Click to enlarge.

Beginner

This pest affects:

Scientific Name
Choristoneura roseceana

Identification
Eggs:

• Laid on the upper surface of the leaves in patches (7-14 mm) that contain several hundred eggs and resemble small overlapping scales
• Masses are light green to yellowish green in colour
• Prior to hatching, contents of individual eggs turn black and the dark head of larva is visible
• After hatching, empty egg masses often remain on leaves and appear white against the dark green leaf

Larvae:

• Six instars
• 20-30 mm long at maturity
• Body is light green to yellowish green to dark green
• Head capsule is usually dark brown or black with a similar coloured segment just behind the head (prothoracic shield)
• The edge between the head capsule and prothoracic shield is often white or cream

Pupae:

• Dark reddish brown
• Develop in protected places, often found inside leaves rolled by the larvae
• 11-14 mm long

Adults:

• A moth that is variably coloured, light tan to dark brown with darker bands on the forewings
• Females are larger and generally darker than the males
• The wingspan of the males 16-22 mm, and the female 24-30 mm
• Females are poor flyers, and both sexes are most active at dusk

Damage:

	Overwintering larvae feed on developing fruitlets resulting in deep gouges; these fruit often abort, if not they have large russetted indentations and corky scars. Summer generation larvae feed on the surface of fruit and can cause extensive damage that scabs over and is often surrounded by light coloured areas where leaves are attached. Late season damage is characterized by several tiny, or a singular circular excavation on the fruit surface.
	Larvae may cause some damage from defoliation Larvae are shaken loose when trunk shakers harvest the cherries and are a serious contamination pest in cherry tanks at harvest.
Other Stone Fruit	Larvae may cause some damage from defoliation but very little direct fruit injury

Often Confused With
Red banded leaf roller larvae -black head capsules and green bodies

Green fruitworm larvae - larger and are exclusively lime green in color

Damage by other spring-feeding caterpillars- Damage to fruit by the obliquebanded leafroller resulting in large russetted indentations and corky scars is indistinguishable from feeding damage by other spring-feeding caterpillars which are predominantly foliar feeders

Codling moth damage - frass, and the hole extends deeper into the fruit; no surface chewing with white webbing around the hole

Bird pecks - no corky scarring, triangular shaped and will appear closer to harvest as the fruit is maturing and softening

Period of Activity
Active from from tight cluster to harvest.

Overwintering generation: Larvae ( 3rd to 6th instars)  are active  from  tight cluster until petal fall. The moths are active from mid June to the beginning of July.

Summer generation: Egg hatch in pears occurs mid to late June. Larvae from this generation are active from July to mid August with moth flight from mid August to September. Eggs for the overwintering generation laid and 1st and 2nd instar larvae will feed in fruit before going into diapause.

Scouting Notes

Monitoring techniques for obliquebanded leafroller vary depending on the generation targeted. For overwintering larvae present during the period between tight cluster and petal fall, check 5 terminal shoots and 5 fruit buds in each of 10 trees (50 terminals and 50 fruit buds in total) for signs of caterpillar feeding activity. After petal fall inspect 10 terminals from 10 trees for damage/larvae. After petal fall, hang four pheromone traps per 10 ha block at a distance of 30 m between traps along the perimeter of an orchard block.  Place in easily accessible areas in block ideally with historically high injury problems. Fasten traps to limbs at eye level where airflow is good. Check traps twice a week and record all moth catches. Predict the timing and application of products to manage the summer generation with pheromone traps and a degree-day model, and then follow up with field monitoring for larvae and fruit damage. Larvae initially feed on tender growing terminals, suckers and developing fruit. After they reach the third instar, larvae cause more damage to fruit. Monitor for emerging larvae by examining 10 shoots and 10 fruit on 10 trees in a 4 ha block for the presence of larvae or feeding damage. Often damage is more apparent in orchards than are larvae.

Monitor for overwintering larvae in the spring. Place pheromone traps in the orchard block ( see pear comments) to determine egg hatch and larval presence backed up monitoring for larvae. Look at 10 fruit clusters and 10 terminals on five trees per orchard. Monitoring should intensify as harvest approaches to help ensure larvae-free cherry tanks.

Thresholds
Apply an insecticide in orchards if 1% to 2% of terminals or buds have larvae or damage, or if orchards have a history of damage. Apply insecticides for overwintering larvae at petal fall.

Predict the timing and application of products to manage the summer generation with pheromone traps and a degree day model, then follow up with field monitoring for larvae and fruit damage.

For sweet cherries, apply an insecticide if three larvae per tree are found when looking at 10 fruitlets and 10 terminals on 5 trees.

Advanced

This pest affects:

Scientific Name
Choristoneura roseceana

Identification
Eggs:

• Laid on the upper surface of the leaves in patches (7-14 mm) that contain several hundred eggs and resemble small overlapping scales
• Masses are light green to yellowish green in colour
• Prior to hatching, contents of individual eggs turn black and the dark head of larva is visible
• After hatching, empty egg masses often remain on leaves and appear white against the dark green leaf

Larvae:

• Six instars
• 20-30 mm long at maturity
• Body is light green to yellowish green to dark green
• Head capsule is usually dark brown or black with a similar coloured segment just behind the head (prothoracic shield)
• The edge between the head capsule and prothoracic shield is often white or cream

Pupae:

• Dark reddish brown
• Develop in protected places, often found inside leaves rolled by the larvae
• 11-14 mm long

Adults:

• A moth that is variably coloured, light tan to dark brown with darker bands on the forewings
• Females are larger and generally darker than the males
• The wingspan of the males 16-22 mm, and the female 24-30 mm
• Females are poor flyers, and both sexes are most active at dusk

Damage:

