kentucky pest news, july 2, 2013

7/28/2019 Kentucky Pest News, July 2, 2013

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Online at: www.uky.edu/KPN

Number 1346 July 2, 2013

TOBACCO

-Disease Update for the Week of July 1

VEGETABLES

-Bacterial Diseases of Tomato and Pepper

FRUITS

-Spotted Wing Drosophila Update

FORAGES-What Hay Producers and Buyers Should Know

About Blister Beetles

PEST OF HUMANS-Insects around Swimming Pools

-Time for “seed ticks” – Newly Hatched Lone Star Ticks

FUNGICIDES-Some Principles of Fungicide Resistance IV:

FRAC Codes

PESTICIDE NEWS AND VIEWS-Oregon Bee Kill Sparks Push for More Education

DIAGNOSTIC LAB HIGHLIGHTS

INSECT TRAP COUNTS

TOBACCO

Disease Update for the Week of July 1By Kenny Seebold, Extension Plant Pathologist

Current situation

Heavy rainfall and warm temperatures have really pushed outbreaks of black shank in some areas.

As was mentioned in last week’s Kentucky Pest News article, supplemental applications of fungicides (Ridomil Gold SL, Ultra Flourish, or MetaStar) can be helpful in reducing losses to

black shank. Timing of the fungicide applicationis important for success, and we tend to see better control in varieties with resistance levels of 4 or

better to races 0 and 1 of the black shank pathogen. If a post-transplanting fungicide

treatment is used, growers must make sure to get

the product onto the soil and incorporated asquickly as possible. Mechanical incorporation

(cultivation) is the best option, followed byirrigation or rainfall; rainfall may be the only way

that some growers can achieve proper incorporation given wet field conditions that we’reseeing around the state. Fungicide applications are

not recommended on tobacco that is too big to

cultivate. The reason for this is that it is very

difficult to deliver soil fungicides to the soil itself;instead, foliage of bigger tobacco tends tointercept the spray. Ridomil Gold and generic

fungicides in this class will not translocate to theroots, but instead will move upward in the plant

after foliar exposure and not afford any protection

against black shank.

Blue Mold

As of July 1, blue mold has yet to be reported inthe tobacco-growing areas of the United States.

VEGETABLES

Bacterial Diseases of Tomato and PepperBy Kenny Seebold, Extension Plant Pathologist

Unusually wet weather has prevailed throughout

many areas of Kentucky, and we’re seeing anumber of disease issues on tomatoes and peppersas a result. Bacterial diseases on both peppers and tomatoes have increased dramatically over the past

Lexington, KY 40546

http://www.uky.edu/KPN






two weeks based on field visits and samples thathave been submitted to our diagnostic labs.

Bacterial spot, which is caused by Xanthomonas

campestris pv. Vesicatoria, will affect peppers and

tomatoes and tends to be the most common bacterial disease of these crops in Kentucky. We

also have seen a little bacterial canker, caused byClavibacter michiganensis subsp. Michiganensis,on tomato this year.

Control of bacterial diseases of tomato and pepper can be difficult if nothing has been done beforesymptoms are observed. Prevention is the bestdefense to reduce potential losses. We

recommend that growers use certified, disease-freeseed or transplants; in the case of pepper, varieties

resistant to the bacterial leaf spot pathogen arehighly desirable. Managing bacterial diseases in

the greenhouse goes a long way in keeping these problems out of the field.

Once in the field, good management practices canhelp reduce the threat posed by bacterial

pathogens. Avoid working tomatoes and peppers

when foliage is wet, as bacterial diseases and caneasily be spread by handling or application of

pesticides. Applications of fixed copper plusmancozeb are effective against bacterial spot whenused as part of a preventive disease management

program; however, these materials have little

effect against bacterial canker of tomato. For those using bell pepper varieties with no resistanceto bacterial leaf spot, or those who are growingnon-bell types, a fungicide/bactericide program is

absolutely necessary. Growers should be awarethat 2013 is shaping up to be a big year for

bacterial diseases on peppers and tomatoes if rainyconditions continue. Refer to ID-36, the“Vegetable Production Guide for Commercial

Growers” and ID-172, “An IPM Scouting Guidefor Common Pests of Solanaceous Crops in

Kentucky” for more information on identification

and control of these problems.

