Crop Profile for Apples in Oregon

1 A = annual problem, control required every year; O = occasional problem; R = rarely a problem.

III. Scale

San Jose Scale, Quadraspidiotus perniciosus
European Fruit Lecanium, Parthenocecanium corni

San Jose scale is by far the most important scale insect found on apples in Oregon. There are two generations in most areas. San Jose scale infests branches, shoots, leaves and fruit. The scales suck plant juices from the trees and inject a toxin. Female scales bear live young (crawlers) which move to new feeding sites including the fruit. Eventually they become sessile, lose their legs, and form a scale cover. Fruit infested by San Jose scale is often bumpy and, in extreme cases, fruit may be severely misshapen and stunted. Fruit with scales or with red spots from scales feeding on the surface are downgraded to culls. San Jose scale can seriously weaken branches and main scaffold limbs and kill fruiting spurs, thus causing permanent injury and even death to mature trees.

European fruit lecanium is seldom a pest of apples in Oregon. The primary injury by European fruit lecanium is the production of honeydew that, in large amounts, can damage leaves and fruit. Sooty mold growing in the honeydew can cause blackened areas on leaves and fruit, causing markings that make fruit unsuitable for the fresh market.

Monitoring and Control. Overwintering populations of San Jose scale can be monitored by examining last year’s shoot growth. The bark on scale-infested shoots often shows a characteristic reddish discoloration. Examination of culls in the packing house is also helpful in determining if San Jose scale is a problem in a particular block. Male San Jose scale flight can be monitored with pheromone traps. However, the trap does not catch well in windy sites. Double sticky tape wrapped around 1-2" branches is useful for monitoring crawler emergence during late spring and summer. Control is best achieved with spray oil or an OP/oil combination at the ‘dormant or ‘delayed dormant’ stage. A regular spray program of azinphos-methyl against codling moth will also control San Jose scale crawlers.

IV. Bugs

Lygus Bug, Lygus hesperus
Consperse Stink Bug, Euschistus conspersus
Stink Bugs, several species

Stink bugs and lygus are most common in orchards with lush ground covers or in orchards surrounded by habitat with lush vegetation. Stink bugs occur in all Oregon apple districts and are a chronic problem in many areas. Stink bugs generally overwinter beneath leaf litter on the orchard floor or in protected places such as bin piles, brush, or ground cover near orchards. Stink bugs are triangular shaped, brown or greenish insects with piercing-sucking mouthparts and are about 3/8 inch long.

Like stink bugs, lygus bugs occur in all major apple districts and can cause severe damage, most often in orchards with permanent ground covers or in orchards located adjacent to crop land or vegetation that harbors lygus bugs (e.g., alfalfa or hay fields). Lygus bugs vary from green to brownish in color and are about ¼ inch long with piercing-sucking mouth parts. Both stink bugs and lygus bugs insert their mouthparts into fruit, causing dimples or irregularly depressed areas, or ‘cat-facing’ in mature fruit. The damaged fruit is culled at harvest. Internally, plant bug feeding produces white pithy areas that turn brown when the fruit is peeled. Often significant damage from true bugs may occur before populations are detected in orchards. Chemicals for true bugs in apples vary from area to area because tolerance and resistance is common.

Monitoring and Control. This group of pests is difficult to monitor since adults which normally do most of the damage are very active and mobile. Sweeping the orchard floor with a sweep net can be helpful to detect the presence of plant bugs. Colored sticky panels have so far not proven very reliable as indicators for plant bug populations. Therefore, timing of sprays is difficult. There are few effective chemical controls currently available. Resistance to insecticides, particularly in lygus bug populations is not uncommon. Most of the available chemical controls which have been used with some success for plant bug control such as pyrethroids, endosulfan or formetanate HC have a poor fit with IPM on apples.

V. Woodborers and rootfeeders

Shothole Borer, Scolytus rugulosus
Flatheaded Borer, Chrysobothris mali
Rain beetles, Scarabaeidae (several species)

Wood-boring beetles generally limit their attacks in apples to severely stressed, damaged or diseased trees. The best way to manage them is by promoting tree health through proper nutrition, irrigation and sanitation practices. However, flatheaded borer can be a serious problem in newly planted orchards by girdling trees and occasionally killing them. Preventive measures such as painting the trunks with white latex paint can be effective.

Grubs of rain beetles can do serious damage to roots of newly planted orchards on recently cleared land. Soil fumigation may be necessary before orchards are established. Rain beetle larvae are difficult to control after trees are planted since larvae can occur several feet below ground. Spot fumigation is used occasionally in established orchards to control rain beetle larvae in small areas. However, the effectiveness of this practice is limited. Infestations spread slowly through established orchards since female beetles do not fly.

