Buckeye Yard and Garden onLine

BUCKEYE YARD AND GARDEN LINE 2008-10

6/5/2008

From: Pam Bennett, Barb Bloetscher, Joe Boggs, Cindy Burskey, Jim Chatfield, Erik Draper, Dave Dyke, Gary Gao, David Goerig, Tim Malinich, Becky McCann, Amy Stone, and Curtis Young.

This is the 10th 2008 edition of the Buckeye Yard and Garden Line (BYGL). BYGL is developed from a Tuesday morning conference call of Extension Educators, Specialists, and other contributors in Ohio.

BYGL is available via email, contact Cheryl Fischnich [ This e-mail address is being protected from spambots. You need JavaScript enabled to view it ] to subscribe. Additional Factsheet information on any of these articles may be found through the OSU fact sheet database [ http://plantfacts.osu.edu/ ].

BYGL is a service of OSU Extension and is aided by major support from the ONLA (Ohio Nursery and Landscape Association) [ http://onla.org/ ] and [ http://buckeyegardening.com/ ] to the OSU Extension Nursery, Landscape and Turf Team (ENLTT). Any materials in this newsletter may be reproduced for educational purposes providing the source is credited.

BYGL is available online at: [ http://bygl.osu.edu ], a web site sponsored by the Ohio State University Department of Horticulture and Crop Sciences (HCS) as part of the "Horticulture in Virtual Perspective." The online version of BYGL has images associated with the articles and links to additional information.

Following are the participants in the June 3rd conference call: Pam Bennett (Clark); Barb Bloetscher (Entomology/C. Wayne Ellett Plant and Pest Diagnostic Clinic (CWEPPDC)); Joe Boggs (Hamilton/Piketon); Jim Chatfield (OSU Extension Center at Wooster/ Hort and Crop Science); Erik Draper (Geauga); Dave Dyke (Hamilton); Gary Gao (Delaware); Michael Loos (Cuyahoga); Tim Malinich (Lorain); Becky McCann (ABE Center); Dave Shetlar (Entomology); Amy Stone (Lucas); Nancy Taylor (C. Wayne Ellett Plant and Pest Diagnostic Clinic (CWEPPDC)); Shawn Wright (OSU Piketon Centers); and Curtis Young (Allen).

In This Issue:

1. WEATHERWATCH.

2. HORT SHORTS: GDD (Growing Degree Days); Very Patchy Frost; Periodic Blooms; Erratum; and Plants of the Week [Cape Daisy; False Indigo; Japanese Tree Lilac; Wild Parsnip]

3. BUGBYTES: A Periodical Update; The Leaves Have Eyes; and Bug Bytes [Pine Needle Scale; Bagworm; Pine Spittlebug; Spruce Spidermite; Arborvitae Spider Mite].

4. DISEASE DIGEST: Suspected Canna Yellow Mottle Virus (CAYMV); Verticillium Wilt; and Moist Chamber [Anthracnose Diseases; Oak Wilt, Botryosphaeria Canker on Juniper; Phomopsis Canker on Spruce; Volutella Leaf Blight and Stem Canker on Pachysandra; Phoma Dieback on Vinca, Downy Mildew on Rose; Phytophthora Canker of Viburnum,; Powdery Mildew of Callery Pear].

5. TURF TIPS: And …They're Off.

6. INDUSTRY INSIGHTS: Balsam Twig Aphid; Not the Ordinary Recommendations; and Sampling 101-3: Knowledge is Power.

7. COMING ATTRACTIONS: Cincinnati BYGLive! Diagnostic Walk-About

1. WEATHERWATCH. This week's weatherwatch takes a look back, beginning at the first of the year. The following weather information summarizes data collected at various OARDC Weather Stations spanning the dates January 1, 2008 - May 31, 2008, with the exception of the soil temperatures, which are readings from Wednesday, June 4 at 6:00 p.m.

For a link to the OARDC Weather Stations, visit: [ http://www.oardc.ohio-state.edu/centernet/weather.htm ]

2. HORT SHORTS.

A. GDD (GROWING DEGREE DAYS). GDD is a measure of the daily maximum and minimum temperature and directly relates to growth and development of plants and insects. The GDD of any zip code location in Ohio is estimated using the GDD of ten OARDC weather stations and available on the web at the site below.

