UMass Extension Landscape Message #10
May 8, 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 - 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. During the months April, May, and June this newsletter will be updated weekly. The next update will be available on or about May 15, 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: Cool, damp weather prevailed over the past week, keeping lawns lush and prolonging bloom on many shrubs and trees.  Soils are moist, and good conditions for transplanting exist.  Early spring perennials and tulips are providing color in the landscape.  Pests/Problems:  Webs of eastern tent caterpillars are noticeable in wild black cherry trees.  Black knot should be pruned out of flowering cherries and plums.  Cedar-apple rust galls are visible on eastern red cedar.  Winter moth caterpillars have hatched, and tiny holes can be seen on just breaking leaves of crabapple.  Many weeds are blooming, including dandelion, creeping veronica, and chickweed.

Southeast Region (Hanson) – General Conditions: Cool sunny weather, with a little rain, has kept spring blooming plants looking good and has delayed development in others, making for a nice spring.  A few nights last week saw temperatures below freezing in many areas in Plymouth County.  Exochorda (Pearlbush), Magnolia 'Elizabeth', Pieris floribunda (Mountain Pieris), Pieris japonica, Pyrus calleryana 'Bradford' (Bradford Pear), Kerria, Arabis, Arisaema, flowering almond,  Sassafras, Pieris 'Brouwer's Beauty', V. carlesii (Mayflower Viburnum), Lamiastrum, Helleborus orientalis, Helleborus foetidus, Vinca, daffodils, Pachysandra procumbans, tulips, Pulmonaria, Epimedium, blueberries, Chaenomeles speciosa (Common Floweringquince), Dutchman's breeches, Trillium, anemones, royal azalea, Phlox subulata, and violets are in full bloom. Tiarella, bleeding heart, Phlox stolonifera, and Phlox divaricata are beginning bloom. In some areas, common lilac is starting to bloom.Norway maple is past bloom.  Pests/Problems: Winter moth caterpillar is in second and third instar, depending on location and plant development.  Winter moths can be found on apples, ash, crabapples, beech, blueberry, oaks, red and Japanese maples, and other hosts.  They often web the leaves together making it difficult to see them.  Right now, we don't know what impact winter moth will have on the landscape this season.  It is still early.  However, on many plants, there is very little sign of feeding by winter moth.  We should know more next week.  Tents of eastern tent caterpillar are visible and expanding; they can be easily removed and destroyed at dusk when the caterpillars retreat to the tent.  Hemlock woolly adelgid, lily leaf beetles, carpenter bees, mosquitoes, mayflies, and dog ticks are all active.  Chickweed, violets, ground ivy, and dandelions are in full bloom.  Beneficial insects are active.

East Region (Boston) – Pests/Problems: Cool and pleasant.  Dandelions are flowering in lawns. Oaks are beginning to leaf out and have pollen tassles.  Researchers at UMass Boston have collected pollen from the following trees and shrubs over the past week:  Rhus aromatica, Berberis manshurica, Betula lenta, Viburnum bitchuense, Enkianthus perulatus, Rhododendron keiskei, Vaccinium corymbosum, Ribes fasciculatum, Fothergilla gardenia, Amelanchier canadensis, Halesea tetraptera, Celtis occidentalis, and Prunus subhirtella.  Pests/Problems:  Winter moth larvae continue to grow.

Metro West (Waltham) – General Conditions: Cool and moist.  Pests/Problems:  Winter moth larvae are active.

Metro West (Hopkinton) – General Conditions: No report.

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

Pioneer Valley Region (Amherst) - General Conditions: After the glorious summer-like stretch of weather near the end of April, the past week was characterized by gray days, showers, and cold nights.  Overnight temperatures dipped below 30° in many areas on April 30 and May 1, with frost observed.  Soil moisture seems to have recovered from the prolonged dry spell last month.  Plant development is steady.  A majority of lawn areas have had their first mowing.  Pests/Problems:  Ladybugs are still being observed in homes.  Deer and dog ticks are active.  Black flies are abundant and hungry.

