• Oystershell scale (7-91)

• White Pine Aphid (7-121)

• Fletcher scale (35-148)

• Honeylocust plant bug (58-246)

• Eastern tent caterpillar (90-190)

• Black vine weevil (148-400)

• Lilac borer (148-299)

• Dogwood borer (148-700)

• Birch leafminer (190-290)

• Holly leafminer (192-290)

• Lace bugs (239-363)

• Boxwood psyllid (290-440)

• Pine needle scale (298-448)

No degree day information is avail-able on these pests:

• Inkberry leafminer

• Magnolia weevil

• Lesser peach tree borer

• American plum borer

Volume IX, Issue 1 April 2005 Pests susceptible to control-based on degree day forecasts ( )=Degree day ranges

Off ice o f State Entomologist

Prune-Out Canker Diseases Pg 3

That’s One Big Aphid Pg 4

Watch For Rust on Heuchera

Pg 4

Calendar for Common KY Shade Tree and Woody Ornamental Pests

Pg 4-6

Lichens Infesting Tree Trunks and Branches

Pg 7

Foliar Nematodes Pg 7

Kentucky Sudden Oak Death Survey

Pg 8

Degree Day Targets Pg 8

Inside this issue:

Foliar nematode symptoms

the USDA explaining the dangers.

Your employees may lose valuable work time and customers may be at risk from stings by imported fire ants when handling the popular landscaping material, pine straw mulch. Pine straw is the term used for fallen pine needles that are gathered

Several Kentucky garden centers and landscapers are beginning to use pine straw or pine needles as mulch. You should be aware that imported fire ants may be accidentally shipped with pine straw. Currently, pine straw is not being regulated by the USDA although this is a known pathway. The fol-lowing is a bulletin from

beneath the trees in a pine forest or plantation. Pine straw can be raked, baled, and sold as mulch or ground cover for use in gardens and landscaping.

The majority of pine straw mulch is baled in areas in the southern United States where fire ants have become established.

Con’t page 2

Pine Straw Mulch—Be Aware of the Dangers Oystershell scale

Giant bark aphid White pine aphids

Right—Rust on Heuchera

Left—Botryosphaeria canker on sweet

gum

Lesser peachtree

borer dam-age (left) and larva

(right)

Fire ants may be gathered accidently with the pine straw during the baling process.

Fire ants are 1/8 to 1/4–inch long and reddish brown to black in color. They look much like ordi-nary ants so they are best distinguished by their aggressive behavior. Fire ants respond rapidly to any disturbance.

A single fire ant can sting their target repeatedly, and sev-eral or even dozens of ants may be on a person before the ants begin to sting. Fire ants inject a dose of venom that causes a burning sensation and skin blistering at the sting site. If not kept clean, these blisters can become sites of secondary infection. Some people stung by fire ants may be allergic to the venom. Allergic reactions can vary, but may include chest pains, nausea, dizzi-ness, shock, or in rare cases, coma.

Every year deaths have been documented as having been caused by fire ant stings but these cases are extremely rare.

To prevent the spread of fire ants to uninfested areas, the U.S. De-partment of Agriculture’s (USDA) Animal and Plant Health Inspec-tion Service (APHIS) requires that most nursery stock and other items likely to carry the pests be inspected and/or treated before traveling from fire ant–infested areas to fire ant–free areas. Regu-lated articles include soil, potted plants (except house plants main-tained indoors and not for sale), grass sod, baled hay, straw that has been stored in contact with the soil, and used soil–moving equipment.

Currently, pine straw mulch is not specifically included as a regu-

lated article and no treatment to remove all fire ants in this type of mulch currently exists. However, the risk of imported fire ants in pine straw is real. Several States

have reported to APHIS the pres-ence of fire ants in pine straw mulch. These States also have reported that employees and cus-tomers of retailers have been stung by fire ants while handling this mulch.

APHIS takes these reports very seriously, and is in the planning stages to revise the fire ant quar-antine regulations to address pine straw mulch. However, before the new regulations can be written, APHIS needs a better under-standing of the pine straw indus-try and the types of treatments that the industry can be reasona-bly expected to implement. APHIS intends to gather much of this information through discussions with pine straw producers, retail-ers, and transporters. APHIS also intends to issue an Advanced No-tice of Proposed Rulemaking solic-iting input and guidance on these issues.