The range of GDD accumulations in Ohio from north to south is 458 to 751. Following is a report of GDD for several locations around Ohio as of June 3, 2008: Painesville, 458; Cleveland, 481; Toledo, 519; Canfield, 484; Lima, 501; Wooster, 512; Coshocton, 556; Columbus, 651; Springfield, 530; Dayton, 543; Cincinnati, 674; Ironton, 710; Portsmouth, 714; and Piketon, 751.

To put these GDD accumulations into perspective, the following is an abbreviated listing of plant and insect species with their respective phenological event and average GDD accumulations at which these events occur. Due to variations in weather, temperature, humidity, etc., these events may occur a few days earlier or later than predicted by the average GDD. By looking at a city, town, or village near you from the above list, or visiting the above web site, you can see what could be taking place in the landscape around you.

Doublefile viburnum, full bloom, 444; black locust, first bloom, 467; common ninebark, first bloom, 478; oystershell scale, egg hatch, 497; smokebush, first bloom, 501; arrowwood viburnum, first bloom, 534; American yellowwood, first bloom, 546; bronze birch borer, adult emergence, 547; black locust, full bloom, 548; American Holly, first bloom, 556; mountain laurel, first bloom, 565; potato leafhopper, adult arrival, 568; juniper scale, egg hatch, 571; common ninebark, full bloom, 596; American yellowwood, full bloom, 599; arrowwood viburnum, full bloom, 621; multiflora rose, full bloom, 643; northern catalpa, first bloom, 675; black vine weevil, first leaf notching due to adult feeding, 677; Washington hawthorn, full bloom, 731; calico scale, egg hatch, 748; and greater peach tree borer, adult emergence, 775.

B. VERY PATCHY FROST. Last week’s forecast of patchy frost was just that, patchy. Tim Malinich reported that his pre-sunrise inspection of the neighborhood found frost, but only in small widely scattered patches. The roofs of compact cars (but not full size cars) parked in driveways were covered with a white coat of frost. Also, patches of frost a few feet across were found in only a few lawns and gardens. These small areas of frost scattered over a wide area could result in diagnostic challenges later this week. Small portions of gardens or landscapes might exhibit signs of frost damage - injury to fruit, flowers or leaves and future leaf expansion. As frost is generally seen as a whole-landscape incident, a patch of frost damage might be mistaken for damage from other factors.

C. PERIODIC BLOOMS. As noted in previous BYGLs and by almost everyone who has ventured outside this Spring - this is a tremendous seed and fruit year for many trees. We all tend to look for simple explanations for such phenomena, but in reality big fruit years can be due to a whole range of factors. Rather than focusing on just one, such as that the big seed year is an evolutionarily advantageous strategy of producing a “stress crop” of seeds by a declining tree, making lots of offspring in the face of the imminent death of the individual tree, realize that multiple things may be going on in landscapes and forests.

There is some evidence that stress crops are sometimes what is occurring. However, there are many other factors that also may be involved. For many trees, heavy “mast” years of heavy seed production actually occur in years after outstanding growing seasons. Excellent vegetative growth in a great growing season leads to enhanced photosynthesis and stored food production one year by the tree, providing the resources to have a great reproductive year the next growing season.

Additional possibilities abound. Sometimes there is a great seed production because there were no damaging frosts or freezes earlier in the season. Sometimes there is bad flower/fruit/seed production one year because of poor conditions for flower bud development during a critical droughty period the previous summer. Sometimes a great reproductive year depletes reserves for producing flower buds and subsequent fruits and seeds for the next season.

Many apples and crabapples are termed alternate bloomers on the basis of this tendency, some more strongly alternate than others. Sometimes this tendency is overcome. For example, at Secrest Arboretum for the past several years groups of three ‘Adirondack’ crabapples always had two that bloomed and fruited heavily while the third had light or non-existent bloom, with the reverse occurring the next year. This year, all three in the triads bloomed and fruited heavily. So, do not jump to a single conclusion as to the specific cause of heavy fruit years on different types of plant. Many factors may be involved and it is certainly not true that heavy fruiting automatically, or even usually, means that affected plants are stressed.

D. ERRATUM. There was an anachronistic mistake last week. As OSU-ATI’s Larry Steward sharply pointed out to Jim Chatfield, modern taxonomists tend to classify the genera Acer and Dipteronia not in the Aceraceae, but on technical characteristics now classify both genera in the Sapindaceae, or soapwort family. Larry’s pointed correction and sharp words are appropriate, as the Latin word “acer” means (sharp point) referring to the pointed lobes of many maple leaves. Wash Jim’s mouth out with soap!

