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Extension Based Tree and Small Fruit Insect Pest Management Strategies

January 1981

Authors:

John Leeper

New Mexico State University

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Number 88, 1981 ISSN 0362-0069

New York State Agricultural Experiment Station, Geneva, a Division of the New York State College of Agriculture and

Life Sciences, a Statutory College of the State University, at Cornell University, Ithaca

Extension Based Tree and Small Fruit

Insect Pest Management Strategies

JOHN R. LEEPER

INTRODUCTION

In 1978, a System for the Computer Management of

Pests (SCAMP) was developed at the New York State

Agricultural Experiment Station as an extension com-

munications and information delivery system. In response

to requests by fruit agents for timely, in-depth strategies for

fruit insect and mite pests, based on the same information

available to the farm advisors in the New York Tree Fruit

Pest Management Program, a STRATEGY file on SCAMP

was developed in 1979. In 1980, a new computer program,

LIBRARY, was developed for easier storage, retrieval, and

editing of the strategies. In addition to the strategies

transferred from STRATEGY, 10 new tree fruit and three

small fruit strategies were placed in LIBRARY.

SCAMP users wishing to use LIBRARY may login and will

be asked:

WHAT WOULD YOU LIKE TO DO NEXT?

They may answer:

LIBRARY

They will then be asked:

ENTER: COMMODITY, HELP, OR END

They may answer:

TFRUIT

They will then be asked:

ENTER: FILE NAME, HELP OR END

They may answer:

APPLE MAGGOT or AM

They will then be asked:

ENTER: WARNING, LIFE HISTORY, MONITORING, CON-

TROL, HELP, OR END

They may then enter and receive whatever information

they wish.

The purposes of this publication are to update the

strategies made available through New York's Food and

Life Sciences Bulletin No. 85, January 1 980, to provide the

new strategies, and to demonstrate and document the ser-

vice provided New York extension agents and their con-

stituents through LIBRARY. Portions or all of the strategies

within this publication may be duplicated and disseminated

if credit is given to the author and the Entomology Depart-

ment, New York State Agricultural Experiment Station.

I wish to thank my colleagues within the department for

advice in writing the strategies. Particular thanks go to

James P. Tette, IPM Coordinator, and Douglas Bruno and

David Way, Tree Fruit Pest Management Farm Advisors, for

their help in developing the tree fruit monitoring and action

thresholds; and to George Schaefers, small fru i t en-

lumologist, for his aid in preparing the small fr uit strategies.

I also wish to thank Janet Walton, Linda Smith, and Tam-

my Caplan for entering and editing the strategies in the

computer.

The information in Library has been prepared by Cornell

University for Cooperative Extension, and may be

reproduced and disseminated if credit is given to Cornell

University and the author.

APPLE GRAIN APHID (AGA)

Rhopalosiphum fitchii (Sanderson)

Life History

The AGA spends most of the growing season on grains

and grasses, and although high populations can be found

on apple in the early spring, it is not considered a serious

pest of apple. The AGA overwinters as a black egg on the

bark of the previous year's growth and can not be differen-

tiated from rosy apple aphid and green apple aphid eggs.

The AGA is the first of the three species to hatch in the spr-

ing as the trees begin to break dormancy; by bloom, heavy

infestations may occur on the new growth and become a

concern to growers. By petal fall, the AGA has begun to

migrate to its alternate hosts and shortly thereafter it cannot

be found on the trees.

Monitoring

Since the AGA is not an economic pest and leaves the

trees shortly after petal fall, no specific monitoring is re-

quired.

Control

Since the AGA is not an economic pest and leaves the

trees shortly after petal fall, insecticides directed

specifically against this pest are not recommended. The

pink and petal fall sprays applied to control the rosy apple

aphid will also control the AGA.

APPLE MAGGOT (AM)

Rhagoletis pomonella (Walsh)

Warning

AM emergence is predicted to occur at about 1137

degree-day units, with a base of 43F. This normally occurs

in mid-June in downstate New York and late June or early

July in upstate New York. AM sticky boards should be

ordered from the pest management program. See

MONITORING for trap use.

Life History

The AM is a native American species that has become a

pest of the introduced apple. Typically, there is a single

generation a year with aduit flies emerging from about mid-

June through apple harvest.

Normally, AM is not resident within commercial apple

orchards, but annually migrates in from unsprayed sites

and must be killed before oviposition occurs. Although

migration can occur whenever flies are out, it is normally

not a serious problem until late July or August. Growers

should, therefore, become more concerned and tighten up

their AM control programs as the season progresses.

AM emergence is related to heat units, soil type, host,

and rainfall.

1. Heat units, more specifically, degree-days, must be

above 1137 with a base of 43F for maggot to emerge.

After the appropriate degree-days have been ac

cumulated from March 1, other factors become impor

tant.

2. Soil type. AM tend to emerge eariier in sandy soil than

in heavy clay soil.

3. Host. AM tend to emerge earlier when they have been

reared on early maturing varieties rather than late

maturing varieties. AM females also prefer to oviposit

on fruit as it begins to ripen, and, therefore, are often

found first around these trees. Early oviposition stings

on late maturing varieties frequently do not result in

wormy fruit. The eggs or newly hatched larvae are

believed to be crushed by the rapidly growing fruit.

4. Rainfall. There is a sharp increase in AM emergence

following a soaking rainfall. It is believed that rain

loosens the soil, especially heavier soils, and makes it

easier for the adult to push its way to the surface.

Once the AM has emerged, a maturation or pre-

oviposition period of 7 to 10 days is required before a

female begins laying eggs. Growers have timed their first

AM spray at least 7 to 10 days after first emergence in order

to take advantage of this fact.

Monitoring

The method of determining when to spray for AM is im-

portant and is based on whether monitoring of adult

emergence and migration into an orchard is being con-

ducted.

The most commonly used monitoring tool for AM

emergence and migration is the yellow sticky board. A few

growers may be using red sticky spheres which are used

the same way as the boards.

First emergence can best be determined for an area by

placing sticky boards in an unsprayed site where early ap-

ple varieties are grown on sandy soil and AM is known to

exist. Besides checking the traps on a regular schedule o,

no longer than 3 days, traps should be checked after the

first warm day following a rain.

Once emergence has been determined for an area, the

boards should be placed along the edge of the block

closest to the area from which the greatest AM migration is

believed to come. The traps should be inspected for AM

adults at least every 3 days, and an insecticide should be

applied as soon as possible after the first catch. The boards

should continue to be monitored for AM, but another insec-

ticide application should not be made until the first fly is

caught after residues from the last spray are no longer pre-

sent in amounts large enough to protect the crop. The

length of this period will vary with conditions; for most

materials, residues remain at effective levels for about 10 to

14 days. Rainfall is probably the most common factor that

can reduce field residues.

Growers wishing to monitor orchards to determine spray

timing should follow the directions provided in "Using

Sticky Traps To Monitor Fruit Flies In Apple And Cherry

Orchards." Copies of this publication are available through

the pest management program or your county agent.

If boards are not being used to monitor migration into an

orchard, growers have historically applied their first AM

spray 7 to 10 days after first AM emergence in their area If

there was not an AM problem within the orchard the

previous season, or the block is not an early variety with an

adjacent unsprayed site that could be a source of early in-

festation, a grower can normally extend the period before

the first spray to 14 to 21 days after first AM emergence.

Additional sprays should be applied on a 10 to 14 day

schedule.

Control

The AM adult is an active insect and excellent control

can be achieved with insecticide coverage that would not

be acceptable for controlling many other insect pests. The

fly will sooner or later come into contact with enough

material to kill it. Growers using alternate middle row spray-

ing, as well as those applying the insecticide high concen-

trate, obtain AM control.

Azinphos methyl, Guthion, Imidan, Penncap-M, and

Zolone are five of the more commonly used AM insec-

ticides. If Vydate is used for spotted tentiform leafminer

control, do not expect AM control. Add a full rate of another

insecticide that will control AM.

APPLE RUST MITE (ARM)

Aculus schlechtendali (Nalepa)

Life History

The ARM is a cone-shaped, straw-colored mite that

cannot be easily seen with the naked eye. It is most com-

monly found on the leaf undersurface, especially along the

leaf midrib.

The ARM overwinters as an adult female under the bud

scales of apple trees. As the trees break dormancy, the

mites become active and remain so until late July or early

The broad spectrum organophosphate insecticides

August when the overwintering females are produced and

the mites become difficult to find.

The ARM feeds on the undersurface of apple leaves.

Feeding injury from high populations can cause the leaves

to take on a rusty appearance. The injured leaves may also

roll longitudinally and give the appearance that the tree is

under drought stress. Apple trees can normally withstand

ARM populations up to 200 or more per leaf before injury

becomes noticeable. Occasionally, the ARM will move to

and can be found at the calyx and stem ends of the fruit.

Even more infrequently, they will russet the fruit.

There are beneficial aspects to maintaining a moderate

ARM population within an orchard. They are a good host for

mite predators and help to build up and maintain predator

populations before European red mite populations in-

crease. Their feeding may also condition the foliage and

make it less susceptible to attack by the European red mite.

Monitoring

A good hand lens is required to monitor ARM pop-

ulations. Pick 10 leaves from 10 different trees in an

orchard for a total of 100 leaves. Because low populations

of the ARM tend to congregate along the basal third of the

leaf midrib, this is a good place to look for the mite on a leaf.

