UMass Extension Landscape Message #21
August 19, 2005

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. This issue has been updated to provide timely pest management information and the latest regional news and environmental data throughout Massachusetts. During the months of July, August and September, the LANDSCAPE MESSAGE will be updated on a bi-weekly basis. The next update will be available in two weeks on Friday, September 2, 2005. 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 the two-week period from August 4 through August 17, 2005. Soil temperature and phenological indicators were observed on August 17, 2005. 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: Dry, Dry, Dry! While other areas of the state have seen relief in the form of thunderstorms, the Cape has remained without sufficient precipitation. Storms fizzle out before reaching us or are so widely scattered that most areas receive nothing at all. With high temperatures and no rain, plants are suffering. Pests/Problems: Trees are beginning to drop much of the excess foliage that formed back in the wet spring. Marginal scorch is showing up on maples. Red maple is showing early fall coloration due to water stress. Rhododendrons are looking sad in unirrigated areas. Soils are hydrophobic at this point, and we need several days of gentle rainfall to soak in. Wasp colonies are getting large, and many reports of ground dwelling wasps are coming in. Japanese, Oriental and Asiatic garden beetles are still feeding. Second generation lily leaf beetle adults are feeding. Powdery mildew is very noticeable on phlox and beebalm.

Southeast Region (Hanson) - General Conditions: The weather continued to be hot and very humid August 9. It's still warm but not as humid. Some areas of Plymouth County received much needed rain from a severe storm that hit the northern part of the county on the afternoon and evening of August 7. Areas around Hingham and Weymouth experienced over five inches of rain in a very short time period, leading to flooding. Microbursts in Hingham brought damage to trees. Hanson received 1.50 inches of rain from that storm while East Bridgewater received 0.9 inches, Halifax 0.75 inches and Middleborough received little to no rain from that storm. Soils in some southeastern parts of the county continue to be dry. Hydrangea paniculata, Albizia julibrissin (Mimosa), Clethra alnifolia, Rose of Sharon, Butterfly bush, Hydrangea quercifolia (Oakleaf hydrangea), Hydrangea macrophylla, Corydalis lutea, Nepeta, Heliopsis 'Summer Sun', Monarda didyma, purple coneflower, Rudbeckia 'Goldsturm', Phlox paniculata, daylilies, and hosta are in full bloom. Filipendula venusta, Lysimachia clethroides, and hollyhocks are ending bloom. Pests/Problems: Asiatic beetles are active. Slugs, snails, black vine weevil adults and ticks are all active. Mosquitoes are still plentiful. Dogday cicadas and katydids are showing up in landscapes. Black tar spot is showing up on Norway maple. Some white pine and spruce are sporting dead, brown terminals due to white pine weevil. Black sooty mold is common on plants with significant honey dew residue on their leaves. Powdery mildew continues to persist on a wide variety of plants including oak, lilac and garden phlox.

East Region (Boston) - General Conditions: Albizia is also in full bloom here.

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

Pioneer Valley Region (Amherst) - General Conditions: The rain and cool weather arrived just in time in the Pioneer Valley after a hot, humid period prior to that. Lawns, gardens, trees and shrubs continue to thrive. Pests/Problems. Powdery mildew is quite visible on herbaceous and woody ornamentals such as phlox, zinnia, flowering dogwood, sycamore and lilac.

Berkshire Region (Great Barrington) - General Conditions: Flash drought, as some meteorologists had described it, was the prominent weather feature of late July and early August. However, some hefty showers in recent days have replenished root-zone soil moisture. The heat and humidity of much of the summer has left many plants looking ragged as the result of various foliar diseases. Pests/Problems: Slugs and deer ticks are the prominent pests. Fall webworm nests are very apparent now, and the population of this foliage feeder seems a little above average for the Berkshires. Japanese beetle adults are still active, but the numbers are relatively low when compared to recent seasons.

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

The hot and humid weather continues to drive lacebugs and warm-season spider mite populations. Infested plants in sunnier locations are experiencing greater injury, overall.

Gypsy Moth - The flight of the male moth has been quite noticeable statewide this year. However, we are very near the end of their mating cycle.

Forest Tent Caterpillar (FTC) - The only evidence of this pest now is the small and black egg masses that are usually wrapped around small stems of the host plant.

