WSU Whatcom County Extension

Integrated Pest Management for Raspberries

Dormant/Pre-Bloom

Decision Making Matrices

(March through Late May)

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

 

 

Climbing Cutworms
(spotted cutworm most common)

 

Up to 1 ½" long.
Body pale brown to ashy gray
Active on canes at night.

 

Feeds on buds and new foliage
Feeds on primocanes below ground.

 

Examine buds and new growth in late March and early April for signs of damage. Inspect 5 buds and new shoots per hill.  Record number of buds/shoots damaged by cutworms.
Search around base of hill to identify.

 

Low tolerance.
Few insects can cause yield loss.

 

Chemical
Apply in the evening when worms are active.
If low levels of larvae are present, biological materials such as BT formulations and/or insect growth regulators could be effective.

 

Revisit infested areas.

 

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

 

OBLR: pale to dark green worm, head and shoulders are brown to black. Maximum 1"
OT: straw to yellow green body, head and shoulders are tan. Full grown larvae ¾". Larvae of both species wiggle rapidly if disturbed.

 

Overwintering larvae feed on new leaves in April and May

 

Look for rolled new leaves in April and early May for presence of OBLR worms. Record % infested hills by checking 20 hills at each of five sites distributed through a field. Examine beating trays for leafroller worms. Place OBLR pheromone traps in field in mid-May.

 

Harvest contaminant thresholds vary according to the end product usage and processor.
Check with your buyer for their suggested threshold.
A starting threshold of 10% or more larvae infested hills is recommended.
An action threshold for beating tray has not been established.

 

Chemical
Microbial insecticide B.t. with spreader sticker on cloudy day. Avoid application of B.t. on sunny or rainy days.
If low levels of larvae are present, biological materials such as BT formulations and/or insect growth regulators could be effective.

 

Beating tray samples
Continue sampling % infested hills.

 

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

 

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.

 

Overwintering larvae feed on new leaves in March and April

 

 

Look for rolled new leaves beginning in April for presence of OT larvae. Record % infested hills by checking 20 hills at each of five sites distributed through a field. Examine beating trays for leafroller worms. Place OT pheromone traps in field by late March.

 

Harvest contaminant thresholds vary according to the end product usage and processor.
Check with your buyer for their suggested threshold.
A starting threshold of 10% or more larvae infested hills is recommended.
An action threshold for beating tray has not been established.

 

Chemical
Microbial insecticide B.t. with spreader sticker on cloudy day. Avoid application of B.t. on sunny or rainy days.
If low levels of larvae are present, biological materials such as B.t. formulations and/or insect growth regulators could be effective.

 

Continue checking traps for adults and sampling % infested hills.

 

Raspberry Beetle
(Fruitworm)

 

Small (3/16" long) golden brown elongate beetle.

 

Adults feed on fruit buds and flower parts, which can reduce yield. Eggs laid in flowers hatch into larvae that bore into and contaminate fruit during harvest.

 

Use beating tray typically during April and May to monitor fruitworm beetles. They are active on warm, sunny days.
Monitor adult flight activity with white sticky traps, such as the Rebell Bianco

 

Counts of 1-2 beetles/10 trays have been recorded with no reported damage to fruit. Lower tolerance for IQF and other high-end fruit.

 

If necessary, insecticides should be applied to control adult stage before egg laying….when blossom buds separate and just before bloom.

 

Continue beating tray samples.

 

Raspberry Crown Borer

 

First year caterpillars are white and about ¼" long. Second year caterpillars are white and up to 1" long. 

 

Caterpillars feed inside lower canes and crown area. Cause spindly canes, uneven bud break, and collapse of laterals.
Larval tunneling can reduce cane vigor and yield

 

Examine lower canes and crown area for this insect. Concentrate efforts in weak areas of a field. 
Record % infested hills.

 

If more than 5% of the plants have damage caused by borer larvae feeding, chemical controls are recommended.
Seemingly low populations can increase quite rapidly. 

 

Spring insecticide drench is advisable to control larvae.

 

Check plants mid to late summer for signs of wilting or dying canes. Inspect suspected plants for signs of boring.

 

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.

 

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 mite predators found. Check every two weeks. 