Berkshire Region (Great Barrington) - General Conditions: Soil moisture levels are good.  Cool temperatures have prolonged bloom period of spring bulbs and flowering trees and shrubs.  Growth of turfgrass is rapid.  Pests/Problems:  Tent caterpillars, ticks, carpenter bees are prominent pests.  Record setting hard freeze (20-25 degrees F) on April 30 has caused some damage to plants, primarily frost burn to emerging foliage of herbaceous perennials and certain crops, i.e. asparagus and strawberries.  It remains to be seen to what extent, if any, there has been damage to buds and emerging leaves on woody plants.

ENVIRONMENTAL DATA -

The following growing-degree-day (GDD) and precipitation data was collected for a one-week period, April 30, 2008 through May 6, 2008.  Soil temperature and phenological indicators were observed on May 6, 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
Aesculus hippocastanum (Horsechestnut)	*	*	begin	*	*	*	begin	*
Syringa vulgaris (Common Lilac)	*	begin	begin	*	begin	begin	begin	*
Halesia spp. (Silverbell)	*	*	b/full	*	begin	*	full	*
Lonicera tatarica (Tatarian Honeysuckle)	*	*	full	*	*	*	*	*
Malus spp. (Crabapple)	begin	b/full	full	begin	full	b/full	b/full	begin
Viburnum spp. (Early Fragrant Viburnums)	begin	b/full	full	*	full	full	b/full	begin
Cornus florida (Flowering Dogwood) - BRACTS	begin	b/full	full	full	full	full	full	*
Cercis canadensis (Redbud)	begin	full	begin	full	full	full	full	*
Spiraea prunifolia (Bridalwreath Spirea)	begin	full	begin	*	full	full	*	*
Chaenomeles speciosa (Floweringquince)	full	full	full	f/end	full	full	full	full
Amelanchier spp. (Shadbush/Serviceberry)	full	full	f/end	full	full	full	f/end	full
Pyrus calleryana 'Bradford' (Bradford Pear)	f/end	full	f/end	f/end	full	full	f/end	full
Rhododendron 'P.J.M.' (PJM Rhododendron)	f/end	full	f/end	full	full	full	end	full
Prunus serrulata (Japanese Flowering Cherry)	f/end	full	full	f/end	end	end	f/end	f/end
Forsythia x intermedia (Border Forsythia)	f/end	full	f/end	end	end	full	f/end	f/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 - Numbers of this pest are expected to be low statewide in 2008.  Many gypsy moth caterpillars were observed last year to have succumbed to the (now) naturally occurring entomopathogenic fungus, Entomophaga maimaiga.  Small problematic populations often pop up somewhere unexpectedly.  Monitor now for viable egg masses and tiny ballooning caterpillars.  Shadbush (Amelanchier) is now blooming statewide, and it is a good phenological indicator for the hatching of gypsy moth eggs. 
  
  
• Forest Tent Caterpillar - After occurring in large numbers throughout the greater Northeast over the past years, this native caterpillar species is now, once again, in low numbers due to natural controls such as the fungus, Entomophaga sp., and parasitoids such as certain flies.  Inspect now for viable egg masses.  In western MA this pest seems to prefer maples; in the eastern part of the state the primary host plants are oaks.  However, this caterpillar does have a rather large deciduous host range overall.
  
  
• Eastern Tent Caterpillar - The small silken webs of this pest began appearing two weeks ago in the warmer regions of the state.  Look for these developing webs in the crotches of the branches.  Although this pest was occurring in large numbers in recent years throughout New England, it is now in limited numbers due to natural controls.  Common on Malus and Prunus species, and sometimes on cotoneaster, this caterpillar makes large silken webs in the crotches of branches.  When in high population numbers, it is a serious defoliator.  Inspect for egg masses now to determine population size.  Tiny silken webs will soon be appearing.  If Bacillus thuringiensis Kurstaki (B.t.K.) is the preferred method of control, applications might be delayed until more foliage has emerged.  B.t. needs to be ingested in order to be effective, and applying it while most of the foliage has not yet expanded will leave much new foliage unprotected when it does emerge from the bud.  Spinosad products also work very well.
  