Fall webworm - The webs have been becoming obvious for the past couple of weeks. When found in small numbers and at reasonable heights, they can be pruned away and destroyed, with the caterpillars inside.

Hymenopteran Caterpillars (Sawflies):

Introduced pine sawfly remains active and may be found on many of the same host plants as European pine sawfly (e.g. mugo, scots and other pines). Inspect and treat when found. While insecticidal soap works well on the younger caterpillars, a product containing spinosad works on caterpillar stages.

Redheaded Pine Sawfly - This yellow caterpillar with black spots and a rust-colored head capsule will become active soon. Treat young larvae with an insecticidal soap spray or treat caterpillars of all ages with a product that contains spinosad.

Dogwood Sawfly - This yellow caterpillar with black spots is usually covered with a dense white pubescence that gives it the appearance of a bird dropping. Larger populations that go untreated can cause much defoliation. When found in considerable numbers, treat with a spinosad product.

Beetles:

Viburnum Leaf Beetle - Adult beetles are no longer active. Look for eggs along the bare twigs, which results in a ‘sandpaper’ texture. Visit the Cornell web site, http://www.hort.cornell.edu/vlb/index.html , for current information on this pest. Report any new findings in MA to Robert Childs, rchilds@psis.umass.edu, 413-545-1053.

Lily Leaf Beetle - This pest remains very active and is well into the next generation. Monitor for its presence, and treat when found. Spinosad products work well against the larvae.

Japanese beetle adults are very active statewide. This pest has a large host plant range and will continue to be very active into September. Monitor favored host plants on a regular basis, and treat when numbers begin to reach unacceptable levels. Pyrethroid products are most likely the best method for treating these adult beetles.

Asiatic garden beetle adults remain somewhat active. These night feeders are most active between the hours of 9 PM and midnight. They are attracted to a wide range of host plants from the landscape to the garden. Their feeding can cause much defoliation. Inspect plants at night with a light; and if necessary, treat.

Black Vine Weevil - Continue to monitor foliage of taxus and rhododendron in the landscape and nursery for notched foliage, especially on the lower part of host plants. The adult weevils will become active soon and begin to feed on foliage. This insect does not fly and must walk up the host plant each night to feed. Place loosely folded burlap strips on the ground around plants and inspect during the day. Adult weevils will use the burlap as a hiding place during daylight hours; collect and destroy beetles. If found in large numbers, treat with a product that contains lambda-cyhalothrin.

Piercing-Sucking Pests:

Spider Mites:

• Inspect the needles and stems of conifers now for injury from spruce spider mite. Now that the hot and humid weather has been here for a while, this pest remains in its summer dormancy but will return by the end of August and can be active well into the fall. Horticultural oil sprays (at the summer rate) can be effective once they return to feed on the plant.

• Two-spotted spider mite (one of the warm-season mites) is now very active on a wide range of host plants. Warm season mites prefer, and thrive, during hot weather. Their rate of development is greatly accelerated by the heat; and at the same time, predatory mites often leave the host plant and go into summer dormancy in the leaf litter or mulch. This gives spider mite populations the potential to explode in numbers and to create much plant injury in a short amount of time. Continue to monitor on a regular basis, and treat increasing populations before they become too large. Horticultural oil sprays used at the summer rate can be quite effective, as are the new mite growth regulator products. Avoid the overuse of chemical pesticides; spider mites are quite adept at developing pesticide resistance.

Hemlock Woolly Adelgid (HWA) - This pest remains in its summer dormancy, and the tiny nymphs are settled along the stems at the base of the needles. Feeding will cease until mid-October. Horticultural oils can still be applied at the summer rate when the correct weather conditions prevail; avoid very hot and humid days for oil applications.

Mealybugs - Inspect the undersides of inner branches for taxus mealybug. Treat when found. They are quite active now. This pest can greatly reduce plant growth. Also, it produces much honeydew, which leads to problems with sooty molds.

Andromeda lacebug is extremely active. Inspect leaf undersides of Japanese andromeda for the activity of this pest. Treat the plant with a soil-applied systemic treatment of imidacloprid, or spray the leaf undersides with an insecticidal soap. Pyrethroid insecticides are also labeled for this pest.

Azalea Lacebug remains extremely active. Plants that are in sunnier locations can be severely damaged by this pest. (See Andromeda Lacebug above for recommendations.) Untreated plants in sunny locations can have foliage with a bleached appearance by mid-late August.

