kentucky pest news june 21, 2011

8/6/2019 Kentucky Pest News June 21, 2011

1/9

Online at:www.uky.edu/KPN

Number 1273 June 21, 2011

WHEAT

-Wheat Disease Situation: What Went Right?

FORAGE CROPS-Leaf Streak (=Brown Stripe) of Orchardgrass

SHADE TREES & ORNAMENTALS

-Whats wrong with My Taxus?

-Asian Longhorned Beetle Detected in SouthernOhio

-Bagworm Feeding Underway

-First of Two Fall Webworm GenerationsAppearing

WHEAT

Wheat Disease Situation: What Went Right?By Don Hershman

If you have been following some of my wheat

disease concerns this spring, you would be pleased

to know that wheat yields and test weights forfields harvested (so far) throughout west Kentucky

have generally exceeded all expectations. Yields

in excess of 90 bu/A and test weights above 60

lb/bu are fairly common. In addition, I have heardof many fields topping the 100 bu/A mark.

Everybody is happy, all the way from the farmer

to the miller to the end-use food manufacturer.

Since FHB and/or leaf and glume blotch appearedto be at significant levels in many fields, one could

reasonably ask, whats up with that? I must

confess I do not have all the answers. But I thinkthe good end result probably has something to do

with the unseasonably hot early June, which

resulted in a very rapid dry-down in fields. For

about a week, temperatures existed in early June

that are normally experienced in late July. I

believe this rapid dry-down, in turn, reduced the

negative effects of disease. In essence, the crop

outraced diseases to the finish line, the result

LIVESTOCK

-Face Fly Control a Part of Managing Pinkeye

PEST OF HUMANS

-Some Insect Nuisances around Swimming Pools

but Control Options are Limited

HOUSEHOLD

-Camel or Cave Crickets Denizens of Basements

and Crawlspaces

INSECT TRAP COUNTS

DIAGNOSTIC LAB HIGHLIGHTS

being that the impact of the infections was far less

than it otherwise would have been. I also believe

many fields started out with a better-than-averageyield potential. Thus, small yield reductions

related to disease development would not be

noticed as much.

A large number of acres remain to be harvested, sothe overall state-wide result may not end up being

as favorable as I have indicated here. Still, I think

2011 will go down as being one of our better years

in terms of wheat yield and quality.

FORAGE CROPS

Leaf Streak (=Brown Stripe) of Orchardgrass

By Paul Vincelli

The most common and destructive disease oforchardgrass in Kentucky is leaf streak. The

disease is also known by other names, including

brown stripe and brown leaf blight. It is caused by

the fungus Cercosporidium graminis (which also

goes by its outdated name, Scolecotrichum

graminis). While orchardgrass is a common host,

Lexington, KY 40546
http://www.uky.edu/KPNhttp://www.uky.edu/KPNhttp://www.uky.edu/KPNhttp://www.uky.edu/KPN


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this fungus has been reported to cause serious

damage on timothy.

This fungus produces spores that are spread

primarily by splashing droplets and wind-blownrain. It survives between growing seasons in crop

residue. Infection results in tan to brown spots ofdead tissue on leaf blades (Figure 1). These spots

may extend into the leaf sheath. They eventually

become numerous and cause leaf blighting. Cool,wet weather in spring and fall provides ideal

conditions for disease development. Substantial

leaf blighting can result in earlier maturity,

resulting in reduced yield and forage quality.

Management

Use high-quality seed of varieties well-adaptedto Kentucky conditions. The best source of this

information is the University of Kentucky ForageTrials, available at

http://www.uky.edu/Ag/Forage/ForageVarietyTria

ls2.htm.

Rotate for two years to a non-grass species.This allows populations ofCercosporidium

graminis and other infectious organisms to decline

to less damaging levels.

Fertility. Avoid high rates of a readily available

form of nitrogen fertilizer, especially in

springtime. Maintain adequate levels ofphosphorous and potassium.

More information on orchardgrass production in

Kentucky is available at

http://www.ca.uky.edu/agc/pubs/agr/agr58/AGR5

8.PDF.

