TPM/IPM Weekly Report

TPM/IPM Weekly Report for Arborists, Landscape Managers & Nursery Managers Commercial Horticulture March 29, 2013 In This Issue... - Weather update - BMSB conference - Periodical cicadas: Brood II - Ticks - Eastern tent caterpillars - Southern red mite - Fall Transplanting - Japanese cedar longhorned beetle - Indian wax scale - Boxwood leafminer - Thousand cankers disease update Beneficial of the Week Weed of the Week Plant of the Week Degree Days Contacts for Questions Conferences Integrated Pest Management for Commercial Horticulture ipmnet.umd.edu Conferences Publications Archived IPM reports If you work for a commercial horticultural business in the area, you can report insect, disease, weed or cultural plant problems found in the landscape or nursery to sklick@umd.edu Coordinator Weekly IPM report: Stanton Gill, Extension Specialist, IPM for Nursery, Greenhouse and Managed Landscapes, sgill@umd.edu. 301-596-9413 (office) or 410-868-9400 (cell) Regular Contributors: Pest and Beneficial Insect Information: Stanton Gill and Paula Shrewsbury (Extension Specialists) Disease Information: Karen Rane (Plant Pathologist) and David Clement (Extension Specialist) Weed of the Week: Chuck Schuster (Extension Educator, Montgomery County) Cultural Information: Ginny Rosenkranz (Extension Educator, Wicomico/ Worcester/Somerset Counties) Fertility Management: Andrew Ristvey (Regional Specialist, Wye Research & Education Center) Design, Layout and Editing: Suzanne Klick (Technician, CMREC) Better Weather Will Be Welcome There has been an excessive number of cloudy days and cold weather over the last month. The snow on Monday, March 25th just added to the lengthy winter. Everyone is reporting very sluggish sales and greenhouses are backing up with plant material. If it warms up and gets sunny, plant and insect activity should pick up quickly. Daffodil after the snow on Monday Photo: David Clement, HGIC Brown Marmorated Stink Bug Program On April 10, 2013 we will hold a special one day conference on BMSB research at Carroll Community College in Westminster, MD. This program is a joint effort with Brian Kunkel and the University of Delaware, Eric Day and Virginia Tech Extension, and myself from the University of Maryland. This will be your opportunity to find out on what the BMSB are feeding in the landscape, whether various types of traps are effective, what are the best insecticides and new developments in the behavior and life cycle of this stink bug. Conference information is posted at http://www.ipmnet.umd.edu

Periodical Cicadas: Brood II Periodical cicadas emerge in different geographical areas and these emergence groups are labeled as Broods. The one we experienced in 2004 in most of Maryland was Brood X. There is another brood of the 17-year periodical cicada that will be emerging in 2013 which is Brood II. In most areas of Maryland you will not see these cicadas, but if you have customers in Virginia, Pennsylvania, North Carolina, New Jersey, and New York they will be seeing activity of Brood II. The parts of Maryland that will have emergence are mainly in southern Maryland, Prince George s County and the lower portion of Montgomery County. In Pennsylvania, entomologists even recorded which counties you can expect to see Brood II emerge in 2013 which includes: Berks, Bucks, Periodical cicada (Brood X in 2004) on Heritage Carbon, Chester, Dauphin, Delaware, Lancaster, Lebanon, birch Lehigh, Luzerne, Monroe, Montgomery, Northampton, Philadelphia, Pike, Potter, Schuylkill, and Wyoming Counties. Adult Magicicada have black bodies and striking red eyes and orange wing veins, with a black W near the tips of the forewings. Most emerge in May and June. You may say wait a minute, I see cicadas every summer in August. Yes, you would be correct. The annual cicada, which are out in August every year, are a large greencolored cicadas and never reach really high populations numbers. They are also called dog-day cicadas. Although annual cicadas life cycle is typically 2-3 years long, they are staggered so we see some emerging every summer. These late summer cicada species, which are sometimes mistaken for the periodical cicadas, are usually in the genus Diceroprocta. The annual cicada is more robust in body size than periodical cicadas and the body is a green color. Periodical cicadas can cause physical damage to small trees or shrubs if too many feed from the plant or lay eggs in the twigs; such damage can cause flagging, or breaking of peripheral twigs. Orchard and nursery owners probably should