The rulemaking process can be lengthy. Therefore, APHIS en-courages pine straw retailers to be aware of the potential hazards of pine straw and to look forward to being part of the rulemaking proc-ess. Throughout the rulemaking process, there will be several op-portunities for public comment.

Should you find fire ants in a pine straw shipment please contact Joe Collins at (859) 257-5838 or joe.collins@uky.edu or the USDA–APHIS State Plant Health Direc-tor (502) 228-8224.

For more information regarding the imported fire ant Federal quarantine, please visit the Plant Protection and Quarantine Web site at www.aphis.usda.gov/ppq/ispm/fireants/index.html.

A map of the areas quarantined for imported fire ant may be found on the web at www.aphis.usda.gov/ppq/maps/fireant.pdf

Pine Straw (con’t) PAGE 2 INSPECTOR FINDINGS IN KENTUCKY VOLUME IX, ISSUE 1

With the Spring Equinox upon us, buds are swelling and leaves will soon begin to emerge on landscape trees and shrubs. These few weeks before leaf emergence provide a good opportunity to prune-out diseased, dying, and dead twigs and branches to improve plant appearance, to re-duce disease spread, and reduce pathogen inoculum. Canker dis-eases on twigs and branches may be easier to see now before emerging foliage obscures them. For some canker diseases, pruning while the plant is still dormant may be the last opportunity to prune without danger of spreading the disease.

What are cankers? Cankers are localized dead areas of twigs, branches, limbs, trunks, and even roots of woody plants. They are of-ten caused by invasion of bark or cambial tissues by fungi or bacteria which then kill phloem, cambium, and the outermost xylem. The bark in an infected area may shrink, crack, and expose the wood beneath. Canker diseases often girdle the in-fected branch, causing the entire branch to die. Infection occurs through wounds such as mechanical injuries, leaf and fruit scars, branch stubs, and cold-injured or sun-scalded tissues. Many fungi and bacteria that cause cankers nor-mally inhabit the surface of the tree, or possibly exist inside the tree as latent pathogens, and only cause disease when the tree is under stress. However, some fungi and bacteria aggressively attack trees and cause cankers. Cankers, or dead areas on the bark not involving pathogenic microbes, can also be caused by mechanical injuries such as hail, heat, or cold.

Perennial cankers. Target-spot cankers caused by fungi such as Nectria or Eutypella on hardwoods are roughly circular or elongate with much callus at the canker edges.

Wounds and branch stubs are in-vaded by the fungus during the tree’s dormant period. The plant forms callus around the infection site during the growing season, but the fungus invades more tissue the following dormant period. This back-and-forth struggle between the tree and the pathogen creates concentric ridges of callus tissue. Although infection spread is rela-tively slow and target cankers sel-dom kill the tree, they do weaken the tree structure and detract from its appearance.

Annual cankers. Weak parasites normally don’t cause disease prob-lems unless the tree is under envi-ronmental stress and low in vigor. Infection occurs during the dor-mant season, but during the grow-ing season host callus tissue walls off the canker and prevents further spread. Although annual cankers do not persist, continued stress makes it likely that more cankers will form and it opens the possibil-ity of invasion by other diseases.

Diffuse cankers. Fungi such as Cytospora, Botryosphaeria, Hy-poxylon, Phytophthora, or Cry-phonectria (chestnut blight) and bacteria such as Erwinia (fire blight) produce cankers with little callus at the margins. Because the pathogens invade so rapidly, the tree tissue at the canker margin is killed and branches or whole trees are girdled and killed, sometimes in one season. Some diffuse can-kers are favored when the tree is under stress, but most are not. Canker blights are diffuse cankers in which the disease develops rap-idly and kills collateral branch and foliage tissue by way of girdling; canker-rots are diffuse cankers that cause significant internal wood decay.