  
• Fall Cankerworm - This is, also, a native species in declining numbers.  It prefers oaks but has a large deciduous host plant range.  Isolated pockets still exist.  In 2007 a defoliating population existed just north of Amherst in western MA.  Random and small populations will be active in eastern MA this year.
  
  
• Winter Moth - Egg hatch occurred last week throughout the range of this pest in eastern MA.  Flight of the adult males was initially healthy last November in several eastern towns, but the earlier-than-normal snowfall may have impeded further emergence of the adults, which therefore may have reduced the number of over-wintering eggs.  Eggs of winter moth are difficult to monitor.  The tiny caterpillars initially wriggled into the buds and began to feed on foliage and flowers.  Now that foliage and flower buds are opening, the winter moth caterpillars are considered to be “free-feeders” like most other caterpillars that feed openly on the foliage.  During years of high population numbers, this pest can cause severe damage, especially if buds are slow to open due to cool weather.  This caterpillar is very difficult to treat until the buds open and the larvae are exposed.  Once buds have opened and the new foliage has expanded, this pest is very treatable with Bacillus thuringiensis Kurstaki, products that contain spinosad, and pyrethroids.  The work of mass-rearing the parasitic fly, Cyzenis albicans, continues in Dr. Joseph Elkinton’s lab at UMass Amherst.  More releases of this fly are scheduled for this spring in select areas of eastern MA.  Last year, parasitized winter moth larvae were recovered on Cape Cod at a site where Cyzenis had been previously released.

Hymenoptera Sawfly (Caterpillar) Larvae:

• European Pine Sawfly − This sawfly caterpillar will appear within the next couple of weeks on such host plants as mugo pine.  Inspect now for the yellow, block-shaped spots lined up on the needles that are an indicator of sawfly eggs embedded within the needles.  If found in limited numbers, remove those needles and destroy them.  Once the dark green larvae hatch, they tend to cluster in large numbers on the tips of needles and continue to feed gregariously.  As they become larger (they grow quickly), they will consume the needle down to the fascicles.  The very young larvae are easily controlled with insecticidal soap or horticultural oil sprays.  For the larger larvae, consider using a product that contains spinosad or one of the pyrethroid insecticides.  This pest usually does not kill its host, but it can greatly impact the aesthetic value of the plant.
  
  
• Azalea Sawfly Caterpillar − This green-colored sawfly caterpillar is virtually the same color as the host plant foliage, which is usually Exbury and Mollis varieties of deciduous azaleas in Massachusetts.  Given that it hugs the margins of the foliage while it feeds, coupled with its coloration, this insect is difficult to see.  Once foliage is fully emerged, inspect for ragged edges of foliage where feeding has occurred; then inspect more closely for the caterpillar.  It tends to consume the soft tissue of the foliage and leaves nothing but the main veins, which is somewhat typical of many sawflies that feed on deciduous plants.   Once found, treat with a product that contain spinosad or with one of the pyrethroid insecticides labeled for this pest.  If not treated, it has the potential to consume all leaves.
  

Beetles:

• Lily Leaf Beetle -The bright red adults have been active now for a couple of weeks.  Eggs will appear later in May on the undersides of foliage.  NEEM works well for the larvae, once they appear, but needs to be reapplied every 10-14 days.  Spinosad products also work well for the larvae.  Adult lily leaf beetle is best controlled with a pyrethroid insecticide.
  
  
• Viburnum Leaf Beetle is established in western MA (randomly throughout Berkshire County) and is expected to become a serious pest there.  It is expected that this pest will continue to expand its invasion of MA now given that it is in CT, RI, VT, NH, ME, and NY states.  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

Piercing-Sucking Pests:

• Snowball Aphid is active and feeding on many different species and varieties of viburnum:  maple leaf, Korean spicebush, and cranberrybush viburnum, in particular.  This small insect overwinters as an egg embedded within shoots and begins feeding at budbreak, which results in very curled foliage.  It does not cause yellowing or loss of foliage, but it is capable of creating unacceptable levels of aesthetic damage.  The aphids continue to feed on the undersides of the foliage (within the curls) until approximately late May.  Systemic imidacloprid is quite effective but needs to be applied in August in order for it to be present and active when feeding begins in the spring.  Otherwise, treatments now are mostly pyrethroid sprays, and they need to be administered at budbreak.  In the warmer areas of the state, it may be too late now to effectively treat for this pest; the damage has already occurred.
  