Without counting the exact number of mites, control is

recommended if there are an average of 200 or more ARM

per leaf. Control is also recommended at the first sign of

leaf injury.

Control

Most insecticides and acaricides will suppress ARM

populations with a single application. Suppression of the

population is normally sufficient. For more complete ARM

control, two applications of an acaricide (Plictran, 4-6

oz./100 gal.; Omite 1-1 1/ 2 lb./100 gal.; Carzol, 1 / 8 -1 /2

lb./100 gal.) with a 7-10 day interval between sprays is

recommended.

BEES

For information on bees, see HONEY BEE in LIBRARY.

BLOOM

Orchards are in bloom atthistime. Although insecticides

cannot be applied now, preparations should be made for

the petal fall spray. During bloom, orchards should be in-

spected to determine what insect and mite pests will need

to be controlled, and a decision should be made as to what

materials to use at petal fall. For further information on what

insects may require control and the recommended

materials, see PETAL FALL in LIBRARY.

CODLING MOTH (CM)

Cydia (Laspeyresia) pomonella (L.)

Warning

In New York, we follow the Michigan model which

predicts CM first emergence to occur at 248 degree-days

from March 1 with a base temperature of 50F. The first CM

traps should be hung when the degree-day accumulation

reaches 200 or at full bloom, whichever occurs first. CM

pheromone traps should be ordered from the pest manage-

ment program.

Life History

The CM has one and a partial second generation in New

York. It overwinters within cocoons as full-grown larva. The

cocoons can be found under loose bark on trees or in

debris on the orchard floor. The overwintering larva

pupates in the spring, beginning about mid-April. The

length of the pupal period is dependent on spring

temperatures and can range from a month or longer to as

short as 10 days. First emergence occurs at about 248

degree-days from March 1 with a base temperature of 50F,

or about the time apples are in full bloom. Peak flight occurs

about mid-June, and flight can continue into July. CM flight

and egg laying occur in the early evening, normally when

evening temperatures at 8 PM are 60F or above.

A female can lay approximately 100 eggs. The eggs are

laid singly, directly on the fruit or upper leaf surface. They

are flat, slightly oval discs. Immediately after being laid, the

eggs are translucent. They later take on a red ring, and 1 -2

days before hatching, the dark head capsule can be seen.

After hatching, the larvae seek out and enter the fruit

where they feed and pass through five instars. The larvae

are cream- to pink- colored and have dark speckling on

their thorasic shield. The absence of an anal comb is a key

characteristic in differentiating the CM from larvae of the

other internal fruit-feeding Lepidoptera. To determine if the

anal comb is present or absent, squeeze the internal body

fluid from the head end of a larva toward the anal end. This

will extend the anal end, and if present, the anal comb will

be easily visible with the aid of a good hand lens.

The larvae of the CM and the other internal fruit-feeding

Lepidoptera tunnel to the core of the fruit and enlarge an

exit hole that they plug with frass. The majority of first

generation CM larvae are mature and leave the fruit by mid-

to late July. About 40 per cent of the larvae pupate and

emerge as adults. Peak flight occurs about thefirstweek in

August. The remaining larvae overwinter and pupate and

emerge as adults the following spring.

The second generation follows a life history similar to the

first. The larvae are active during the latter half of August

and September. When mature, the larvae exit the fruit and

construct cocoons in which they overwinter.

Monitoring

CM first emergence and flight are monitored with

pheromone traps which should be placed in both commer-

cial and abandoned orchards. In commercial orchards, a

trap station should be placed for every 50 acres of orchard,

and traps should be checked at least once a week. Traps

and caps should be replaced during the last week in July in

preparation for monitoring the second CM flight. It should

also be pointed out that the flights overlap.

Although the CM has been a serious pest in the past and

retains that potential, insecticides are no longer applied

regularly to specifically control it. The insecticides applied

to control the plum curculio at petal fall and the apple

maggot later in the summer also control the CM in most in-

stances. Therefore, the action threshold based on trap

catches in New York is higher than in areas where these

other insects are not present. Sprays directed specifically

at the CM are not recommended unless pheromone trap

catches within commercial orchards exceed the trap catch

in a nearby abandoned block, or a total of 14 or more moths

are trapped in a commercial orchard in a week.

Control

Guthion, azinphos methyl, Imidan, and Zolone are four of

the more commonly used insecticides that will control the

CM as well as the plum curculio and apple maggot.

Penncap-M and Sevin will also give good control of all three

insects. Sevin is also used as a fruit thinner and will control

the white apple leafhopper, but may precipitate woolly ap-

ple aphid problems. Penncap-M, if used, will provide woolly

apple aphid control if the aphids are present on the wood or

terminals. Both Penncap-M and Sevin are highly toxic to

honey bees. For precautions to take to help reduce bee

poisoning, see HONEY BEE in LIBRARY.

EARLY LEPIDOPTERA (EL)

The term EL is used to collectively refer to the

Lepidoptera that are out feeding as larvae by petal fall. It is

frequently difficult to identify the species present, and it is

difficult to differentiate the fruit injury at harvest. See

GREEN FRUITWORM, OBLIQUEBANDED LEAFROLLER,

and PETAL FALL in LIBRARY.

EUROPEAN RED MITE (ERM)

Panonychus ulmi (Koch)

Life History

The ERM is a perennial apple pest with up to eight

generations per year. It overwinters in red egg masses on

the tree, frequently on or around the base of fruit spurs. The

overwintering eggs begin hatching between tight cluster

and pink; normally all have hatched by petal fall.

Upon hatching, the mite passes through three stages

before becoming an adult. The first or larval stage is six-

legged. The protonymph and deutonymh are progressively

larger and are eight-legged. The time period from hatching

to becoming an adult ranges from about 6 to 16 days. Nor-

mally, the ERM does not become a problem until mid-July

or later. Overwintering eggs begin to be produced in mid-

August.

Excessive ERM feeding on leaves can cause bronzing. If

bronzing is excessive and occurs early, it can affect fruit

maturation and yield. Under high populations, the mites will

also move to and lay eggs at the calyx end of the fruit. This

is particularly undesirable on the lighter colored varieties

destined for the fresh fruit market.

There are a number of predators that feed on the ERM. In

the Hudson and Champlain Valleys, the mite, Amblyseius

fallacis, is the most common predator and can be very

effective in keeping ERM populations in check. In western

New York, the mite Typhlodromaspyri is the most common

predator. However, at best, it is inconsistent in controlling

ERM populations. Both/A. fallacis and T.pyri are small, fast-

moving, pear-shaped mites that may be tan to straw-

colored or may take on a red tinge from their food source,

the ERM.

Monitoring

If in inspecting 10 leaves per tree from 10 trees in an

orchard, an average of six or more ERM per leaf are found

and the average number of predator mites is below one per

leaf, use of an acaricide is recommended.

Control

Dormant - Oil may be applied in the early spring to kill

overwintering eggs. The oil application will also control San

Jose Scale. Complete coverage is essential.

Pink- Plictran (4-6oz./100gal.) must be applied before

newly hatched mites become adults.

Post Bloom - A reduced rate Vendex spray program (3

oz./100 gal.) at petal fall and first and second cover may be

substituted for the oil spray. If used, all three Vendex sprays

must be applied at 7-10 day intervals. The program has

given seasonal control of ERM. Vendex is not recommend-

ed for the summer control of the ERM.

Summer - Plictran (4-6 oz./100 gal.) and Omite (1-1 1 /2

lb./100 gal.) are two of the more commonly used summer

acaricides. With either material, two applications 7-10 days

apart are recommended. The split applications help kill the

mites as they hatch from their eggs.

GREEN APPLE APHID (GAA)

Aphis pomi De Geer

Also see PETAL FALL in LIBRARY.

Life History

Although the GAA remains on apple trees throughout

the year, it does not reach serious population levels, if at all,

until summer.

The GAA overwinters as a small black egg on the bark of

trees. It is difficult, if not impossible, to differentiate between

GAA eggs and those of the apple grain aphid and the rosy

apple aphid. Early New York literature states that the GAA

eggs tend to be laid in groups while the eggs of the two

other species are more uniformly distributed throughout

the orchard. The eggs hatch as the apple trees break dor-

mancy and after about two weeks the nymphs mature and

begin producing living young.

The GAA has up to 17 generations per year. A portion of

each generation develops into winged adults that fly off to

start new colonies. The GAA favors new growth on which to

develop and is most common on suckers and water

sprouts late in the season.

The sexual forms are produced only in the fall. After they

become adults and mate, the females lay their eggs on the

bark of the trees.

The GAA is an indirect pest in that it does not feed on the

fruit itself. Fruit injury occurs when the honey dew produced

by the aphid colony drops onto the fruit.

There are a large number of beneficial insects (parasites

and predators) and a disease that play an important role in

controlling the GAA. Due to the relative lack of seriousness

of a low GAA population and in order to promote the

beneficial insects, growers need not spray until about 50

per cent or more of the terminals with tender growth are in-

fested.

Monitoring

In checking 10 terminals with tender growth on each of

10 trees in a block, treatment is recommended if 50 per

cent of the terminals are infested with healthy GAA

colonies.

