UMass Extension Landscape Message #18
July 10, 2008

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Quick Info Menu ------------------------------- SCOUTING INFORMATION REGIONAL NOTES - Cape Cod - Southeast - East - Metro West Waltham - Metro West Hopkinton - Central - Pioneer Valley - Berkshire ENVIRONMENTAL DATA PHENOLOGY WOODY ORNAMENTALS - Insects - Diseases - Weeds LANDSCAPE TURF 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. During the months of July, August, and September this newsletter will be updated bi-weekly. The next update will be available on July 24, 2008. Missed a previous message? Visit the Landscape Message Archive. Interested in additional turf-oriented content? UMass Extension Turf Program Management Updates

SCOUTING INFORMATION BY REGION

REGIONAL NOTES -

Cape Cod Region (Barnstable) – General Conditions: Generally, warm and muggy conditions have prevailed over the past two weeks.  While pop-up thunderstorms provided some precipitation, overall accumulation has not been great and soils will dry out quickly.  Many ornamentals are coming into bloom and, in general, plant development is advanced over the average year.  Blue hydrangeas provide great color in the landscape and are about one to two weeks ahead of normal schedule.  Pests/Problems:  Cicada adults are gone while the damage from egg laying is now quite visible.  In many cases, the damage is cosmetic, with many flagging tips on hardwoods, especially oaks.  There are some trees where the flagging is quite extensive, occurring in the majority of the crown.  Trees that have been defoliated by caterpillars in previous years and that have extensive flagging may be at risk.  Keep these trees well watered during dry periods.  Oriental and Japanese beetle adults are active.  Cottony taxus scale crawlers are active.  Needle cast has been observed on Douglas fir.  Powdery mildew is present on some phlox and beebalm; leaf spots of various causal agents are common on herbaceous plants.  Slime molds are sprouting on bark mulch while mushrooms are popping up in lawns.

Southeast Region (Hanson) – General Conditions: Hot, hazy, humid weather was the norm for the past two weeks with most day-time temperatures in the eighties.  Rainfall varied in many areas of the county, and Hanson received 0.44 inches.  Soils are dry and rain is needed. It is a very good year for Hydrangea macrophylla with many plants displaying numerous blue or pink flowers.  The mild winter certainly contributed to this beautiful display.  Some Kousa dogwoods are still in full bloom while others have ended.  Koelreuteria paniculata, Stewartia pseudocamellia, landscape roses, Hydrangea paniculata 'Praecox' (Panicle Hydrangea), Hydrangea quercifolia (Oakleaf Hydrangea), Hydrangea macrophylla 'Blue Billows', etc., southern catalpa, Lysimachia clethroides, Yucca filamentosa, daylilies, Corydalis lutea, shasta daisy, nepeta, Heliopsis 'Summer Sun', Monarda didyma, Filipendula venusta, Liatris, Thermopsis, Persicaria polymorpha, Astrantia, Campanula sp., butterflyweed, Achillea, hosta, Coreopsis verticillata, and astilbe are in full bloom.  Campsis radicans and Phlox paniculata are beginning bloom.  The native smoke tree (Cotinus obovatus) and the European Smokebush (Cotinus coggyria) continue to provide the landscape with their colorful “smoke.”  The smokebush and smoketree produce small greenish flowers in June, and the subsequent “smoke” is the result of plume-like hairs which form on the sterile flowers.  Pests/Problems:  Cottony camellia/taxus scale is active on taxus and blue hollies.  Oriental, Asiatic, and Japanese beetles are active.  Oriental beetles appear to be more numerous this year and were found feeding on several perennials.  Brown terminals of white pine are usually indicative of white pine weevil damage; too late for chemical management.  Colorado potato beetle adults and larvae are feeding on Datura, Brugmansia, and Nicotiana.  Snails are doing considerable damage to herbaceous material.  Four-lined plant bug, Pieris or andromeda lacebug, aphids, cutworms, earwigs, ladybugs (and their colorful larvae), slugs, snails, ticks, and mosquitoes are all active.  Monitor ornamental cherries, lilac and privet for white prunicola scale.  Mosquitoes are numerous this year.  Powdery mildew is active on Phlox paniculata.  Plymouth County Extension does not spray for mosquitoes.  The number for residents of Plymouth County to call is 781-585-5450.

East Region (Boston) – General Conditions: Hazy hot and humid, occasional cloudbursts.