FRUITS

Spotted Wing Drosophila UpdateBy Ric Bessin, Entomologist

Patty Lucas and I have been processing a largenumber of spotted wing drosophila (SWD) traps

this summer and through June all of the sampleswere negative, no SWD were found. However, asample from Breathitt Co. (Robinson Substation)collected on the July 1 had one SWD female. Thisis the first SWD of the year in Kentucky. While

this is significant for the blueberry planting whereit was found, other growers should not use sprays

for SWD during the harvest period if they have notseen the pest.

Figure 1. Spotted wing drosophila female displayingenlarged ovipositor.

SWD is a potential threat to small fruits and other thin skinned fruits. Unlike other fruit flies in

Kentucky, this fly lays its eggs underneath the skinof otherwise sound fruit. Within a couple of daysthe eggs hatch and the maggots feed on the fleshcausing the flesh of the fruit to collapse in thisarea. Fruits become susceptible to damage as they

begin to turn color close to harvest throughharvest. Growers managing infested fields need tospray SWD insecticides during the harvest period to prevent egg laying. Growers need to carefullyselect and manage these sprays to allow for

required pre harvest intervals to maintain saferesidues.



FORAGES

What Hay Producers and Buyers Should Know

About Blister BeetlesBy Lee Townsend, Extension Entomologist

Several species of blister beetles occur inKentucky but large populations are not common.These mid- to late summer insects are active from

about mid-July through early August. They areespecially attracted to and feed on flowers. Anaggregation pheromone released by the insects asthey feed results in accumulations of beetles or “hot spots”, often along field margins.

Tips For Hay Producers

• Learn to recognize blister beetles and understand their behavior. A proactive

preventive program will reduce the

chances of infested hay.

• Blister beetles are not active when the first

cutting is made in Kentucky; harvest at thelate bud stage or when the first flowersopen for high quality hay for horses.

• Blister beetles are attracted to blooms.

Manage harvest intervals to minimize

flowering of alfalfa or weeds in grass hay.Practice good broadleaf weed

management. If flowering plants are present at harvest, inspect them carefully

for blister beetles.

• Avoid crimping hay during harvest.

Straddle cut swaths to avoid crushing beetles with tractor tires.

• There is no efficient way to inspect baled hay carefully enough to be sure that it isfree of blister beetles.

Tips For Horse Owners

• Buy first cutting hay; blister beetles are

not active then.

• Develop a relationship your hay producer so that you know their production

practices and hay quality. Buy from local

sources.

Blister beetles have long (3/4" to 1-1/4"), narrow bodies, broad heads, and antennae that are about

1/3 the length of the entire body. The segment behind the head is narrow, so the beetle appears to

have a "neck". The front wings are soft and flexible in contrast to the hard front wings of most

beetles. The black blister beetle (jet black) and themargined blister beetle (black with thin gray stripe

around wing covers) are common species inKentucky.

Female blister beetles lay clusters of eggs in thesoil in late summer. The small, active larvae thathatch from these eggs crawl over the soil surface

entering cracks in search for grasshopper egg podswhich are deposited in the soil. After finding theegg mass, blister beetle larvae become immobileand spend the rest of their developmental time as

legless grubs. Blister beetles will not lay eggs inhay and the larvae do not feed on or develop in

hay bales.

PESTS OF HUMANS

Insects around Swimming PoolsBy Lee Townsend, Extension Entomologist

Swimming pools attract a variety of insects. Mostcan be removed with a dip net; small ones,especially thrips, (thrips) are harder to deal with

but are usually just a temporary nuisance. Do not put insecticides into swimming pool water or

allow nearby spray applications to drift into pools.

Bees and wasps need water for colonymaintenance so they can be common visitors butare not aggressive or defensive unless disturbed.