If parasites, predators, or the disease appear to be in-

fluencing the GAA populations, postpone spraying a week

and resample to determine whether chemical control is re-

quired.

Control

Systox and Phosphamidon are two of the more com-

monly used materials for controlling the GAA during the

summer. The GAA has developed resistance to many of

the organophosphates in many apple growing areas of the

state, and the materials will no longer even suppress the in-

sect. If Vydate is used for controlling the second generation

of the spotted tentiform leafminer, it will also control GAA

and another material to control the aphid need not be add-

ed.

GREEN FRUITWORM (GFW)

GFW is a collective common name used in New York to

refer to a number of Lepidoptera. The life history presented

here is that of one of the more common members of that

group, Orthosia hibisci Guenee. Also see PETAL FALL in

LIBRARY.

Life History

The GFW'has a single generation per year and

overwinters in the pupal stage in the soil. Adult emergence

begins at about green tip and is complete by pinkfor Mcln-

tosh apples. The adults are about 2/3 of an inch long. They

are grayish-pink in color and have two purplish-gray spots

on the forewings.

Egg laying begins at about half-inch green. Eggs are laid

singly or in pairs. They are white to grayish in color and

have ridges radiating from the center.

GFW larvae begin hatching between tight cluster and

pink. The larvae feed on new leaves, flowers, and develop-

ing fruit. Fruit feeding is normally restricted to larger larvae.

The larvae mature between late May and late June, at

which time they drop to the ground and pupate in the soil at

a depth of two to four inches.

Monitoring

At pink and at weekly intervals through first cover, check

20 fruit clusters per tree on 5 trees per block. On each tree,

look for larvae or evidence of fresh feeding on 6 clusters on

the outside of the tree, 6 clusters in the center of the tree,

and 8 clusters in the top of the tree. Treatment is

recommended if there are an average of two or more larvae

or fresh feeding sites per tree. Monitoring for the GFW is the

same as monitoring for the obliquebanded leafroller and

both species may be considered together in making a con-

trol decision.

Control

In the past, sprays were applied at pink and petal fall to

control the GFW. Recent research has indicated that a

single spray at petal fall provides comparable control to the

two spray program.

Guthion, azinphos methyl, and Imidan are three of the

standard insecticides used to control GFW; however, they

are not providing adequate control in a few areas of New

York. In those areas, Thiodan still offers control. If Thiodan

is used, a full rate of one of the above materials should also

be included to control the plum curculio.

If GFW populations are mixed with populations of obli-

quebanded leafroller, Lannate, Nudrin, or. Penncap-M

should be used. Lannate and Nudrin are the preferred

materials where they can be used. If Lannate or Nudrin is

used at petal fall, a 1 /4 to 112 rate of one of the first three in-

secticides should be included to pick up where Lannate

and Nudrin fall down on plum curculio control. Lannate and

Nudrin are labeled for peaches and apples, but should not

be used on Early Mclntosh, Wealthy, or Dutchess varieties.

They are not labeled for use on pears or cherries. Where

Penncap-M must be used, care should be taken to reduce

the threat of bee poisoning. Also see HONEY BEE in

LIBRARY.

HONEY BEE (HB)

Apis me II if era L.

HB play an important role in pollinating crops and are,

therefore, beneficial insects to the fruit grower. It is impor-

tant to protect HB from poisoning due to their exposure to

insecticides applied to control insect pests.

The following precautions should be taken to help

reduce the possibility of HB kills when insecticides are

applied:

1. Cover or remove hives from the orchard before spray

ing at petal fall.

2. Have 90 per cent of the petals off before spraying an in

secticide.

3. If there are five or more flowers in bloom per square

yard of ground cover, mow before spraying. This is im

portant throughout the growing season.

4. Whenever possible, spray insecticides in the evening

after the HB have stopped foraging and the flowers

have closed.

5. Whenever possible, choose the insecticide with the

lowest HB toxicity to get the job done.

Forfurther information on HB poisoning, pesticide toxici-

ty to HB, HB as pollinators, HB behavior, etc., see the

current edition of "The Cornell Recommendations for

Commercial Tree Fruit Production."

MITES

For mite strategies see APPLE RUST MITE, EUROPEAN

RED MITE, PEAR RUST MITE, and TWO SPOTTED

SPIDER MITE in LIBRARY.

OBLIQUEBANDED LEAFROLLER (OBLR)

Choristoneura rosaceana (Harris)

Also see PETAL FALL in LIBRARY.

Life History

The OBLR has one or two generations a year; there are

two generations in New York. OBLR overwinter as third in-

star larvae on the tree and become active at about pink.

They begin feeding on the tender new foliage, flower buds,

and after petal fall, on the fruit.

OBLR larvae have pale green bodies. Their head cap-

sules may vary in color from black to light brown, and their

thorasic shields vary from black to pale tan. The larvae are

very active when disturbed and will drop from the tree on a

silk thread. By petal fall, the first of the larvae are full-grown

and shortly thereafter they pupate, frequently within a rolled

leaf.

The first OBLR flight begins about three weeks after

petal fall and continues for about a month. Females begin

egg laying about 24 hours after emergence. The eggs

appear as greenish-yellow masses of up to 200 or more

eggs. As the females continue laying eggs, the masses

become progressively smaller.

The eggs hatch in 10-12 days and the larvae begin

feeding on new foliage, frequently on water sprouts or in the

tops of the trees. The larvae often move to and feed on the

fruit as they become larger. They complete their develop-

ment in late July or early August and begin to pupate.

The second adult OBLR flight occurs from early August

through early September. The young produced by these

adults develop into the third instar overwintering larvae.

Monitoring

Pheromone traps may be used to determine OBLR flight.

The OBLR has a wide host range; high trap catches need

not indicate previous in-orchard problems, but may be from

outside OBLR populations that may be a source of future

in-orchard problems. The pheromone trap catches can,

therefore, indicate when OBLR adults begin flying, their

relative abundance in the area, and when peak flight oc-

curs. The need to treat should not be based on pheromone

trap catches, but should be determined by inspecting in-

dividual blocks for larvae or their feeding.

At late bloom or early petal fall, check 20 clusters per

tree on 5 trees per block. On each tree look for larvae or

evidence of fresh feeding on 6 clusters on the outside of the

tree, 6 clusters inthecenterofthetree,and8clusters in the

top of the tree. Treatment is recommended if there are an

average of.two or more larvae or fresh feeding sites per

tree. Monitoring for the OBLR at this time is the same as

monitoring for the green fruitworm, and both species may

be considered together in making a control decision.

From about June 25 through August, monitoring of the

summer brood should be conducted weekly by checking

10 fruit clusters and 10 terminals in the outside, center, and

top of 5 trees per block. Treatment is recommended if there

are an average of three or more OBLR larvae per tree.

Control

In the past, sprays were applied at pink and petal fall to

control the OBLR. Recent research has indicated that a

single spray at petal fall provides comparable control to the

two spray program.

Guthion and azinphos methyl have not given adequate

control of larger OBLR larvae. Where larger larvae (third in-

star or larger) are present at petal fall or in the summer,

Lannate, Nudrin, or Penncap-M should be used.

Lannate and Nudrin are not registered for use on pears.

Penncap-M is the only material available that will give

acceptable control at petal fall. If Penncap-M must be used

at this time, take every possible precaution to avoid bee

kills. Also see HONEY BEE in LIBRARY.

OYSTERSHELL SCALE (OSS)

Lepidosaphes ulmi L.

Life History

Normally the OSS is not a problem in commercial

orchards. It is believed that insecticides applied to control

other pests are responsible for maintaining OSS at low pop-

ulation levels.

The OSS overwinters in the egg stage protected by the

scale of its dead mother. The small, white eggs hatch in

mid- to late May. The minute, pale yellow to white nymphs

or crawlers crawl out from the scale and after finding a

suitable site, settle down and begin feeding; soon after, they

begin secreting a waxy covering. The scales become

adults about mid-July when the winged, minute, non-

feeding males emerge and mate with the female OSS that

remain under this 1/8 inch brown, oyster-shaped scale

covering. Each female lays between 30 and 150 eggs and

then dies.

There are one or two generations of OSS per year.

Monitoring

The easiest time to find OSS infestations is in the winter

while pruning. During the growing season, look for crawlers

on the present year's growth in late May through early July.

After that period, look for the developing scales in areas of

the trees where poor coverage is likely.

Control

Most insecticides applied against other orchard pests

will also control OSS crawlers. This is probably why the

scale normally does not become a problem in commercial

orchards.

OSS infestations found while pruning should be pruned

and destroyed.

PEAR PSYLLA (PP)

Psylla pyricola Foerster

Life History

The PP is the most important pest of pears in New York

and the nation. It overwinters as an adult that measures

about .08 inches long and resembles a miniature cicada.

During the first warm days of spring, the overwintered

adults mate and lay their eggs on spurs, twigs, and around

bud scales. As the foliage appears, the eggs are laid on the

tender new growth, particularly on the undersurface of

leaves along the midrib. The first eggs hatch at about the

time foliage begins to appear. The nymphs pass through

five instars and produce a honeydew that collects in

droplets. The honeydew can burn the leaves under hot, dry

conditions, or drop onto the fruit. It is an excellent media for

sooty molds and trees that have had serious PP problems

in the past are characterized by black bark. There are about

four PP generations a year.