VI. Occasional pests

In addition to the more common pests listed here, there are a number of occasional pests which are normally controlled by the regular insecticide treatments against the major pests (e.g., codling moth, leafroller, etc.). As more and more selective tactics are used for control of major pests some occasional pests may become more important including the fall webworm, Hyphantria cunea; the redhumped caterpillar, Schizura concinna; and others.

Biological control can play an important role in the population regulation of several apple pests such as spider mites, tentiform leafminer, leafhoppers and aphids. However, as long as broad-spectrum pesticides remain the principal tools for control of major apple pests the opportunities for biological control will be limited. The most dramatic improvement in the biological control area has occurred with those apple pests where their principal antagonists have acquired a degree of resistance to commonly used pesticides (e.g., OPs) which allows them to survive a regular spray program. This has occurred with phytodseiid mites, the most important natural enemies of spider mites on apple in the Pacific Northwest. As more selective control tactics become available and are used by growers for the control of key pests (e.g., mating disruption for codling moth and leafroller control; IGRs, microbial insecticides, etc.) biological control will attain a more prominent role and reduce the need for chemical intervention, especially for secondary pests. Below is a brief summary of the current and potential use of biological control agents in apple pest management.

Codling moth. Although codling moth is attacked by a large number of parasitoids and predators, none are capable of preventing economic damage. Codling moth has not been a very successful target for biological control approaches because of its low economic threshold. In addition, the contribution natural enemies can make to the control of codling moth in commercial orchards is limited due to the disruptive nature of pesticides, often those which are applied against the pest itself. It has been shown in recent field tests that augmentative releases of large numbers of Trichogramma, an egg parasitoid, can reduce codling moth. Although releases of Trichogramma do not achieve the level of control required for commercial apple production, augmentative releases of parasitoids have a natural fit and could be used as a supplement with other selective control tactics.

Leafrollers. The major natural enemies of leafrollers are hymenopterous and tachinid parasitoids. However, in frequently sprayed commercial apple orchards parasitization levels are usually low. The hymenopterous parasitoid Colpoclypeus florus, originally introduced from Europe, has become an important biological control agent of leafroller populations in tree fruits in the Pacific Northwest.

Green fruitworms. A number of parasitic wasps attack green fruitworms. Generalist predators such as pirate bugs, green lacewings, and predatory plant bugs probably feed on young larvae. However, little is known about the impact they have on populations.

Aphids. Predators such as lady beetles, green and brown lacewings, and syrphid fly larvae help to control green apple aphid, spirea aphid and rosy apple aphid populations. These predators are active throughout the season and can have a positive impact on reducing colonies in the absence of broad-spectrum insecticides. However, in many cases control by natural enemies is too late to prevent build-up of populations. The parasite Aphelinus mali can completely control aerial colonies of the woolly apple aphid.

Leafhoppers. Potentially, hymenopterous parasitoids can be important in regulating leafhopper populations, but use of broad-spectrum insecticides for codling moth control prevent them from being important population regulators.

Thrips. Populations of this pest develop primarily on native vegetation outside orchards. Little is known about the biological control of thrips.

Plant bugs. The role of predators and parasitoids has not been well investigated. Generalist hemipteran predators and parasitic wasps are important in controlling lygus bugs in other crops. Stink bug eggs are attacked by hymenopterous egg parasitoids. However, their impact on stink bug populations is not clear.

Tentiform leafminer. Leafminer populations are usually kept at low levels by several species of parasitoids, even where a regular spray program is applied. Among the more important ones is Pnigalio flavipes, a small hymenopterous wasp. The occasional outbreaks of this insect in Oregon apple orchards occur probably as the result of chemical disruption of the parasitoid complex.

San Jose scale. San Jose scale is attacked by the parasitic wasps Aphytis spp. and Prospaltella spp. In situations where broad-spectrum insecticides are not being used, parasitoids and predaceous beetles generally keep scale populations below damaging levels.

Spider mites. Predators are critical for regulating mite populations. The most dependable predator is the western predatory mite, Galandromus occidentalis, which, if not disturbed with pesticides applied for other pests, can usually keep populations below damaging levels in well managed orchards. G. occidentalis is well adapted to the arid apple-growing areas east of the Cascades. A related species is Galandromus pyri which is found in the more humid growing areas under marine influence. In the Hood River Valley G. occidentalis as well as G. pyri often occur in the same orchards. In orchards where predatory mites are present and are not disturbed by pesticides, spider mite outbreaks have become rare events. G. occidentalis as well as G. pyri are resistant to most organophosphates applied for codling moth and leafroller control but are very susceptible to synthetic pyrethroids and carbamates. Other important mite predators include six-spotted thrips, minute pirate bug, and a small black lady beetle, Stethorus sp.