Potato Leafhopper - This leafhopper cannot survive a Massachusetts winter, yet it is a problem here every summer. It arrives about this time from more southern states and can be a problem on maples, especially in the nursery. They feed by sucking plant juices from the foliage, and heavy populations will create a bleached appearance on the foliage. Inspect for new piercing-sucking injury that is very fine and expanding. Also, look for the pale-colored leafhoppers on the foliage undersides. Treat with a pyrethroid insecticide when found in unacceptable numbers.

Scale Insects:

Armored Scales - A group of scale insects characterized by a hard, convex covering over their bodies, such as pine needle scale, euonymus scale , juniper scale and white prunicola scale can be monitored now using a piece of black electrical tape that has been repeatedly daubed on the stems; the tiny euonymus scale crawlers will appear as orange spots on the tape. Treat with a horticultural oil spray (summer rate) when plant phenology and correct weather conditions prevail.

Soft Scales.

• Tuliptree scale and azalea bark scale can be monitored now. Look for sooty mold on the host plants. In the case of tuliptree scale (found on tuliptree and magnolia), one can also find the large, dark brown coverings on the stems. Azalea bark scale will appear white and cottony and will mostly be found in branch axils along the main trunk. Treat with a horticultural oil spray or systemic imidacloprid. These can be difficult to manage and may require future monitoring and treatments.

• Cottony Camellia Scale (a.k.a. Cottony Taxus Scale) remains active. Inspect leaf undersides for the nymphs. Females, when present, are tan-colored and round with an elongate and white egg-sac attached to their covering. When they are present in large numbers, this pest can greatly diminish plant growth and also be responsible for much unwanted sooty mold.

Leaf Miners:

Arborvitae Leafminer caterpillars have now invaded new foliage. Inspect the undersides of new foliage with a hand lens for the tiny entrance holes. Many new holes indicate a population that will cause damage in the form of browned tips. However, browning will not appear until January or February. Also, if treatments were administered for this pest earlier in the season and if new holes are being seen now, it means that the control measures were not successful. This is a difficult pest to manage at this stage. Systemic imidicloprid products do not achieve the desired levels of control.

Wood Borers:

Dogwood Borer - The adult moths remain active. Pheromone traps are available for this pest. Keep flowering dogwood free of wounds from mowers and line trimmers, which encourage invasion by this insect. Treat infested trees in August with a trunk/branch spray of entomopathogenic (beneficial) nematodes.

Rhododendron Borer - This is another clear-winged moth caterpillar that is a wood borer and a close relative to the dogwood borer (Sesiidae Family). Inspect around the base of rhododendrons, on the ground, for coarse sawdust that has been expelled by the caterpillar boring in the shoot. Physically prune out and destroy infested shoots or use a coarse spray of entomopathogenic nematodes.

Bronze Birch Borer - This wood-boring beetle requires a previously weakened tree for successful colonization. Keep birches healthy by watering during drought, mulching and avoiding soil compaction. Some advise that birches not be pruned from June into September to avoid releasing plant volatiles that may attract female beetles. However, healthy trees should be able to withstand pruning at this time and still naturally defend itself against this pest.

White-spotted pine sawyer (WSPS) beetle adults have been active for at least a couple of weeks. This native longhorned beetle bears a strong resemblance to the Asian longhorned beetle (ALB). However, WSPS is not a pest. It only attacks pines that are already very weakened. UMass Extension receives many calls every year about WSPS due to its resemblance to ALB. White-spotted pine sawyer is a grayish/ black color with diffuse white spot(s) while ALB has a black body that looks like shiny black patent leather. The white spots on its body are crisp and obvious.

The tilehorned prionus (tilehorned beetle) remains active as an adult. This very large (2 inches long) and robust dark-colored beetle is somewhat common. It often lays its eggs in the buttress roots of oaks, often in specimen oaks in parks. The larvae tunnel these roots and can kill the tree. The presence of this pest is generally not known until the infested dies. Fortunately, only a small number of trees are attacked. No controls are available.