Monitoring

Pre-bloom:

A beating tray is used in the pest management program

to sample adults. A less precise but acceptable method is

to make a quick count of adults on several terminals.

In the early spring, terminals and spurs should be check-

ed for the first signs of egg laying. It is particularly important

to do this after temperatures have been above 50F.

Once foliage is present, eggs and nymphs may be

monitored by looking on the tender new growth and, later in

the season, on water sprouts.

Post bloom:

On each of five trees within an orchard, sample terminal

growth rather than hardened-off leaves. The PP is a flush

feeder and prefers to lay eggs and feed on new growth. In

checking the leaves, look along the midrib, especially on

the leaf undersurface. Only consider eggs and small

nymphs in making the spray decision. If only eggs are pre-

sent, hold off control until hatch begins. Treatment is

recommended if three or more of the sample sites have 10

per cent or more of their terminals infested. Spot treatment

within a block is recommended if an average of 5-10 small

nymphs per terminal are found in a portion of an orchard. If

hot, dry conditions prevail, tend to act on counts at the

lower end of the range. If it is rainy, tend to act on the higher

end of the range. The rain will wash the honeydew from the

leaves and fruit and a higher PP population can be

tolerated.

Control

The PP has developed resistance to all of the materials

registered for its control in the past except oil. We have,

therefore, had to rely on two newly registered materials

(Pydrin, Baam) for the control of the PP.

Pre-bloom:

Oils have been used in the dormant stage to inhibit egg

laying. The oil must be applied as the first eggs are laid.

Although oil is effective, the pre-bloom use of Pydrin makes

the oil spray no longer necessary. Pydrin should be applied

to pear orchards between green cluster and white bud. It

will kill adult PP and the nymphs, and is a long lasting insec-

ticide and should kill additional nymphs as they hatch.

Pydrin may precipitate mite problems later in the season,

and particular attention should be given to monitoring pear

rust mite following bloom.

Post bloom:

Baam is the recommended material for summer PP con-

trol. Quite frequently, growers who have applied Pydrin will

not have to apply another PP spray until mid- to late July

and in many cases, a single Baam application is all that is

required for the summer. Baam is also an excellent

acaricide for controlling the European red mite and the

pear rust mite, and when used in PP control, should aid in

the control of these pests. If the two spotted spider mite

becomes a problem, another acaricide is recommended

because Baam is inconsistent in its control.

Baam is a slow acting material and three to five days

should be allowed for control. Baam should not be applied if

daily maximum temperatures are below 70F.

PEAR RUST MITE (PRM)

Epitrimerus pyri (Naplepa)

Life History

The PRM is a very small, cone-shaped mite and, unlike

the apple rust mite, it can cause damage at a very low pop-

ulation level. The most serious damage occurs when the

mites feed on and russet the fruit. The extent of russetting

will vary with the number of mites feeding and the length of

time they feed.

The PRM overwintersas an adult female under the bud

scales and becomes active in the spring as the trees break

dormancy. The number of PRM a year in New York is not

known, but they are present on the tree throughout the

growing season.

In the early spring and on into the summer, PRM may be

found on the leaves. They are most frequently found along

the basal portion of the midrib on the undersurface of the

leaf. PRM injury to leaves causes a gray to brown russetting

which typically runs in a narrow band along either side of

the midrib. A serious PRM level may be present before leaf

russetting occurs. On the fruit, the PRM normally con-

gregate at the calyx end, but with high populations will also

move to the stem end of the fruit.

Monitoring

To sample PRM, use a good hand lens (10X or better)

and good lighting. In sampling 25 fruit clusters throughout

an orchard, treatment is recommended if 5 or more are

found to have PRM.

Control

Use one of the standard acaricides registered for use on

pears for the control of the PRM. Dr. Lienk obtained poor

PRM control in tests with Sevin and Thiodan in 1979 and

1980 and they should no longer be relied upon to provide

acceptable control.

Coverage is essential and spraying dilute is

recommended. Two sprays with a 7-10 day interval are ad-

vised. Baam, when used to control the pear psylla, will also

provide PRM control, and may be substituted for one of the

two sprays.

PETAL FALL (PF)

Introduction

While apple trees are in bloom insecticides cannot be

applied. During bloom, orchards should be inspected to

determine what arthropod pests will need to be controlled,

and the decision should be made as to what materials to

apply at petal fall.

It is interesting and important to note that the petal fall

spray is the only regularly scheduled insecticide applica-

tion made in the pest management program, and, through

intensively monitoring for rnsect pests, the Farm Advisors

can delay this spray up to ten days past actual petal fall.

Orchards not under an intensive monitoring schedule

should not have their sprays delayed, but should be

sprayed at petal fall.

Pests

The following is a list of the principal arthropod pests that

may be present at petal fall:

1. Codling Moth (CM)

2. European Red Mite (ERM)

3. Green Apple Aphid (GAA)

4. Green Fruitworm (GFW)

5. Obliquebanded Leafroller (OBLR)

6. Plum Curculio (PC)

7. Rosy Apple Aphid (RAA)

8. San Jose Scale (SJS)

9. Spotted Tentiform Leafminer (STLM)

10. Tarnished Plant Bug (TPB)

11. White Apple Leafhopper (WALH)

12. Woolly Apple Aphid (WAA)

Insecticides

With few exceptions, three insecticides (Lannate,

Guthion, Penncap-M) fit into practical petal fall spray

strategies.

A. Lannate

Whenever Lannate is used throughout this text, Nudrin

may be substituted.

The first thing to remember in the use of Lannate is to not

even consider it for spraying Early Mclntosh, Wealthy, and

Dutchess varieties. Lannate has caused fruit and leaf injury

and premature fruit drop on these varieties. These

problems have not occurred with Mclntosh, Red Delicious,

Golden Delicious, Cortland, Rome, or Rhode Island Green-

inq varieties.

Lannate is the petal fall insecticide to use if first genera-

tion STLM need to be controlled. With the varieties on

which Lannate cannot be used, anticipation of a STLM

problem should have led to a Vydate spray at pink where

needed. Vydate should not be applied for 30 days after

petal fall or thinning may result; we do not fully understand

its thinning capabilities, and its label specifically does not

allow for its use at this time. Lannate will pot only knock

down the adult STLM, but will also kill the sap-feeding lar-

vae. To adequately control the larvae, Lannate must be

applied prior to the onset of the tissue-feeding stage.

Lannate is a carbamate insecticide atid will give good

control of organophosphate-resistantWALH. Therefore, if

Lannate is used at petal fall, Sevin need not be used as a

thinner to give added WALH control.

Lannate can be expected to give good control of the ma-

jority of the other insect pests present at petal fall. It will fit in

well in controlling the Early Lepidoptera (OBLR, GFW)

where Guthion has begun to jail down.

Lannate will only give fair control of PC. To aid Lannate in

controlling PC, add 1 /4 to 112 rate of Guthion to the tank.

Do not cut back on the Lannate if you have a STLM

problem.

Lannate will not control ERM, but will kill the predator

mites. Therefore, if ERM is a problem, an acaricide could be

added now or in the summer.

A final note on Lannate: although it will clean up the

aphids (except RAA), growers using Lannate are more likely

to experience WAA outbreaks later in the season.This is

believed to be because it eliminates the WAA parasites. A

similar problem may be precipitated with the use Sevin.

Therefore, be prepared for potential secondary pest

problems if carbamates are used at petal fall or later in the

season.

8. Guthion

Although Guthion is specifically mentioned throughout

this text, azinphos methyl, Imidan, and Zolone have similar

properties and can be substituted wherever Guthion

appears.

Guthion has been an old standby at petal fall and

throughout the summer for a number of years. Although it is

still good at controlling PC, it has begun to fall down in the

control of OBLR and GFW in some areas. Guthion is still a

good petal fall insecticide to use where the STLM is not a

problem. Guthion can also be used where it still works on

the Early Lepidoptera or if they are not a problem. The

STLM has developed resistance to Guthion. Therefore,

where the STLM is present and needs to be controlled,

refer to the Lannate section. Where the STLM does not

need to be controlled and Guthion is no longer adequately

controlling the Early Lepidoptera, refer to the Penncap-M

section.

When used in a regular seasonal spray program,

Guthion will suppress but not control the GAA. Itshould not

be counted on to even suppress RAA or WAA. If Systox did

not clean the RAA up at pink, it may be added again, at full

rate, at petal fall, but expect to see some RAA injury. Systox

may be used now or later in the summer to control WAA.

Where STLM needs to be controlled in the second genera-

tion with Vydate, a special Systox spray to control WAA nor-

mally will not be needed.

With the exception of ERM and WALH, Guthion will con-

trol most of the other insect pests present at petal fall. If

WALH is a problem, consider thinning with Sevin to get the

added benefit of WALH control. If ERM is a problem, add an

acaricide now or in the summer.

C. Penncap-M

Penncap-M fits into the petal fall spray program when

Guthion is not adequately controlling the OBLR and the

GFW, and the STLM does not need to be controlled. A few

extra precautions should be taken to avoid bee kills. Also

see HONEY BEE in LIBRARY.

With the exception of STLM, WALH, and ERM, Penncap-

M will control most of the insect pests present at petal fall. If

first generation STLM needs to be controlled, refer to the

Lannate section. If WALH is a problem, consider thinning

with Sevin to get the added benefit of WALH control. If ERM

is a problem, consider adding an acaricide now or in the

summer.