not plant young trees or shrubs in the years preceding an emergence of periodical cicadas because young trees may be harmed by severe flagging. Mature trees and shrubs, however, usually survive even dense emergences of cicadas. Moles are said to flourish on the fully grown nymphs in the weeks prior to emergence. Other wild animals that feed on them include snakes and spiders. So, at least some of nature s wildlife gets a benefit out of the nymphs that emerge from the soil. Chemical sprays are really not practical to control the periodical cicadas. Beyond the concern by owners of fruit orchards and nurseries, periodical cicadas are not regarded as pests. Their loud noises may be annoying, but tolerable, since it only lasts for a couple of weeks. You can prepare your customers in Virginia, Pennsylvania and southern Maryland for the activity this late spring to early summer. Ticks Are Active Bob Nixon reported on March 21 he found a tick on his side after weeding and pruning on one of the warmer days during in March. He noted that his family physician said he s already treated one case of lyme disease this year. Be sure to check yourselves carefully for ticks after working outside. Black legged or deer tick 2

Eastern Tent Caterpillars Mike Raupp, University of Maryland, found eastern tent caterpillars hatching in College Park on March 28. He reported that larvae were about 3 mm long and just beginning to move from the egg mass. Stanton noted that crabapples were still in tight bud with no sign of leaf emergence yet in Frederick. College Park is closer to the city and in a warmer area so caterpillar hatch is earlier there. Monitor in your areas for the hatching of these larvae. Control: Mike noted that they can be mechanically controlled by crushing or removed by pruning. They are also easily controlled during the early instars with applications of Bt or spinosad to the expanding foliage. Southern Red Mites Sudeep Mathew, University of Maryland Extension, sent a sample of Japanese holly that had eggs and a few adults of southern red mites. Monitoring: Look for red eggs that overwinter on the undersides of foliage and twigs of Japanese hollies, cherry laurel, camellia, and azalea. A tap test over white paper can show whether mites are present on the plant. Also look for signs of stippling and webbing on the foliage. Control: A dormant rate of horticultural oil can be applied at this time of year. Eastern tent caterpillars hatching Photo: M. Raupp, University of Maryland Southern red mite and eggs found on Japanese holly Why Is It Hard To Transplant Red Oak in Fall? Last fall we were asked why it is hard to transplant red oak in the fall and checked with others for ideas. Below are are two responses: From Roger Harris, Virginia Cooperative Extension A fall dug tree often must hang on until spring before new roots will grow since by the time they recover from the shock of being transplanted, the soil is too cold to support root growth. Species vary greatly in their propensity to regenerate roots. This is mostly, but not entirely related to the natural coarseness or fineness of the root system (more intact root tips on a fine root system). The fine root system also rehydrates much more easily. So coarse-rooted trees like a lot of oaks can be difficult to transplant in the fall. I personally have not had trouble with red oaks, but the even coarser rooted scarlet oak can be difficult. Some species (like American beech) are just slower to grow roots and do much better in the spring when root regrowth happens much more quickly. Growers will often get the process started by sweating them in a warm humid greenhouse first. If a tree is not all that hardy, it would be more sensitive to cold soil so it is likely to be a difficult fall transplant in marginal areas. Trees with fleshy roots, especially magnolias, are more prone to root damage when being transplanted and usually don t transplant well in the fall, particularly in marginal areas where winter damage will compound the issue. Cross the wide variation of species with variable post-transplant care and with the skill of the folks doing the operation and anything can happen on trees that are not very easy to transplant! 3