SHADE TREES & ORNAMENTALS

Whats wrong with My Taxus?By John Hartman

Taxus (yew) is a popular landscape shrub in

Kentucky, but occasionally homeowners havedifficulty growing them in the landscape.

Problems associated with Taxus may be related to

infectious disease, insects, or adverse growing

conditions. There are numerous conditions that

cause Taxus to turn yellow or brown. For

diagnosis, a thorough examination of the affected

shrub, an investigation of the surrounding area,

and some knowledge of possible environmental

stresses are needed to diagnose Taxus problems.

The following are questions that may be posed to

County Extension Agents by clients inquiring

about the health of their yews. The answers mayhelp Agents to assist their clients in determining

the cause of their shrub's decline.

1. Question: Why are the tips of thebranches ofTaxus shrubs turning brown?

Answer: There are multiple causes for

death of taxus shoot tips in the landscape

and they range from disease to weather.

Examine the trunk, branches, and twigstems for wounds from physical injury.

Taxus cannot tolerate much injury and is

easily damaged (Figure 2). Childrenfalling into the shrubs or snow and ice

sliding off the roof into shrubs can causeinjury. Bark torn from as little as one-

third the circumference of a branch may

cause the branch to die from that point all

the way to the growing tip. Also, look for

nursery tags wired to a branch which mayeventually constrict its growth. Even

termites, which can build their mud

tunnels up the trunk and branches of

Taxus, can kill parts of the shrub due to

feeding activity. Injured branches oftendo not die immediately but dead branches

may be evident the following summer.

Dead twigs should be pruned back to

healthy tissue.

Twig blight on scattered branches canresult from canker diseases. Cankers

(dead, sunken areas) may be associated

with various fungi (Pestalotia,Figure 1. Close-up of leaf streak (=brown stripe) symptoms onorchardgrass (from http://oregonstate.edu/valleyfieldcrops/pest-

management). More images available at

http://www.gov.mb.ca/agriculture/crops/diseases/fac60s00.html.
http://www.uky.edu/Ag/Forage/ForageVarietyTrials2.htmhttp://www.uky.edu/Ag/Forage/ForageVarietyTrials2.htmhttp://www.uky.edu/Ag/Forage/ForageVarietyTrials2.htmhttp://www.ca.uky.edu/agc/pubs/agr/agr58/AGR58.PDFhttp://www.ca.uky.edu/agc/pubs/agr/agr58/AGR58.PDFhttp://www.ca.uky.edu/agc/pubs/agr/agr58/AGR58.PDFhttp://www.ca.uky.edu/agc/pubs/agr/agr58/AGR58.PDFhttp://www.ca.uky.edu/agc/pubs/agr/agr58/AGR58.PDFhttp://www.uky.edu/Ag/Forage/ForageVarietyTrials2.htmhttp://www.uky.edu/Ag/Forage/ForageVarietyTrials2.htm


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Physalospora, and Sphaeropsis.) These

fungal cankers can girdle twigs and

branches, causing them to die back from

the tip. Where canker disease is present,

dead twigs should be pruned out anddestroyed.

Browning tips of individual branches canbe due to cold temperature injury. Tender

new growth in late spring or current

season's growth in fall may show damage

shortly after a frost. The plant usuallygrows out of this condition (Figure 3).

Tips may turn brown with individualneedles twisted and curled due to exposure

to growth-regulator type herbicides

(Figure 4).

Browning and death of 1-year-old or olderfoliage can be due to winter injury.

Symptoms become evident on olderneedles in spring, while new growth is

unaffected. Damage may occur mainly on

portions of the shrub exposed to prevailing

winds. This condition occurs as the resultof moisture lost from foliage on warm,

windy days in winter. Because the ground

is frozen, moisture cannot be replenished

rapidly enough and needles dry out.

During the drought late last summer andfall, Taxus should have been watered as

needed up until the ground froze. Avoid

planting Taxus on sites that are exposed todrying winter winds.

2. Question: Why are major branches oreven the whole Taxus shrub turning

yellow, then brown, and dying?

Answer: There are several causes for

decline and death ofTaxus in the

landscape. They range from excess soil

moisture to mechanical injury to the roots.