VIII. Cultural control

There is some potential for using cultural measures to keep pest populations in check or at least slow their build-up. Cultural control often involves preventive measures. The objective is to make the orchard environment less favorable for orchard pests by making adjustments in the horticultural management program and by adopting sound orchard hygiene practices. The following are examples of cultural control measures which can be used together with other control tactics to keep pest populations at sub-economic levels.

Codling moth. Orchard sanitation, collection and destruction of infested fruit, elimination of cocooning sites on the tree trunk and around pruning wounds, and removal of sources of infestations near orchards are helpful measures to reduce codling moth populations. Also, thinning fruit clusters down to singles will make it more difficult for young larvae to enter fruit and increase larval mortality.

Leafrollers. Larvae often prefer clusters with multiple fruit. As in the case of codling moth, thinning clusters down to singles can be helpful to reduce fruit damage.

San Jose scale. Proper irrigation and nutritional management minimize tree stress and allow trees to tolerate higher populations without damage.

Plant bugs. Clean cultivation or destroying alternate hosts such as blackberries outside orchards will tend to reduce population pressure from cat-facing insects. However, destruction of outside hosts is often not possible.

Green apple aphid. Excessive vegetative growth will invite aphid build-up. Adjustments in the irrigation and fertilizer program are helpful to reduce excess tree vigor and make the tree a less favorable host for aphids and other foliage feeders. Also, pruning out infested shoot growth in early spring will help to control aphid populations and reduce the likelihood of re-infestations. However, this is a labor-intensive option and may not always be practicable.

Woolly apple aphid. The best way to control root infestations is by selecting resistant rootstocks. Where woolly apple aphid is a serious problem, especially on light soils, resistant stocks such as MM.111 can be used.

Spider mites. Dust from orchard roads or in clean cultivated orchards encourages spider mite build-up. Avoiding dusty conditions and maintaining a well managed ground cover will minimize spider mite outbreaks. Also, healthy trees which are adequately supplied with water and nutrients are less susceptible to mite damage. However, excess vigor (especially too much nitrogen) will invite mite problems. Avoiding the use of disruptive materials such as synthetic pyrethroids or carbamates is also important.

Wood borers. This group of pests generally attacks trees or tree limbs which are in a state of decline. Sound orchard hygiene, quick removal of diseased or dying trees, and other preventive measures are often more successful than chemical control. For instance, flatheaded borer establishment in newly planted trees can be prevented by painting the trunk with white latex paint or using trunk wraps to prevent sunburn injury. Shothole borers are managed by keeping trees healthy and removing and destroying infested trees. Piles of recently cut prunings near orchards should be avoided since they are often a source of wood borers.

IX. Postharvest Control

Apple pests which may be found on or in the fruit after harvest can become a quarantine issue. Except for fumigation with methyl bromide, chemical control of insects and mites is generally not permitted on harvested fruit. Diapausing codling moth larvae can survive cold storage conditions in the fruit for a long time. However, they can be controlled with fumigation. Apple maggot larvae, on the other hand, will die in cold storage if fruit is stored for 7 weeks or longer. Methyl bromide may not be available much longer since it depletes ozone. The United States is signatory to an international agreement which threatens to cancel the use of methyl bromide for fumigation purposes.

X. Chemical Control: Insecticides

Oregon’s apple growers still rely to a large extent on chemical control although they make increasing use of alternative control measures (e.g., biological mite control, mating disruption of codling moth, etc.). In the absence of effective and economical alternatives, apple growers still depend on a range of broad-spectrum pesticides, in particular organophosphate (OP) insecticides, for control of major pests such as codling moth, leafrollers, and San Jose scale (Table 2). The use of chemical control agents and registered alternative controls in three major Oregon fruit-growing areas is discussed below and summarized in Table 2 for insecticides and Table 3 for miticides. Pesticides with insecticidal and miticidal activity are listed in either Table 2 or 3 depending on their principal uses. Horticultural spray oil use during the foliar period is summarized in Table 2 and pre-bloom use in Table 3.

• A. Abamectin. This fermentation product of a soil fungus has activity against mites and leafminer on apple. It must be applied with spray oil to assist with translaminar translocation into the leaf. Abamectin is more effective in the first half of the foliar season when leaf tissue is tender. Hood River reported abamectin use on 22% of the apple acreage. In Milton-Freewater, 50% of apple orchards were sprayed once in 1998 with abamectin (Table 2). Abamectin initially has broad-spectrum activity and temporarily disrupts biological control. However, its impact on beneficials is brief since surface residues break down quickly.