Honey bees need lots of water to maintainoptimum hive temperature and humidity. A nearby

swimming pool may be the most convenientsupply. Worker bees that find a good water sourcewill recruit colony mates to join them. Over time,hundreds of bees may be appear. Some will fallinto the water and drown but others will keep

coming. They are preoccupied with this task and generally are not a threat. Dealing with bee visitsto small kiddy pools can be as simple as movingthe pool to a different spot in the yard every fewdays. Bees follow directions very strictly and if the



pool is not where it should be, they will not find iteasily. You can stay ahead of them with the

moves.

Figure 2. Giant water bug or “toe biter”.

Some water bugs and beetles see it as a new home;to them, a swimming pool is just another pond.Giant water bugs and backswimmers are predators

adapted for aquatic life. Giant water bugs havegrasping from legs and a short, stout beak used to

pierce their prey. They can give a painful bite.

Figure 3. Backswimmer.

Backswimmers row along with their long back

legs. They are less likely to bite but are good fliersand significant numbers of them can show up fromnearby ponds.

There will not be enough food to keep these

predators around for very long but it is best toremove them with a dip net as they arrive.

Figure 4. Thrips.

Tiny (1/16 inch long thrips) usually are thegreatest nuisance. Hundreds can appear as a resultof disturbance to their habitat – mowing of nearbylawns, clipping of hay fields or wheat harvest.Those that land on the water drown. Those that

land on skin may cause an irritating “bite” withtheir rasping mouthparts.

A strong jet of water may be used to plaster themto decks and other surfaces where they have

accumulated. Covering the pool when it is not inuse may be the best and only way to excludechronic problems with unwanted creatures.Fortunately, this may be needed for only a few

days at a time.

Time for “Seed Ticks” – Newly Hatched Lone

Star TicksBy Lee Townsend, Extension Entomologist

Figure 5. Newly hatched lone star ticks.

Earlier in the summer, female lone star ticks laid masses of several thousand eggs on the ground;

these are beginning to hatch. Anyone unfortunate



enough to stand in or to pass through such a sitecan easily pick up hundreds of hungry larvae.

These tiny 6-legged creatures, also called "seed

ticks and turkey mites", are active between Julyand September. These blood-thirsty larvae climb

low vegetation and wait with outstretched frontlegs to latch on to passing animals or humans.Once "on board", they crawl around to find a

suitable place to attach and feed. The painfulfeeding site can be irritating for days after the tick has detached or been removed.

Hikers, hunters, and persons working outdoors

should be aware that seed ticks apparently aremuch more abundant than normal this year. Use

repellents and check regularly for ticks. Clothingrepellents that contain permethrin (eg Permanone)

can greatly reduce, but not necessarily eliminateencounters with ticks. These products are for clothing not application to the skin.

FUNGICIDES

Some Principles of Fungicide Resistance IV:

FRAC CodesBy Paul Vincelli, Extension Plant Pathologist

The previous three articles in this series showed how fungicide resistance develops, and why over-reliance on fungicides is risky. This fourth

installment “switches gears” by considering thesubmicroscopic world of fungicide resistance.

Although they are too small to see with the naked eye, cells of fungi are quite complex (Figure 6).

Fungicide manufacturers take advantage of thiscomplexity by creating chemicals that poison the

biochemical activity of one or more of these cellstructures.

Figure 6. Structure of a typical eukaryotic cell. From:

http://www.uic.edu/classes/bios/bios100/lecturesf04am/l

ect06.htm.

In order to understand how fungicides poisonfungi, it is important to understand the normal

metabolism of a healthy fungal cell. See Figure 2for an example. In a healthy cell, enzymes turn acertain molecule (called “substrate”) into another molecule (called “product”). Without thesimultaneous, furious activity of many thousands

of enzymes, the cell would be unhealthy or dead.

Figure 7. Normal molecular function within a living cell.

From: http://waynesword.palomar.edu/molecu1.htm.

