present in apple orchards through October. There are three to four generations
per year.
Monitoring and thresholds
Currently, there are no thresholds for OFM in Ontario apples. In orchards
with a history of damage from this pest, monitor populations using pheromone
traps.
Management notes
Oriental fruit moth is a pest of apples in southern Ontario (Niagara,
Norfolk, Essex, Middlesex). Codling moth damage is similar to OFM damage
so proper identification of the pest is essential for good control. Use
pheromone traps to monitor OFM activity.
Currently there are two insecticides and two mating disruption products
registered for managing OFM in apples.
Insecticides: Insecticides are applied to coincide with
egg-hatch. When following an insecticide program, apply sprays six to
ten days after upswing in moth flight for the first generation and three
to six days after upswing in moth flight for subsequent generations. For
more information on the timing of OFM sprays, contact a crop consultant.
Mating disruption: Two products are registered for mating
disruption of OFM in apples. For a season-long mating disruption program,
apply the pheromones prior to flight of the overwintering generation,
which is generally around half-inch green to tight cluster. Supplemental
insecticides directed towards first generation larvae may be necessary
if population pressure is high to moderate. Regional crop and pest reports
can help determine the need for and timing of pest management decisions.
For a partial mating disruption program, apply an insecticide to reduce
the first generation of OFM populations. Apply mating disruption products
for subsequent generations. Be aware of how long the pheromone is effective,
since some products may need to be re-applied for season-long control.
Mating disruption is species specific and will not manage other pests
in the orchard. The use of this technology requires specific knowledge
and management practices. As with other pests, monitoring is required.
For more information on mating disruption refer to Oriental fruit moth
on this page and/or OMAFRA Factsheet Mating Disruption for Management
of Insect Pests, Order No. 03-079
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