UMass Extension Landscape Message #4
March 17, 2006

Quick Info Menu ------------------------------- ENVIRONMENTAL DATA REGIONAL NOTES - Cape Cod - Southeast - East - Central - Pioneer Valley - Berkshire PHENOLOGY WOODY ORNAMENTALS - Insects - Diseases - Lab Report - Weeds TURFGRASS - Insects - Diseases - Weeds INFO RESOURCES DIAGNOSTIC SERVICES Use this menu to instantly jump to any portion of the message!

The LANDSCAPE MESSAGE is an educational newsletter intended to guide landscape, nursery and urban forestry professionals in identifying pests in the landscape, monitoring their development, planning management strategies and creating site-specific records for future management reference. UMass Extension has updated this issue to provide timely pest management information and the latest regional news and environmental data throughout Massachusetts. The next update will be available on Friday, March 13, 2006. Missed a previous message? Visit the Landscape Message Archive. Interested in additional turf-oriented content? UMass Extension Turf Program Management Updates

ENVIRONMENTAL DATA

The following growing-degree-day (GDD) and precipitation data was collected for a three-week period, March 2, 2006 through March 15, 2006. Soil temperature and phenological indicators were observed on March 15, 2006. Accumulated GDDs represent the heating units above the 50° F baseline temperature collected via our instruments since the beginning of the current growing season. This information is intended for use as a guide for monitoring the developmental stages of pests in your location and planning management strategies accordingly.

REGIONAL NOTES

Cape Cod Region (Barnstable) - General Conditions: No report.

Southeast Region (Hanson) - General Conditions: Nice spring-like weather for most of the past two weeks. A few days in the high 50's-60. Brief snow shower on March 15th that did not amount to anything. Silver maple, Hamamelis 'Arnold Promise' and 'Pallida', Helleborus foetidus, Helleborus x orientalis, Helleborus niger, winter aconites, early crocus and snow drops are in full bloom. Red maples are in bloom in some areas and just beginning in others. The fruit of cranberry viburnum, the berries of many hollies, and the bark of Acer griseum are still providing color and interest in the landscape. Pests/Problems: Skunks are digging up lawns. Deer continue to browse. Many trees have numerous egg masses of forest tent caterpillar and gypsy moth caterpillar. Lady bugs and western conifer seed bugs are active indoors.

East Region (Boston) - General Conditions: Cool, windy.

Central Region (Boylston) - General Conditions: No report.

Pioneer Valley Region (Amherst) - General Conditions: Cold nights (below freezing) and cool days (above freezing) were the pattern for the first week, then a warm-up, and now it is cool again. It is great for maple syruping! And, even though some rain and snow fell, there was only one significant snow event (~5" on March 2). Tulip and daffodil leaves are poking out of the soil in many gardens. Pests/Problems: No significant pests or disease problems to report.

Berkshire Region (Great Barrington) - General Conditions: Typical March weather, i.e. very unsettled. Very little happening in the landscape. Pests/Problems. Nothing to report.

PHENOLOGY

The phenological indicators are a visual tool for correlating plant development with pest development. The following are the indicator plants and the stages of bloom observed for this period:

CAPE COD REGION - Roberta Clark, Horticulturist for Barnstable County, Barnstable.

SOUTHEAST REGION - Deborah Swanson, Horticulturist for UMass Extension in Plymouth County, Hanson.

EAST REGION - James R. Allen, Horticulturist and Greenhouse Manager for UMass Biology Department, Boston.

CENTRAL REGION - Joann Vieira, Superintendent of Horticulture, Tower Hill Botanic Garden, Boylston.

PIONEER VALLEY - Dan Gillman, Plant Pathologist, Urban Forestry Diagnostic Lab, UMass, Amherst.

BERKSHIRES - Ron Kujawski, Specialist, UMass Extension Landscape, Nursery & Urban Forestry Program, Amherst.

WOODY ORNAMENTALS

INSECTS

Winter moth - Monitor now for the presence of winter moth eggs. Currently, the eggs are small, oval and have turned orange. These can be found on the trunk and branches throughout a tree. Egg hatch is projected to occur in about 4-5 more weeks. Once the tiny caterpillars emerge from the eggs, they will seek buds that are just beginning to swell. Winter moth caterpillars wriggle into buds and feed on both foliage and flower parts within the buds. This exotic pest has been recently shown to be far more prevalent than previously understood. Most of eastern MA, all of RI, some spots in southeastern NH, southeastern CT, southern NH, and certain areas along the Maine coast have this pest. The highest population numbers, by far, are in MA and RI.