• B. Attract and Kill. ‘Attract and Kill’ is another application of the sex pheromone for codling moth control. Large numbers of small droplets (about 1,200/acre) of a sticky substance containing sex pheromone and a knock-down (e.g., permethrin) insecticide are applied with a special hand applicator to the bark of trees. Male moths are attracted to the droplets and are killed on contact. Droplets must be reapplied every four to five weeks. This control method was labeled in 1998 and will be marketed under the trade name ‘Last Call’ (IPM Technology, Portland, Oreg.) in 1999. ‘Attract and Kill’ may be used in combination with a reduced insecticide program or with mating disruption.

• C. Azinphos-methyl. Although many orchard pests have by now developed resistance to azinphos-methyl, this OP is still effective against important apple pests such as codling moth, apple maggot, San Jose scale (crawler stage), green fruit worms, grape mealy bug, and other minor pests. In 1998, azinphos-methyl was still the most widely used codling moth insecticide in Oregon. All three apple-growing districts reported high use of azinphos-methyl for codling moth control (90 to100% of acreage treated with one or more sprays; Table 2). However, the recent label changes in the reentry interval will very likely reduce its use for codling moth control during the 1999 season. Azinphos-methyl is applied after bloom beginning with codling moth egg hatch at an average rate of 1lb AI per acre. Some decline in efficacy has been noted in southern Oregon. Resistance development is suspected. Its long residual covers the extended codling moth egg hatch. Azinphos-methyl is disruptive to natural enemies. However, the western predatory mite tolerates this material (see Biological Control section).

• D. Bacillus thuringiensis (BT). Until a few years ago the use of BT on apple was very limited. On apple, it is used primarily for leafroller control. It may also have activity against green fruit worm. Many BT formulations are being marketed now. BT formulations do not contain a live microbial but the endotoxin produced by the BT microbe. BT has a short residual and will break down quickly after it is applied. Two to three applications may be necessary to bring leafroller under control. BT formulations can be applied up to harvest. BTs are widely used now in Milton-Freewater for leafroller control on 80% of the apple acreage (Table 2). Hood River reported BT use in 1998 on 20% of the acreage. BT is selective and will not disrupt biological control of mites and other pests.

• E. Carbaryl. In Oregon this carbamate is used on most of the apple acreage as fruit thinner and also some for leafhopper nymph control (Table 2). When used as thinner, carbaryl will also provide some codling moth control and can replace an OP or other insecticide at the first cover spray timing. Carbaryl is disruptive to the biological control of mites and other pests.

• F. Chlorpyrifos. When applied during the ‘delayed-dormant’ period, chlorpyrifos is still the most effective leafroller material on apples in Oregon. The WP formulation is also labeled for foliar use. However, the only reported use of chlorpyrifos in Oregon apples is during the pre-bloom for leafroller and San Jose scale control. Most apple orchards are annually sprayed with the EC formulation of chlorpyrifos (Table 2). There are indications that azinphosmethyl-resistant codling moth in California exhibit negative cross-resistance to chlorpyrifos which would make this OP a valuable tool in resistance management programs.

• G. Diazinon. This insecticide is still used some for San Jose scale control. Only southern Oregon reported substantial Diazinon use (on 30% of the apple acreage) for control of San Jose scale crawlers (Table 2). Diazinon is effective against many lepidopterous pests if properly timed. Diazinon has also been used for codling moth control but is not as effective as azinphosmethyl or phosmet. Effect on aphids will vary depending on resistance levels. Diazinon is selective for predaceous mites but toxic to parasitic wasps and generalist predators.

• H. Dimethoate. This OP is systemic and is effective on aphids, leafhoppers, and other hemipterous pests. It is disruptive to the biological control of mites. No use was reported on apples in Oregon in 1998.

• I. Endosulfan. This is still an effective aphid material in many orchards and will also control plant bugs. In 1998, endosulfan was used on 12% of the apple acreage in Hood River. In Milton-Freewater, endosulfan was used primarily for control of the lacanobia fruitworm on 20% of the acreage. In southern Oregon, one third of the apple acreage was treated in 1998 with endosulfan for control of plant bugs (Table 2). Endosulfan is selective to predatory mites but is toxic to larger predators. This material cannot be used near waterways because of its toxicity to fish.