From: Bill Flemer III, Princeton Nurseries Ever since the early days of the landscape business, it has been known that some species of shade and flowering trees are easy to transplant in the fall, whereas others are extremely difficult or even impossible to get to survive. The difficult species are successful if they were dug the previous spring and held over the summer or if they were grown in containers during the previous summer as we are now doing on a much larger scale. However, even if they are dug B&B for immediate fall moving, survival is a very chancy affair. Just why some species of trees are safe to move in the fall while others, which appear to be quite similar, are very difficult remains an intriguing question, which has never been the subject of serious research or received a definite answer. There will probably never be a single reason for fall losses of all difficult shade trees, but rather several reasons that apply to different species or groups of species with similar characteristics. The most important of these causes are detailed as follows. 1. Evergreen Foliage: Broadleaf evergreens in general are notoriously difficult to transplant in the fall because if they have not rooted fast into their new location they can rapidly desiccate during cold windy periods in the winter. The same problems apply to broadleaf evergreen trees, especially in the northerly portions of their hardiness zones. Examples are: Ilex opaca, aquifolium, pendunculosa, etc.; Magnolia grandiflora. 2. Thin Barked Trees With Abundant Twigs: These trees are especially prone to water loss in winter months, particularly when the ground is frozen and there are high winds. Just as laundry will rapidly dry on a windy, sub-zero day, even though it freezes solid when first hung out, so trees of this group dry out beyond the survival point even when they have no leaves. Thin bark is a very poor moisture barrier and abundant twigs, like abundant foliage, also make heavy drains upon the trees internal moisture supplies. Trees with abundant twigs are usually those with very small leaves such as willow oaks and birches. In contrast, trees with large, compound leave like Fraxinus, Gleditsia, and Gymnocladus have relatively fewer branches and are safe to transplant in the fall. Problem trees are: Quercus phellos (really difficult); Betula alba and B. papyrifera, etc.; Salix babylonica. 3. Trees With Coarse Roots Which Regenerate Slowly: Here the problem is that, especially in B&B trees, the trees do not have enough roots to replace water loss during the cold dry periods during the winter. To compound the problem, trees included in the group have roots that are very slow to heal and push out new branch roots whenever they are severed. Research done at Rutgers University on the quite closely related scarlet and pin oaks (both in the black oak section of the genus) showed that severed scarlet oak roots required three to four times more time to regenerate than pin oak roots needed to heal the cuts and thrust out new branch roots. The ideal time to dig and transplant trees of this type is just as they are breaking dormancy in the spring. At that point there is no large crown of foliage to support and the approaching flush of growth makes healing a much more rapid process than in the fall when the growth process are slowing down with the approach of dormancy. If transplanting cannot be accomplished at this ideal period because of construction delays, trees of this class benefit from being pre-dug at the best period and then being carefully maintained above ground as we do in our wholesale yards. The new mechanical balling machine methods with tightly fitting wire baskets encasing the root balls are especially well adapted to pre-digging for late season planting because the wires securing the balls do not rot as does rope. Examples are: Quercus coccinea, Q. rubra and Q. velutina; Nyssa sylvatica. 4. Trees Which Harden Up Late In The Fall: There are a few species which grow late in the summer and which harden up very late in the fall. They retain their leaves very late and the abscission layer, which causes the leaves to drop, is especially tardy in developing. Thus, while early ripening trees like Fraxinus pennsylvanica can be dug quite early and will quickly ripen and drop their leaves, late ripeners like the Bradford callery pear dug at the same time will promptly dry up without dropping a single leaf. Then it is absolutely necessary to transplant late ripening trees in this group in the fall, it is essential to dig them as late as possible. The later they are dug in the fall or early winter, the better the chance of survival. Severe pruning at transplanting time, whenever possible, is also helpful in improving survival. Examples are: Pyrus calleryana 4