	Overwintering larvae feed on developing fruitlets resulting in deep gouges; these fruit often abort, if not they have large russetted indentations and corky scars. Summer generation larvae feed on the surface of fruit and can cause extensive damage that scabs over and is often surrounded by light coloured areas where leaves are attached. Late season damage is characterized by several tiny, or a singular circular excavation on the fruit surface.
	Larvae may cause some damage from defoliation Larvae are shaken loose when trunk shakers harvest the cherries and are a serious contamination pest in cherry tanks at harvest.
Other Stone Fruit	Larvae may cause some damage from defoliation but very little direct fruit injury

Often Confused With
Red banded leaf roller larvae -black head capsules and green bodies

Green fruitworm larvae - larger and are exclusively lime green in color

Damage by other spring-feeding caterpillars- Damage to fruit by the obliquebanded leafroller resulting in large russetted indentations and corky scars is indistinguishable from feeding damage by other spring-feeding caterpillars which are predominantly foliar feeders

Codling moth damage - frass, and the hole extends deeper into the fruit; no surface chewing with white webbing around the hole

Bird pecks - no corky scarring, triangular shaped and will appear closer to harvest as the fruit is maturing and softening

Biology
OBLR can be a problem in pears and sour cherries in Ontario.  While other stone fruit can host this insect, it has not been a problem in these crops in the past decade or two. The overwintering generation exists as second or third instar larvae in hibernacula (temporary cocoons) under the bark or in the limb crotches. Larvae become active in early spring (tight cluster to bloom), once temperatures rise above 10ºC, and move to developing fruit spurs and flower buds. As leaves expand, larvae move to new terminal growth where they web and roll up the terminal leaves. This protects larvae from insecticide treatments so spray timing is critical. Pupation usually takes place in early June inside rolled leaves. Moths emerge over a four to five week period starting in early June. Much of the mating and egg laying occurs in the upper portions of the trees, and egg masses are also found in the lower canopy. Newly emerged larvae (or summer generation larvae) disperse from egg masses by crawling to other leaves or dangling from silken threads. Wind currents disperse these larvae to surrounding trees where they initially feed on leaves in and around terminal growth. By early July, when terminal growth begins to harden off, larvae move to fruit clusters and feed on fruit and adjacent leaves. Larvae then pupate and adults emerge from early August through early September. Adults mate and lay eggs and larvae from this generation are active well into September when they enter overwintering sites. The obliquebanded leafroller has two generations a year.

Period of Activity
Active from from tight cluster to harvest.

Overwintering generation: Larvae ( 3rd to 6th instars)  are active  from  tight cluster until petal fall. The moths are active from mid June to the beginning of July.

Summer generation: Egg hatch in pears occurs mid to late June. Larvae from this generation are active from July to mid August with moth flight from mid August to September. Eggs for the overwintering generation laid and 1st and 2nd  instar larvae will feed in fruit before going into diapause.

Scouting Notes

Monitoring techniques for obliquebanded leafroller vary depending on the generation targeted. For overwintering larvae present during the period between tight cluster and petal fall, check 5 terminal shoots and 5 fruit buds in each of 10 trees (50 terminals and 50 fruit buds in total) for signs of caterpillar feeding activity. After petal fall inspect 10 terminals from 10 trees for damage/larvae. After petal fall, hang four pheromone traps per 10 ha block at a distance of 30 m between traps along the perimeter of an orchard block.  Place in easily accessible areas in block ideally with historically high injury problems. Fasten traps to limbs at eye level where airflow is good. Check traps twice a week and record all moth catches. Predict the timing and application of products to manage the summer generation with pheromone traps and a degree-day model, and then follow up with field monitoring for larvae and fruit damage. Larvae initially feed on tender growing terminals, water sprouts and developing fruit. After they reach the third instar, larvae cause more damage to fruit. Monitor for emerging larvae by examining 10 shoots and 10 fruit on 10 trees in a 4 ha block for the presence of larvae or feeding damage. Often damage is more apparent in orchards than are larvae.

Monitor for overwintering larvae in the spring. Place pheromone traps in the orchard block ( see pear comments) to determine egg hatch and larval presence backed up monitoring for larvae. Look at 10 fruit clusters and 10 terminals on five trees per orchard. Monitoring should intensify as harvest approaches to help ensure larvae-free cherry tanks.

Thresholds
Apply an insecticide in orchards if 1% to 2% of terminals or buds have larvae or damage, or if orchards have a history of damage. Apply insecticides for overwintering larvae at petal fall.

Predict the timing and application of products to manage the summer generation with pheromone traps and a degree day model, then follow up with field monitoring for larvae and fruit damage.

For sweet cherries, apply an insecticide if three larvae per tree are found when looking at 10 fruitlets and 10 terminals on 5 trees.

Management Notes
A number of parasitic wasps and flies (Tachnidae) will attack obliquebanded leafroller larvae. These parasitoids can suppress population numbers but will not provide complete control.

Thin fruitlets to singles make less favourable feeding sites.

Prune to maintain an open canopy improves spray coverage.

Avoid excess nitrogen to prevent excessively lush and prolonged vegetative growth that is attractive to obliquebanded leafroller.

Management with insecticides – Insecticides are used to control OBLR in commercial orchards see OMAFRA Publication 360, Fruit Crop Protection Guide.

	Chapter 5 Pear Calendar: Recommendations for OBLR Petal fall and Summer sprays.
	Chapter 5 Sweet Cherry Calendar: Recommendations for OBLR : Special sprays.
	Chapter 5 Sour Cherry Calendar: Recommendations for OBLR First cover, Second cover.

Some information included above excerted from;

http://news.msue.msu.edu/news/article/preventing_obliquebanded_leafroller_infestation_in_cherr