• J. Esfenvalerate, permethrin. These two pyrethroid insecticides have a broad spectrum of activity and are effective against codling moth, leafrollers and other pests, but are very disruptive to biological control agents. Pyrethroids applied after bloom are known to induce spider mite outbreaks by stimulating reproduction (hormolygosis) and by eliminating predatory mites. Therefore, use during the foliar period has never been recommended. None of the three apple-growing areas in Oregon report any use of pyrethroid insecticides.

• K. Granulosis virus. One granulosis virus formulation is federally registered for codling moth control but is not yet commercially available. Granulosis virus is specific to codling moth and has been shown to be somewhat effective if applied frequently and at short intervals. The number of applications per season vary depending on the number of generations in an area (e.g., 8-10 applications in an area with two generations). Young larvae must ingest the virus to be effective. Typically, some feeding damage occurs with virus treatments since larvae do not die instantly after ingesting virus.

• L. Imidacloprid. This relatively new insecticide controls aphids (except woolly apple aphid), leafhoppers, and leafminers on apple. It also shows activity against lygus and stink bugs. Imidacloprid has become the material of choice for aphid and leafhopper control on apples. Use on apples in Oregon averaged between 50 and 60% of the acreage in 1998 (Table 2). High rates or repeated applications may induce spider mite outbreaks. Rates required for aphid and leafhopper control are generally safe and will not cause mite build-up.

• M. Malathion/methoxychlor. A mixture of these two insecticides is commercially available and has been used some for control of leafminer adults in Hood River. Substantial use of this mixture is being reported from Milton-Freewater where it was used on 50% of the apple acreage for control of obliquebanded leafroller adults (Table 2).

• N. Mating disruption. This novel control technology, first registered in the United States in 1991, has proven to be a viable selective alternative to OP insecticides for codling moth control. Two different pheromone dispenser systems were used in 1998 in Oregon apple orchards for codling moth control: Isomate C Plus (Pacific BioControl, Vancouver, Wash.) and Disrupt CM (Hercon Environmental, Emigsville, Pennsylv.). Checkmate CM dispensers (Consep Membranes, Bend, Oreg.) were not used in 1998 on apples in Oregon. The Isomate C-Plus dispenser is the most widely used slow-release pheromone technology at the present time. In 1998, about 12% of the apple area in the Hood River Valley was under mating disruption. Mating disruption use approached 25% of the apple acreage in Milton-Freewater and southern Oregon (Table 2). Most of the mating disruption programs in 1998 consisted of the combined use of pheromone dispensers at half the label rate and additional OP sprays (usually one azinphos-methyl or phosmet). This is a more economical program than mating disruption alone at full label rate. It works well provided the initial population is low (e.g., less than 0.5% infested fruit at harvest in the previous year), orchards are uniform and not close to sources of moths, and the borders are short relative to the treated area. Supplementing mating disruption with limited insecticide (preferably a selective insecticide) use is necessary in most orchards to achieve the desired control efficiency. In southern Oregon, some growers are applying mating disruption together with three oil sprays at 200, 400, and 600 degree-days to help to control codling moth eggs. If current trends continue, mating disruption for codling moth control will significantly reduce OP use on apples in Oregon in the years ahead. Mating disruption is presently under development for control of other pest species on apples (e.g., obliquebanded leafroller).

• O. Methidathion. This OP is only used at the dormant or delayed dormant stage. It is still an effective material for scale control but has been largely replaced by chlorpyrifos for that purpose. Only Hood River and Milton-Freewater reported some use of methyl-parathion for San Jose scale control in 1998 during the pre-bloom period (Table 2). Methidathion is toxic to beneficials.

• P. Methomyl. This is another systemic carbamate with broad-spectrum activity against leafrollers, leafminers and other pests. However, it is toxic to predatory mites and other beneficials and, therefore, does not have a good fit with IPM on apples. There has not been any use of this product on apples in Oregon in recent years.

• Q. Methyl-parathion. This OP is available as a micro-encapsulated formulation (Penncap M). Methyl-parathion applied for leafroller or San Jose scale control after bloom will also provide some codling moth control. Use in Oregon apples has declined in favor of other materials with lower mammalian toxicity and better IPM fit. In Milton-Freewater, methyl-parathion was at one time an important insecticide for leafroller control but is not used any more for that purpose because of resistance development. Recent data from California indicate that azinphos-methyl resistant codling moth exhibit negatively correlated cross-resistance not only to chlorpyrifos but also to methyl-parathion. This would make methyl-parathion a valuable material in managing organophosphate resistance in codling moth. In southern Oregon, one spray of methyl-parathion was used in 1998 on 30% of the acreage for control of codling moth with low azinphos-methyl resistance. Methyl-parathion was used very little in 1998 in the other two areas (Table 2). Similar to other OPs, methyl-parathion allows predatory mites to survive but is disruptive to other biological control agents

• R. Oxamyl. This systemic carbamate is primarily used for control of leafminer eggs and sap-feeding larvae. In 1998, oxamyl was applied to 7% of the apple acreage in Hood River and to 20% of the acreage in Milton-Freewater (Table 2). Oxamyl is disruptive to the biological control of mites and other pests.

