WSU Whatcom County Extension

Integrated Pest Management for Raspberries

Harvest

Decision Making Matrices

(July through mid-August)

PEST
BRIEF DESCRIPTION
DAMAGE/REASON FOR CONCERN
MONITORING APPROACHES
DECISION POINTS/ TOLERANCE
MANAGEMENT OPTIONS
FOLLOW UP
INSECTS

 

 

Armyworms and Cutworms

 

 

Pale green to brown larvae. More active at night

 

Some can cause significant defoliation; harvest contaminants.

 

Check harvesting belt. Beating tray samples.

 

Recent and widespread defoliation. Presence of numerous worms in beating trays or on harvesting belt.

 

Synthetic or microbial insecticide. Both are more effective when targeting early to mid-stage worms.

 

Continue checking harvester belt and beating tray samples.

 

Obliquebanded Leafroller
(OBLR)
(Most common in Whatcom County)

 

OBLR: pale to dark green worm, head and shoulders are brown to black. Maximum 1". Leafroller larvae wiggle rapidly if disturbed. Adult stage may still be present at onset of harvest.

 

Web and feed on foliage and ripe fruit. Harvest contaminant.

 

Check pheromone traps weekly during June and July to determine peak OBLR flight. Look for OBLR worms in new growth 10 days after peak flight. Record % infested hills; frequency of sampling increases if approaching threshold. Check harvester belts and beating trays.

 

10% or more infested hills.
Detection of leafrollers on beating trays and on harvester belt.
Harvest contaminant thresholds will vary according to the end product usage and processor. Processors of IQF fruit have low tolerance for contaminants. Talk to your buyer for their threshold.

 

Synthetic or microbial insecticide (B.t.). Target 3-4th instar stage with B.t. in the evening or on a cloudy day. Include a sticker. The insect must consume this biological insecticide to be killed.

 

Resample about 4 days after treatment. Continue checking harvester belt and beating tray samples.

 

Orange Tortrix Leafroller
(OT)
(Most common in Western Oregon and SW Washington)

 

Adults and larvae may be present during this time. The larvae are light brown to yellow green with a brown heard and can range from 2-3 mm to ¾-inch long. When disturbed, they wiggle backwards and drop to the ground on a silken thread. Adults are gray or fawn colored with a wingspan of ¾ inch.

 

Larvae web and feed on foliage and ripe fruit. Harvest contaminant.

 

Check pheromone traps weekly and record OT moth catch. Starting at 10-14 days after peak flight: Examine 20 hills per site for worm infested shoots. Check 4-5 sites per field. Record % infested hills. Increase sampling if approaching threshold. Check harvester belt and beating trays. 

 

10% or more infested hills.
Detection of leafrollers on beating trays and on harvester belt
Harvest contaminant thresholds will vary according to the end product usage and processor. Processors of IQF fruit have low tolerance for contaminants. Talk to your buyer for their threshold.

 

Synthetic or microbial insecticide (B.t.). Target 3-4th instar stage with B.t. in the evening or on a cloudy day. Include a sticker. The insect must consume this biological insecticide to be killed.

 

Continue checking harvester belt, beating tray samples and percent hill infestation.

 

Raspberry Beetle (Fruitworm)

 

Most will be in larval stage during harvest. Mature worm is 1/3-inch long with light brown areas on the back of each segment. Larval contamination most likely during first two weeks of harvest.

 

Feeds in center of developing fruits. Tunnels into the core, often working into the drupelets. Worms feed for 30 days or more, drop to ground.

 

Examine fruit for feeding damage in the field or on harvesting belt.

 

No threshold established. Pre-bloom adult stage is preferred stage for control, prior to egg laying.

 

Difficult to control fruitworm larvae with insecticides due to their habit of feeding within the developing fruit.

 

Fields which are infested should be monitored closely in the following season during the pre-bloom period.

 

Spider Mites
(Two-spotted mite is the most common spider mite)

 

Adults are about 1/50" long, have eight legs, and are light tan or greenish in color with a dark spot on each side, which looks like a saddle.

 

Feed on underside of foliage.
Reduced plant vigor, water loss and
premature defoliation. Usually increase during harvest.
Excessive defoliation during harvest can reduce yield 25% the following season

 

Examine foliage at several sites using a 10X hand lens beginning in early May.
Collect 10 leaflets at each site and record the number of spider mites and predator mites.
Pay particular attention to mite egg density.

 

An increasing mite population with many eggs and few predators.

Timing of treatment also depends on pre-harvest interval of available miticides.

 

Chemical miticides.
Use insecticides only when necessary to avoid killing mite predators.

 

Fields that have been sprayed should be sampled 5-7 days after the application.

 

Spotted Wing Drosophila (SWD)

 

Adults are small flies (2-3 mm) with red eyes and a pale brown thorax and abdomen with black stripes on the abdomen. Adult males have a black spot towards the tip of each wing. Adult females have a large, saw-like ovipositor for inserting eggs into fruit.