Reported by Robert Childs, Entomologist, UMass Extension Landscape, Nursery and Urban Forestry Program, Amherst

DISEASES

Black spot on rose can be ugly and destructive to highly susceptible plants. Black, rounded spots develop on infected leaves and rose hips. In addition, infected first-year canes exhibit lesions that are reddish colored initially, which later turn black. Black, pinhead-sized fruiting structures develop in the center of the spots. Repeated black spot infection cycles will occur during wet periods throughout the remainder of the growing season. Eventually, spotted leaves turn yellow and drop off prematurely. Roses that sustain considerable leaf loss fail to thrive and are more prone to winter damage. Remove and destroy infected leaves and canes. Minimize the duration of foliage wettings after irrigation. Irrigate so leaves dry before sunset. The longer leaves and canes are wet the more time the black spot fungus spores have to infect the rose. Many beautiful, black spot resistant rose varieties are available. To protect susceptible roses, apply fungicide sprays at intervals specified on the label. The numerous fungicides labeled to protect foliage on susceptible plants are listed in the UMass Extension Management Guide for Woody Ornamentals.

Mushrooms in lawns often develop from thatch, buried logs, dead roots, stumps, or even construction debris. They have many different sizes, colors, shapes, and habits of growth and invade lawns after prolonged wet weather. The fungi that produce these mushrooms are beneficial because they decompose organic matter in the soil, making nutrients available to other plants. These mushrooms usually are harmless to grasses, but some people consider them unsightly or want to get rid of them because young children play in the area. Neither spray applications nor drenches of fungicides are effective in controlling these mushrooms. Remove mushrooms growing from buried wood or roots by picking them as they appear or by digging out the wood. Elimination of excess thatch and aerating the soil to improve water penetration also helps in some cases. In addition, if the mushrooms are left to themselves, they just disappear when the weather becomes dry.

Cedar-apple rust is visible as reddish-yellow spots on susceptible hawthorn, apple and crab apple leaves. Many of the undersides of the reddish-yellow spots have tiny tube-like fruiting structures extending from infected leaves. From now to leaf fall, spores are wind-carried from the apple leaves and, when conditions are wet for several hours duration, they infect green shoots and needles of junipers. Pea-sized to two inches in diameter round, brown galls develop on susceptible juniper needles and twigs between 12 and 20 months after infection. The best long-term approach to manage this disease is to grow cedar-apple rust resistant apple and juniper varieties. Also, prune dormant galls on juniper during the summer, fall, winter and early spring (before jelly-like horns form). Avoid growing susceptible junipers close to apples. The time to apply fungicides to protect high value apples from cedar-apple rust has passed for this spring. Fungicide protection of eastern red cedar and Rocky mountain junipers is seldom performed; but if it were desired, it would be from now through September when there are extended wet periods.

Horsechestnut (Guignardia) leaf blotch is evident as irregularly shaped orange-brown blotches on infected leaves. As the summer progresses, the impact of the disease is often more noticeable; but chemical intervention at this time for this season is of little benefit. Likewise, it has been noted that horsechestnut that suffer repeated severe infections continue to grow vigorously in spite of Guignardia leaf blotch.

Powdery mildew fungi are now visible as a dusty, gray to white spots/blotches on horsechestnut, phlox, dogwood, sycamore and rose leaves. Once established on plants, powdery mildews grow superficially on both upper and lower leaf surfaces as well as green shoots and flower buds. They are obligate parasites and derive sustenance only from living host plants. They do this using minute, tube-like structures (haustoria) that penetrate the epidermal cells and draw out material they need to survive. Spherical, black fruiting structures (cleistothecia) are becoming visible with a hand lens on the underside of infected leaves in the dusty, gray mycelia. Generally, the damage caused by powdery mildew is of minor consequence to healthy plants and does not warrant chemical control if unsightliness is not a critical concern. If chemical control is desired, there are a number of unconventional applied materials that are labeled to protect susceptible plants. They include summer horticultural oil, commercial baking soda preparations (sodium bicarbonate and potassium bicarbonate), anti_transpirants, as well as a number of conventional fungicides. Chemical spray programs are most effective when begun just as symptoms of powdery mildew begin to show. Once powdery mildew is extensive on the plant, there is little benefit from chemical control that season. Applications need to coat both surfaces of all susceptible plant parts to prevent infection. Spray on a regular schedule, and repeat more often during warm, humid weather.