• S. Phosmet. This OP has lower mammalian toxicity than azinphos-methyl and is not a restricted use pesticide. Use rates vary from 3 to 5 lbs/acre per application. Phosmet has long been considered a less effective codling moth material than azinphos-methyl, but is more selective to biological control agents. Use of phosmet for codling moth control was still relatively low in 1998 (Table 2) but is expected to increase in 1999 due to the new use requirements (e.g., longer reentry, longer day-to-harvest intervals) for azinphos-methyl on apples and pears. Phosmet will suppress grape mealy bug, OP-susceptible leafrollers and other lepidopetrous pests. Phosmet is considered to have a lower impact on natural enemies than azinphos-methyl. Predatory mites survive field rates of phosmet.

• T. Spinosad. Also a fermentation product produced by a fungus, spinosad controls leafrollers and leafminers. It can be applied up to one week before harvest. In Milton-Freewater, spinosad has become an important insecticide for leafroller control on apples due to widespread OP resistance (80% of acreage treated in 1998; Table 2).

• U. Spray oil (Horticultural). Narrow-range paraffinic spray oils are available under various trade names (e.g., Volck Supreme, Omni, JMS Stylet Oil). They have similar specifications and have been designed to combine maximum pesticidal activity with plant safety. Historically, most spray oil use has occurred during the dormant or delayed dormant period for control of European red mite eggs, aphid eggs, and scale insects. All three apple growing areas in Oregon report high spray oil use during the pre-bloom period (Table 3). Post-bloom applications of spray oils are still not a common practice because of concern about phytotoxicity, especially on stressed trees. Repeated applications of 1% spray oil after bloom will keep mites, leafhopper, and other foliage feeders suppressed. Only Hood River reported spray oil use after bloom on 8% of the apple acreage, mostly by organic growers, to help control codling moth in orchards under mating disruption (Table 2). Spray oils are selective materials and effective miticides when mite populations are low and predators are present. Oils fit in well with IPM programs due to their selectivity.

• V. Table 2. Registered insecticides, use requirements, target pests and estimated use statistics in three apple-growing districts in Oregon in 1998.

  Registered insecticides/control methods			REI	PHI	Target	% of crop treated, use frequency & rate form./acre
  Common name	Trade name & formulation	Chemical group				Hood River Valley (2,200 acres)	Milton-Freewater (3,500 acres)	Southern Oregon (400 acres)
  Azinphos-methyl*	Guthion 50WP	OP	48, 72 h 14 d	14 d	Codling moth San Jose scale Leafrollers	87% 1-4 sprays 1.5-2 lbs	100% 1-4 sprays 1.5-2 lbs	100% 2-3 sprays 2-3 lbs
  Phosmet	Imidan 70WSP	OP	24 h	7 d	Codling moth Leafrollers	5% 1-4 sprays 3-5 lbs	25% 1-4 sprays 3-5 lbs	25% 1-2 sprays 3-5 lbs
  Diazinon*	Diazinon 50WP	OP	24 h	14 d	Codling moth Leafrollers Green fruitworm San Jose scale	3% 1 spray 4 lbs	Not used	30% 1 spray 4 lbs
  Chlorpyrifos*	Lorsban 50WP	OP	24 h	28 d	Codling moth Leafrollers San Jose scale	Not used	Not used	Not used
  Chlorpyrifos*	Lorsban 4EC	OP	24 h	D** DD	San Jose scale Leafrollers	90% 1 spray (pre-bloom) 4pts	80% 1 spray (pre-bloom) 4pts	100% 1 spray (pre-bloom) 4pts
  Methidathion*	Supracide 25WP	OP	48 h- 14 d	D** DD	San Jose scale	8% 1 spray (pre-bloom) 8 lbs	10% 1 spray (pre-bloom) 8 lbs	Not used
  Methyl- parathion*	Penncap M	OP	48 d	14- 30 d	San Jose scale Leafrollers	2% 1 spray 4-8 pts	1% 1 spray 4-8 pts	30% 1 spray 4-8 pts

  * restricted use pesticide

  ** D, DD = dormant, delayed dormant

   

  Table 2. Registered insecticides, use requirements, target pests and estimated use statistics in three apple-growing districts in Oregon in 1998 (cont.).