 

This fly damages ripe and ripening fruit. Females lay 1-3 eggs per fruit by inserting their ovipositor into the fruit revealing small scares and indented soft spots and bruises on the fruit surface.
Eggs hatch and the larvae develop and feed inside the fruit, causing the flesh to collapse around the feeding site within as few as two days.

 

As soon as fruit begins to ripen place traps in fields using a 16oz plastic cup containing about ½” apple cider vinegar. Monitor traps twice per week and record number of adults found.
Check 20 fruit at each site for larvae and/or small puncture (oviposition scar) wounds on fruit. Record % infested fruit.

 

Thresholds are currently not available for this pest.
In most cases detection is the advised threshold.

 

This is a new pest to the Pacific Northwest; therefore, thresholds and management are not well established.

 

Continue to monitor traps and check fruit for small scares and the presence of larvae.

 

Strawberry Crown Moth
(SCM is common in the Willamette Valley and Southwest Washington)

 

Adults emerge in Late June and July, mate, and lay eggs which hatch in about two weeks.
Mature larvae are about 20 mm long, white, with a dark brown head.

 

Larvae can cause economic damage by girdling the canes causing the plants to become stunted and have poor vigor.

 

Continue to check pheromone traps weekly to identify emergence.
Watch for weakened areas in the field and signs of feeding on the outside of the crown.

 

No threshold is established. Consider chemical control if adults are consecutively found in the trap.

 

The same fall insecticidal drench used to control Raspberry Crown Borer will also control SCM.

 

Continue to monitor traps for adult moths.

 

Weevil,
Black Vine
(BVW is the most commonly found species)

 

Most, if not all, adult BVW have emerged from the soil before harvest begins.

 

Harvest contaminant. Adults lay numerous eggs which hatch into grubs in soil and feed on roots during fall and winter.

 

Check harvester belt for presence of weevils. Take 10 beating tray samples at each of several sites in a field and record the number and type of weevils detected. For best results, sample at night.

 

Excessive # weevils on harvesting belt. Continued presence of weevils in beating tray samples, rough threshold one weevil per 10 beating tray samples.

 

Chemical insecticide; choose based on pre-harvest interval, bee safety and toxicity to mite predators.

 

Resample soon after treatment with beating tray or by riding mechanical harvesters.

DISEASES

 

 

Botrytis Fruit Rot

 

Botrytis infection of blossoms not easily seen. Gray powdery spores form on rotting berries.

 

Reduces fruit quality and yield. Spores from fruit infection can infect and weaken cane tissue.

 

Examine fruit for gray mold.
Record severity on a scale of 0-3.

 

Disease prevention strategy.

 

Presence of diseased fruit may indicate need for fungicides during harvest period. Avoid excessive overhead irrigation. Pick fruit frequently as it ripens. Avoid excessive canopy.

 

Examine fruit and canes during harvest.

 

Cane Blight

 

Fruiting canes are weak/brittle at catcher plate level. The fungus only enters canes through wounds. Primocane wounds during harvest allow for infection.

 

Infection of new canes allows fungus to carry over to following season.

 

Examine primocanes for evidence of damage from catcher plates. Current season infection cannot be seen until later in the fall.
Inspect 10 hills & record % infected.

 

Catcher plate damage to primocanes. History of infection.
If 1-3 % of fruiting canes are infected, consider treatment.

 

Adjust catcher plates on mechanical harvesters to minimize wounding and subsequent infection. Fungicide application directed to base of primocanes to protect wounds.

 

Check lower primocane buds for infection in the fall.

 

Phytophthora Root Rot

 

Soilborne fungus which can cause root and crown rot. Infection favored by saturated soil conditions. Diseased plants have lack of feeder roots, poor vigor canes. Interior of major roots and crown are brown to black.

 

Damage seen as collapse of fruiting laterals, wilting primocanes with onset of hot weather. Reduced vigor and yield.

 

Target yellow plants with sudden wilting.
Pull samples as soon as symptoms are seen.  Send for ELISA/ PCR test.

 

There is no threshold, decision making around this pest complex is complicated.
Growers should consider these factors: age of planting, size of effected area, results of pathogen testing, variety.

 

No controls available during harvest. Sample suspect areas to confirm infection. Samples need to be tested by a qualified lab to confirm the presence of the pathogen.

 

Treat infected areas in the fall.

 

Spur Blight

 

Brown irregular shaped lesions on fruiting laterals. Brown wedge shaped lesions on primocane leaves. Petiole left attached to primocanes. Dark brown area on cane around bud may be present.

 

Can damage leaves and weaken buds. Increases susceptibility to winter injury.

 

Continue to examine foliage for spur blight lesions and lower primocane area for cane lesions.
Record severity on a scale of 0-3.

 

Consider field history - past incidence of infection. Wet weather during harvest increases likelihood of continued infection of new canes.

 

Optimum timing for chemical control is prior to and during early bloom.

 

Examine primocanes for purplish lesions in late harvest.

 

Secondary content using h2 tag.

Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

Heading using the h3 tag

Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.

WSU Whatcom County Extension 1000 N. Forest St., Suite 201, Bellingham, WA 98225 (360) 778-5800 whatcom@wsu.edu