Gypsy moth is expected to be in high numbers in MA and other Northeastern states. The fungus, Entomophaga maimaiga, that controls gypsy moth naturally has not performed well during the past two springs. This is primarily a function of spring weather conditions; rainy periods at critical times during the caterpillar stage are essential for the spread of this pathogen to gypsy moth caterpillars. There has been some anecdotal evidence provided recently that E. maimaiga may have been more active and successful in the westernmost part of MA last year (Berkshires) than it was in the rest of southern New England.

Eastern tent caterpillar is once again expected to be in large numbers and attacking their favored host plants of apple and cherry. Egg hatch will occur once the leaves are half to fully emerged from the buds.

Forest tent caterpillar is also expected to be in large population numbers once again in MA and other surrounding states. Last year, this pest caused more than 200,00 acres of defoliation in MA. Forest Tent Caterpillar has been a problem in eastern MA for several years, primarily on oaks, but it is now building in serious numbers statewide and in VT on sugar maple, as well.

Fall cankerworm is expected to be in large numbers in eastern MA and on parts of Long Island, NY in 2006. Parts of RI may also experience some of this pest’s activity. Egg hatch will occur about early to mid May.

Hemlock woolly adelgid has been actively feeding since last October and is now about to start laying eggs. This will be the time when the cottony masses that surround the eggs will be most visible, especially from the undersides of the branches. Make note of those plants that will require treatment with oil sprays once the correct weather conditions prevail.

Spruce spider mite from last fall has not yet shown up yet. It will “suddenly” become apparent on those affected plants, but no mites will be seen at that time. However, make note of those plants that were injured from last fall’s feeding and expect to have more mites on those plants this spring. Once the correct weather conditions prevail, treat with an oil spray or, if eggs are present, they can be treated with one of the Mite Growth Regulators that has ovicidal activity.

White pine weevil has most likely become active. This species over-winters as an adult in sheltered places and will break its dormancy once we have achieved 7 growing degree days, which has already occurred. Female weevils seek the base of terminal buds on white pine and spruce to chew small holes and lay their eggs. Larvae then tunnel downward through 2-3 years of growth and eventually cause the terminal to wilt and die. If treatments are deemed necessary, they should be applied while the adults are active to prevent (reduce) egg-laying.

Trees and shrubs - The spring of 2005 was wet in many parts of New England and resulted in a lot of leaf spot and shoot blight diseases. These diseases, as well as branch cankers, may disfigure woody plants but they seldom kill otherwise healthy plants. However, if leaf spots and blights were serious problems last year, infected plant material from last year may produce fungal fruiting structures this spring that release an abundance of inoculum. During wet springs, these spores infect young leaves and shoots. For high value plants where appearance is important, consider several applications of fungicides beginning as buds open if conditions are wet this spring. Alternatively, consider replacing plants with recurring leaf spots and blights with resistant varieties or other plant materials better adapted to the site.

In addition, if there was extensive branch dieback due to canker infections, this may be an indication that the tree or shrub is in a weakened condition. Useful management interventions consist of those activities that enhance the vitality of the woody plants. Suggestions include soil aeration, weekly soaking irrigations during dry periods, fertilization of poor soils, maintenance of a 2-3 inch layer of organic mulch over as much of the root zone as possible, as well as removal of dead branches and pruning to improve branch structure and air movement throughout the crown.

Ramorum Blight, also known as Sudden Oak Death (SOD). Since the early 1990’s, oaks and tanoaks were dying in the coastal counties of California. Since then, other types of plants have been found to be infected or associated with this disease, referred to as Sudden Oak Death, ramorum leaf blight or ramorum dieback, or by regulation as Phytophthora ramorum. The first positive identification of the disease was in 1995 on tanoak in Mill Valley (Marin County), California. Since that time, surveys confirmed Phytophthora ramorum on various native hosts and nursery plants in several locations in California, Oregon, Washington, and British Columbia. When nursery surveys find infected plants prompt quarantine and/or eradication activities ensue. Research conducted by the Agriculture Research Service, US Forest Service, universities, and others is under way to better identify hosts, improve methods of detection, and develop effective treatments. Currently, 84 plants are regulated, two of which at the genus level (Camellia and Rhododendron). There are no chemical treatments currently available to eliminate Phytophthora ramorum from infected plants.