  Registered insecticides/control methods			REI	PHI	Target	% of crop treated, use frequency & rate form./acre
  Common name	Trade name & formulation	Chemical group				Hood River Valley (2,200 acres)	Milton-Freewater (3,500 acres)	Southern Oregon (400 acres)
  Malathion/ methoxychlor		OP/ organochlorine		7 d	Leafminer Leafroller (adults)	1% 1-2 sprays 4 pts	50% 1-2 sprays 4 pts	Not used
  Carbaryl	Sevin 4F, XLR	Carbamate	24 h	1 d	Fruit thinning Leafhoppers Codling moth	93% 1 spray 1.5-2 qts	80% 1 spray 1.5-2 qts	100% 1 spray 1.5-2 qts
  Oxamyl	Vydate	Carbamate	48 h	14 d	Leafminer	7% 1 spray 2 pts	20% 1 spray 2 pts	Not used
  Esfenvalerate	Asana	Pyrethroid	24 h	21 d	Codling moth Leafrollers Other pests	Not used Not recommended	Not used Not recommended	Not used Not recommended
  Permethrin	Ambush, Pounce	Pyrethroid	24 h	PF**	Codling moth Leafrollers Other pests	Not used Not recommended	Not used Not recommended	Not used Not recommended
  Endosulfan	Thiodan 50WP	Organochlorine	48 h	21- 30 d	Aphids Stinging bugs Cutworms	12% 1 spray 4 lbs	20% 1 spray 4 lbs	30% 1 spray 4 lbs
  Imidacloprid	Provado 1.6F	Chloronicotynil	24 h	7 d	Aphids Leafminer Leafhoppers	62% 1-2 sprays 4-8 oz	60% 1-2 sprays 4-8 oz	50% 1 spray 4-8 oz
  Abamectin	Agri-Mek 0.15EC	Avermectins	24 h	28 d	Leafminer Mites	22% 1 spray 10-20 oz	50% 1 spray 10-20 oz	Not used

  * restricted use pesticide

  ** PF = petal fall

  Table 2. Registered insecticides, use requirements, target pests and estimated use statistics in three apple-growing districts in Oregon in 1998 (cont.).

  Registered insecticides/control method			REI	PHI	Target	% of crop treated, use frequency & rate form./acre
  Common name	Trade name & formulation	Chemical group				Hood River Valley (2,200 acres)	Milton-Freewater (3,500 acres)	Southern Oregon (400 acres)
  Spinosad	Success 2F	Naturalyte (Spinosyn A&D)	4 h	7 d	Leafrollers Leafminer	2% 1-2 sprays 4-10 oz	80% 1-2 sprays 4-10 oz	Not used
  Bacillus thuringiensis	Dipel, Biobit, Javelin, Crymax	BT endotoxins	1 d	12 h	Leafrollers	20% 1-3 sprays 1-2 lbs	80% 1-3 sprays 1-2 lbs	Not used
  Horticultural spray oil	Volck Supreme Omni JMS Stylet Oil	Paraffinic hydrocarbon	--	--	Codling moth Mites Leafhoppers	8% 1-3 sprays (foliar) 1% (v/v)	Not used	Not used
  Mating disruption	Isomate C-Plus	Codlemone Sex pheromone	--	--	Codling moth	12% 1 application 200-400 dispensers	25% 1 application 200-400 dispensers	25% 1 application 400 dispensers
  Mating disruption	Check-Mate CM	Codlemone Sex pheromone	--	--	Codling moth	Not used	Not used	Not used
  Mating disruption	Disrupt CM	Codlemone Sex pheromone	--	--	Codling moth	Not used	Not used	25% 1 application 200 dispensers
  Attract & Kill	Last Call	Codlemone plus permethrin	--	--	Codling moth	Not used in 1998 Every 4-5 weeks 1,200 droplets	Not used	Not used

  * restricted use pesticide

   

  XI. Chemical controls: Miticides

  • A. Clofentezine. This ovicide has properties very similar to hexythiazox and is equally selective. However, it cannot be used past the ‘tight cluster’ stage. In 1998, this miticide was used on 7 and 10% of the apple acreage in Hood River and southern Oregon, respectively. Clofentezine was also used by apple growers in Milton-Freewater but no use estimates were available (will be provided in fall of 1999). Clofentezine does not disrupt biological control of mites and other pests.