Probably the most common cause of taxusproblems is Phytophthora root rot which isassociated with excessive soil moisture

(Figure 5). Where the shrub bed soil is

poorly drained, where plants are

overwatered, or where a downspout from

the house empties into the bed, taxus

plants or parts of plants often turn yellow,

then brown and die (Figure 6). In a taxus

hedge, it is usually the plant in the lowest

part of the hedge that dies. Wet soil

provides conditions favorable for root

decay caused by the fungus Phytophthora

(Figure 7). Infected roots will be brown

and rotted; sometimes the disease

progresses to and decays the lower trunkof the plant. When roots fail to function,

the Taxus plant declines and eventually

dies. Gardeners should avoid this "wet

feet" condition by planting Taxus shrubsin well-drained sites away from a

downspout.

Taxus can also turn yellow, decline anddie over a period of several months or

years when growing in soil where pH is

unfavorable (Figure 8). Taxus is often

planted near ornamentals in the heath

family (e.g. andromeda, azalea, laurel,rhododendron). Species in this group are

considered "acid-loving" plants and prefera soil pH of 4.5 to 5.5. Taxus, on the other

hand, requires a less acid soil (pH 6.0 to

6.5). Fertilizers prepared specifically for

plants in the heath family tend to make

soil more acidic. This can cause nearby

Taxus shrubs to turn yellow and die. Soil

which is naturally too acidic will also

cause problems. Gardeners will want to

have shrub bed soil tested to be sure that

the pH is optimum for the plants beinggrown. Contact your County Extension

Office for details on the correct procedure

for collecting a soil sample. Your County

Extension Agent will advise you on how

to raise the soil pH with ground limestone,

should this be necessary.

Other stresses can cause Taxus to die inthe landscape. Shrubs that die a year or

two after transplanting may have been

killed by transplant shock, that is, the

stress of moving from one environment to

another. New transplants often passthrough a period of shock, regardless of

the care taken. However, by following

correct cultural procedures fortransplanting, this stress can be

minimized. Planting too deeply is a

common transplanting problem that must

be avoided.


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Additional stresses causing yellowing,browning and death include holes orditches dug for gas and sewer lines or

during home construction that can result in

damage to Taxus roots. Digging within

several feet of the shrub may damage

roots that supply water and mineralelements to the plant. Injured plants turn

yellow, wilt and can eventually die. Even

tunnels dug through the root zone by

chipmunks or moles may damage rootssufficiently to cause top symptoms.

If only inside foliage turns yellow in latesummer or early fall it may be due to

normal needle drop. At this time, 3 to 5-

year-old needles may suddenly turn

yellow. Needles remain on the shrub forseveral weeks and then drop. This is a

normal process and should not causeconcern.

Figure 2. Dead Taxus twigs due to stem injury associated

with chunks of ice and snow falling from a nearby

rooftop.

Figure 3. A late spring frost has caused newly emerged

Taxus shoots to droop and die.

Figure 4. Taxus needles curling and turning

brown due to misapplication of growth-

regulator herbicide.

Figure 5. Phytophthora root rot left this bed with

numerous dead Taxus. The soil in this bed had poor

internal drainage and when dead plants were removed,

water remained in the planting hole.

Figure 6. Taxus plant with Phytophthora root

rot. Root rot disease has begun to cause

branch dieback.


5/9

Asian Longhorned Beetle Detected in Southern

OhioBy Lee Townsend

The Asian

longhorned

beetle (ALB)(figure 9) was

detected in

Bethel, OH,

which is 30

miles east

southeast of

Cincinnati,

according to anews release from state and federal officials late

last week. The insect was discovered when a

resident investigated unusual damage to three

maple trees. The site is being surveyed todetermine the extent of the population. The ALB

has been found in Illinois, Massachusetts, New

Jersey, and New York.

ALBs are large distinct black beetles spotted with

white; their long antennae (1.5 to 2.5 times body

length) are banded with black and white. Adults

emerge from round 3/8- to -inch diameter holes

in infested trees. See this pest alert for more

details:

http://www.na.fs.fed.us/pubs/palerts/alb/alb_pa.pd

f

In the United States the ALB prefers maple

species (Acerspp.), including boxelder, Norway,

red, silver, and sugar maples. Other preferred hosts

are birches, Ohio buckeye, elms, horsechestnut,

and willows. Occasional to rare hosts include

ashes, European mountain ash, London planetree,

mimosa, and poplars.

