• 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 XI, Issue 1 April 2007 Pests susceptible to control-

based on degree day forecasts

( )=Degree day ranges

Offi ce o f State Entomologist

Twig Blights of Juniper Pg 2

Disarm® - A new fungicide for Turf Disease Control

Pg 2

Common Maple Galls Pg 3

Spruce Spider Mite Pg 4

Maple Petiole Borer Pg 5

Cankerworms Pg 5

Calendar for Common KY Shade Tree & Woody Ornamental Pests

Pg 6

Degree Day Targets Pg 8

Western Kentucky Inspector Leaves

Pg 8

Canada Shipments Made Easier

Pg 8

Inside this issue:

Maple spindle gall

Above: Spruce spider mite damage;

Right: Euonymus scale

Maple bladder gall

Above: European pine sawfly larvae Below: Holly leafminer (photo by M. Masiuk, Penn St)

Left: Pine needle scale; Right:

white pine aphids

PAGE 2 INSPECTOR FINDINGS IN KENTUCKY VOLUME XI , ISSUE 1

Twig and branch dieback is a com-mon sight in many juniper plantings in Kentucky. While other factors can cause these general symptoms, two fungal diseases are frequently re-sponsible for the dieback.

These fungi (Phomopsis junipero-vora and Kabatina juniperi) attack several species of Juniperus, includ-ing red cedar, common juniper and creeping juniper. Arborvitae is also susceptible.

Phomopsis Twig Blight

Symptoms:

This disease begins as a foliar in-fection which then spreads to and kills stem tissues. Newly developing needles in the yellowish-green stage are especially susceptible, while more mature, darker green needles are not. Phomopsis blight can occur during the growing sea-son anytime there is new shoot growth. Symptoms are evident a week or two after infection. When the fungus invades young stem tis-sue, terminals and branches distal to the point of infection become light green, red- brown and finally ashen-grey.

Small branches up to 1 cm in di-

ameter are generally girdled by the disease. When a side shoot is in-fected, Phomopsis may progress to a main branch. Lesions on larger branches, however, develop into cankers but they seldom girdle the branch.

Fungal fruiting bodies (pycnidia) develop within 3 to 4 weeks after infection. Well- developed pycnidia can be found on needles and twigs that have dried up and turned grey. The pycnidia appear as tiny black specks at the base of the infected portion.

Disease Management

1. Use regular, season-long appli-cations of benomyl or fixed copper to protect twig tips from infection. Weekly applications are generally needed as long as there is new shoot growth occurring.

2. Prune out and destroy infected twig tips. Pruning should be done when the twigs are dry in order to minimize the spread of fungal spores.

3. Overhead irrigation should be done early enough in the day that water has a chance to evaporate from the foliage prior to sunset.

4. Avoid planting highly susceptible cultivars. Instead, select varieties that are known to be resistant to Phomopsis.

Kabatina Twig Blight

Symptoms:

This twig blight disease causes symptoms very similar to those due to Phomopsis. Kabatina fruiting bodies (acervuli) are also produced at the base of infected tissues. The acervuli are initially white to grey in color, later becoming black.

Disease Management

1. Prune out and destroy infected twig tips. Pruning should be done when the foliage is dry in order to minimize fungal spread.

2. Use an approved insecticide to control insect pests. It is possible that insects, such as the juniper midge, create the wounds neces-sary for Kabatina infections.

Which is Which??

Because the diseases are so simi-lar in appearance, the time of symp-tom development can be helpful in distinguishing between the two. Ka-batina twig blight symptoms de-velop early in the spring before new growth begins, presumably as the result of infections that occurred the previous summer or fall. Phomopsis twig blight symptoms, on the other hand, can develop any time during the growing season. If twig blight symptoms are evident in the spring on junipers that appeared healthy in the fall, Kabatina is likely responsi-ble.