  • B. Dicofol. Resistance to this material is widespread. Mite resurgence often follows the use of this material because it also kills predaceous mites. No use on apples was reported from Oregon in 1998.

  • C. Fenbutatin oxide. This is the only organotin miticide still registered on apples. Resistance to this organotin miticide may be present. Hood River apple growers used fenbutatin oxide in 1998 on 8% of the acreage (Table 3). Fenbutatin oxide was also used by apple growers in Milton-Freewater but no use estimates were available (will be provided in fall of 1999). Fenbutatin is effective against mobile stages. It does not work well in cool weather. Used at lower label rates, fenbutatin is selective and does not disrupt biological mite control.

  • D. Formetanate HCl. This miticide/insecticide has a wide spectrum of activity and is disruptive to biological control of mites and other pests. Some spider mite populations are resistant to formetanate HC. No use on apples was reported from Oregon in 1998.

  • E. Hexythiazox. This miticide will not eradicate a mite population since it is primarily active against eggs. It will also disrupt development of young mobile stages. Hexythiazox can be applied up to the ‘pink’ stage. Only Hood River growers used hexythiazox in 1998 on 7% of the acreage (Table 3). Hexythiazox was also used by apple growers in Milton-Freewater but no use estimates were available (will be provided in fall of 1999). Hexythiazox is selective and does not disrupt biological control of mites. Hexythiazox has no activity against rust mites which serve as a valuable alternative food source for predatory mites on apples. Due to its selectivity it has a natural fit with IPM on apples.

  • F. Pyridaben. This new contact miticide is more effective against European red mite than against other Tetranychus species. In 1998, pyridaben was used on 20 and 25% of the apple acreage in Hood River and southern Oregon, respectively (Table 3). Pyridaben was also used by apple growers in Milton-Freewater but no use estimates were available (will be provided in fall of 1999). However, pyridaben may not be as useful in an integrated mite control program as other selective miticides since it also reduces apple rust mites and predatory mites.

  • G. Table 3. Registered miticides, use restrictions, target pests and estimated use statistics in three apple-growing districts in Oregon in 1998.

    Registered miticides			REI	PHI	Target	% of crop treated, use frequency & rate form./acre
    Common name	Trade name & formulation	Chemical group				Hood River Valley (2,200 acres)	Milton-Freewater (3,500 acres)	Southern Oregon (400 acres)
    Horticultural spray oil	Volck, Omni JMS Stylet Oil	Paraffinic hydrocarbon		D** DD	Mite eggs San Jose scale	100% 1 spray (pre-bloom) 1-2% (v/v)	90% 1 spray (pre-bloom) 1-2% (v/v)	100% 1 spray (pre-bloom) 1-2% (v/v)
    Fenbutatin oxide	Vendex 50WP	Organotin	48 h	14 d	Spider mites Apple rust mite	8% 1 spray 1.5-3 lbs	Used but no estimates available 1 spray 1.5-3 lbs	Not used
    Pyridaben	Pyramite 60WP	Pyridazinone	12 h	25 d	Spider mites Apple rust mite	20% 1 spray 4.4-13.2 oz	Used but no estimates available 1 spray 4.4-13.2 oz	25% 1 spray 4.4-13.2 oz
    Hexythiazox	Savey 50WP		24 h	PK**	Spider mites	7% 1 spray (pre-bloom) 4-6 oz	Used but no estimates available 1 spray (pre-bloom) 4-6 oz	Not used
    Clofentezine	Apollo 50SC	Tetrazine	12 h	TC**	Spider mites	7% 1 spray (pre-bloom) 4-8 oz	Used but no estimates available 1 spray (pre-bloom) 4-8 oz	Not used
    Formetanate HC*	Carzol SP		48 h	7 d	Spider mites Apple rust mite Thrips Leafminer Leafhopper Plant bugs	Not used	Not used	Not used

    * restricted use pesticide

    ** D, DD = dormant, delayed dormant; TC = tight cluster; PK = pink

     

    XII. Acknowledgements:
    The authors would like to thank M. Cardon, United Agricultural Products, Hood River; Bruce Decker, Wilbur Ellis, Hood River; and Mel Henage, GS Long?, Hood River, for their help with the pesticide use information in the Hood River Valley. Rick Hilton, Southern Oregon Experiment Station, helped with pesticide use estimates for apples and pears in southern Oregon. We are also grateful to Mr. Bill Barnett, Univ. of California Cooperative Extension IPM Specialist (emeritus), who graciously provided information on pest species and monitoring procedures.

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    Database and web development by the NSF Center for Integrated Pest Managment located at North Carolina State University. All materials may be used freely with credit to the USDA.