Common fungal cankers in Ken-tucky include:

- Botryosphaeria canker of many kinds of trees and shrubs, - Cryphonectria canker of chestnut (chestnut blight),

- Cytospora (Leucostoma) canker of fruit trees and spruce trees, - Discula canker of dogwood (dogwood anthracnose), - Hypoxylon canker of oaks, - Nectria canker of many kinds of trees, - Phomopsis canker of a variety of trees and shrubs, - Seridium canker of Leyland cypress, - Sphaeropsis canker of Austrian and Scots pines (pine tip blight disease), and - Thyronectria canker of honey locust and other woody plants. In Kentucky, pine tip blight, dogwood anthracnose, and chestnut blight are observed to kill trees or at least cause significant dieback. The most common bacterial canker occurs mainly on ap-ple, crabapple, pear and flowering pear and is caused by Erwinia, the fire blight bacterium.

Canker disease management. For canker disease management, integra-tion of several cultural practices may be needed.

- Inspect woody plants in the nursery and landscape for cankers. Look for: dead twigs and branches, especially the area between diseased and healthy tissue, localized areas of roughened or cracked bark, especially around wounds and branch stubs; ridges of callus formation; small red, dark brown, or black pimple-like fungal fruiting bodies in the center of, or around the edges of, the cankers. - Prune-out cankers during dry weather, preferably when trees are dormant, and avoid pruning during the growing season when canker fungi may be active. When pruning, be careful to avoid damage to the branch collar. - Plant well-adapted species and culti-vars, matching the plant with the site. Use proper transplanting techniques. Promote tree vigor so that the tree’s natu-ral resistance to disease can be expressed and wound healing can begin promptly and develop rapidly. Apply mulch, water plants during dry periods, and aerify com-pacted soil. Apply fertilizer only where there is a known mineral element defi-ciency. General fertilization, especially with nitrogen, can make some canker diseases worse. - Control weeds and other competitors, but avoid herbicide injury. - Prevent mechanical injury. - Protect trees from defoliating insects and diseases. - Remove trees weakened by cankers.

Prune-Out Canker Diseases John Hartman, Extension Plant Pathologist, Univ. of Kentucky

PAGE 3 INSPECTOR FINDINGS IN KENTUCKY VOLUME IX, ISSUE 1

Calendar for Common KY Shade Tree & Woody Ornamental Pests Lee Townsend, Extension Entomologist, Univ. of Kentucky

This calendar shows many of the common insects and mites that feed on shade trees and woody ornamentals in Kentucky. It should be helpful in anticipating pest activity or in identifying po-tential pests when trying to diag-nose problems during the season. The pests are listed alphabetically by month, in most cases with in-formation on where to look for them (usually on the foliage). For

pests such as scales and borers, there is information on when the vulnerable stage is active rather than when the more visible adults are present. The “When to look” column indicates when the feed-ing stages should be present. Pests with multiple generations appear more than once on the cal-endar. This PUBLICATION (Click Here) has been prepared to serve as an aid in evaluating landscape plantings for pests, it is not in-tended to be a spray schedule.

The geographical and seasonal weather variations across Ken-tucky will result in pests appear-ing sooner or later in a particular year. Both plant and insect devel-opment are temperature-

dependent so seasonal appearance of particular pests should follow a predictable sequence that corre-lates with the flowering of par-ticular landscape plants. More accurate predictions can be made by using ENT-66, “Timing control actions for landscape insect pests using flowering plants as indica-tors”. The information in ENT-66 will help you to know when to check plants for pests and to schedule control measures more effectively. ENT-66 can also be found in the May 1997 and April 2000 Inspector Findings Newslet-ters. These may be viewed on-line at www.uky.edu/Agriculture/NurseryInspection just click on the newsletters button.

As the largest aphid in North America, the giant bark aphid comes by its name legitimately. It is found over most of the US and can develop on basswood, hickory, oak, pecan, sycamore, and walnut. Typically, aphids feed on terminal leaves but giant bark aphids feed through the bark on twigs and branches. Colonies are most no-ticeable during the cool weather in the fall and spring. These sap feeders excrete large volumes of

sugar-rich waste (honeydew). The sticky honeydew

accumulates on limbs or objects beneath the infestation and can support the growth of a blackish sooty mold. Abnormally black limbs or branches can be the first visible sign of giant bark aphids. Usually they do not cause serious damage but feeding by large num-bers of them can kill individual twig or branches.