Metro West (Waltham) – General Conditions: Lawns are green.  There has been a good amount of rain and no signs of drought stress, yet.  Pests/Problems:  Some “flagging” has been noticed on elm trees indicating possible Dutch elm disease.  Some crabapples have signs of cedar-apple rust.  Crabgrass is growing well in certain areas.

Metro West (Hopkinton) – General Conditions: Tropical conditions prevail with frequent showers and thunderstorms.  Lawns are remaining green in most areas.  Pests/Problems:  Signs of Phytophthora are showing up in area landscapes on rhododendrons.  Powdery mildew is showing up on monarda, phlox, and asters.

Central Region (Boylston) – General Conditions: No conditions report available. See Environmental Data and Phenology below.

Pioneer Valley Region (Amherst) - General Conditions: The regular rainfall during the last two weeks maintained soil moisture levels in spite of the warm temperatures.  Daylilies, black-eyed Susan, and a bevy of summer annuals are coming into their own in gardens, lawns remain lush and green, and trees and shrubs are thriving in Valley landscapes.  Pests/Problems:  Lily leaf beetle on lilies as well as a couple ticks and plenty of mosquitoes troubled gardeners this past weekend.  An interesting assortment of mushrooms is visible in many lawns.  With the warm, humid weather powdery mildews are conspicuous on a variety of host plants.

Berkshire Region (Great Barrington) - General Conditions: No report avialble this week.

ENVIRONMENTAL DATA -

The following growing-degree-day (GDD) and precipitation data was collected for a two-week period, June 25, 2008 through July 8, 2008.  Soil temperature and phenological indicators were observed on July 8, 2008.  Accumulated GDDs represent the heating units above a 50° F baseline temperature collected via our instruments from the beginning of the current calendar year.  This information is intended for use as a guide for monitoring the developmental stages of pests in your location and planning management strategies accordingly.

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:

Indicator Plants - Stages of Flowering (begin, b/full, full, f/end, end)
PLANT NAME (Botanic/Common)	CAPE	SOUTH EAST	EAST	METRO W.		CENT.	P.V.	BERK.
				Waltham	Hopkinton
Rhododendron maximum (Rosebay Rhododendron)	b/full	*	*	f/end	full	*	*	*
Lythrum salicaria (Loosestrife)	full	begin	*	full	full	*	*	*
Koelreuteria paniculata (Goldenrain Tree)	*	full	*	end	*	begin	*	*
Cotinus coggygria (Common Smokebush)	full	full	end	f/end	begin	full	full	*
Hydrangea arborescens (Smooth Hydrangea)	full	full	*	*	full	full	full	*
Stewartia pseudocamillia (Japanese Stewartia)	full	full	full	*	full	full	*	*
Rhus typhina (Staghorn Sumac)	begin	red	full	end	full	*	f/end	*
Tilia cordata (Littleleaf Linden)	full	end	full	end	end	full	f/end	*
Ligustrum spp. (Privet)	full	f/end	end	f/end	end	*	end	*
Sambucus canadensis (American Elderberry)	f/end	*	*	f/end	full	f/end	f/end	*
Cornus kousa (Kousa Dogwood)	end	f/end	end	f/end	end	f/end	end	*
Itea virginica (Virginia Sweetspire)	f/end	end	*	*	*	end	*	*
Oxydendron arboreum (Sourwood)	*	*	*	end	*	*	*	*
* = no activity to report/information not available

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.

METRO WEST REGION – James Martin, Consulting Arborist, reporting from the UMass Extension Center, Waltham.

METRO WEST REGION – Mark Sawyer, Horticulturist, Weston Nurseries, Hopkinton.

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

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

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

WOODY ORNAMENTALS

INSECTS -

Lepidopteran Caterpillars:

• Gypsy Moth - Pupation has occurred, and moths have been present, albeit in very limited numbers.  Any threat from this pest is now past.  No noticeable defoliation from gypsy
  
  
• Forest Tent Caterpillar moths have been quite active during the past two weeks.  There is no feeding in this life stage, just mating and egg-laying.  In the greater Amherst area, at least, the numbers of moths have been significant.  It is expected that this area will see more of this caterpillar in 2009.
  

Hymenoptera Sawfly (Caterpillar) Larvae:

• Imported Pine Sawfly - This sawfly is more commonly found in the eastern parts of MA than it is in the central and western parts.  It will become active by late June or early July.  It shares many of the same host plants as the European pine sawfly, including mugo pine.  Monitor for the yellow blocky egg patches within needles.  Remove and destroy needles with eggs.  Once the larvae emerge, treat with an insecticidal soap or a product that contains spinosad.
  
