Oriental Fruit Moth
Beginner
This pest affects:
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Scientific Name
Grapholitha molesta
Identification
Eggs:
- Laid individually,
- Appear as flat scales,
- Semi-transparent white,
- 0.5-0.7 mm in diameter.
- Eggs are rarely seen in orchards
- Newly hatched larvae are 1.5 mm long with a black head capsule and white body
- Mature larvae reach 9-13 mm long with a brown head capsule and a cream to pinkish body
- A small, dark, comb-like structure called an “anal comb” can be seen using a good quality hand lens or, if the larvae are very small, using a microscope
Adults:
- Small moth (about 6-7 mm)
- Greyish-brown with silvery scales on wings
- Underside of forewings is light coloured
Damage:
Shoots
- First generation larvae attack young shoots of peach, plum and nectarine
- Infested shoots and terminal leaves wilt and bend over. After larval emergence, the entire tip and its leaves dry up, and bend down even further. These are called “flags” or “strikes”
- Affected shoots have a small entry hole, with frass and sometimes a larva present
- Larvae tunnel into and feed on the flesh of the fruit from the calyx or stem ends
- Fruit that are infested when very small often drop. Early-infested peaches that do not drop have obvious entrance holes with frass and gum exuding from them
- Larvae attacking nearly ripe peaches usually enter the fruit near the stem, leaving only a very small, inconspicuous entrance hole. The larvae tunnel in the fruit, and frequently excavate cavities near the pit
- Infested plum fruit often colour prematurely.
Often confused with
Codling moth
- larvae do not have an anal comb; adults have bronzed area at the wing
tip; larvae usually tunnel directly to the seed cavity and feed on the
fruit seeds
Lesser appleworm - may cause flagging but are usually fruit feeders; have an anal comb and are difficult to distinguish from oriental fruit moth; feeding is often just under the surface of the skin; adults are similar in appearance to oriental fruit moth, but have a metallic copper hue and thin bands of pale blue on their wings
Plum curculio - larvae are legless, white, slightly curved
Blossom blight (shoot) on apricot, peach and plum - blossoms brown and collapsed, sunken canker on shoot; no frass and tunneling in the shoot
Period of Activity
There are three or four generations of oriental fruit moth each year.
First generation: half-inch green to bloom (peach) until mid-June.
Subsequent generations: Early July through harvest.
Scouting Notes
Terminal flagging may begin to appear in peach, plum and apricot orchards in mid June. Inspect terminals for flagging throughout the season beginning at bloom. Inspect fruit of all crops for signs of holes and/or frass at the calyx or stem end throughout the season.
Use pheromone traps to monitor oriental fruit moth adult activity and determine insecticide application timing. Place traps in the orchard prior to the anticipated first flight in the spring. Replace traps at the end of the flight period for each generation. Leave traps in the orchard until harvest is completed. A minimum of one set of five traps per four hectares is recommended to provide an accurate representation of activity in the field. Trap height for oriental fruit moth is not critical. Ensure trap openings are not blocked by foliage. Place traps around the perimeter of the orchard block at 40 m intervals. Use sentinel pheromone traps in blocks where mating disruption for oriental fruit moth has been applied. Be aware if mating disruption being used in the orchard or in the area nearby as this may affect the success of this type of monitoring for seasonal moth activity.
Monitor traps twice per week on the same days each time (e.g. Mondays and Thursdays) during periods of activity. Remove all moths and record the data. The specific timing of pest control products varies depending on the target life stage, the insecticide’s mode of action and residual activity. Pheromone trap catch data provides critical information for management of oriental fruit moth using either insecticides or mating disruption technology.
Fluctuating spring temperatures affect trap catch data. Just as there is a base temperature below which no development occurs in larvae, there is also a minimum temperature required for activities including adult flight, searching for a mate and egg laying. During cool night time periods early in the growing season, adult oriental fruit moth may not be active in the orchard. When warmer temperatures resume, so does flight activity. This may give the impression that flight of the second generation has begun, when in fact the activity represents a split or bimodal peak of the overwintering generation. Bimodal peaks often carry over to the next generation. Pheromone traps provide information on insect activity, and degree day models predict when subsequent generation flight occurs.
Where mating disruption for oriental fruit moth has been applied, use sentinel pheromone traps. Monitoring methods will be the same as above except that the fifth trap is placed in the centre of the orchard block. If mating disruption is working properly, very low or no oriental fruit moth should be captured in these traps. This indicates that mating disruption is performing effectively.