A fungicide is merely a chemical that interfereswith the normal function illustrated in Figure 2.One way it might interfere is illustrated in Figure3: by binding the active site of the enzymes. Other

fungicides interfere in other ways, but in all cases,they interfere with some molecule normally

present in healthy fungal cells.

http://www.uic.edu/classes/bios/bios100/lecturesf04am/lect06.htm



http://waynesword.palomar.edu/molecu1.htm








Figure 8. The red chemical is a toxin that interferes with the

normal functioning of the enzyme pictured in Figure 2. It

binds to the active site of the enzyme, preventing

enzymatic activity. From:

http://waynesword.palomar.edu/molecu1.htm.

Thus, each fungicide has a particular biochemicalway of poisoning the cell. Why is this importantfor users of fungicides? This is the key point: if

two fungicides poison the cell in precisely the

same way, they are the same fungicide, from the

point of view of the fungus. It does not matter:

• Whether the active ingredients havedifferent chemical structures

• Whether the active ingredients have

different names

• Whether they are sold under different

trade names

• Whether they are made by different

manufacturers

• Whether they are formulated differently.

From the point of view of the fungus, if they poison the cell in the same way, they are the same

fungicide.

Here is a classic example. Benomyl was the firstsystemic fungicide. It was sold under varioustrade names, including Agrocit®, Benex®,

Benlate®, Tersan 1991®, and others. Another fungicide that continues to be important today isthiophanate-methyl, which has been sold under awide variety of trade names, including Cleary’s3336®, Fungo®, Topsin M®, and many others.

Benomyl and thiophanate-methyl have differentchemical structures1. However, they both poison

1For the “geeks” like me, you can see these chemical

structures at

http://webbook.nist.gov/cgi/cbook.cgi?ID=C17804352

&Mask=200

the fungal cell in exactly the same way. Thereforethey are both considered to be benzimidazole

fungicides, a name which communicates thisshared mode of action. This means that, even if

you alternate between fungicides within afungicide group, the fungus “sees” them as the

same fungicide. It also means that if resistancedevelops to one member of the group, usuallyresistance is present for all members of that group.

So which group a fungicide belongs to is reallyimportant for crop producers who want to steward fungicides wisely. Our producers have a lot “ontheir plate”, so fortunately, you don’t have to learn

any biochemistry, or even learn the names of fungicide groups. Several years ago, members of

the global Fungicide Resistance Action Committee(FRAC) decided to represent fungicide groups

using numbers. So the benzimidazole group(which includes benomyl and thiophanate-methyl)is represented as FRAC Code 1. Any fungicidewith FRAC Code 1 poisons fungi in the same way.This also means that any product with any other FRAC Code poisons a different biochemical

target, so any fungicides with a FRAC Code other than #1 truly are different from the members of FRAC Code 1.

FRAC Codes are present on the labels of most

fungicidal products sold in the USA. See Figure 4

for an example. This makes it easy to alternate products having different biochemical modes of action—just look for products having a differentFRAC Code.

and : http://toxnet.nlm.nih.gov/cgi-

bin/sis/search/a?dbs+hsdb:@term+@DOCNO+6937



http://webbook.nist.gov/cgi/cbook.cgi?ID=C17804352&Mask=200



http://toxnet.nlm.nih.gov/cgi-bin/sis/search/a?dbs+hsdb:@term+@DOCNO+6937











Figure 9. Example of a FRAC Code on a product label. From:

http://www.ipm.iastate.edu/ipm/icm/2006/6-

12/fungicides.html.

Bottom line: Active ingredients within the same“fungicide group” poison fungi in exactly thesame way. From the point of view of the fungus,

such fungicides are identical, regardless of whomarkets the product. Fungicides in the samefungicide group share the same FRAC Code. Thiscode makes it easy for growers to use fungicidesin ways that reduce the risk of fungicide

resistance.

More information on FRAC Codes is available at

http://www.frac.info/index.htm. Watch for

additional installments in this series of articles onfungicide resistance.