An Added Caution:

If the SJS has been a problem in the past, Lannate,

Guthion, or Penncap-M at petal fall should not be expected

to alleviate the problem. The presence of SJS in an orchard

is an indication of inadequate spray coverage. It may take 2

or more years to control this pest and require pruning, dor-

mant oil applications, and seasonal spray programs with in-

secticides to kill emerging males and crawlers.

Mites:

Although the ERM was listed among the potential pests

present at petal fall, none of the insecticides discussed will

control this pest. One or two oil sprays before pink will act

as an ovicide on overwintering ERM eggs. Coverage is then

the key to control. If coverage was insufficient for adequate

control or oil was not applied, there are two post-bloom

strategies to cleaning up the problem.

If mites are present in number at petal fall, three Vendex

sprays at 3 oz./100 gal. beginning at petal fall and again 10

and 20 days later will give seasonal control. In order to be

successful once started, the Vendex program must be

adhered to. This is the only time and method that we

recommend the use of Vendex.

The second mite control program is the old standby

utilizing two Plictran sprays at 4to6oz./100gal. at 7 to 10

days apart when the mites become a problem.

PLUM CURCULIO (PC)

Conotrachelus nenuphar (Herbst)

Also see PETAL FALL in LIBRARY. Life

History

The PC has a single generation peryear and overwinters

as an adult in debris on the ground in woodlots and in

hedgerows. The adults are about 1 /5 inch long, have four

pairs of humps on their wing covers, and are a mottled

black, gray, and brown color. The adults become active in

the spring when temperatures rise above 60F. After mating

in the spring, the females lay their eggs under a crescent-

shaped slit which they cut with their mouthparts. Each

female may lay several hundred eggs.

The eggs hatch in about a week and the larvae begin

tunneling to the center of the fruit. The larval period lasts

about 16 days. The majority of the infected fruit fall to the

ground with the June drop. Upon reaching maturity, the lar-

vae leave the fruit and enter the soil where they pupate.

About a month later, the adults emerge from the soil and will

feed on the fruit until they are forced into hibernation as

temperatures drop below 60F.

Monitoring

The seriousness of the PC as an orchard pest requires

the use of an insecticide at petal fall. The petal fall spray

can be delayed as much as ten days if maximum daily

temperatures remain below 60F, PC feeding and oviposi-

tion wounds are not observed, and there are no other insect

problems that require immediate action at petal fall.

Because the PC is not normally an in-orchard problem, but

migrates in from woodlots and hedgerows in the spring, it is

wise to monitor unsprayed apple and cherry trees in your

area and time your petal fall spray to coincide with the first

sign of injury in the unsprayed trees.

In the summer, emerging adult PC are controlled by in-

secticides applied against other orchard pests and,

therefore, a monitoring program for these insects is not re-

quired.

Control

Guthion, azinphos methyl, Jmidan, and Zolone are four

insecticides applied at petal fall to provide PC control.

Penncap-M will also provide control, but care should be

taken to prevent bee kills. Also see HONEY BEE in

LIBRARY. Lannate or Nudrin will provide fair PC control

when applied at petal fall to control the Early Lepidoptera or

the spotted tentiform leafminer. Growers may wish to add a

half rate of another material to get additional PC control

when using Lannate or Nudrin at petal fall. Sevin will

provide good PC control and, if used in thinning, will help

control any stragglers that migrate into the orchard.

Growers may wish to spray the edges of hedgerows and

woodlots adjacent to their orchards at petal fall in order to

help reduce PC migration into the orchards.

ROSY APPLE APHID (RAA)

Dysaphis plantaginea (Passerini)

Also see PETAL FALL in LIBRARY.

Life History

The RAA overwinters as a small, black egg on the bark of

apple trees. The eggs of the RAA cannot be differentiated

from the apple grain aphid or the green apple aphid.

Overwintering RAA eggs usually hatch by half-inch green

or tight cluster. The hatching nymphs are all females and

move to fruit buds where they begin feeding. These

nymphs mature into stem mothers during bloom and begin

giving birth to living young which mature in 2-3 weeks and

continue the cycle. If the RAA is present at petal fall or per-

sists into June or early July, fruit injury proportionate to the

population and duration of the infestation will result.

A few winged adults are produced in the second genera-

tion and proportionately more are produced in the third and

fourth generations. These winged adults, produced

between May and mid-July, leave the apple trees and move

to weed host plants to spend the summer. Narrow-leaved

plantain and dock are two of the more important summer

hosts for the RAA.

In the late summer or early fall, winged adults are again

produced and the RAA migrate back onto the apple trees.

These adults produce offspring that in turn produce male

and female offspring. This is the only time that male RAA

are produced. When these males and females become

adults, they mate and the females lay eggs to carry the

species through the winter.

Monitoring

Monitoring of the rosy apple aphid should be conducted

from tight cluster through petal fall. Check 100 fruit clusters

in the middle of the most susceptible varieties in a block.

Cortland, Rhode Island Greening, Monroe, Twenty Ounce,

Golden Delicious, and Ida Red tend to be very susceptible,

while the Red Delicious varieties are intermediate. Mcln-

tosh tend to be the least susceptible to RAA injury. Treat-

ment is recommended if an average of one colony or more

per tree of the susceptible varieties is found.

Treatment with a systemic aphicide at pink has been a

standard practice. If for some reason RAA are not con-

trolled at pink, a systemic insecticide with activity against

the RAA should be applied at petal fall.

Control

Coverage is essential in the control of the RAA. Control

is best achieved when the insecticide is applied dilute or at

least no greater than 6X. Growers with sprayers that cannot

go below 20X are often the first to find that they have a RAA

problem.

Systox has been the standard insecticide applied at pink

and, when need be, at petal fall for the control of RAA.

Systox has been inconsistent in controlling RAA where

growers have been spraying high concentrate. If a grower

cannot spray at 6X or below, Vydate should be used at pink.

Vydate has better systemic properties than Systox and will,

therefore, redistribute itself better within the plant. Vydate

applied at pink will also aid in the control of the spotted ten-

tiform leafminer if it is a potential problem. Vydate should

not be used at petal fall.

Several instances of Systox not working when applied at

6X or below were reported in 1979. Laboratory tests in-

dicated the development of resistance to Systox in several

colonies tested. If poor RAA control has been experienced

with Systox applied at low concentrations, it is suggested

that Zolone, Thiodan, or Phosphamidon be used at pink.

These materials remained effective in controlling Systox-

resistant colonies in the laboratory.

SAN JOSE SCALE (SJS)

Quadraspidiotus perniciosus (Comstock)

Also see PETAL FALL in LIBRARY.

Life History

The SJS attacks apple, pear, quince, peach, nectarine,

plum, apricot, and sweet cherry trees. It frequently

becomes a problem in larger, poorly pruned trees that pre-

vent adequate spray coverage. On heavily infested trees,

the scales are crowded together and give the bark a gray,

roughened appearance. The fruit and bark around the

scales are frequently reddened. If not controlled, a heavy

infestation can kill a tree.

The SJS overwinters as a yellow second instar nymph

under a gray, waxy scale covering. With the return of sap

flow in the spring, the nymphs begin to feed and develop. By

bloom, they are fully developed and the sexes can be easily

differentiated. The male scale covering is oval with a raised

dot near the larger end and is about 1 /25 inch long and half

as wide. The female scale covering is circular with a

diameter of about 1 /12 inch and has a raised dot in the

center.

The males emerge from their scales as minute, yellow,

two-winged insects at about bloom. The females remain

immobile and sac-like in appearance undertheir protective

scales. Mating occurs soon after the males emerge. The

females can produce an average of 200 young in the six

week period that they remain productive.

First instar nymphs, called crawlers, are yellow, six-

legged, and resemble a mite. They crawl about until they

find a place to settle and feed. Shortly after settling down to

feed, they moult, lose their legs, and become yellow sacs

attached to the plant by their mouthparts. A waxy, flaky

secretion is produced that in two or three days is matted

down to form the protective scale under which the nymph

develops.

There are at least three broods of SJS each season in

New York. By fall, all stages of the insect can be found, but

only the second instar nymphs overwinter. Those scale in

the other stages of developement die during the winter.

The SJS are carried from orchard to orchard in the

crawler stage by birds and larger insects. They are also

carried through the air by the wind.

Monitoring

It is difficult to detect the SJS on fruit before it has

become a problem because of its small size and because it

blends in with the color of the tree. The presence of the SJS

on fruit at harvest indicates the need for special control

measures the following season.

Control

Pruning is important in SJS control. It is important to cut

out heavily infested branches in the winter to reduce the

possibility of the infestation spreading the following

summer. Pruning also opens the trees up and allows for

better penetration and coverage of insecticides.

There are several beneficial insects that attack the SJS.

They do not provide satisfactory control and are sup-

pressed in commercial orchards by insecticides required

to control the SJS and other insect pests.

Concentrate spraying is acceptable for general

maintenance spraying, but complete coverage is important

in controlling the SJS and dilute spraying is advised. An oil

spray at half-inch green will provide excellent SJS control

and kill overwintering European red mite eggs if coverage

is complete.