Apple scab is visible on susceptible crab apple leaves. Some leaves are curling or cupping where lesions developed before the leaves were mature, and the dead leaf tissue constricted leaf expansion. Within a few weeks after infection the olive green fruiting bodies produce new spores. There is little benefit from fungicide applications at this time in the season. Prune to increase sunlight penetration and air circulation to promote rapid drying of wet foliage. If apple scab is a chronic problem and if replacement is an option, consider planting resistant varieties of crabapple. This fall remove and destroy fallen leaves in the vicinity of the tree to reduce primary inoculum available for initial infections next spring.

Dogwood anthracnose is visible as brown-tan spots/blotches as well as some shoot blighting. Remove and dispose of dead leaves, twigs and branches to reduce anthracnose inoculum in infected trees. Dogwoods receiving good cultural care are better able to limit the extent of dogwood anthracnose damage. Water during dry periods and maintain two to four inches of composted bark mulch over as much of the root area as possible. It is too late this spring to protect new shoots and leaves with fungicide applications. Next spring begin as buds break open, when bracts have fallen, and four weeks later. Later this summer, a fungicide application may be beneficial to protect the flower buds from infection if the weather is cool and wet in the fall. If dogwood anthracnose is a persistent problem, consider planting one of the many resistant cultivars of Cornus florida and C. kousa now commercially available.

Ramorum Blight, also known as Sudden Oak Death (SOD). Since 1995, oaks and tanoaks have been 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. SOD was first seen in 1995 in Mill Valley ( Marin County) on tanoak. Since that time, the disease has been confirmed on various native hosts in fourteen coastal California counties (Marin, Santa Cruz, Sonoma, Napa, San Mateo, Monterey, Santa Clara, Mendocino, Solano, Alameda, Contra Costa, Humboldt, Lake and San Francisco), and in Curry County, Oregon. Research being conducted by the Agriculture Research Service, US Forest Service, universities and others is under way to better identify hosts, methods of detection and effective treatments. Currently, 64 plants are regulated, two of which at the genus level (Camellia and Rhododendron). There are no chemical treatments currently available to eliminate the disease in nursery stock.

Status of Phytophthora ramorum Monitoring Surveys . The 2005 National Nursery Survey is underway. As of August 3, 44 states have reported National survey results—2,599 nurseries have been reported visited and 42,859 samples collected. Forty-eight positives sites in six states have been identified through national survey or Federal order and annual cleanliness compliance surveys. Outside of the three regulated west coast states, seven national survey positives have been confirmed. Georgia reports four positive nurseries, Louisiana reports two positives nurseries, and Tennessee reports one positive nursery. In the regulated states, California has found 23 positive nurseries during their Federal Order compliance surveys and annual cleanliness surveys. Oregon has identified 11 positive nurseries during their Federal Order and compliance surveys. Washington has reported seven national survey positive sites.

The US Forest Service and states are conducting nursery perimeter and general forest detection surveys in 38 states during 2005. As of August 3, USFS reports 390 nursery perimeter surveys in 28 states with 932 samples collected; results are available for 246 samples and all are negative. USFS reports 303 general forest surveys have been conducted in 27 states; 661 samples have been collected. There are no confirmed positives based on 128 results.

There were no new positives in the Eastern Region in the last month. However, in the Western Region during the last month five nurseries were determined to be infested with Phytophthora ramorum—one in California, two in Oregon, and two in Washington. California Department of Food and Agriculture confirmed the presence of P. ramorum in a production nursery in Shasta County. In Oregon, APHIS confirmed the presence of P. ramorum at one nursery in Coos County, and one in Lane County. While in Washington, APHIS confirmed that two large nurseries were infested with P. ramorum. One is a large retail nursery in Pierce County and the other is a nursery in King County.

As of this time last year, August 5, 2004, the total number of confirmed positive sites from trace forward, national, and other surveys was 154 in 20 states versus the 85 confirmed finds in 6 states reported for 2005. This represents an overall reduction in positives sites of 45%. Excluding finds in the three regulated west coast states, the number of detections has declined from 67 sites in 17 states during 2004 to 7 sites in three states during 2005, a reduction of nearly 90%. The decline in positive finds in the regulated west coast states has been less dramatic—87 positive sites at this time in 2004 versus 78 in 2005, a 10% reduction. This smaller decline may be due in part to increased survey of nurseries in these states under the December 21, 2004 Federal Order.