E. PLANTS OF THE WEEK. Read all about perennials and landscape trees and shrubs in the ONLA publications "Perennial Plants for Ohio" and "Landscape Plants for Ohio." The descriptions and photographs of plants were provided for these publications by the OSU ENLT Team along with other industry plant lovers. These full-color publications are available at [ http://Buckeyegardening.com ] for $5.00. Click on "garden store" and then "ONLA plant guides." ONLA members can purchase these in quantities at a reduced price at [ http://onla.org ].

*ANNUAL PLANT OF THE WEEK. CAPE DAISY (Osteospermum spp.) Very few people knew about this plant 20 years ago and today it graces containers, hanging baskets, and garden beds with a multitude of colors with its bright daisy shaped blossoms. The colors are usually rose, purple, white, pink, peach, bi-color, and yellow. They prefer full sun to partial shade and are quite drought tolerant. They prefer cooler temperatures and bloom like crazy in the spring, sporadically in the summer, and return with a vengeance with cooler fall night temperatures. Varieties such as 'Soprano' are supposed to continue to bloom during the summer but in Ohio trials flower production is slower during the summer.

*PERENNIAL PLANT OF THE WEEK. FALSE INDIGO (Baptista australis) One of the first perennials to emerge in the spring, false indigo starts out with an asparagus-like appearance before the leaves unfold. Now the bluish foliage has unfurled, revealing a high-impact perennial that is making a bold blooming statement in perennial gardens in central Ohio this week. The indigo-blue pea-like flowers (legume family) are held on 12" long flower stalks above the plant and last for around 3-4 weeks. The plant itself is around 3-4' tall and as wide. Once blooms fade, attractive brown to black seed pods form and remain until a hard frost. The pods are excellent for dried arrangements or craft projects.

*WOODY PLANT OF THE WEEK. JAPANESE TREE LILAC (Syringa reticulate) is a very large shrub or small tree. Growing in full sun with moist, well drained, and slightly acid soil, it can reach 15-25' tall. Its showy creamy white flowers, borne in early summer, are the main ornamental feature. The flowers are clustered in large terminal panicles, 4-12" long and fragrant. Similar to other plants in the family Oleaceae, the Japanese Tree Lilac is subject to bacterial and fungal disease problems including; bacterial blight and canker, Gray Mold, Powdery Mildew, wood rots and decays. Borers and scale insects can attack, but this species is less troubled by them than other lilacs. A few cultivars worth selecting include: 'Ivory Silk'- Produces large clusters of creamy-white flowers produced when the plant is still young. 'Summer Snow'- A rounded form producing creamy-white flowers. 'Willamette' (Ivory Pillar TM) - A more upright and narrow cultivar that attains a nice pyramidal shape.

*THE WEEKLY WEED. Last week, POISON HEMLOCK (Conium maculatum) earned the status of Weekly Weed. This week, WILD PARSNIP (Pastinaca sativa) rises to the occasion. Both of these impressively tall non-native members of the carrot family (Apiaceae (= Umbelliferae)) are reaching their full height in southern and central Ohio, and both are nearly in full bloom. These weeds share the umbellate flower arrangement which looks like an upside-down umbrella that is characteristic of the family. However, wild parsnip has umbels topped with yellow flowers while poison hemlock has white flowers.

Wild parsnip plants can grow to impressive heights topping 8'. The weed is a native of Eurasia and has been gradually making its way into Ohio fields and landscapes. Some consider it to be highly invasive. Gardeners should exercise extreme caution around this plant; the plant's juices can cause phytophotodermatitis to the skin. If plant juices on the skin are exposed to sunlight, a severe rash or blistering can occur, as well as skin discoloration that may last several months.

Although wild parsnip is considered a perennial, it has an interesting life-cycle. The first year is spent as a rosette, with leaves confined to growing from a short stem only a few inches above the ground. While in this stage, the plant produces a long, thick taproot. During subsequent years, the plant will generate a single, thick, deeply ridged, greenish-yellow stem that sprouts lateral branches topped with hundreds of clusters of yellow umbellate flowers. Wild parsnip is a prolific seed producer, which is the primary means by which the plant spreads. Leaves are alternate, pinnately compound, branched, and have saw-toothed edges. Each leaf has 5-15 ovate to oblong leaflets with variable toothed edges and deep lobes.