From petal fall throughout the remainder of the season,

SJS are suppressed by the insecticidal action of most

broad spectrum insecticides on the adult males and the

crawlers.

A serious SJS problem may take several years to clean

up,

SPOTTED TENTIFORM LEAFMINER (STLM)

Phyllonorycter hlancardella (F.)

Phyllonorycter crataegella Clemens

Also see PETAL FALL in LIBRARY. Life

History

Both P. blancardella and P. crataegella occur in New

York and are similar in appearance, biology, and injury

caused. They also possess the same common name, the

STLM. P. blancardella is the only species occurring in

western New York. It is present in the Champlain Valley and

is the predominant species found on the western side of the

Hudson River. P. crataegella occurs in the Hudson Valley

and was found in the Champlain Valley in 1980. It is the only

species found on the eastern side of the Hudson River and

is the lesser species on the western side of the river.

The STLM has three broods a year. They overwinter in

the pupal stage within their mines in leaves on the ground.

Adults begin emerging at half-inch green or tight cluster.

The adults are small, weak fliers that are commonly found

at rest in the ground cover or on the trees. The moths

become active in the evening, when both mating and egg

laying occurs.

The eggs are very small and difficult to see with the nak-

ed eye. They have the appearance of small elliptical

blisters on the leaf undersurface and hatch in 5 to 16 days

depending on the temperature.

The STLM has five larval instars. The first three instars

are referred to as the sap-feeding stage; they feed on the

sap from the spongy mesophyll in the leaves. Injury from

the sap-feeding stage is only visible from the leaf undersur-

face and appears as an area where leaf tissues have

separated. The fourth and fifth instars are collectively

referred to as the tissue-feeding stage. In this stage, the lar-

vae begin feeding on the leaf tissues and the mines

become visible on the upper leaf surface as an oblong

green tent with whitish spots. Larval development takes

about 24 days.

The STLM pupates within the mine and changes from

yellow when first formed to a dark brown color. The STLM

remains in the pupal stage for about 1 -112 weeks for the

first and second broods and overwinters in the pupal stage

for the third brood. Prior to emerging as an adult, the pupa

cuts a hole in the leaf undersurface and partially protrudes

from the leaf. The pupal skin remains attached to the leaf

after the adult emerges, until it is weathered off.

Monitoring

Monitoring for the STLM requires close observation of

leaves at pink or shortly before petal fall and again as the

second brood begins to hatch and mine the leaves. Control

at pink is recommended if an average of six or more eggs

are found per leaf. Control recommendations at petal fall

and later in the summer are based on the number of sap-

feeding mines present for any particular brood. An insec-

ticide application is recommended prior to the larvae enter-

ing the tissue-feeding stage if there is an average of one or

more mines per leaf for the first brood, and two or more

mines per leaf for the second brood. Insecticide

applications are not recommended against the third brood,

no matter how serious the problem. A serious third brood

STLM problem is normally due to a high second brood pop-

ulation that was not properly controlled. The injury to the

leaves by the second brood would have been substantial,

and any further injury should not add to the seriousness of

the problem. The third brood larvae are normally well

parasitized, and spraying against the STLM will reduce

parasitization. The parasite, if protected, can significantly

reduce the overwintering STLM population.

Control

STLM control is effected with four principal insecticides:

Thiodan, Nudrin, Lannate, and Vydate. The choice of in-

secticide depends in part on the brood that is to be con-

trolled.

A few additional comments about Lannate, Nudrin, and

Vydate should be made. They are carbamate insecticides

and can precipitate mite outbreaks, are harmful against

predator mites, and can also precipitate other insect out-

breaks, such as woolly apple aphid. If these materials are

used to control STLM, be prepared for secondary pest out-

breaks. Do not let the secondary pests get out of hand.

First Brood

The first opportunity to control the STLM is as they

emerge as adults in the spring. Thiodan is the material to

use solely for the control of adults. This control strategy,

however, is not recommended as a standard practice for

several reasons.

1. The preceding fall's STLM problem or population can

not be equated with an expected spring problem forthe

present season.

2. Pheromone trap catch numbers cannot be equated

with the need to spray.

3. The adult stage is not the stage that treatment or con

trol should be aimed at.

This spray is best suited forthe conservative grower who

had a serious problem with STLM the preceding season.

More than one Thiodan application will be needed. One

Thiodan spray should be applied at half-inch green and

another at pink. A third Thiodan spray may be required

between the two if it turns cool and the period lengthens

out.

The second strategy is to control the first generation

miners within the leaves. There are two different timings

and materials available for action against the first genera-

tion larvae. If Vydate is the preferred material by the grower,

it should be applied at pink if there are an average of six or

more eggs per leaf. The Vydate will enter the leaves and kill

the hatching larvae as they begin to feed. It should not be

applied for 30 days after bloom because it can thin the

apples, and at present, we do not know enough about its

thinning capabilities.

The recommended material and time of application to

control first generation STLM larvae is Lannate or N udrin at

petal fall. The action threshold for spraying at petal fall is an

average of one or more mines per leaf. Lannate or Nudrin

should be applied before the larvae go from the sap- to the

tissue-feeding stage. Therefore, the mines that must be

counted will only be visible on the undersurface of the leaf

and will appear as a separation of the undersurface of the

leaf. Lannate or Nudrin applied at petal fall will also control

white apple leafhopper as well as most of the other insects

out at that time.

Second Brood

Whether it is determined to spray or not to spray for the

first brood, you should be prepared to monitor the second

generation larvae which begin to appear in July. If your

counts indicate that an insecticide application is required,

you may use Lannate, Nudrin, or Vydate. Vydate is

preferred because it has better systemic action within the

leaf.

Vydate applied against the second generation of STLM

larvae will suppress the white apple leafhopper and some

of the other insects present at that time. Vydate will not con-

trol apple maggot.

Third Brood

The STLM has a third generation which first appears in

August. No action is advised against the third generation,

TARNISHED PLANT BUG (TPB)

Lygus lineolaris (Palisot de Beauvois)

Note: A separate strategy for the TPB on strawberry may be

found in the LIBRARY program for SFRUIT. Also see

PETAL FALL in LIBRARY.

Life History

The TPB overwinters as an adult and with the onset of

warm temperatures emerges to feed. Tree fruits are a very

attractive early food source in the spring. Later in the spr-

ing, the TPB moves to weeds and a wide range of other

crops. It is a serious pest of strawberries.

On tree fruits, the TPB prefers to feed on the developing

flower buds beginning at about tight cluster and continuing

after the fruit have set. The feeding done prior to bloom

causes the buds to abort and therefore the insect acts as a

natural thinner.

Feeding done after pollination does not drop the fruit, but

causes the typical cone-shaped indentation or injury on

apples and pears and cat-facing and scabbing on

peaches.

Monitoring

From tight cluster through first cover, particularly during

bloom and petal fall, attention should be given to looking for

the TPB. It is difficult to monitor the TPB because it is a very

active insect that can rapidly enter or leave an orchard

depending on the availability of alternate food sources and

climate conditions, and also frequently hides when ap-

proached. Therefore, no action thresholds have been

developed.

Control

The standard recommendation in the past has been to

apply up to two pre-bloom sprays (tight cluster and pink)

and a petal fall spray. Even with these sprays, injury to the

fruit can occur. The TPB is a very mobile insect and, once

the plants are free of effective insecticide residues, new in-

dividuals can move into the orchard and begin feeding. The

injury seen at harvest is caused by the feeding of insects

that move into the orchard during bloom. During years of

prolonged bloom, it is nearly impossible to prevent this in-

jury. Therefore, we no longer recommend pre-bloom TPB

sprays as a common practice. Pre-bloom sprays may be

used if a grower feels that he has an unusally h igh TPB pop-

ulation pre-bloom and is concerned about having ade-

quate fruit set. The pre-bloom sprays may kill the TPB that

are present and reduce their fruit thinning effect.

Bloom is the best time to spray for the TPB. That,

however, cannot be done. Insecticides cannot be applied

during bloom.

Normally, a petal fall spray will not eliminate TPB injury,

but it will keep it at a minimum. If a grower feels that he has a

TPB problem during bloom, the petal fall spray should

come as soon as possible after petal fall (be sure the bees

are out) instead of trying to stretch the interval until the plum

curculio are out.

Most of the commonly used insecticides will control the

TPB.

TWO SPOTTED SPIDER MITE (TSM)

Tetranychus urticae Koch

Life History

Although a few immature TSM overwinter, the majority of

the overwintering populations are gravid adult females.

They overwinter under loose bark or protected under leaf

litter on the ground. With the onset of warm weather in the

spring, they begin feeding and egg laying.

The TSM is commonly found on weeds in the orchard

ground cover and normally does not move into the trees

until hot, dry conditions occur in the summer. When moving

into the trees, the TSM either climb the trunk and first infest

the lower shoots and water sprouts, or use weeds touching

lower limbs as bridges to climb up to and infest the trees.

Feeding injury to pear leaves can develop rapidly under

hot, dry conditions and causes the leaves to blacken and

appear scorched. One or two TSM per leaf can cause this

injury on pears. By the time the injury becomes apparent,

the mites are frequently no longer present. On apples, TSM

injury resembles European red mite injury.