These aphids occur in clusters or colonies. Wingless forms of the aphid are about 1/4inch long and

light to dark brown with some black spots. The winged forms have dark head and thorax. Much of the abdomen is white with 2 rows of black spots. Identification isn't much of a problem.

Lady beetles and other natural enemies can keep this aphid in check when temperatures are warm but cool temperatures slow them down and surviving aphids can thrive. Direct application of insecticidal soap can be effective but repeated applications may be needed.

That’s One Big Aphid! Lee Townsend, Extension Entomologist, Univ. of Kentucky

PAGE 4 INSPECTOR FINDINGS IN KENTUCKY VOLUME IX, ISSUE 1

Growers of Heuchera should be monitoring plants for rust. The rust is commonly associated with cooler temperatures in the spring and growers should be examining the underside of leaves for the presence of raised, brownish blis-ter-like pustules. As the pustules grow older, they will create chlorotic spots on the upper surface of the leaf, which may also drop out of the leaf, leaving a hole. Leaf pus-

tules contain spores that are spread by air movement. Rust can be introduced by infected plant material, so monitor incoming plants closely for symptoms. The fungal pathogen Puccinia heucherae, which causes this rust, is specific to Heuchera and Saxi-fraga.

Control in the greenhouse can be aided by increasing the day tem-perature to above 70°F and the night temperature to about 60°F. Raising the temperatures for a week combined with a spray treat-ment is usually enough for control.

An effective spray program is to clear the infection in the beginning with Zerotol, then alternate be-tween Contrast, which is both and eradicant and a protectant, and then use a mancozeb product. If possible, clean up infected leaves to reduce spread of the spores. This program also works for most other types of rust.

Like many diseases, rusts spread rapidly and the key to control is scouting and identifying the patho-gen before the spots show up on the top of the leaf.

Watch For Rust on Heuchera

PAGE 5 INSPECTOR FINDINGS IN KENTUCKY VOLUME IX, ISSUE 1

Homeowners sometimes ask: What is that profuse, greenish, crusty stuff growing on my tree a disease? Is that crusty, green or gray mate-rial that covers the bark of tree trunks and branches going to harm the tree? What are those leathery things covering the tree bark? The short answers are that the grayish-green crusty things are lichens and that lichens are not tree parasites.

Lichens often appear as a perennial green or gray coating on the trunks and branches of trees. They are actually two organisms in one, be-ing composed of a fungal body har-boring green or blue-green algae, which live together in complete harmony. In the symbiotic rela-tionship, the algae, through photo-synthesis, supply carbohydrate food to the fungus and, in turn, receive protection and trapped water and mineral elements from the fungus. In this relationship, the algae and the fungus are not distinguishable

except with a microscope, and the lichen persists longer than the alga or the fungus would sepa-rately.

Lichens do not parasitize trees, but merely use the bark as a me-dium on which to grow. In fact, lichens can be seen growing on rocks, weathered lumber, or on dead branches fallen from the tree. Some may consider lichens unsightly, but they are not gener-ally injurious except that, when extensive, they may interfere with the gaseous exchange of the parts they cover. Because of their ex-treme sensitivity to sulfur dioxide air pollution, lichens seldom ap-pear on trees in industrial cities. They rarely develop on rapidly growing trees, because new bark is constantly being formed before the lichens have an opportunity to grow over much of the surface. Because of this, lichens on certain species may indicate poor tree growth. We have noticed that in some plantings, those trees that are more vigorous have fewer li-chens than those of the same age nearby in a state of decline. Few studies have been conducted to verify any correlation between

lichen growth and tree vigor.

Lichens on trees take on various forms. Some are closely ap-pressed to the bark surface and are described as crustose. Lichens which are foliose have leaf-like lobes which extend out from the bark surface. Others have hair-like or strap-like forms and are referred to as fruticose lichens. Lichen color may include forms that are green, blue-green, yellow-green, brown, gray, or even red. Increases in lichens are some-times associated with moist cli-mate - perhaps the relatively moist weather of the past two summers accounts for increases in lichen questions. Lichens prolifer-ate when more light is provided, which could explain why they are more frequently seen on dead, leafless branches.