Twig Blights of

Juniper John Hartman & Brian Eshenaur, Dept. of

Plant Pathology, Univ. of KY

Disarm® 480 SC fungicide (containing the active ingredient fluoxastrobin) is a relatively new systemic QoI fungicide for turf dis-ease control from Arysta Life Sci-ence. The QoI family of fungicides currently sold for turf disease con-trol are chemically classified as strobilurin fungicides, and readers may know them by that name. This

fungicide family includes Heritage® (azoxystrobin), Compass® (trifloxystrobin), and Insignia® (pyraclostrobin).

Diseases Controlled

Disarm® is labeled for control of a wide variety of diseases. The sym-bol (*) indicates that the disease is important in Kentucky turfgrass; (º) indicates the disease occurs in Kentucky but rarely warrants fungi-cide treatment.

-Anthracnose (*) -Brown patch (*) -Cool-weather brown patch (=yellow patch) (*)

-Fusarium patch (=Microdochium patch) (*) -Gray leaf spot (*) -Leaf spot caused by Bipolaris so-rokiniana (*) -Melting Out caused by Drechslera poae (*) -Pink patch (º) -Pink snow mold (*) -Typhula blight (º) -Pythium blight (*) -Pythium root rot (*) -Red thread (*) -Southern blight (º) -Spring dead spot (*) -Summer patch (*) -Take-all patch (*) -Target spot (con’t)

Disarm®, A New

Fungicide For Turf

Disease Control Paul Vincelli, Extension Plant Pathologist,

Dept. of Plant Pathology, Univ. of KY

PAGE 3 INSPECTOR FINDINGS IN KENTUCKY VOLUME XI , ISSUE 1

Common Maple Galls Lee Townsend, Extension Entomologist

Dept. of Entomology, Univ. of KY

Galls are irregular plant growths which are stimulated by the interac-tion between plant hormones and growth-regulating chemicals pro-duced by some insects and mites. The maker receives food and pro-tection from the gall tissue. Gall populations fluctuate from year to year, occasionally becoming very abundant. Despite the aesthetic impact and premature leaf drop dur-ing outbreaks, tree vigor is not af-fected significantly.

Gall makers must attack at a par-ticular time in the year to be suc-cessful. Otherwise, they may not be able to stimulate gall production. Generally, initiation of leaf galls oc-curs around "bud break" or as new leaves begin to unfold in the spring. Once the symptom or gall appears, the organism is protected in the structure, making remedial actions ineffective.

Several types of mites can cause maples to produce three types of galls:

·rounded bladder galls,

·narrow spindle galls, and

·felt-like erineum galls

Most galls occur on early spring foliage that develops near the trunk and on larger branches. Additional galls are formed on newly develop-ing leaves later in the summer but mites are most active early in the season. Galls usually form on a small proportion of the leaves and tree health is unaffected.

Maple Bladder Galls

Maple bladder galls occur on silver and red maples. They are irregular, spherical growths that are usually found on the upper surfaces of the leaves. These hollow, purple-green to red structures are attached to the leaves by short hollow stems. Large numbers may cause infested leaves to "cup" and to drop prematurely. The single mite inside each gall feeds and lays eggs. Activity usu-ally ends in July and the mites pass the winter under bud scales, mov-ing back to leaves as they open in the spring. An application of car-baryl (Sevin) or chlorpyrifos (Dursban) to the lower leaf surface when the leaves are about 1/4 ex-panded and again 10 days later may reduce infestations.

Felt or Erineum Galls

Felt or erineum galls are produced by several species of mites. These appear as light green to yellow-

green velvet-like patches on the underside of leaves.

Maple Spindle Galls

Maple spindle galls occur most fre-quently on the upper surface of sugar maple leaves. The life cycle is similar to that of the maple blad-der gall.