The oval eggs of the TSM are white in color and are

usually laid on the undersurface of leaves. The immature

and adult mites can be white to dark green in color, depen-

ding on their food source; they have a dark spot on either

side of their body. The mites produce a webbing which

covers the leaves they infest.

Monitoring

Monitoring for the TSM in trees should begin in early

summer and continue until harvest. From 10 trees in an

orchard, pick a total of 100 leaves (10 per tree) from the

lower shoots and water sprouts along the trunk. If the

ground cover is high and touches the lower limbs, pick an

additional 100 leaves from the lower limbs touched by the

weeds.

On apples, control is recommended if there are an

average of six or more TSM per leaf and the average

number of predator mites is below one per leaf.

On pears, control is recommended if there are an

average of one or more TSM per leaf.

Control

Keeping the ground cover mowed and climbing weeds

out of the trees will help prevent TSM from climbing into the

trees.

Plictran (4-6 oz./100 gal.) and Omite (1-1 1/2 Ib./100

gal.) are two of the more commonly used summer

acaricides. With either material, two applications 7-10 days

apart are recommended. The split applications help kill the

mites as they hatch from their eggs.

WHITE APPLE LEAFHOPPER (WALH)

Typhlocyba pomaria (McAtee)

Also see PETAL FALL in LIBRARY.

Life History

The WALH has two generations per year. It overwinters

as eggs deposited under the bark of one to five year old

twigs. The eggs appear as very small, elongated blisters on

the bark. Egg hatch normally begins during pink and is

complete shortly after petal fall. The young nymphs are

white with red eyes, and as they feed and develop, they

become creamy-white to a pale yellow-green color and

lose the red color in their eyes. By early June, the wedge-

shaped adults of the first generation (measuring about 1 /8

inch) begin to appear and lay their eggs in the leaf tissue.

The second generation eggs begin hatching in late July

and have developed into adults by late August or early

September. These adults are present until early October

and can be a nuisance to pickers.

The WALH is an active insect when disturbed. The

nymphs will run to the opposite side of a leaf while the

adults will either run or fly off. The WALH can be differen-

tiated from the potato leafhopper, which can also be a

periodic pest of apple, by the way they run when disturbed.

The WALH will normally run straight ahead or backward,

while the potato leafhopper normally runs sideways or in a

crab-like manner.

The WALH normally remains on the undersurface of the

same leaf or cluster of leaves as it develops. Its cast skins

also remain on the leaf undersurface until they weather off.

WALH feeding removes the chlorophyll from the leaf. Light

feeding injury appears as white spots on the upper leaf sur-

face, and as feeding increases, the loss of chlorophyll and

evidence of leaf injury increases. The WALH also produces

a honeydew which can drop onto the fruit and appear as

tan to brown spots or streaks. The honeydew is an ex-

cellent media for the growth of sooty molds and both the

honeydew and molds can russet the fruit. Fruit injury from

honeydew deposits is more common from second genera-

tion infestations.

The following facts should be kept in mind while

developing a control program for the WALH:

1. The first generation will be less strung out than the se

cond generation and is, therefore, easier to control.

(The second generation may require two sprays to

control.)

2. The small nymphs are easier to kill than the large

nymphs and adults.

3. WALH egg hatch normally peaks during bloom and the

majority of nymphs have hatched by petal fall.

4. The WALH has developed a high level of tolerance to

the organophosphate insecticides.

Monitoring

From bloom through petal fall, check 50 leaves per tree

from 10 trees per block for the first generation WALH

nymphs. Particularly check the leaves of clusters in the in-

side of the trees. Treatment is recommended if there is an

average of 1/2 nymph or greater per leaf.

For the second generation WALH, check 50 leaves per

tree from 10 trees per block for nymphs from late July

through August. Treatment is recommended if there is an

average of one or more nymphs per leaf. Due to the

protracted egg hatch of the second generation, two

treatments may be necessary to control this generation.

Control

The WALH is easiest to control in the small nymphal in-

stars. In New York, the WALH is resistant to many of the in-

secticides used in tree fruit production. The insecticides

Sevin, Lannate, Nudrin, Carzol, Vydate, and Thiodan re-

main effective materials.

If the spotted tentiform leafminer, obliquebanded

leafroller, or green fruitworm are not a problem and you

plan on thinning the orchard, Sevin is the preferred material

to use to control the first generation WALH. For the second

generation, Sevin has an added benefit over Lannate,

Nudrin, and Vydate in that you can also expect to get apple

maggot control from the two sprays that may be necessary

to control the WALH.

When Lannate or Nudrin is applied at petal fall to control

the spotted tentiform leafminer, obliquebanded leafroller, or

green fruitworm, it should provide the needed control of the

first generation WALH. When used to control the second

generation spotted tentiform leafminer, Lannate or Nudrin

also provide control for the early hatch of the second

generation WALH. A second spray of Lannate, Nudrin, or

Sevin may be required to control the late hatch of the se-

cond generation.

Vydate, when applied at pink to control the spotted ten-

tiform leafminer, should also control the WALH nymphs that

are out at that time. Unfortunately, we cannot rely on

residual activity to carry through bloom. Therefore, Vydate

may hold down the first generation WALH, but cannot be

counted on to control it. When applied against the second

generation spotted tentiform leafminer sometime in July,

Vydate may control an early portion of the second genera-

tion WALH, but should not be expected to provide adequate

control. A second spray of Sevin will normally be required.

CHERRY FRUIT FLY (CFF)

Rhagoletis cingulata Loew

A second species, the black cherry fruit fly (BCFF),

Rhagoletis fausta Oster Sacken, occurs in New York.

Growers frequently refer to both species collectively as

CFF. The biology and control of the species are similar and

will be covered together.

Warning

BCFF adults normally begin emerging at about the time

Mclntosh apples begin petal fall. The CFF adults begin

emerging about a week later. Sticky boards should be

ordered from the pest management program to monitor

CFF and BCFF emergence.

Life History

Both the BCFF and CFF are native to North America, and

along with the plum curculio, rank among the top insect

pests of cherries. Both species have a single generation a

year. They overwinter as pupae in the upper three inches of

the soil. The BCFF adults begin emerging at about the time

Mclntosh apples begin petal fall and the CFF adults begin

emerging about a week later. A number of factors, including

soil type and moisture, play important roles in emergence.

Adults of both species can be found into August.

There is a pre-oviposition period of about a week during

which the flies mate and the females cut the fruit with their

ovipositors and feed on the fruit juices. The females can lay

eggs for about 25 days and in egg laying puncture the skin

and oviposit directly into the flesh.

The eggs hatch in five to eight days and the maggots

pass through three instars in about two weeks. When

mature, the maggots drop to the ground, pupate, and re-

main in the soil until the following spring.

Monitoring

Sticky boards can be used to determine first emergence

of both the BCFF and CFF, but cannot be used to time or

determine the need to spray commercial cherry blocks.

Hang sticky boards near unsprayed cherry trees to deter-

mine first emergence in an area. The traps should be

checked at least every three days and a regular maggot

spray program should begin no later than four days after

the first fly is caught in the area.

For futher information on fly identification and trap place-

ment refer to "Using Sticky Traps to Monitor Fruit Flies in

Apple and Cherry Orchards." Copies of this publication are

available, along with sticky boards, through the pest

management program.

Control

Parathion, Guthion, azinphos methyl, and Penncap-M

are standard fruit fly insecticides. Imidan can also be used,

but is labeled for tart cherries only. Mesurol, when used for

bird control, will also provide fruit fly control.

BLACK CHERRY FRUIT FLY (BCFF)

Rhagoletis fausta Oster Sacken

See CHERRY FRUIT FLY in LIBRARY.

EUROPEAN APPLE SAWFLY (EAS)

Hoplocampa testudinea (Klug)

Life History

The EAS was first discovered in the United States on

Long Island in 1939. In New York, its distribution is

restricted to the Hudson Valley and the Champlain Valley.

Although the EAS is not a serious pest of commercial

orchards, it has persisted as an occasional problem.

The EAS overwinters as a mature larva within the soil.

Pupation occurs in the early spring and adults normally

begin emerging by bloom. During cool, cloudy weather the

adults are inactive. Although they will mate and lay eggs at

temperatures below 60F, higher temperatures combined

wth sunny days favor EAS activity.

Egg laying normally begins during bloom and may con-

tinue for 20 days. The eggs are laid within the calyx cup and

the hatching larvae burrow directly into the fruit. The larvae

feed directly beneath the fruit surface and cause the typical

spiralling scar seen at harvest. The larvae can continue to

develop on the initially infested fruit or may move to a se-

cond fruit to continue development. The larger larvae bore

into the center of the fruit and cause it to drop. The mature

larvae leave the fruit and enter the soil, where they remain

until pupation the following spring.

Monitoring

Effective monitoring of the EAS to determine the need to

spray has yet to be developed. Dr. Prokopy (Univ. of Mass.)

is working on this problem. One of the difficulties is that the

best time to control the EAS is when the adults emerge dur-

ing bloom, a period when insecticides cannot be applied.

This undoubtedly is why the EAS persists as a pest. The

petal fall sprays applied to control such pests as the plum

curculio and the Early Lepidoptera do aid in controlling the

EAS and maintaining its status as a pest of minor impor-

tance.

Control

The broad spectrum insecticides applied at petal fall are

effective in controlling adult EAS and reducing injury to the

fruit.