As a rule, lichens can be eradi-cated by spraying the infested parts with Bordeaux mixture or any ready-made copper spray. Read the fungicide label to be sure that this use is permitted for the product chosen. However, sup-pression of lichens with chemical sprays should not be expected to improve tree health.

Lichens Infesting Tree Trunks and Branches John Hartman, Extension Plant Pathologist, Univ. of Kentucky

Plant parasitic nematodes are mi-croscopic worms that are usually found in the soil attacking plant roots. There are some nematode species, however, that can cause damage on aboveground plant parts. Foliar nematodes (Aphelenchoides spp.) have be-come a more common pest in her-baceous perennials over the past few years. Foliar nematodes move in films of water on plant surfaces and enter leaf tissues through natural openings in leaves called stomates. Like root-attacking nematodes, foliar nematodes have

a needle-like structure called a stylet that they use to pierce plant cells and feed on the cell contents, resulting in cell death. Lesions caused by foliar nematodes are first chlorotic, then necrotic. Movement of the nematodes within leaf tissues is restricted by larger leaf veins, which gives the lesions their typical angular shape.

Foliar nematodes overwinter in plant debris. They survive for long periods of time in leaf tissues, and are spread by propagating in-fested plants and by splashing water (rainfall, overhead irriga-tion). The list of plants suscepti-ble to foliar nematodes is quite large, and includes woody plants

like azaleas as well as numerous herbaceous perennials (such as hosta, hellebores, ferns, begonias, salvia, anemone). The easiest way to manage foliar nematode problems is to avoid introducing the pest into the garden. Carefully inspect plants for foliar nematode symptoms before purchasing. If symptoms develop, remove and destroy affected plants. Do not put affected plants in a compost pile, since the nematodes can survive in plant debris and may be re-introduced to the garden from this source. Commercial growers can use chemical treatments for con-trolling foliar nematode, but there are no effective pesticides avail-able to homeowners.

Foliar Nematodes Karen Rane, Plant Disease Diagnostician, Department of Botany & Plant Pathology, Purdue University

S-225 Agricultural Science Center - North Lexington, Kentucky 40546-0091

OFFICE OF STATE ENTOMOLOGIST

State Entomologist— John Obrycki, Ph.D

Joe Collins, Nursery Inspections, newsletter, pest surveys & phytosanitary certificates

Carl Harper, Slow-the-Spread gypsy moth trapping coordinator, nursery inspections, web design, &

phytosanitary certificates

Phone: (859) 257-5838 Fax: (859) 257-3807

Email: joe.collins@uky.edu carl.harper@uky.edu

We’re on the web! www.uky.edu/Agriculture/

NurseryInspection

Our office along with the Depart-ment of Plant Pathology will be conducting a survey for Sudden Oak Death again this year. Nurs-eries and dealers that import plant material from the west coast will be visited during April, May and June, if necessary, to collect samples from suspect looking plants. Last year we visited over 120 businesses and inspected more than 35,000 plants. 65 ELISA and 126 PCR tests were performed. 18 positive samples were sent to the USDA laboratory for confirmation. After DNA se-quencing was preformed, it was determined that Sudden Oak Death was not present in any of the samples.

The Department of Plant Pathology will also be conducting a survey of Kentucky forests this year to make sure the disease is not present there. Updates will be posted in

this newsletter throughout the year.

Degree Day Totals One very important fact to re-member is that degree days can vary widely across the state. Cal-culating degree days for your local area is the best way to prepare for spray programs.

Degree Day Totals through March 24, 2005

Bardstown—73 Bowling Green—108 Covington—41 Henderson—87 Huntington WV—91 Lexington—67 London—82 Louisville—66 Mayfield—69 Paducah—115 Princeton—94 Quicksand—86 Somerset—77

Degree Day Totals through March 26, 2004

Bardstown—94 Bowling Green—134 Covington—60 Henderson—116 Huntington WV—100 Lexington—84 London—105 Louisville—87 Mayfield—103 Paducah—152 Princeton—148 Quicksand—96 Somerset—116

Kentucky Sudden Oak Death Survey