The ALB is not known to occur in Kentucky.

Report suspected infestations to the Office of the

State Entomologist - (859) 257-5838.

Figure 7. When Taxus seedlings are exposed to

Phytophthora in the soil (+) and periodic flooding, (pair

of plants to the right) roots and shoots are nearly dead

while those in well drained soil and no Phytophthora (-)

have healthy roots and shoots (pair of plant of plants to

the left). Flooding without Phytophthora (-) or

Phytophthora (+) with well-drained soil resulted in

Taxus stunting (middle two pairs of plants) but not

plant death.

Figure 8. Yellowing ofTaxus needles can

sometimes be caused by plants growing

in soil that is too acidic.

Figure 9. Asian longhorned beetle

(ALB).
http://www.na.fs.fed.us/pubs/palerts/alb/alb_pa.pdfhttp://www.na.fs.fed.us/pubs/palerts/alb/alb_pa.pdfhttp://www.na.fs.fed.us/pubs/palerts/alb/alb_pa.pdfhttp://www.na.fs.fed.us/pubs/palerts/alb/alb_pa.pdfhttp://www.na.fs.fed.us/pubs/palerts/alb/alb_pa.pdfhttp://www.dispatch.com/live/export-content/sites/dispatch/local_news/stories/2011/06/17/beetle.jpg


6/9

Bagworm Feeding UnderwayBy Lee Townsend

Small bagwormlarvae (figure

10) have beenfeeding and

growing for

about a weekand the bags

that they carry

are getting

larger. They

are still small

and the damage

is easy to

overlook but

now is the timeto check for them in the landscape, especially

where they were a problem last year.

Bagworms prefer juniper, arborvitae, spruce, pine,

and cedar but also attack deciduous trees. They

can be controlled but success requires early

detection and some persistence to make sure the

first application was successful. If only a few

small trees or shrubs are infested, handpicking and

destroying attached bags may provide satisfactory

control. This must be done effective during fall,

winter or early spring before the eggs hatch.

When many small bagworms are present andfeeding, an insecticide may be needed to prevent

serious damage. It is best to treat while the larvae

are still small (less than 1/2-inch long), usually in

early June. Small larvae are more vulnerable to

insecticides, and feeding damage is relativelyminor. Carefully inspect susceptible landscape

plants. Young bagworms are hard to see at first;

look closely for the small, upright bags which

have the appearance of tiny ice cream cones made

of bits of plant material.

Control options include products containing Bt,

carbaryl, neem, pyrethriods, and spinosad sprays.

See ENT 440 Bagworms on landscape plants formore details and options.

http://www.ca.uky.edu/entomology/entfacts/ef440.

asp

First of Two Fall Webworm Generations

AppearingBy Lee Townsend

The light

gray silktents of fall

webworm

caterpillars(figure 11),

recently

hatched from

masses of

400 or soeggs, are

beginning to

appear at the ends of tree branches. These

caterpillars are covered with long white to yellow-tan hairs. They feed on over 100 species of

deciduous trees but black cherry, walnut, hickory

and mulberry are favorites.

Fall webworm larvae incorporate the leaves they

are eating into their tent. The tent is expanded to

include more leaves as needed. Usually, there are

not enough caterpillars to completely defoliate

trees but the webbing makes their presence

obvious.

Accessible nests can be pruned out and discarded.Products listed for bagworms are effective on

small larvae if control is necessary and the sprayer

can reach foliage around the nest. There are two

generations in Kentucky each year- from mid-June

to early July and again in August.

Figure 10. Small bagworm with

developing cases on pine (Photo by S.

Vanek).