Eyespot Midge Gall

The most striking gall on red maple, and occasionally sugar and silver maple, is caused by a small fly (midge). The small fly lays its eggs in the undersurface of leaves. The maggot that hatches from the egg develops quickly, producing a growth regulating-hormone which causes the development of bright red and yellow rings around the gall, usually in June. The 1/4" di-ameter area later turns brown. The maggot inside the gall completes its development in about 10 days. It then drops to the ground to pupate and transforms into the adult. There is one generation each year.

Application of some formulations of carbaryl (Sevin, etc) are labeled for control of mites on shade trees. However, because the galls do not affect tree health, applications are not necessary.

Efficacy There isn’t much readily accessible data at this point on efficacy of this fungicide. Prior to 2006, a variety of tests were conducted at universi-ties under a code name; in these tests, almost all of the diseases listed above were tested at least once. However, the full reports of these tests are unavailable to me at this time. Extensive university test-ing was conducted with Disarm® last season, and those tests are soon to be published. Thus, I’ll be soon able to form a clearer picture of the efficacy of the product.

Resistance Management There are very specific use guide-lines on the Disarm® label relating

to reducing the risk of fungicide re-sistance. Resistance to QoI fungi-cides has been reported in gray leaf spot, anthracnose, and Pythium blight, and I don’t think it is overly pessimistic to predict that other dis-eases will develop resistance with continued use of these fungicides. Therefore, it is important to pay close attention to the use restric-tions on the Disarm® label as well as the labels of all QoI fungicides. Any time you apply fungicide which is at-risk for the development of resistance, you run the risk that you are selecting resistant biotypes of the pathogen. You cannot prevent the development of resistance if you are using the chemical. All you can hope to do is reduce the risk that the resistance will develop.

The label guidelines are based on sound biological principles and will help reduce that risk.

Disarm® con’t

PAGE 4 INSPECTOR FINDINGS IN KENTUCKY VOLUME XI , ISSUE 1

Species: Oligonychus ununguis (Jacobi)

Distribution: Worldwide

Hosts:

In spite of its name, this pest at-tacks over 40 species of conifers. This includes all trees used in Christmas tree production as well as juniper, arborvitae, hemlock and yew (Taxus).

Damage:

Spider mites have tiny mouthparts which are often grouped in the sucking category along with sucking insects. This is not exactly correct, though these mites are capable of inserting their mouthparts into plant tissues and withdrawing fluids. This causes yellowish spots to occur on the needles. Extensive feeding re-sults in "bronzing" of the foliage and premature needle drop.

Description and Life Cycle:

This mite is closely related to other true spider mites, such as the Euro-pean red mite and twospotted spi-der mite. They have egg-shaped bodies which are only 1/64-inch long or less. In the field, they ap-pear to be an olive-green color with reddish-yellow legs. Like all spider mites, the nymphs and adults have four pairs of legs rather than the three pairs found on all insects. Un-der a microscope, two red eye spots can be seen and a paler stripe is evident along the back. The larvae which hatch from eggs are almost spherical in form and only have three pairs of legs.

Spruce spider mites are considered to be "cool season" mites. That is, they seem to do best during the spring and fall seasons when tem-peratures are in the 60's and low 70's F. In hot, dry summers, this mite becomes dormant and preda-tors take their toll. Spruce spider mites overwinter in the egg stage attached near the base of needles. These eggs can hatch as early as

mid-March but most hatch by mid-April. The larvae feed on needles and molt within a few days into the first stage nymphs, called proto-nymphs. The protonymphs gain a pair of legs and continue to feed for a week. The protonymph rests for a day or two before molting into the second stage nymph, the deuto-nymph. Again the deutonymphs feed for a week to ten days before settling again to molt into the adults. The adult female has a rounded abdomen while males are smaller and have pointed abdomens. The entire development time from egg to adult can take from 11 to 24 days, depending on the tempera-ture. Usually six or more genera-tions are common in a season and each female can lay up to 25 eggs in 8-10 days. By late spring, all stages are common and genera-tions overlap considerably. When temperatures consistently reach the upper 80's or 90's F, this mite tends to lay over-summering eggs. Activ-ity often doesn't return until the fall. When summers are cooler than normal, this mite remains active. Conifers seem to react slowly to spider mite attack. The yellow speckles and bronzing may not be evident until hot weather occurs. Therefore, much of the damage which becomes very visible in June and July actually occurred the pre-vious fall and spring.