Bradford, Aristocrat, etc.; Liquidambar styraciflua; Prunus subhirtella pendula, etc.; Prunus serrulata varieties; Prunus cerasifera varieties; Crataegus species; Tilia tomentosa; Quercus robur and Q. fastigiata. Of course deadlines for landscape planting jobs cannot always wait for ideal planting items. Losses can be minimized by changing varieties from hazardous to safe species of trees, digging the risky ones with larger than normal earth balls, and by planting trees re-established in containers. Thinning out or cutting back tree crowns and wrapping the trunks with tree wrap paper also help to reduce winter drying and losses on the planting site. Japanese Cedar Longhorned Beetle Mark Raab, Howard County Recreation and Parks, brought in four adult female beetles that were identified as Japanese cedar longhorned beetle. These beetles were taken from a white Atlantic cedar log. The log had been processed at a Baltimore County lumber mill. If you find Leyland cypress, arborvitae or cyrptomeria with dieback, examine the branch for borer holes. The adult females are overwintering in the heartwood and should be emerging sometime this spring. Japanese cedar longhorned beetle (female) Indian Wax Scale Amanda Ramey, National Park Service, found indian wax scale in December on a large Magnolia soulangiana at the Hampton National Historic Site in Towson. She noted that three looked normal and five looked like they had been victim of a predator - like their caps had been chewed on. Indian wax scale is one of the insects we are monitoring closely this year to get more data on the timing of its crawler period in this area. Boxwood Leafminer Amanda Ramey is also finding boxwood leafminer in high numbers this year. The leafminers will go from the larval stage to pupal stage in April and emerge late in the month or in early May. Thousand Cankers Disease Update RALEIGH The N.C. Department of Agriculture and Consumer Services has placed Haywood County wood products under quarantine due to a recent detection of thousand cankers disease in the Great Smoky Mountains National Park. This marks the first time the disease has been detected in the state, and by placing restrictions on a variety of plant material and wood products, we hope to keep the disease from spreading into other counties, said Agriculture Commissioner Steve Troxler. Something as simple as moving firewood from an infected area to an uninfected county could increase the risk of spreading this disease. Thousand cankers disease is a newly recognized disease primarily affecting black walnut trees. It is caused by the Geosmithia morbida fungus, which is spread by the walnut twig beetle. Thousand cankers disease has produced widespread death of black walnuts in many western states during the past decade. Other species of walnut, such as Arizona walnut, English walnut and California walnut, have also shown varying degrees of susceptibility to this fungus. The following items fall under the quarantine restrictions: walnut plants and plant parts including firewood, lumber, logs, stumps, roots, branches, and composted and uncomposted chips. Regulated items cannot be moved outside the county. Exceptions to the quarantine restrictions include nuts, nut meats, hulls, processed 5

lumber with square edges that is 100 percent bark free and kiln-dried, and finished wood products without bark, such as furniture, instruments and gun stocks. NCDA&CS Plant Industry Division and N.C. Forest Service personnel will continue to monitor counties across North Carolina for the presence of this disease. Beneficial of the Week, Paula Shrewsbury It is still cold Are any natural enemies active? Surprisingly, about 2 weeks ago my assistant, Nancy Harding, saw her first natural enemy of the season... always an exciting event! She found the twice-stabbed lady beetle, Chilocorus stigma, on the trunk of a maple tree that happened to have some of this lady beetle s favorite food scales. In this case it was Japanese maple scale. You can see where the name twice stabbed comes from with this predator. Nearly all species in the genus Chilocorus are predaceous on scale insects, although some will feed on aphids or other insects too. Adults appear shiny black with a large red spot in the center of each elytron (front wings) and average ¼ in length. There are two generations in the northern U.S. and more in warmer states. Larvae are black or grey and spiny in appearance. Both larvae and adults voraciously feed on Japanese maple scale. The twice-stabbed lady beetle is a native predator that we see commonly on trees infested with Japanese maple Twice-stabbed lady bird beetle adult scale, and sometimes