Figure 11. Webworm caterpillars.
http://www.ca.uky.edu/entomology/entfacts/ef440.asphttp://www.ca.uky.edu/entomology/entfacts/ef440.asphttp://www.ca.uky.edu/entomology/entfacts/ef440.asphttp://www.ca.uky.edu/entomology/entfacts/ef440.asphttp://www.ca.uky.edu/entomology/entfacts/ef440.asp


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LIVESTOCK

Face Fly Control a Part of Managing PinkeyeBy Lee Townsend

The face fly (figure 12) often is one of the factorsinvolved in pinkeye outbreaks in cattle herds. The

sponge-like mouthpart of this pasture fly is used to

blot up moisture from cattle including tears, saliva,

mucous, and blood. The blotting surface is raspy

enough to stimulate tear flow, giving the fly the

protein-rich liquid it needs.

While not the sole factor in pinkeye outbreaks inherds, the face fly can play an important role. It is

a strong flier and its irritating feeding abrades the

eye allowing it to pick up the pathogen from an

infected animal and to transfer it to an uninfectedone. Feeding by face flies is often interrupted soan individual may visit several animals before

getting the liquid and protein it needs. This

provides the opportunity to spread the pathogen,

Moraxella bovis, especially since it can survive onthe fly for up to three days. See ID-135 Pinkeye in

cattle: infectious bovine keratoconjunctivitis for

more information.

http://www.ca.uky.edu/agc/pubs/id/id135/id135.ht

m

Face flycontrol is an

important

component

of a herdprogram to

limit

pinkeye.

However, this is a difficult insect to manage for

two reasons: 1) it spends relatively little time on

animals and 2) visits are primarily limited to the

face, an area that is difficult to treat. While

elimination of face flies is not a practical goal, it is

possible to reduce their numbers. Some

insecticide impregnated ear tags can cut face flynumbers by 70% or more. In general though,

forced use applicators (such as dust bags) that

animals must contact while getting water or

minerals, or back rubbers with fly flips (figure 13)

are a means of getting the head and face treated

regularly enough to provide very good results.

PEST OF HUMANS

Some Insect Nuisances around Swimming Pools

but Control Options are LimitedBy Lee Townsend

Pools will attract certain

aquatic insects every year

but during dry periods the

rush to water may bring inmany seldom seen

creatures. The most

dramatic are thrips (figure14), tiny elongate yellow

insects that usually are

described on the

accompanying Insect IDform as follows: "These little biting things covered

an aboveground pool and deck. They were so thick

that you could wipe them off with your hand. They

have a painful bite, children could not play in the

pool for them."

Thrips have shown up in these circumstances

before, probably drawn to water and perhapsdriven there from nearby recently-cut hay fields.

On normal days thrips use their abrasive

mouthparts to rasp at plant tissue, especially

flowers. However, they will scrape skin, perhaps

as they attempt to pick up small amounts of

moisture. An occasional thrips scrape probably istolerable but lots of them do not add to the

Figure 12. Face flies feeding on tears and mucous (l) and

sponging mouthpart with raspy undersurface (r).

Figure 13. Mineral feeder with insecticide

applicator hanging at opening.

Figure 14. Thrips (Photo

cals.ncsu.edu).
http://www.ca.uky.edu/agc/pubs/id/id135/id135.htmhttp://www.ca.uky.edu/agc/pubs/id/id135/id135.htmhttp://www.ca.uky.edu/agc/pubs/id/id135/id135.htmhttp://www.ca.uky.edu/agc/pubs/id/id135/id135.htmhttp://www.ca.uky.edu/agc/pubs/id/id135/id135.htm


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swimming experience. A strong jet of water maybe used to plaster them to decks and other surfaces

where they have accumulated.

Honey bees need water to air condition their hive.They are able to communicate with hive mates and

recruit increasing numbers of workers to a goodwater source. A small wading pool could be

relocated if necessary but this is not an option with

large pools. Usually, the bees are focused on theirtask and are not aggressive. Their presence may be

disconcerting but if not disturbed, they should

pose no problem. The occasional wasp may show

up, too but they are less likely to bring help with

them.

Several water bugs will come plopping into pools

because they figure any water is fair game and

some unlucky non-aquatic insects may fall in andbe unable to escape. These can be taken out with a

dip net.

Some persistent problems can develop around

chronic wet areas. Springtails are particularly

common in these situations. Correcting these wet

areas should lead to the elimination of the

infestation.