Wild parsnip can be controlled by mechanical means, but with extreme care to avoid contact with the sap. Continual mowing will eventually cause plants to die, but it should be noted that mowers can release a significant amount of sap. Growth and establishment of young plants can be stopped by using a sharp shovel to cut the tap root below ground-level. This will prevent re-sprouting. Plants that are flowering can be cut, but they must be taken off-sight since seed will still develop and mature. Wild parsnip is also susceptible to glyphosate (e.g. Roundup). This may be the safest approach given the serious concerns with the sap.

3. BUGBYTES.

A. A PERIODICAL UPDATE. Joe Boggs reported that 17-YEAR PERIODICAL CICADAS (Magicicada spp.) are making their presence known in parts of southern Ohio. Males are beginning to "sing" loudly in unison to attract females. The synchronized rising and falling pitch of their chorus is testing the nerves of besieged homeowners. The male's efforts are being rewarded; Joe reported photographing numerous mating pairs. This means that oviposition and the subsequent damage to twigs and branch is just around the corner.

While the overall geographical distribution of BROOD XIV is spotty, there are localized pockets that are experiencing heavy emergence activity. Cicada emergence has been reported from Hamilton County north to eastern Montgomery County, and east to Athens County. Chris Simon at the University of Connecticut is conducting a study sponsored by the National Geographic Society to more accurately define the geographical distribution of this brood. Readers are urged to help with this study by reporting cicada observations using the following website: [ http://magicicada.org/magicicada.php ]. The website also has a continuously updated map of 2008 periodical cicada sightings.

B. THE LEAVES HAVE EYES. Joe Boggs noted that MAPLE EYESPOT GALLS are becoming very evident on red, sugar, and silver maples in southwest Ohio. The galls appear as circular spots on the upper and lower leaf surfaces. They are produced by the midge fly, Acericecis ocellaris (Diptera Family: Cecidomyiidae). The midge's scientific name is very descriptive since ocellaris comes from the Latin word ocellus, meaning "eye". The galls consist of spots with dark red centers that are bounded by concentric rings of white, red, black, and occasionally yellow. Indeed, this striking ring arrangement makes the galls look like eyes.

The midge flies spend the winter as pupae in the soil. Adults emerge in early spring and lay eggs on newly expanding leaves. The resulting maggots secrete chemicals that direct undifferentiated leaf tissue to form dimples (galls) around the maggots. The sessile maggots imbibe plant juices that ooze into their gall. The colorful concentric rings around the gall develop as the maggots mature. Once their development is complete, the maggots drop from the bottom of the leaf to pupate in the soil. There is only one generation per season.

The damage caused by maple eyespot galls rarely matches their dramatic appearance. In some years, the midges produce enough galls to catch the eye. However, in most years, the galls are somewhat rare since the flies are eyed as fodder by a range of predators, parasitoids, and pathogens.

C. WINDSHIELD WIPES.

* Curtis Young reported PINE NEEDLE SCALE (Chionaspis pinifoliae) is hatching in Allen County, Ohio. A little over half of the eggs were hatched. Crawlers were dispersing to new feeding sites. Southern populations should be farther along in their development, but should still be susceptible to treatment for a short time. Plants that should be inspected for pine needle scale activity include: the mugo pine (Pinus mugo), Scotch pine (P. sylvestris), Austrian pine (P. nigra), red pine (P. resinosa), eastern white pine (P. strobus), spruces (Picea spp.), firs (Abies spp.), Douglas-fir (Pseudotsuga menziesii) and cedars (Cedrus spp.).

* Joe Boggs reported BAGWORM (Thyridopteryx ephemeraeformis) hatching in large numbers in Butler and Hamilton Counties, Ohio. Joe caught the hatch at the right time to see the caterpillars (larvae) streaming out of the bottoms of their mothers' bags on silken threads. These threads don't last long, but if one is there at the right time, it is a visible sign that the bagworms had hatched. Joe also noted that the Japanese Tree Lilacs are in full bloom in Cincinnati, Ohio.