Thresholds
Models have been developed to time the application of insecticides for OFM. Begin accumulating degree days (base 7.2˚ C) at the first sustained moth catch of the first generation (biofix). The rate of development of oriental fruit moth differs between apples/pears and stone fruit so different degree day accumulations are used. Because newer insecticides work in on different life stages, specific degree accumulations are also used for different products.
Advanced
This pest affects:
|
|
|
|
Scientific Name
Grapholitha molesta
Identification
Eggs:
- Laid individually,
- Appear as flat scales,
- Semi-transparent white,
- 0.5-0.7 mm in diameter.
- Eggs are rarely seen in orchards
- Newly hatched larvae are 1.5 mm long with a black head capsule and white body
- Mature larvae reach 9-13 mm long with a brown head capsule and a cream to pinkish body
- A small, dark, comb-like structure called an “anal comb” can be seen using a good quality hand lens or, if the larvae are very small, using a microscope
Adults:
- Small moth (about 6-7 mm)
- Greyish-brown with silvery scales on wings
- Underside of forewings is light coloured
Damage:
Shoots
- First generation larvae attack young shoots of peach, plum and nectarine
- Infested shoots and terminal leaves wilt and bend over. After larval emergence, the entire tip and its leaves dry up, and bend down even further. These are called “flags” or “strikes”
- Affected shoots have a small entry hole, with frass and sometimes a larva present
- Larvae tunnel into and feed on the flesh of the fruit from the calyx or stem ends
- Fruit that are infested when very small often drop. Early-infested peaches that do not drop have obvious entrance holes with frass and gum exuding from them
- Larvae attacking nearly ripe peaches usually enter the fruit near the stem, leaving only a very small, inconspicuous entrance hole. The larvae tunnel in the fruit, and frequently excavate cavities near the pit
- Infested plum fruit often colour prematurely.
Often confused with
Codling moth - larvae do not have an anal comb; adults have bronzed
area at the wing tip; larvae usually tunnel directly to the seed cavity
and feed on the fruit seeds
Lesser appleworm - may cause flagging but are usually fruit feeders; have an anal comb and are difficult to distinguish from oriental fruit moth; feeding is often just under the surface of the skin; adults are similar in appearance to oriental fruit moth, but have a metallic copper hue and thin bands of pale blue on their wings
Plum curculio - larvae are legless, white, slightly curved
Blossom blight (shoot) on apricot, peach and plum - blossoms brown and collapsed, sunken canker on shoot; no frass and tunneling in the shoot
Biology
Oriental fruit moth can infest pears, peaches, nectarines, apricots, plums and apples.
There are three generations of oriental fruit moth in Ontario. A partial fourth generation may develop in some years, with adult flight and egg-laying activity extended into October. Eggs from this generation hatch and larvae move into fruit prior to harvest. Late season damage is difficult to detect because larvae are small. Infested fruit may get through packing lines undetected.
The insect overwinters as a late stage (fourth or fifth instar) larva within a cocoon under bark scales, crevices and other protected areas on the tree or on the ground. The larva pupates in the spring and emerges as an adult in late April or early May.
First and early second generation OFM adults lay eggs on upper leaf surfaces, frequently on the terminal leaf of young shoots of peach, nectarine, apricot or plum. Mated females lay up to 200 eggs. Shortly after hatching, larvae enter young terminals and begin to feed. Infested shoots and terminal leaves wilt and bend over. After larval emergence, the entire tip and its leaves dry up, and bend down even further. Larvae will tunnel up to 15 cm into the shoot, or they may exit and enter one or more new shoots before maturing. If a terminal becomes unsuitable as a food source before larval development is complete, larvae seek other terminals, or move to fruit to complete their development. Mature larvae leave their feeding sites to spin cocoons in which they either pupate on the trunk (usually within two feet of the ground) or in debris on the ground under the tree. Adults are considered to be strong fliers.
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Development occurs more slowly in pears than in stone fruit. |
Fruit is attacked by all but the first generation of oriental fruit moth. Females appear highly attracted to fruit previously damaged by other internal feeders. When larvae hatch, they enter the fruit through either the calyx or stem ends. Very few oriental fruit moth larvae enter the fruit by the side of the fruit. Most larvae enter fruit within hours of hatching. Frass produced by the developing larvae is often evident on the fruit surface and infested fruit develop colour prematurely.
Period of Activity
There are three or four generations of oriental fruit moth each year.
