Integrated Pest Management for Raspberries

A Guide for Sampling and Decision-Making for Key Raspberry Pests in Northwest Washington

Key Pests: (Not To Scale)	Clay Colored Weevil	Western Raspberry Fruitworm

PEST	BRIEF DESCRIPTION	DAMAGE/REASON FOR CONCERN	MONITORING APPROACHES	DECISION POINTS/ TOLERANCE	MANAGEMENT OPTIONS	FOLLOW UP
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 in several areas for signs of damage. Search around base of hill to identify. Check canes at night with flashlight.	Low tolerance. Few insects can cause yield loss.	Chemical Apply in the evening when worms are active.	Revisit infested areas.
Leafrollers (OBLR, obliquebanded is most common in Whatcom Co. OT, Orange Totrix is rare.)	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.	Detection of leafroller larvae at most sites indicates pre-bloom insecticide application may be necessary. 10% or more OBLR- infested hills (Threshold based on examination of a minimum of 20 hills per acre). An action threshold using the 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.	Beating tray samples Continue sampling % infested hills.
Black Vine Weevil (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.
Clay Colored Weevil (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.	No threshold established. Consider damage to foliage and buds.	Chemical	Beating tray samples. Examine soil around plant base.
Western Raspberry Fruitworm	Small (3/16" long) golden brown elongate beetle.	Adults feed on fruit buds and flower parts. Eggs laid in flowers hatch into larvae that bore into fruit.	Use beating tray typically during April and May to monitor fruitworm beetles. They are active on warm, sunny days.	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.	Examine lower canes and crown area for this insect. Concentrate efforts in weak areas of a field.	Seemingly low populations can increase quite rapidly.	Post-harvest fall applied insecticide.
Spider Mites (Twospotted 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.	An increasing mite population with many eggs and few predators. No established threshold for this crop stage. Look closely for key predators; Stethorus beetles and predator mites.	Chemical. Use insecticides only when necessary to avoid killing mite predators.	Fields that have been sprayed should be sampled 5-7 days after the application.

G.W. Menzies & C.B. MacConnell, WSU Cooperative Extension Whatcom County
June 1998

Funded in part by: Washington State Department of Ecology through U.S. Environmental Protection Agency, Section 319 Funds