PESTICIDE NEWS AND VIEWS

Oregon Bee Kill Sparks Push for More

EducationBy Ric Bessin, Entomologist

Last week there was a bumble kill in Oregon as aresult of an insecticide application. While this wasnot an agricultural incident, this was a landscaper

treating aphids in Lindens on a commercial property, the EPA has requested more education inorder to help protect pollinators. As a result The

Oregon Department of Agriculture told thecompany that manufactures the product in

question (dinotefuran) the use would be suspended for 180 days.

This incident highlights the need for users of

pesticides to read and follow all labelrequirements. Pesticide labels will have an

‘ENVIRONMENTAL HAZARDS’ section thatclearly outlines potential risks associated with

particular products. In this case the label had

indicated a significant risk to bees:

“This product is highly toxic to bees exposed to

direct treatment or residues on blooming crops or

weeds. Do not apply this product or allow it to drift to

blooming crops or weeds if bees are visiting the

treatment area.”

Another product with the same active ingredient

but labeled for ag use states:

“This compound is toxic to honey bees. The persistence

of residues and potential residual toxicity of

dinotefuran in nectar and pollen suggest the possibility

of chronic risk to honey bee larvae and the eventual

instability of the hive.

This product is toxic to bees exposed to treatment for

more than 38 hours following treatment. Do not apply

this product to blooming, pollen-shedding or nectar-

producing parts of plants if bees may forage on the

plants during this

time period, unless the application is made in response

to a public health emergency declared by appropriate

state and federal authorities.”

Following these restrictions is just as important as

following any other label requirements includingusage rates, REIs, and PHIs. Using a product thatis in any way inconsistent with the label is illegaland sets the user up for potential penalties. Thelabel protects wild pollinators as well as honey

bees.

DIAGNOSTIC LABORATORY HIGHLIGHTS

By Julie Beale and Brenda Kennedy

Agronomic samples diagnosed in the PDDL in the

past week have included Fusarium head blight on

http://www.frac.info/index.htm





wheat; stinkbug injury on corn; black shank,Rhizoctonia stem rot, Pythium and Rhizoctonia

root rots, Fusarium wilt, alfalfa mosaic virus,tomato spotted wilt virus, temporary phosphorus

deficiency and symptoms of transplant shock ontobacco.

On fruit and vegetable samples, we havediagnosed black rot, bitter rot and anthracnose on

grape; common leaf spot, Phomopsis leaf blightand black root rot complex on strawberry; fire

blight on pear; cedar-apple rust on apple; scab on peach; Ascochyta leaf spot on rhubarb;anthracnose and bacterial blight on bean; bacterial

wilt on cantaloupe; bacterial blight on pea; purple blotch on garlic; bacterial leaf spot on pepper;

bacterial spot, Septoria leaf spot, early blight,Botrytis leaf blight, leaf mold (Fulvia) and

buckeye rot on tomato; and Pythium root rot onwatermelon.

On ornamentals and turf, we have seenanthracnose on dianthus; anthracnose and Rhizoctonia root rot on daylily; and Phytophthora

root rot on arborvitae; and brown patch on fescue.

FYI Each year, more than 3,300 plant samples are

processed at the Plant Disease Diagnostic Labs;

60,000 cases a year are completed at theVeterinary Diagnostic Laboratory; 61,000 soilanalyses are completed at Regulatory Services;and more than 4 million people engage in a

Cooperative Extension Service activity.

http://news.ca.uky.edu/article/name-change-reflects-broad-work-uk-college-agriculture-food-and-environment#.Uc3e9lEmZZ4.facebook

2013 INSECT TRAP COUNTS

June 21 - 28

Graphs of insect trap counts for the 2013

season are available on the IPM web site at -http://www.uky.edu/Ag/IPM/ipm.htm.

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 41 23Armyworm * 332

European corn

borer

0 4

Corn earworm 5 1

Southwestern

corn borer

14 5

Fall armyworm 0 1





http://www.uky.edu/Ag/IPM/ipm.htm.






kentucky pest news, july 2, 2013

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