Status of Phytophthora ramorum Monitoring Surveys - The 2005 National Nursery Survey involved 49 states and Puerto Rico. It reported that 3,790 nurseries have been visited and 68,275 samples collected. The surveys identified 56 positives sites in seven states. Overall, 99 positive sites have been reported this year. The breakdown by state is: CA (55), GA (4), LA (2), OR (20), TN (1), SC (1), and WA (16).

New Hosts Added - USDA APHIS issued a Federal Order on November 15 adding Abies concolor (white fir) and Viburnum opulus (= V. trilobum) (American cranberry viburnum) to the official USDA APHIS list of host and associated host plants. In addition, USDA APHIS issued a Federal Domestic Quarantine Order on February 10 adding Frangula purshiana (formerly listed as Rhamnus purshiana), Adiantum aleuticum, and Adiantum jordanii to the APHIS list of P. ramorum hosts. They also identified 13 new plants as associated hosts. One of the plants, found in an infested area of California and identified by Washington State, was Abies magnifica. The other 12 new species were reported from Canada, and include: Acer davidii, Ardisia japonica, Euonymus kiautschovicus, Gaultheria shallon, Hamamelis X intermedia (H. mollis & H. japonica), Leucothoe axillaris, Magnolia grandiflora, Michelia maudiae, Michelia wilsonii, Osmanthus decorus (=Phillyrea decora; =P. vilmoriniana), Prunus lusitanica, and Rosa rugosa. Koch’s postulates for these plants, the process of isolating the pathogen from the plant and reinfecting healthy plants to confirm infectivity, is not complete so they will be added to the associated host list.

Dan Gillman, Plant Pathologist, based in the UMass Extension Plant Diagnostic Lab at UMass, Amherst.

WEEDS

The warm weather from last weekend was just enough to get some perennial weeds to produce some new growth. New growth, predominantly in warm sites, can be seen on silvery cinquefoil and wild carrot. Annual bluegrass also responded with the initiation of new leaves and some growth was also seen with corn speedwell.

Reported by Randall Prostak, Weed Specialist, UMass Extension Landscape, Nursery and Urban Forestry Program, Amherst.

TURFGRASS

Insects: No report: Visit the Landscape Message Archive for previous messages.

Weeds: No report: Visit the Landscape Message Archive for previous messages.

Don't forget to visit the UMass Extension Online Weed Herbarium!

UMass Extension’s Turf Management Guide and IPM Facts: For more information about the pests mentioned in this message, you will need to refer to the following publications: the Professional Guide for IPM in Turf for Massachusetts, 2003-2004 edition and Turf IPM Facts . Call (413) 545-2717 to order these publications from the UMASS Outreach Bookstore.

DIAGNOSTIC SERVICES

UMass Laboratory Diagnoses for Turf and Landscape Problems - Accurate diagnosis for a turf or landscape problem can often eliminate or reduce the need for pesticide use. The UMass Extension Plant Diagnostic Lab is available to serve commercial landscape contractors, turf managers, arborists, nurseries and other green industry professionals. It provides woody plant and turf disease analysis, woody plant and turf insect identification, turfgrass identification, weed identification, and offers a report of pest management strategies that are research based, economically sound and environmentally appropriate for the situation. Send specimens and payment (payable to the University of Massachusetts) to UMass Extension Plant Diagnostic Lab, Holdsworth Natural Resources Center, 160 Holdsworth Way, UMass, Amherst, MA 01003. The fee for a woody plant disease analysis is $50; the fee for turf disease analysis or nematode assay is $75. All insect, weed and turfgrass identification samples are $25 each. For more detailed submission instructions see http://www.umass.edu/agland/diagnostics

NEXT UPDATE: The next issue will be available on Friday, March 31, 2006.

This message is produced by the UMASS Extension, Landscape, Nursery and Urban Forestry Program. The copy is prepared by Anna Greene from data and reports provided by the staff and faculty of the UMass Landscape, Nursery and Urban Forestry Program and the UMASS Extension Turf Program as well as cooperating horticulturists and Green Industry professionals. The text is adapted for access via the internet by Jason Lanier and made available to subscribers via electronic transmittal by Ellen Weeks.

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