in great abundance. This is interesting since Japanese maple scale is an exotic insect from Asia. Hopefully, as the weather warms we will see additional predators joining in the fight against scales, one of the most common pest insects of ornamentals. Weed of the Week, Chuck Schuster Lesser-seeded bittercress, Cardamine oligosperma, seems to be abundant in the landscape at this time of year. This is a newer weed in this area, and can be found in turf, landscapes, in ground nursery and also container nursery production. Very similar to hairy bittercress, it is typically a summer annual, but can also be found in some locations as a fall germinating weed. Lesser-seeded bittercress, is in the Mustard family and native to Eurasia. It is now found throughout the United States and is moving into this region. This weed grows three to five inches in height, originates from a basal rosette, and has a taproot with dense fibrous hairs. The leaves are lobed, opposite and the petiole does not have hairs. The flowers are in clusters at the end of Lesser-seeded bittercres Photo: Chuck Schuster, UME flowering stems with four petals that are narrow and white. The fruit of this weed is a silique which is a narrow capsule that is designed to release the seeds held within in an explosive manner, spreading the seed up to eight feet from the plant. Control of this weed is difficult especially with having it germinate this time of year. Cooler temperatures can make post emergent control harder without the plant being in active growth. Hairy bittercress control can be accomplished with the use of pre-emergent products that include oxadiazon (Ronstar), flumioxazin (Broadstar) or isoxaben (Gallery). It is too late at this point to use pre-emergent products for what we see now. Post emergent products can provide excellent control in turf, and they include, 2,4D and triclopyr (Chaser) 6

Metsulfuron (Blade), and Speedzone (tri-mec + Quicksilver) which works better in the cooler weather so it can be a useful tool now. These products should provide ninety percent or greater control. Sureguard (Flumioxazin) is a pre-emergent, post-emergent herbicide that is labeled for container and field grown nursery settings as well as landscapes. Lesser-seeded bittercress Photos: Chuck Schuster, UME Plant of the Week, Ginny Rosenkranz Prunus x incamp Okame or Okame cherry tree is usually the first flowering cherry to bloom in the late winter or early spring. The plant grows 15-30 feet tall and wide in an upright arching vase shape that spreads out to an oval as it matures making it a wonderful flowering plant for small courtyards, ranch style homes or small gardens. The slightly fragrant, single flowers are a pale pink with red calyx, red filaments that hold the anthers, and a red style that shows through the pink petals. The effect of the tree in full flower is not reduced by the addition of the leaves which appear after the flowers have bloomed. Because it blooms so early in the spring it is susceptible to some frost damage, but because it blooms so early in the spring it has a longer period of bloom than many other cherries whose flowers can wither in the heat of late spring. The bark of the Okame cherry is a polished reddish brown with horizontal lenticels. The 1-2 inch dark Prunus x incamp Okame Photo: Ginny Rosenkranz, UME green, serrated leaves are arranged in an alternate fashion on the stems and turn a bronze red to copper orange in the fall. The Okame cherry prefers full sun, slightly acid to neutral well drained soils like most cherries, and once established can become slightly drought tolerant. It is a hybrid of the Formosan and Fuji cherries and is hardy from USDA zone 6-9. Pests include the cankerworm and Verticillium wilt. Plant Phenology: What is in bloom PLANT PLANT STAGE (Bud with color, LOCATION First bloom, Full bloom, First leaf) Acer rubrum First bloom Columbia (March 24) Cornus mas (cornelian cherry) First bloom Ellicott City (March 28) Forsythia First bloom Columbia (March 27) Clinton (March 23) 7