  
• Spider Mites - Inspect spruce, hemlock, fir, and others for the signs of last year’s feeding damage by these tiny but very prolific and potentially damaging pests.  Once found, inspect very closely for over-wintering eggs, 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 that targets spider mite eggs.
  
  
• Hemlock Woolly Adelgid - This pest is on the rebound in MA after several years of being in low numbers due to the exceptionally cold winter of 2005.  However, it reproduces quickly and not much else controls its number naturally here.  Inspect for the new cottony egg masses that have been appearing for the past couple of weeks.  Treat with a dormant oil spray now. (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 cases, 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 hemlock woolly adelgid, tends to provide minimal control for this scale.  Safaritm (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.

Leaf Miners:

• Birch Leafminer − This pest is active in the warmer regions of the state.  Place yellow sticky cards out now in native, white-barked birches.  Once the adults appear, the females will be visually drawn to the cards and become stuck.  If large numbers are found, apply a pyrethroid insecticide to prevent their egg-laying in the foliage. 
  
  

Cool Stuff:

• Periodical Cicada − This unique insect only appears every 17 years in the adult stage.  Specific populations of these occur in the eastern USA as different broods that have peak years at varying times.  This year, it is Brood #14 that is peaking, and a part of that once large brood still exists on parts of Cape Cod.  Homeowners have already been reporting finding large round holes in the ground.  These holes are made by the nymphs as they take advantage of moist and pliable soil now to prepare an emergence hole that will get utilized in late May/early June.  At that time, millions of these nymphs will pour out of the ground, climb up on virtually everything, and molt for the last time into the large, red-eyed, winged adult cicadas.  This emergence brings much speculation about the remaining size of this population given the enormous development that has occurred on Cape Cod in recent decades.

Nuisance Pests:

• Ladybugs - The Multi-Colored Asian Ladybird Beetle (Harmonia axyridis) was introduced into this country decades ago to combat certain agricultural pests such as the pecan aphid in the Gulf States.  It, apparently, established itself quite well and now thrives in most states.  This particular species of ladybug (synonymous with "ladybird") is a dull orange color and has anywhere from zero to 19 black spots on its wing covers.  It is beneficial by feeding on pest insect species such as aphids and scales.  However, as is the case with most ladybug species, it seeks sheltered areas as over-wintering sites, such as rock cliffs, in the late fall.  Oftentimes, this species congregates on/in homes.  Lighter-colored homes that are exposed and those on hilltops seem to experience the worst infestations.  Houses are not a good choice for these ladybugs given that they are heated through the winter, and this often prevents them from entering into the dormant stage causing many of them to starve.  This ladybug does not bite nor sting people nor do they feed or breed indoors through the winter.  However, they have a natural defense mechanism known as "reflex bleeding" to protect themselves from danger.  Their "blood" is an orange color and has a rather offensive odor.  When disturbed (as by humans picking them up), they "bleed" this noxious liquid from their joints.  As mentioned above, it smells bad, and it can stain fabrics and wallpaper.  Therefore, vacuuming is the best solution.  When finished vacuuming, the bag should be remove from the cleaner and placed outside.  Otherwise, the ladybugs will just crawl out of the bag back into the home.  It is recommended that homes be inspected for holes in screening, which includes doors, windows, and attic vents.  Caulking around all of these points of entry should also be inspected and repaired if needed.  The ultimate key to managing these unwanted home invaders is to prevent them from entering in the first place.  If large numbers are being seen now on the outside of a house, the chances are good that they were within the house all winter, most likely in an attic, crawl space, under siding, or within the wall voids.  There are no traps available that I know of for catching these beetles.  Using a "pesticide bomb" within the house is not advised. These are ultimately our friends by feeding on the pest insects that are outdoors.

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

LANDSCAPE TURF

INSECTS -

No report this week.

WEEDS -

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 May 15, 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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