* SPITTLE IN THE NEEDLES. Curtis Young reported that PINE SPITTLEBUG (Aphrophora parallella) is active on white pine (Pinus strobus). Their presence is evidenced by the spittle masses that the individual developing nymphs produce as they feed. Despite the name of the masses being called spittle, these masses are not produced by the mouth of the nymph but rather by special glands associated with the anus of the insect. Thus, the alternative name of these insects proposed by Dave Shetlar is the "anal bubble bugs.

These insects may not be obvious on all trees upon which they are feeding; rain storms may wash away their masses. Inside the masses, the nymphs may be protected from predation and parasitization.

Pine spittlebug does not often require management. However, heavy infestations may stunt or kill shoots as the feeding activity clogs the tree vascular system. Black sooty mold grows on the spittle which drops onto needles and branches. This is the most common damage caused by this pest. The feeding wounds are also sites for infection of various fungi, especially Diplodia tip and stem blight. See OSU Extension Bulletin 504, "Insect and Mite Control on Woody Ornamentals and Herbaceous Perennials," for insecticide recommendations.

* MITES ON ARBORVITAE. Pam Bennett reported observing heavy mite damage on arborvitae. Which mite it was that was causing the damage needed to be determined. Was it the SPRUCE SPIDER MITE (Oligonychus ununguis) or the ARBORVITAE SPIDER MITE (Platytetranychus thujae)? Both mites can infest arborvitae and both mites are active in the cool temperatures of the spring, but as temperatures increase, the spruce spider mite will enter a summer aestivation (dormancy). However, the arborvitae spider mite may remain active deeper into the summer months, causing greater damage to the plants if they are not managed. It is important therefore to properly identify the species present to know when and which treatments should be applied.

Both mites are tiny and somewhat difficult to see. Dave Shetlar discussed the distinction between the two mites using the "smear test." Scouting for mites involves knocking the mites onto a sheet of paper, then sliding a hand over the mites to produce streaks of color from smearing their little bodies on the white paper. Spruce spider mites will produce a dark olive-green smear streak, while the arborvitae mite produces a yellow-green smear streak.

Arborvitae mites need to be treated now to prevent additional damage in the early summer. These mites are easily controlled with most registered miticides. Spruce spider mites may become inactive shortly as temperatures reach into the 90s over the next few days and into next week. If this happens, treating now may be useless for controlling this mite. One would have to wait until the fall when cooler temperatures return and the mites become active again. See OSU Extension Bulletin 504, "Insect and Mite Control on Woody Ornamentals and Herbaceous Perennials," for insecticide recommendations.

4. DISEASE DIGEST.

A. SUSPECTED CANNA YELLOW MOTTLE VIRUS (CAYMV). While visiting a local greenhouse, Dave Dyke was shown some cannas which the grower suspected were infected with a virus. Approximately 25% of the cannas exhibited mottling and yellow streaks along the veins. The C. Wayne Ellett Plant and Diagnostic Clinic tentatively diagnosed the problem as CAYMV and did not offer a positive diagnosis because there is no commercially available test for this disease.

Stunting and yellow and brown leaf flecks are also common symptoms of this disease. The yellow mottle virus is spread by the propagation of infected stock plants. Insects have not been found to transmit this disease. Plant virus disease infections are systemic in the plant and the only treatment is to remove and destroy infected plants. It is very important to use only virus free rhizomes or plants for production. Ask your supplier if the plants you are considering purchasing have been tested to confirm they are virus-free.

It should be noted that, while commercial tests are not available, researchers at the University of Minnesota will conduct PCR tests for this virus at a cost of $65.00. Make checks payable to the University of Minnesota. (Call ahead to confirm.) They request that a lab form be completed and sent with the sample. It can be found at the University of Minnesota Plant Disease Clinic website under how to submit a sample. U. of Minnesota Plant Clinic, Plant Disease Clinic, 495 Borlaug Hall, 1991 Upper Buford Circle, University of Minnesota, St. Paul, MN 55108-6030 (612) 625-1275