Degree Days (As of March 28) Baltimore, MD (BWI) 7 College Park 23 Dulles Airport 18 Frostburg, MD 14 Martinsburg, WV 12 National Arboretum 23 Reagan National 23 Salisbury 42 To check degree day (DD) accumulations in your local area go to: http://www.weather.com/outdoors/agriculture/growing-degree-days/ USMD0100 Operator Certification for Writing Nursery Nutrient Management Plans April 17th, 2013 Wye Research and Education Center 124 Wye Narrows Road, Queenstown, MD 21658 July 10th, 2013 Central Maryland Research and Education Center 11975-A Homewood Road, Ellicott City, MD 21042 Nursery Operator Certification for writing nursery nutrient management plans will be offered in two separate programs to accommodate growing season schedules. These training programs will assist you in writing a nutrient management plan for your nursery or greenhouse operation. You must write a nursery nutrient management plan if you use fertilizers and you gross over $2500 per year in sales. With this certification, you will be able to sign-off and submit your own plan. Each program consists of a Training Day and an Exam/Signoff Day. The Training Day will consist of learning the plan-writing process. After the Training Day you will have about 4 weeks, during which time you will study the Nursery Nutrient Management Training Manual and develop your plan. The Exam/Signoff Day will be for taking the exam and going over your newly developed plan. The process is relatively simple for small (or low-risk) operations, so if your operation size is less than 5 acres, we would strongly encourage you to think about becoming a certified operator. If your operation is larger than 5 acres, we would still encourage you to become a certified operator, even though the nutrient management process may be a little more complicated. Drs. John Lea-Cox and Andrew Ristvey will be happy to help you write your water and nutrient management plan. The first Training Day will be April 17th, 2013 at Wye Research and Education Center. We have scheduled the Exam/Signoff Day for May 15th at Maryland Department of Agriculture in Annapolis, MD. After passing the exam, you will be able to sign off on your plan and submit it. The second program s Training Day will be July 10th, 2013 at Central Maryland Research and Education Center just outside Ellicott City. We will schedule an Exam/Signoff Day for this program on the 10th of July. To express your interest in taking this training, please contact Mike Webster, Maryland Department of Agriculture at (410) 841-5957. Call Andrew Ristvey (410) 827-8056 x113 for directions to Wye Research and Education Center and the Central Maryland Research and Education Center. 8

Commercial Horticulture Industry Contact for Help With Plant Problems Diseases: Karen Rane: rane@umd.edu, 301-405-1611 Go to www.plantclinic.umd.edu to find out how and where to submit suspected disease samples to her lab. Insects: Stanton Gill: sgill@umd.edu, 410-868-9400 (cell) or 301-596-9413 (office) Paula Shrewsbury: pshrewsb@umd.edu, 301-405-7664 Brian Clark: bpclark@umd.edu, 301-868-8780 (Brian covers Prince George s County) Weeds: Chuck Schuster: cfs@umd.edu, 301-590-2807 Soil Substrates Plant Fertility: Andrew Ristvey: aristvey@umd.edu, 410-827-8056 Horticulture: Ginny Rosenkranz: rosnkrnz@umd.edu, 410-749-6141 ext 106 (Wicomico, Worcester and Somerset counties) For questions from homeowners and master gardeners, contact the Home and Garden Information Center, http://hgic.umd.edu or 800-342-2507, or your local Extension office. Upcoming Programs Interstate Ornamental Plant Mangement Conference April 3, 2013 Location: Maritime Institute, Linthicum Heights, MD Contact: Avis Koeiman, 301-405-3913, akoeiman@umd.edu MNLA Nursery Field Day June 20, 2013 Location: Waverly Farm, Adamstown, MD Contact: MNLA, 410-823-8684 Brown Marmorated Stink Bug Conference April 10, 2013 Location: Carroll Community College, Westminster, MD Contact: Suzanne Klick, 301-596-9413 or sklick@umd.edu CONTRIBUTORS: Stanton Gill Extension Specialist sgill@umd.edu Paula Shrewsbury Extension Specialist pshrewsb@umd.edu Karen Rane Plant Pathologist rane@umd.edu Chuck Schuster Extension Educator cfs@umd.edu Ginny Rosenkranz Extension Educator rosnkrnz@umd.edu David Clement Plant Pathologist hgic.umd.edu Andrew Ristvey Extension Specialist aristvey@umd.edu Brian Clark Extension Educator bpclark@umd.edu Thank you to the Maryland Arborist Association, the Landscape Contractors Association of MD, D.C. and VA, the Maryland Nursery and Landscape Association, Professional Grounds Management Society, and FALCAN for your financial support in making these weekly reports possible. Photos are by Suzanne Klick or Stanton Gill unless stated otherwise. The information given herein is supplied with the understanding that no discrimination is intended and no endorsement by University of Maryland Extension is implied. University of Maryland Extension programs are open to all citizens without regard to race, color, gender, disability, religion, age, sexual orientation, marital or parental status, or national origin.