HOUSEHOLD

Camel or Cave Crickets Denizens ofBasements and CrawlspacesBy Lee Townsend

Camel crickets or

cave crickets

(figure 15), call

them what you

like, are unsettlingcreatures to have

around. The

camel cricket

name comes from

the insects

humpbackedappearance. Cave

cricket refers to the dark, damp, musty placeswhich they inhabit.

They are creepy; very long thin antennae and long

spider-like legs are their main features. The stronghind jumping legs launch them several feet into

the air when approached. Its an unnerving sightwhen you unexpectedly disturb one.

These insects usually occur in cool, damp places,such as in the soil under rock or wood piles.

Around houses, they can be found in basements,

crawlspaces, storage rooms, or garages. These

insects often move indoors in the fall and spend

the winter in buildings. The crickets will eatalmost anything and can damage stored articles

where they are living.

Camel crickets lay their eggs in moist soil, in dirtfloors of crawl spaces or along foundations. The

immature and adult stages are active at night and

can move easily through cracks and crevices or

under doors into other areas of a structure.

As with many pests, habitat modification is the

most effective way to reduce or eliminate

problems.

Reduce humidity by improving airmovement in areas where crickets are seen

regularly.

Ventilation openings should be screenedto prevent entry from the outdoors.

Eliminate clutter; stack stored items offthe floor and away from walls to improve

drying and to allow placement of sticky

traps to capture crickets and monitor their

locations and abundance.

Clean overgrown vegetation alongfoundations.

Boric acid dust or any of a variety of household

insecticides, such as Ortho, Spectracide, or Raid

indoor / outdoor aerosols, will kill camel crickets.They should be applied into cracks and crevices

where the crickets hide according to label

directions.

Figure 15. Sticky traps are an

effective way to catch camel

crickets.


9/9

DIAGNOSTIC LAB HIGHLIGHTSBy Julie Beale and Paul Bachi

Agronomic samples this week have included

potassium deficiency and compaction in corn;

potassium deficiency in soybean; glume blotch on

wheat; leaf streak (Cercosporidium) onorchardgrass; and target spot, Pythium root rot,

potassium deficiency and lightning injury on

tobacco.

On fruits and vegetables, we have seen black rot

on grape; double blossom on blackberry;

Phytophthora root and crown rot on blueberry,

raspberry and strawberry; brown rot on nectarine;leaf spot (Coccomyces) on cherry; fire blight,

cedar-apple rust and frogeye leaf spot on apple;

Alternaria leaf blight on cantaloupe; Cercospora

leaf spot on turnip; Fusarium stem rot on pepper;Botrytis blight, early blight, leaf mold and

chemical injury on tomato.

On ornamentals and turf, we have seen Fusarium

wilt on petunia; Fusarium stem rot on aster;

Pythium root rot on impatiens; scab on crabapple;

anthracnose on ash and oak; Botryosphaeria

canker on hydrangea; Verticillium wilt on redbud;

Rhizosphaera and Stigmina needlecasts on spruce;

Phyllosticta leaf blotch on witchhazel; brown

patch on fescue; and summer patch on mixed

turfgrass.

INSECT TRAP COUNTS

June 3-10

June 10-17

Graphs of insect trap counts for the 2011 season are available

on the IPM web site at -http://www.uky.edu/Ag/IPM/ipm.htm.View trap counts for Fulton County, Kentucky at -http://ces.ca.uky.edu/fulton/InsectTraps

Note: Trade names are used to simplify the information

presented in this newsletter. No endorsement by the

Cooperative Extension Service is intended, nor is

criticism implied of similar products that are not

named.

Location Princeton,

KY

Lexington,

KY

Black cutworm 21 1

Armyworm 12 359

Corn earworm 11 17

European corn

borer

1 1

Southwestern

corn borer

2 0

Fall armyworm 0 0

Location Princeton,

KY

Lexington,

KY

Black cutworm 19 1

Armyworm 34 206

Corn earworm 35 2European corn

borer

0 2

Southwestern

corn borer

7 0

Fall armyworm 0 0

kentucky pest news june 21, 2011

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