  
• Red-Headed Pine Sawfly is becoming active as well.  This species has a rust-colored head capsule and a yellow body with black spots.  (See Imported Pine Sawfly, above, for monitoring and management techniques.)
  
  
• Birch Sawfly − The caterpillars of this pest are active and feed by wrapping their bodies around the margins of foliage of birches as they consume all but the main veins of the leaves.  Although not abundantly common in the state, it does appear somewhere here every year and is capable of causing serious defoliation if not treated.  Spinosad products or one of the registered pyrethroids work well.  Also, insecticidal soap works well when the larvae are still quite small.   
  

Beetles:

• Japanese Beetle adults have finally begun to emerge.  Only slight damage can be found now; but as more and more adult beetles emerge from the soil per day, the damage to preferred host plants will increase quickly.  Adult beetles will need to be treated with a chemical insecticide, such as a pyrethroid, in order to protect plants.  New beetles will be emerging every day from now until early September.  Continue to monitor for the buildup of unacceptable numbers of this serious defoliator.  
  
  
• Asiatic Garden Beetle remains active and is becoming more common, along with its feeding damage. This small, robust and oval-shaped scarab beetle is only active at night.  It feeds on a wide variety of deciduous landscape plants as well as many different garden plants.  Monitor at night with a flashlight between the hours of 9 PM and midnight.  This pest can cause much ragged foliage to favored plants.
  
  
• Lily Leaf Beetle - Continue to monitor for the next generation of this beetle.  Larvae can be treated with a product that contains spinosad.
  
  
• Viburnum Leaf Beetle  - Adult beetles will be emerging any day now.  Monitor those plants that were damaged by the larvae last month.  Treat adult beetles with a pyrethroid insecticide spray. Report any new finds in MA to Bob Childs rchilds@psis.umass.edu or 413-545-1053.  Treat the same as for lily leaf beetle. For current information about this pest, visit the Cornell web site at http://www.hort.cornell.edu/vlb
  
  
• Imported Willow Leaf Beetle remains active.  The adult beetle is rather small, rounded, and metallic green/blue in color.  The adult beetles will chew holes into the foliage, but it is the small black-colored larvae that create most of the injury.  Larvae will line up together on the foliage and scrape the upper layers.  This action causes the still-intact leaf to eventually die and turn brown.  This pest has multiple generations per year, and its damage can become severe by August when virtually all of the foliage on a willow will appear bronze in color, as if fire-swept.  All willows are susceptible.  Treating the adult beetle requires a pyrethroid insecticide while a product that contains spinosad works well for the larvae.   

Piercing-Sucking Pests:

• The Red-Banded Leafhopper (a.k.a. Sharpshooter Leafhopper) has most likely arrived in MA now from more southern states.  This pale green leafhopper with two chevron-shaped stripes on its back is attracted to rhododendrons that continue to produce new foliage through July and August.  The egg-laying in the new leaf tissue causes the leaves to become stunted and distorted.  It is purely an aesthetic pest, but it can be an important pest, especially in the nursery.  Visually monitor for this insect by gently shaking foliage to dislodge the leafhoppers, which will fly up and then land again nearby.  When found in large numbers this pest should be treated.
  
  
• Maple Leafhopper − This is another leafhopper that migrates into the state every year and is mostly attracted to maples in the landscape and nursery.  Their piercing sucking feeding can create such extensive injury that foliage will appear to have been damaged by bleach; very chlorotic yet finely stippled foliage.  Monitor visually by shaking branches.  Treat if found in large numbers. 
  
  
• Lacebugs remain very active.  These serious pests always feed from the underside of the foliage, but they create the fine, yellow stippling feeding injury on the upper surface of the leaves.  Look at the bottom leaf surface of such affected leaves for the telltale signs of the brown fecal spots and the lacebugs themselves.  Inspect common host plants for this pest for last year’s damage.  Common hosts are Japanese andromeda, evergreen azaleas, rhododendron, cotoneaster, and hawthorn.  Systemic imidacloprid appears to be quite effective for managing this pest.  Also, horticultural oil sprays OR insecticidal soap sprays that are targeted to the foliage underside is also effective for the small nymphs.  Susceptible plants growing in sunny areas will experience more damage given that heat greatly encourages lacebug populations. 
  