Control Hints:

Since the damage caused by this pest usually doesn't appear until the populations are beginning to de-cline from high summer tempera-tures, constant monitoring is needed to detect damaging popula-tions. Sample for this pest by taking a white colored piece of cardboard or a white tray and hold it under a branch. Strike the branch sharply three or four times with a stick so as to dislodge the mites off the foliage. Wait for about 10 seconds and pour off any of the dirt, loose needles and other trash. The spider mites will remain and will appear as tiny black or olive-green specks walking slowly on the tray. Other mites may be present which do not damage

conifers. In order to distinguish these, crush one of the suspected mites in a streak. If the streak is greenish, the mites are probably spruce spider mites. If the streak is black, brown or reddish, the mites are probably scavengers or benefi-cial mites.

Option 1: Biological Control - En-courage Natural Predators and Parasites - There are numerous predators of spruce spider mites. These include lady beetles and their larvae, predatory mites and dusty wings (a relative of the lace-wing). These predators often do a good job during the warmer months. Therefore, be sure to spray for spruce spider mites early or late in the season when the predators are at lowest numbers. Too many growers spray during the summer when the damage becomes visible and the mite populations are declin-ing.

Option 2: Chemical Control - Dor-mant Oil Sprays - Since these mites overwinter as eggs, dormant oil sprays (3-5%) applied in late fall and early spring can greatly reduce the mite population. Hydraulic sprayers are suggested in order to obtain thorough coverage. Remem-ber that oil sprays on glaucous trees will remove the silvery blush and turn the foliage dark green.

Option 3: Chemical Control - Horti-cultural Oil and Soap Sprays - Hor-ticultural oil (1.5-2%) and insecti-cidal soaps have been very effec-tive in controlling this pest in the spring and fall. Refer to the caution on foliage color above.

Option 4: Chemical Control - Stan-dard Miticide Sprays - Registered miticides are most effective if ap-plied in the early spring, usually before mid-May, or in the fall, after mid-September. If damage is de-tected in June or July, be sure to sample first in order to determine if the mites are active.

Spruce Spider Mite David Shetlar, Ohio State University

Christmas Tree Fact Sheets

Spruce spidermites can

web over foliage if not disturbed for a considerable time

The maple petiole borer, Caulo-campus acericaulis (MacGillivray), was first introduced into the United States from Europe. This sawfly is wasp-like in appearance and is rarely seen because of its small size. Although several species of maple are subject to attack by this insect, sugar maples are preferred.

Life Cycle

Adult sawflies emerge in early to mid-April. After mating, the female uses her ovipositor (egg-laying structure) to puncture the petioles and lay a single egg near the leaf blades. The larvae are yellowish and smooth with brownish heads. Larvae are weevil-like in appear-

ance because the abdominal legs are very small. Full-grown larvae are one-third inch long. After hatching, larvae tunnel and con-sume the contents of the petioles about one-half inch from the leaf blade.

Early larval activity results in dis-coloration of the upper portion of the petiole. This area later be-comes black and shrunken. The attached leaf shrivels and changes color. After a short period of time, the petioles break and damaged leaves fall to the ground (during late April to May). Larvae continue to feed in the portion of the petiole remaining attached to the twig for seven to 10 days. Larvae drop to the ground, burrow down 2 to 3 inches into the soil and overwinter.

In the spring, mature larvae pupate and emerge as adults in early to mid-April. There is one generation a year.

Control

Defoliation seldom exceeds a third of the total foliage. Damage of this type causes considerable concern to the homeowner. However, the leaf drop seldom causes injury to the tree and control recommenda-tions are usually not warranted.