 

Thresholds are variable depending on plant vigor.
Pre-harvest guideline is an average of 10 mites/leaflet in the absence of predators, or an average of 25 mites /leaflet if predator to spider mite ratio is greater than 1:10.
Predator: spider mite ratios of 1:10 indicate potential for effective biological control.

 

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

 

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

 

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

 

SCM overwinters in the crown as dormant larvae and become active in April and May and feed for a short time before pupating in the crowns in May and June. Adults emerge in Late June and July, mate, and lay eggs.

 

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

 

Watch for weakened areas in the field containing brittle or collapsed canes. Signs of feeding on the outer crown and root surface may be present. Examine the crown and lower canes for signs of boring.

 

No threshold is established.
Consider chemical control if signs of boring or feeding on the outer crown and root surface are visible; or if SCM has historically been a problem in the field.

 

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

 

Place pheromone trap in field early June to monitor traps for adult moths.

 

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

 

Most weevils are in the larval stage at this time.
Black vine weevil larvae are about ½" long in March and April, white with tan heads. Adults begin to emerge in mid to late May.

 

Larvae feed on and damage roots, develop into adults which are a fruit contaminant

 

Examine top 4" soil around base of plants to detect larvae in several areas of a field, using a shovel.

 

A few weevil larvae indicate that a preharvest clean up spray will be necessary for adult weevil control.

 

Most weevils have not emerged yet.

 

Begin beating tray samples usually in mid- May to detect emerging adults.
 

 

Weevil,
Clay Colored
(sporadic early season pest)

 

Adults emerge early in the season as buds start to break. Also called bud weevil. Slightly smaller than BVW adult, reddish legs.

 

Adults feed on foliage, leaf stems, and buds.

 

Look for leaf flagging and notched leaves. Use beating tray to dislodge them from canopy.

 

Consider damage to foliage and buds. Consider treatment with detection of 1 weevil/10 beating trays.

 

Chemical

 

Beating tray samples.
Examine soil around plant base.

DISEASES

 

 

Cane Botrytis

 

Brownish tan lesions on canes. May contain black bodies called sclerotia which produce spores which infect blossoms.

 

Weakens canes.
Source of inoculum for blossoms and fruit.

 

Examine canes for lesions and sclerotia.
Record severity on a scale of 0-3.

 

Presence of overwintering sclerotia and sporulation indicates potential for blossom infection.

 

Early bloom foliar fungicide to protect blossoms from infection.

 

Fruit inspection during harvest period.

 

Cane Blight

 

Reddish vascular lesion below bark extends up cane from wounds associated with catcher plate damage. Need to scrape cane to expose vascular layer.

 

If serious, can girdle or weaken the fruiting cane, wilt plants, and reduce yield.
Infection is usually more severe during wet growing seasons.

 

Inspection of fruiting canes by scraping away bark at catcher plate height to see reddish vascular tissue beneath.
Record % infected hills.

 

If 1-3% of canes are infected, consider treatment during harvest period.

 

Avoid overhead irrigation as spores are rain splashed.

 

Watch closely during and after harvest.

 

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.
Sample propagules.

 

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

 

Overwinters as cracked gray areas on canes around buds. Tiny black pimples form in affected areas. Key infection period is in early summer.

 

Inoculum for summer foliar infection of floricanes and primocanes.
Can damage leaves on fruiting laterals and weaken buds on primocanes.

 

Evaluate fruiting canes to rate the severity of past disease incidence (overwintering lesions).
Record % infected hills.

 

Disease prevention based partly on field history.
A starting threshold is recommended if 10% of hills were shown to be infected after harvest the previous season.

 

Dormant Lime Sulfur at bud swell.
Early summer, pre-bloom fungicide.

 

Check fruiting lateral foliage for infection particularly in wet years just before and during harvest.

 

Yellow Rust

 

Orange-yellow fruiting structures produced on upper leaf surface.

 

Premature death of leaves on fruiting canes can cause fruit to die before maturing.
Reduced winter hardiness.

 

Starting in late April, examine older leaves near the wire for infection. Integrate into mite sampling procedure.
Record severity on a scale of 0-3.

 

Consider field history and degree of infection.

 

Liquid lime-sulfur as delayed dormant application if present the previous year.
Consider fungicides based on disease severity and wet weather conditions.

 

Continue to examine leaves for infection as part of mite sampling.

 

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