  
• Miscellaneous Aphid species are building in numbers.  Monitor for honeydew and sooty mold.  Treat if necessary.  Systemic imidacloprid, or insecticidal soap sprays, or horticultural oil sprays are all effective treatments.  Maples, catalpa, tuliptree, lindens, and many others are common hosts.
  
  
• Taxus Mealybug remains active.  Move the foliage of taxus back and inspect the inner branches and smaller stems for white, cottony masses.  This insect produces honeydew, which leads to the  unsightly buildup of sooty molds.  Also, large populations can cause stunting and chlorosis of the foliage.  Treat with a systemic imidacloprid product, or spray the inner branches and stems with either a horticultural oil spray or one of the registered pyrethroid insecticides.
  
  
• Spider Mites - Inspect spruce, hemlock, fir, and others for the signs of feeding damage by these tiny but very prolific and potentially damaging pests.  Inspect very closely for the active mites, which will require a good hand lens or microscope.  If found, treat with an oil spray or with one of the new mite growth regulators.  Monitor for the actual mites by shaking a branch over a white piece of paper and then inspecting with a hand lens for the mobile mites.
  
  
• Hemlock Woolly Adelgid - This pest will go dormant in another one to two weeks, but it can still be managed even in that stage.  A horticultural oil spray (at the summer rate), systemic imidacloprid, or systemic dinotefuran (Safari™) are all effective against this very serious pest. Note: Safari™ is a State Restricted Use pesticide in Massachusetts.  (See Elongate Hemlock Scale, which appears next.)
  
  
• Elongate Hemlock Scale (aka Fiorinia Scale) − Inspect hemlocks closely for this pest.  If the plant appears weakened or sickly and has hemlock woolly adelgid, which is very obvious, take the extra time to closely inspect the undersides of the needles for this scale.  Fiorinia scale is very small, brown and mostly oval in shape.  Many of these may be present per needle (on the underside only).  In some case, it will be the primary reason that a hemlock looks to be in ill-health.  Imidicloprid, which works pretty well systemically for hemlock woolly adelgid does not have much of an impact on this scale.  Horticultural oil sprays, which also work well on hemlcok woolly adelgid tends to provide minimal control for this scale.  Safari™ (dinotefuran), a relatively new neonicotinoid, does show good promise for fiorinia scale and works well when utilized as a systemic.  However, in Massachusetts, it has a “State Restricted Use” labeling due to groundwater concerns.  Fiorinia scale is difficult to control.  Unlike most armored scales in the Northeast, it produces crawlers throughout much of the growing season.  If found, treat it aggressively.  Fiorinia scale is a very serious pest of hemlock and can occur on conifers other than hemlock. 
  
  
• Tuliptree Scale - Inspect the small branches of tuliptree and magnolia for the presence of this pest.  The adult females may still be on the foliage feeding and will be rather flattened and translucent, but once they move to the stems to produce eggs the covering over the female body raises up into a “gumdrop” shape and darkens.  This is one of the soft scales that can be a challenge to manage.  In large numbers it produces much honeydew and can weaken branches to the point of severely stunting growth.  It usually attacks tuliptree from the bottom branches and moves upwards over the years, often killing those branches.  In MA it can also be found on magnolia.  There is a remarkably similar scale known as magnolia scale, but it will not be found on landscape magnolia in MA due to the severity of our winters.  Crawlers can be treated with horticultural oil sprays.  Systemic imidacloprid or systemic dinotefuran can be effective. 
  

Wood Attackers:

• Bronze Birch Borer − The adults of this pest have been emerging for the past couple of weeks and will continue to emerge and be active into September.  This pest kills trees, but it can only survive in previously weakened trees.  Keep trees healthy to avoid attack.  Drought stressed trees are candidates for attack as are old trees or those growing in compacted soils.  Treatments become a challenge once infestation occurs.  Some arborists do not like to prune birches from June into September to avoid releasing plant volatiles that may attract beetles.  However, if the tree is healthy, then there should be little concern for colonization by this insect. 

• Dogwood Borer − This clear-winged moth is active and is seeking wounded dogwood trees from now until late August.  The females deposit eggs near bark crevices, such as branch collars, and around wounds.  The wood-boring caterpillar of this species tunnels into the cambium and later into the older wood.  Signs of an infestation now will be sap exudation on the trunk and scaffold branches.  Avoid wounding dogwood trunks with mowers and line trimmers.  Pheromone traps are available to monitor for the adult moths.  This caterpillar pushes out the sawdust as it tunnels thus leaving its tunnels open, unlike most wood borers.  Nematode products sprayed on the trunk are extremely effective for new infestations. 