Some of the maple petiole borer damage can be prevented by apply-ing Scimitar, Talstar, Tempo, De-cathlon, Bayer Advanced Rose & Flower Insect Killer, or Tempo SC Ultra sprays to the foliage in mid-April.

Maple Petiole Borer Frank Hale, University of Tennessee

PAGE 5 INSPECTOR FINDINGS IN KENTUCKY VOLUME XI , ISSUE 1

Cankerworm is the general name given to a group of inchworm cater-pillars that feed on deciduous trees and move with a distinctive crawl. A reduced number of fleshy legs on the abdomen gives these caterpil-lars a unique looping gait. Most cankerworms have five pairs of fleshy abdominal legs compared to six on the typical caterpillar. The

spring cankerworm has two pairs of prolegs and a single stripe alone the side while the fall cankerworm has three pairs of legs and three stripes. The color of both species is variable.

Cankerworms are present every year, usually the damage goes un-noticed and healthy trees are not

harmed by light feeding. However, damaging outbreaks occasionally occur and can continue for two to three seasons. Feeding begins in early spring as leaves start to ex-pand and continues for three to four weeks. These caterpillars eat elm, apple, oak, and many fruit and shade trees, consuming entire leaves and leaving only the large veins. The greatest feeding occurs about the time the leaves become fully developed. Trees may be completely stripped of leaves dur-ing outbreak years and may be stressed or weakened as they use reserves to refoliate. Full grown cankerworms either crawl or drop to the ground on silken threads and pupate in the soil. There is one generation each year.

Generally, is is not practical to control cankerworms in forests and woodlots but homeowners may choose to protect landscape trees from defoliation. If an outbreak can be anticipated, tanglefoot applied to tree trunks in a band two to four feet aboveground will prevent fe-male moths from crawling up and laying eggs in the trees. This tech-nique may be preferred to insecti-

cide sprays, especially when dealing with very large trees. Insecticides labeled for caterpillar control on shade trees should be applied be-fore most larvae are more than one inch long.

Cankerworms Lee Townsend, Extension Entomologist,

Dept. of Entomology, Univ. of KY

Picture courtesy of James B. Hanson, USDA Forest Service

http://www.uky.edu/Ag/Entomology/entfacts/trees/ef447.htm

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

PAGE 6 INSPECTOR FINDINGS IN KENTUCKY VOLUME XI , ISSUE 1

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

Janet Lensing, Nursery Inspections, Cooperative Ag. Pest

Survey Coordinator

Phone: (859) 257-5838

Fax: (859) 257-3807

Email: joe.collins@uky.edu

carl.harper@uky.edu

janet.lensing@uky.edu

We’re on the web!

www.KyStateEnt.org

Terri Gater, the inspector for Western Kentucky, has resigned to take a position as an Agricultural Inspector with the Department of Homeland Security, Customs and Border Pro-tection. She will be working at the Northern Kentucky/Cincinnati Airport.

Our intent is to refill the vacant posi-tion as soon as possible.

Canada Shipments

Made Easier Canada has revised the Japanese beetle requirements for shipping into Canada. Shipments can now be made into Ontario and Quebec Prov-inces without Japanese beetle treat-ments. A phytosanitary certificate is still required. There will be more about Japanese beetle regulations in the next issue.

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

Degree Day Totals through March 27, 2007

Bardstown—204

Bowling Green—237

Covington—148

Henderson—162

Huntington WV—204

Lexington—182

London—238

Louisville—184

Mayfield—181

Paducah—229

Princeton—254

Quicksand—176

Somerset—172

Degree Day Totals through March 27, 2006

Bardstown—110

Bowling Green—173

Covington—58

Henderson—116

Huntington WV—116

Lexington—93

London—138

Louisville—104

Mayfield—113

Paducah—179

Princeton—193

Quicksand—122

Somerset—96

Western Kentucky

Inspector Leaves