B. VERTICILLIUM WILT. Nancy Taylor reported that there was a positive culture for Verticillium wilt on smoke tree (Cotinus) in the Plant and Pest Diagnostic Clinic this past week. An arborist in southern Ohio reported that there was streaking in the sapwood and some branch dieback of GOLDEN RAIN-TREE (Koelreuteria) and wondered if it was a host for the Verticillium fungus. It is. Verticillium dahliae, the species that most commonly attacks woody plants, unlike many fungal pathogens, has a wide host range, including: MAPLE, BUCKEYE, TREE-OF-HEAVEN, SERVICEBERRY, BARBERRY, CATALPA,REDBUD, YELLOWWOOD, SMOKE TREE, RUSSIAN OLIVE, ASH, KENTUCKY COFFEE TREE, GOLDEN-RAIN TREE, PRIVET, TULIPTREE, HONEYSUCKLE, CRABAPPLE, TUPELO, POPLARS, PRUNUS, PEAR, OAK, SASSAFRAS, LILAC, LINDEN, ELM, VIBURNUM, and many others. Many others have resistance, including all gymnosperms such as needled-conifers, and all monicots including grasses and palms. For a more complete list of Verticillium-susceptible and Verticillium-resistant woody plants refer to “Diseases of Trees and Shrubs, 2nd edition” by Wayne A. Sinclair and Howard H. Lyon (Cornell University Press).

C. MOIST CHAMBER. A number of ANTHRACNOSE DISEASES were noted again this week. The following were noticed: tannish to grayish to blackish discoloration of lower leaves on oaks, especially in the WHITE OAK group, ash anthracnose, linden anthracnose, beech anthracnose, and most severely and noticeably sycamore anthracnose on SYCAMORE and less prominently on LONDON PLANE. In the vast majority of cases it is expected that plants will recover without major damage to overall plant health.
Nancy Taylor reports from the C. Wayne Ellett Plant and Pest Diagnostic Clinic (PPDC) a positive sample for OAK WILT on pin oak from Lake County, samples of BOTRYOSPHAERIA CANKER on JUNIPER, a sample of PHOMOPSIS CANKER on SPRUCE and continuing samples of VOLUTELLA LEAF BLIGHT AND STEM CANKER ON PACHYSANDRA and PHOMA DIEBACK ON VINCA. There was a sample of DOWNY MILDEW OF ROSE, a potentially deadly problem if it worsens, but hot, dry weather should alleviate this problem in the field here in Ohio.

Other samples and observations include PHYTOPHTHORA CANKER OF VIBURNUM, which probably developed last season, POWDERY MILDEW OF CALLERY PEAR, causing some leaf distortion, symptoms of yellowing on upper leaf surfaces, and presence of the powdery mildew fungal growth on the lower leaf surfaces.

5. TURF TIPS.

A. AND... THEY’RE OFF! Dave Shetlar saw the bluegrass webworm moth Parapediasia teterrell, this week and stated that their flight has begun. This moth is found in the Eastern USA where Kentucky bluegrass is the predominant turfgrass. Although they commonly live in bluegrass country, caterpillars will also eat tall and fine fescue and perennial ryegrass.

The moth is often seen at porch lights standing with the head pointed downward and the wings rolled on top of its back. Its prominent “snout” protrudes forward from its head. The wingspan is 9/16-13/16" with striations of grays, light purples, light colored veins, and a faint yellow-orange line which traces the wing tip. Seven dark spots can be seen along the edge of the wing tip. The moths may be noticed at dusk hovering over the turfgrass, where they are dropping small round, ribbed eggs.

Northern Ohio has two main webworm species, the bluegrass and larger sod webworm (SWW), both of which have two generations per year. Adults fly at dusk in June and August, dropping eggs into the turfgrass below. Upon egg hatch, small spotted caterpillars nibble on the grass leaf surface, then after molting, drop onto the ground and construct silken tunnels mixed with thatch and leaves. The fall brood will overwinter in its hibernacula deeper in the ground and then emerge in the spring. As one travels south, the frequency of generations increases, so that Kentucky may have 3 generations of the bluegrass webworm a year and Gulf states may have continuous cycles.

Normally, small populations of SWW in lawns can be left untreated as the plants are not killed but merely scalped. From a distance, small patches of grass may appear thin or unthrifty. Lawns treated in June with halofenozide (MACH2) will control these and other caterpillars as well as grubs. To determine if control is necessary, mix 2 Tablespoons of Joy dishwashing detergent in 2 gallons of water and douse a suspect area about 1 square yard. SWW larvae will soon come to the surface coughing and spluttering before they die. If the soil is dry, water the area before using the soap flush. If control is warranted, most pyrethroids will stop them. Biological controls include Bt, azidiractin (NEEM), and Spinosyn. Refer to OSU Bulletin L-187 “Management of Turfgrass Pests Weeds, Diseases, and Insects”, http://ohioline.osu.edu/l187/index.html

6. INDUSTRY INSIGHTS.

A. BALSAM TWIG APHID. Jim Chatfield reported observing heavy infestations of balsam twig aphids (Mindarus abitinus) on the expanding candles of various firs in northeast Ohio. The characteristic symptom of twisted needles caused by the aphid's feeding activity was becoming evident. The light-green to bluish-green aphids reside near the base of the new needles, and their location and color makes aphid colonies difficult to spot. However, once the aphids become covered by waxy, white, flocculent material, they are more easily detected.