Other Stuff:

• Periodical Cicada − Thousands upon thousands of cicadas emerged, mated and laid eggs in the stems of various deciduous trees, especially oaks.  This activity is now causing those affected shoots to die. 

• White-Spotted Pine Sawyer (WSPS) is now active as an adult.  This adult beetle is commonly confused with Asian Longhorned Beetle (ALHB), which has never been found in MA.  WSPS is native and is only attracted to very weak or freshly dead pines.  It is not considered to be a pest. 

A Few Comparisons/Differences Between ALHB and WSPS:

• ALHB has a very shiny black body, like that of patent leather; the pine sawyer is more of a dark mottled grey.
• ALHB has crisp white spots; pine sawyer has more diffuse white spots.
• ALHB has a blue-ish cast to the color of its tarsi (feet); pine sawyer does not.
• Both have antennal segments that alternate between white and black.

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

WEEDS -

Summer annual weeds have made a major push in the last one to two weeks.  Continue to scout.  Germination of spotted spurge, carpetweed, and purslane is occurring now.  Treat these weeds before they get too large.  Spot spraying with a non-selective herbicide is usually a better strategy than hand-weeding because it does not break the mulch barrier.

Scout for weeds that may be creeping into beds from adjacent turf areas.  Use a non-selective herbicide to edge the bed.

Inspect areas of landscape where new trees or shrubs, especially those that were field grown, have been planted in the last year.  Look for perennial weeds that may be growing from the root ball.  Canada thistle, mugwort, quackgrass, bindweed and horsenettle are some of the possible culprits.  Treat with a non-selective systemic herbicide (ex. glyphosate).  Contact herbicides (Sycthe™, Reward™) or the non-chemical burndown materials will not provide adequate control.

LANDSCAPE TURF

INSECTS -

Armyworms − The turf manager in eastern Massachusetts who suspected armyworm activity sent me some specimens, and I was able to confirm that the caterpillars were indeed armyworms (Pseudaletia unipuncta).  In addition, I received information from Indiana and Ohio that indicated turf managers in both of those states are reporting outbreaks of armyworms in some areas.  So, it appears that the potential exists for armyworm outbreaks throughout New England this summer.  Check your turf areas now to see whether there is any armyworm activity. The earlier you diagnose a problem, the better your chances of achieving some level of control if that turns out to be necessary.  (See Landscape Message #17 dated June 26, 2008 for identification and management hints.)  I failed to include indoxacarb (Provaunt™) as a treatment option in the earlier update.  Provaunt normally™ is very effective against many kinds of caterpillars, including armyworms.

White grubs − Oriental beetles, European chafers, and asiatic garden beetles are all emerging now as adults.  Japanese beetles won't be far behind (and in fact are probably already flying in some parts of New England).  If you plan to use a neonicotinoid (e.g., imidacloprid, chlothianidin, or thiamethoxam), you should try to make the application during the month of July if at all possible.

Reported by Pat Vittum, Extension Entomologist, UMass Department of Plant, Soil and Insect Sciences, Amherst.

WEEDS

Crabgrass continues to mature at a fast rate.  Continue to actively monitoring for crabgrass and treat with a postemergence crabgrass herbicide such as fenoxaprop or quinclorac.  In some areas, the effective control window for fenoxaprop is coming to an end.  The second application in a split-application program for crabgrass should be completed by now.

Broadleaf herbicide applications should be in nearing completion.  Beware of hot weather applications as injury may occur.

Yellow nutsedge is becoming apparent.  Postemergence applications for yellow nutsedge should be occurring now.

DIAGNOSTIC SERVICES

UMass Laboratory Diagnoses 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

Soil and Plant Tissue Testing - The University of Massachusetts Soil and Plant Tissue Testing Laboratory is located on the campus of The University of Massachusetts at Amherst. Testing services are available to all. The function of the Soil and Plant Tissue Testing Laboratory is to provide test results and recommendations that lead to the wise and economical use of soils and soil amendments. For complete information, visit the UMass Soil and Plant tissue Testing Laboratory web site at: http://www.umass.edu/plsoils/soiltest Alternatively, call the lab at (413) 545-2311.

NEXT UPDATE: The next issue will be available on July 24, 2008.

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.

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