First generation: half-inch green to bloom (peach) until mid-June.
Subsequent generations: Early July through harvest.
Scouting Notes
Terminal flagging may begin to appear in peach, plum and apricot orchards in mid June. Inspect terminals for flagging throughout the season beginning at bloom. Inspect fruit of all crops for signs of holes and/or frass at the calyx or stem end throughout the season.
Use pheromone traps to monitor oriental fruit moth adult activity and determine insecticide application timing. Place traps in the orchard prior to the anticipated first flight in the spring. Replace traps at the end of the flight period for each generation. Leave traps in the orchard until harvest is completed. A minimum of one set of five traps per four hectares is recommended to provide an accurate representation of activity in the field. Trap height for oriental fruit moth is not critical. Ensure trap openings are not blocked by foliage. Place traps around the perimeter of the orchard block at 40 m intervals. Use sentinel pheromone traps in blocks where mating disruption for oriental fruit moth has been applied. Be aware if mating disruption being used in the orchard or in the area nearby as this may affect the success of this type of monitoring for seasonal moth activity.
Monitor traps twice per week on the same days each time (e.g. Mondays and Thursdays) during periods of activity. Remove all moths and record the data. The specific timing of pest control products varies depending on the target life stage, the insecticide’s mode of action and residual activity. Pheromone trap catch data provides critical information for management of oriental fruit moth using either insecticides or mating disruption technology.
Fluctuating spring temperatures affect trap catch data. Just as there is a base temperature below which no development occurs in larvae, there is also a minimum temperature required for activities including adult flight, searching for a mate and egg laying. During cool night time periods early in the growing season, adult oriental fruit moth may not be active in the orchard. When warmer temperatures resume, so does flight activity. This may give the impression that flight of the second generation has begun, when in fact the activity represents a split or bimodal peak of the overwintering generation. Bimodal peaks often carry over to the next generation. Pheromone traps provide information on insect activity, and degree day models predict when subsequent generation flight occurs.
Where mating disruption for oriental fruit moth has been applied, use sentinel pheromone traps. Monitoring methods will be the same as above except that the fifth trap is placed in the centre of the orchard block. If mating disruption is working properly, very low or no oriental fruit moth should be captured in these traps. This indicates that mating disruption is performing effectively.
Thresholds
Models have been developed to time the application of insecticides for OFM. Begin accumulating degree days (base 7.2˚ C) at the first sustained moth catch of the first generation (biofix). The rate of development of oriental fruit moth differs between apples/pears and stone fruit so different degree day accumulations are used. Because newer insecticides work in on different life stages, specific degree accumulations are also used for different products.
Management Notes
Degree-day models provide important information for predicting the timing of insecticide applications, but are not a replacement for continued monitoring of pest activity with pheromone traps and field scouting for damage.
Monitor flight for each generation; check residual activity for each product and re-apply product if necessary. If emergence and/or activity for that generation are prolonged (bimodal or split peaks), apply a second application of the same product.
Manage each generation as separate units when using insecticides. Use products from a single chemical group to manage a given generation of a pest.
Mating disruption of oriental fruit moth is a highly effective alternative to insecticides. For more information, consult OMAFRA Factsheet, Mating Disruption for Management of Insect Pests, and OMAFRA Factsheet, Mating Disruption for Management of Oriental Fruit Moth in Stone and Pome Fruit. and See OMAFRA Publication 360, Fruit Crop Protection Guide.
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Chapter 5 - Peach Calendar : Recommendations for OFM: Prebloom. |
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Chapter 5 - Apricot calendar : Recommendations for OFM: Bloom. |
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Chapter 5 - Pear Calendar : Recommendations for OFM: Green tip. |
Management with insecticides: Insecticides are used to control oriental fruit moth in many commercial orchards. Products are recommended at different timings because they work best on specific life stages of the pest. Apply within the appropriate degree days specified for best results. Monitor populations and reapply 10-14 days later if required. See OMAFRA Publication 360, Fruit Crop Protection Guide.
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Chapter 5 - Peach Calendar : Recommendations for OFM shuck split to shuck fall, Second generation, Third generation and Prepick. |
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Chapter 5 - Apricot Calendar : Recommendations for OFM at shuck split, Special sprays. |
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Chapter 5 - Plum Calendar : Recommendations for OFM at Shuck fall, Second cover, Prepick |
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Chapter 5 - Pear Calendar : Recommendations for OFM at Second cover, Special sprays. |
Some information included above excerpted from;