Aside from producing twisted needles, the aphids also exude copious quantities of sugary, sticky honeydew which gives the needles a shiny appearance. Needles and twigs may become blackened if the honeydew is colonized by black sooty molds. The aphids are only a cosmetic problem on trees in landscapes since their feeding damage does not hurt the health of the tree. However, on trees in nurseries and Christmas tree plantations, heavy aphid infestations can reduce the marketability and value of the trees. Their management often requires insecticide applications.

Application timing is critical to avoid aphid damage to new needles. The ideal timing is to make the application when the accumulated GDD for the season reaches 100-140. Unfortunately, this GDD range has already been surpassed throughout Ohio. While an application made now cannot reverse the damage that has already occurred, it will prevent further damage and help to reduce populations for next season. Fortunately, pyrethroid insecticides labeled for use on the targeted firs are very effective in controlling these aphids.

B. NOT THE ORDINARY RECOMMENDATIONS. The need to control common problems on plants, such as anthracnose, leaf galls and frogeye leaf spot, to name a few, would normally be dismissed as unneeded in most landscapes. However, as Jim Chatfield and Tim Malinich pointed out, high profile landscape specimens or production nurseries would view the situation quite differently. In these areas, simple problems that would normally be tolerated must be addressed and treated. The take-home message is to consider the bigger picture when making not only diagnosis but recommendations as well. What is a standard prescription for a common malady would not hold in all situations.

C. SAMPLING 101-3: KNOWLEDGE IS POWER. This is the third in a series of tips on getting the most from your plant diagnostic samples sent to the PPDC or any other lab.

Always remember that the information provided on the sample form is of utmost important. Physicians can ask questions of their patients, though we usually lie. However, plant doctors only have the sample itself and the information provided with the sample. Small leaves, off-color leaves and branch dieback have a lot more meaning when a diagnostician learns that the plant involved was transplanted as a 30 foot tree. A sample of yellow leaves of American holly taken from a plant in the spring with 95% of the leaves yellow has a different meaning than those taken from an American holly with 20% yellow leaves (the latter is probably normal seasonal needle yellowing of this broadleaf evergreen). How many plants are affected, whether plants of different species are affected, what part of the plant is affected, when did symptoms first appear, what is the cultivar, what is the horticultural program of pesticides and fertilizers applied - all this matters. Improve your output from the Clinic with your best input of information. Speak for the trees!

7. COMING ATTRACTIONS.

A. CINCINNATI BYGLIVE! DIAGNOSTIC WALK-ABOUT. The 3rd monthly BYGLive! Diagnostic Walk-About for 2008 will be held Monday, June 9, from 12:00-3:00 pm., at the Stanley M. Rowe Arboretum, 4600 Muchmore Rd., Indian Hill, 45243. This monthly hands-on training for green industry professionals focuses on diagnosing plant pest, disease and physiological problems. ISA Certified Arborist CEU's will be available. For more information, contact Joe Boggs at 513-946-8993.

8. BYGLOSOPHY. "In my garden there is a large place for sentiment. My garden of flowers is also my garden of thoughts and dreams. The thoughts grow as freely as the flowers, and the dreams are as beautiful." - Abram L. Urban

Where trade names are used, no discrimination is intended and no endorsement by Ohio State University Extension is implied. Although every attempt is made to produce information that is complete, timely, and accurate, the pesticide user bears responsibility of consulting the pesticide label and adhering to those directions.

OSU Extension embraces human diversity and is committed to ensuring that all educational programs conducted by Ohio State University Extension are available to clientele on a nondiscriminatory basis without regard to race, color, age, gender identity, or expression, disability, religion, sexual orientation, national origin or veteran's status. Keith L. Smith, Associate Vice President for Ag. Adm. and Director, OSU Extension, TDD No. 800-589-8292 (Ohio only) or 614-292-1868.