PEACHTREE BORER (PTB)

Synanthedon exitiosa (Say)

Life History

The PTB, a pest of all stone fruits, overwinters as larva

within burrows under the bark of the trees at or just below

soil level. While the majority of individuals complete their

development in one year, some require two years. The lar-

vae resume feeding on the cambium and inner bark of the

trunk just below and above the soil surface when warm

temperatures return'in the spring.

Prior to pupation, the larvae normally enter the soil,

where they construct a cocoon of silk, trass, and soil. The

combined period of cocooning and pupation is about a

month. PTB adult emergence begins in early July, peaks in

August, and can continue into October. The steel-blue

moths have a single wide orange band on the abdomen of

the female and three or four narrow yellow stripes on the

male's abdomen.

Mating occurs soon after emergence and egg laying

begins soon thereafter. A single PTB female may lay up to

800 eggs. Egg laying tends to be on trees previously in-

fested with PTB or trees with mechanical injury to the trunk.

The eggs take about ten days to hatch; hatch normally

begins in mid-July.

Monitoring

Pheromone traps may be used to monitor PTB

emergence and flight activity. Studies indicate the traps are

most effective when placed at or near ground level in

orchards free .of weeds. Orchards with high weeds will

hamper dispersal of the pheromone at lower levels;

therefore, under such situations the traps should be placed

above the weeds. Insecticide sprays should begin after first

trap catch.

Control

Preplant:

A preplant root dip in a Thiodan solution has been found

to provide complete control the first season and a high

degree of control the second season.

The WAA has a very effective parasite, Aphelinus mali,

which normally keeps the aphid population in check. The

use of carbamate insecticides to thin the crop or control

such pests as the white apple leafhopper, spotted tentiform

leafminer, obliquebanded leafroller, or the green fruitworm

can eliminate the parasite from the orchard and may

precipitate a WAA outbreak if the pest is present in the

orchard. If carbamates must be used, particular attention

should be paid to the monitoring and control of WAA.

Monitoring

WAA infestations on the trunk and scaffold limbs are not

cause for control. These sites of infestation should be

noted and checked periodically to determine if movement

of the infestation to the current year's growth has begun. If

carbamate insecticides have been used to thin your crop or

control some other orchard pest, the periodic checks

should become more frequent. WAA control with an insec-

ticide is recommended at the first sign of the infestation

moving to the current year's growth.

Control

Only Thiodan and Penncap-M are known to effectively

control the WAA. If Penncap-M is used, even in the

summer, precautions should be taken to help reduce the

poisoning hazard to bees; see HONEY BEE in LIBRARY.

STRAWBERRY BUD WEEVIL (SBW)

Anthonomus signctus Say

The SBW is also known as the Strawberry Weevil or

Clipper.

Life History

The SBW has one generation a year and overwinters as

a dark reddish- brown adult, about 0.1 inch long, in fence

rows and woods adjacent to strawberry plantings or

beneath the mulch in the plantings themselves. The SBW

becomes active at about 60F and can be found causing in-

jury from when blossom buds appear through harvest. The

female SBW lays an egg in a bud and then cuts it from its

stem. The bud then either falls to the ground or hangs to the

stem by a few threads of plant material. The eggs hatch in

about a week into white, legless grubs that feed within the

bud for three to four weeks. The SBW pupates within the

bud it has fed upon and the adults appear in early summer

and feed on the pollen of various flowers before seeking a

hibernation site in midsummer where they remain until the

next spring.

Monitoring

Since it is difficult to find the adult SBW, monitoring to

determine the need for control is based on the first obser-

vation of buds being clipped. This normally occurs at

temperatures at or above 60F when blossom buds are pre-

sent. It is estimated that one cut bud per 1.5 linear feet of

row justifies control. This level of injury can be caused by a

single female SBW per 40 linear feet of row.

Control

Two insecticide sprays are required for SBW control.

The first spray should be applied at the first sign of clipping

and the second spray should be applied about ten days

later. It is also helpful to spray adjacent hedgerows or

woodlot borders. Guthion, azinphos methyl, and parathion

may be used for SBW control. Phytotoxicity has occurred

from time to time with the use of parathion.

CLIPPER

See STRAWBERRY BUD WEEVIL (SBW) in LIBRARY.

TARNISHED PLANT BUG (TPB)

Lygus lineolaris (Palisot de Beauvois)

Note: A separate strategy for TPB on tree fruit may be

found in the LIBRARY program forTFRUIT.

Life History

The TPB feeds on a wide range of hosts, with

strawberries appearing to be one of their favorites. On

strawberry, the TPB prefers feeding on the achenes

located on the blossom tip. Injury from such feeding has

been referred to as apical seediness, buttoning, nubbining,

or cat-facing. Growers frequently attribute early TPB injury

to frost injury or poor pollination.

The TPB overwinter as adults and become active in the

spring when temperatures reach about 60F. The adults

move to strawberries as the blossom buds appear and lay

their eggs within the tender tissues of the plant. The

nymphs are the important damaging stage on strawberries.

They quite often confine their feeding to the achenes at the

tip of the strawberry blossom. Due to their later bloom, the

late and everbearing strawberry varieties are more

susceptible to TPB injury than are the early-bearing

varieties.

Monitoring

Dr. George Schaefers has found that a white, 6-inch pot

saucer or plate makes an excellentTPB sampling tool. Tap

a cluster of buds on the saucer and count theTPB nymphs

that fall to the saucer. Disregard the adult TPB. An average

of one nymph per cluster can result in about 30 percent fruit

injury. Therefore, control is recommended at the first sign of

TPB nymphs in the planting.

Control

Parathion, Thiodan, and malathion may be used to con-

trol the TPB. The insecticide should be applied at the first

sign of nymphs in the planting. Do not spray during bloom. A

post-bloom spray may be required. The days to harvest in-

terval is fourteen for parathion, four for Thiodan, and three

for malathion. Parathion has been known to cause

phytotoxicity on strawberry plants.

CYCLAMEN MITE (CM)

Steneotarsonemus pallidus (Banks)

Life History

The CM is normally not a problem in strawberries but

can occasionally become serious in older plantings.

The CM is a minute mite that is not easily seen by the

naked eye. They are white to light tan or pink in color and

are found in crevices of new, expanding leaves and stems

within the crown of the plant. CM injury causes the young

expanding leaves to become distorted, stunted, and bronz-

ed. Severe CM infestations may kill the leaves and cause

fruit distortion. Infested plants frequently become un-

productive within a season.

CM overwinter as adult females in protected areas

within the crown of strawberry plants. CM populations

begin to rise in late May and peak in July, followed by a

sharp decline in numbers. A second population peak oc-

curs in late September.

Monitoring

The appearance of stunted, disfigured, and/or bronzed

leaves within the crown of the strawberry plant is an indica-

tion of the presence of the CM. This is frequently seen first

at harvest. Young leaves from the crowns of strawberry

plants suspected of being infested with CM should be ex-

amined under a binocular microscope or with a good hand

lens. Teatment is recommended if CM are found in the

sample taken.

Control

Planting material found to be infested with CM should be

returned to the nursery.

Established strawberry plantings requiring CM control

should be treated at the time the beds are renovated. Com-

mercial growers should use Thiodan. Homeowners are

limited to Kelthane. The material should be applied as a

drench.

Effects of Aculus schlechtendali (Acari: Eriophyidae) population densities on Golden Delicious apple production

Article

Full-text available

Sep 2018

Field trials were carried out in order to evaluate the seasonal abundance and the impact on yields of the Apple Rust Mite (ARM) Aculus schlechtendali (Acari: Eriophyidae) in an experimental fruit orchard located in northern Italy (Trentino region). The effect of ARM on yield and market quality parameters were assessed on Golden Delicious apple fruits. Fruit size, fruit weight, round colour hue, presence of russet as well as inside quality, i.e. soluble solids, acidity and Perlim index, were evaluated over two seasons considering three population levels of ARM that were determined applying different pesticide strategies. Effects of rust mites on return bloom and yield efficiency were also evaluated. ARM seasonal abundance showed a peak in mid-summer. Relationships between ARM and predatory mites were weak. Moderate to high ARM densities affected fruits size, fruit weight, and round colour hue of Golden Delicious fruits. In contrast, ARM populations did not affect russet on fruits, return bloom and yield efficiency. Additional studies were conducted in the laboratory, on detached Golden Delicious apple leaves, to evaluate the potential for population increase at temperatures close to those recorded in field conditions. These studies evidenced a high potential for population increase.

Russeting of apples caused by apple rust mite Aculus schlechtendali (Acarina: Eriophyidae)

Article

Feb 2008
ANN APPL BIOL

Significant correlations were found between the numbers of apple rust mites Aculus schlechtendali feeding on fruitlets shortly after the blossom period and the amounts of russet on the calyx-end and cheek of apples at harvest. Stalk-end russet was not usually affected. Fruits from clusters or trees on which rust mite numbers had been reduced with an acaricide pre-blossom had less calyx-end and cheek russet than apples from untreated comparisons. Histological studies showed that feeding by mites on flower receptacles/fruitlets in May and June damaged epidermal cells, resulting in russet formation.

ResearchGate has not been able to resolve any references for this publication.

Extension Based Tree and Small Fruit Insect Pest Management Strategies

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