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

WEEDS

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

TURFGRASS

Insects:

Grubs: In areas where soils have been unusually dry, I would expect that egg laying of Japanese beetles, Oriental beetles, Asiatic garden beetles, and European chafers to be delayed. Adult females seek sites with "adequate" soil moisture, because the eggs are very vulnerable to desiccation. In some locations where there was considerable rain early in the summer, some eggs would have been laid at that time. Since then, many areas in New England have been without rain for several weeks, and the air temperatures have been unseasonably (and unreasonably!) high. Therefore, I would expect that female beetles are holding on to the rest of their eggs until conditions improve. This means we may see newly laid eggs as late as the last week of August or the first week of September.

Nevertheless, we have seen eggs and small larvae in a variety of turf settings, all within the last week or so. Clearly some grubs will be right on schedule and feeding more and more on the turf roots.

Because there may be a delayed egg hatch, imidacloprid (Merit™) might still be effective at this point, particularly in northern New England. And, remember that there is a new product out that is very similar to Merit™ chemically but claims to have better activity against medium-sized larvae. That product, chlothianidin (Arena™) has looked excellent in our field trials when it was applied before eggs hatched, but we have not yet tested it for later season applications. (Note that while Arena™ received federal registration during the winter, each state must approve the product as well. I do not know the state registration status of Arena™ for each state.)

Meanwhile this would be an excellent time to apply halofenozide (Mach 2™) against Japanese beetle grubs, but it may be too late for European chafers. (Remember that Mach 2™ has been very inconsistent over the years on Oriental beetle populations.) Because this has been such a dry period, Mach 2™ must be watered in, despite what the label might say. (In a previous dry year, we tested a variety of Mach 2™ treatments and withheld water from half those plots. When we returned in the fall to rate the products, the plots that had not received water after the application were essentially dead from grub feeding while the identical treatments that had been watered in were green and healthy.)

Webworms? Just as a curiosity report, I saw literally hundreds of webworm adults flying just above my lawn the other night while I was mowing. There are several species of webworms that occur in New England. Normally we notice webworm activity in lawn turf, but the caterpillars rarely cause visible damage in such settings. However, they can also occur on golf courses and cause damage. Fortunately, the insecticides used against cutworms will also work against most webworms. This late in the season, I would not worry about them in most situations. The moths may lay eggs that will hatch into small caterpillars, but those caterpillars will not be feeding actively for another week or two. By then we should be seeing a break in this hot weather.

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

Two UMass Extension Web Sites are specially designed to provide Green Industry professionals with resources, upcoming educational programs and events, and other relevant information. The Internet address for the Landscape, Nursery, and Urban Forestry Program is http://www.umassgreeninfo.org. The Turf Program address is http://www.umassturf.org .

New England Guide to Weed Control in Turfgrass - The updated 2005 New England Guide to Weed Control in Turfgrass is now available. It contains extensive information about currently registered turf herbicide products, including specifics on application, timing and environmentally responsible use. The guide is available as a free, downloadable PDF file in the Online Publications section of http://www.umassturf.org

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 Extension 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 Urban Forestry Diagnostic Laboratory is available to serve commercial landscape contractors, turf managers, arborists, nurseries, and other green industry professionals. It provides woody plant disease analysis, woody plant and turf insect identification, turfgrass identification, landscape and turf 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 made payable to the University of Massachusetts to Urban Forestry Diagnostic Lab, 160 Holdsworth Way, Holdsworth Natural Resources Center, UMass, Amherst, MA 01003. The fee for a woody plant disease analysis is $50.00. All insect, weed, and turfgrass identification samples are $25.00 each. For complete information and instructions on how to send specimens, visit the Urban Forestry Diagnostic Lab page.

Turfgrass disease samples should be directed to the UMass Turf Disease Diagnostic Lab . This service is available ONLY to green industry professionals such as landscapers, lawn care companies, and golf course managers. For more info specifically on turf disease diagnostics, visit the Disease Diagnostics page at www.umassturf.org .

NEXT UPDATE: The next issue will be available in Friday, September 2, 2005.

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.

DISCLAIMER. This message is intended for commercial use. UMASS Extension assumes no liability for recommendations. The use of trade names does not imply endorsement. Similarly, there may be other products you prefer to use.

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