UMass Extension Landscape Message #8
April 24, 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 1, 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: The Cape seems to actually be having a spring this year!  Mild, sunny weather has prevailed over the past week, with plants growing rapidly.  Many spring shrubs are in bloom; lawns are green and in need of their first cut, and dandelions are blooming with vigor.  Pests/Problems:  The first silken threads of ballooning winter moth caterpillars were detected on 4/19.  Lily leaf beetle adults have been observed.  Cicada nymphs are lurking about an inch below the surface, soon to emerge.  Dog ticks are active along with deer tick adults.  Wasps are seeking nesting sites.

Southeast Region (Hanson) – General Conditions: Hanson had no rain this past week, and soils are drying out. Norway maple, Pieris japonica, Pieris floribunda (Mountain Pieris), Pieris 'Brouwer's Beauty, Cornus mas, Pyrus calleryana ‘Bradford’ (Bradford Pear), Corylopsis spicata, Lindera benzoin, Cherry 'Holly Jolivette', Chaenomeles speciosa (Common Floweringquince), Leonard Messel Magnolia, Pieris floribunda (Mountain Pieris), Forsythia x intermedia (Border Forsythia),  Helleborus orientalis, Helleborus foetidus, Corydalis solida, Omphalodes, Dutchman's breeches, bloodroot, vinca, daffodils, Pulmonaria,  early tulips, and violets, are in full bloom.  Trillium, Epimedium, and anemones are beginning bloom.  Abeliophyllum distichum (White Forsythia) is ending bloom.  Pests/Problems:  Winter moth caterpillars are active and were found inside developing buds of plants including: apple, European beech, and Japanese maple.  Carpenter bees, honeybees, bumblebees, wasps, mosquitoes, mayflies, and ticks are all active.  Violets, chickweed, bittercress, and dandelions are in full bloom. Reports have come in of solitary bees nesting in lawns.  Wild turkeys have been observed under birdfeeders and 'pecking' at perennials.  Deer continue to browse, and skunks are digging up lawns.

East Region (Boston) – Pests/Problems: Fair and pleasant.  Researchers at UMass Boston have collected pollen from the following trees and shrubs over the past week:  Betula pendula, Mahonia bealei, Cryptomeria japonica, Corylopsis sinensis, Lindera obtusiloba, Forsythia 'Meadowlark', Taxus baccata, Taxus floridana, and Ulmus thomasii.  The weather forecasters on the news have indicated that we are at a one inch deficit for rainfall in April though not for the 2008 season.  Rain is needed.  There is potential for fires in dry leaves and mulched areas when smoking items are not extinguished.  Pests/Problems: Early larval stages of winter moths have been seen.  Silk is present along the trunks of trees.  Applications for hemlock wooly adelgid have continued over the past week.

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

Metro West (Hopkinton) – General Conditions: Some early tulips are beginning to flower.  Daffodils are in their full glory now.  The sweet aroma of magnolias fills the air at Weston Nurseries.  We’ve had blue skies and mild nights for most of the week, and the soils are no longer saturated.

Central Region (Boylston) – General Conditions: Dry, warm, sunny!!

Pioneer Valley Region (Amherst) - General Conditions: The weather has generally been above normal and dry in the last week, which stimulated steady bud break and foliage development on many plants.  Daffodils and hyacinths along with Japanese flowering cherry and magnolias are adding color to yards and gardens now.  Many lawn areas are about ready for a first mowing.  Pests/Problems: Although about an inch and a half of rain fell this month in Amherst, none has fallen since April 13.  Consistent wind and low relative humidity dried ground surfaces, but subsoil moisture appears adequate at this time.  However, brush fire danger warnings are in effect for much of central and western Massachusetts.  Possible rain in the forecast for the coming weekend should reduce fire dangers.

Berkshire Region (Great Barrington) - General Conditions: Combination of high temperatures, sun, and wind has left surface layers of soil very dry.  High temperatures have also accelerated plant development.  Pests/Problems:  None observed.

ENVIRONMENTAL DATA -

The following growing-degree-day (GDD) and precipitation data was collected for a one-week period, April 16, 2008 through April 22, 2008.  Soil temperature and phenological indicators were observed on April 22, 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
Spiraea prunifolia (Bridalwreath Spirea)	*	*	begin	*	*	*	*	*
Amelanchier spp. (Shadbush/Serviceberry)	*	*	begin	*	full	*	*	*
Chaenomeles speciosa (Floweringquince)	begin	full	begin	*	*	*	b/full	*
Pyrus calleryana 'Bradford' (Bradford Pear)	begin	full	b/full	*	*	*	full	*
Magnolia soulangiana (Saucer Magnolia)	begin	full	full	begin	begin	begin	b/full	*
Rhododendron 'P.J.M.' (PJM Rhododendron)	begin	full	full	full	begin	*	begin	*
Acer saccharum (Sugar Maple)	*	*	full	*	begin	begin	full	*
Acer platanoides (Norway Maple)	begin	full	full	full	begin	*	full	full
Prunus serrulata (Japanese Flower’g Cherry)	begin	full	full	full	begin	*	full	full
Forsythia x intermedia (Border Forsythia)	full	full	full	full	full	b/full	full	full
Pieris japonica (Japanese Pieris)	full	full	full	full	full	full	full	begin
Magnolia stellata (Star Magnolia)	full	full	f/end	full	full	full	full	full
R. mucronulatum (Korean Rhododendron)	full	full	f/end	full	full	full	full	*
Cornus mas (Corneliancherry Dogwood)	f/end	full	f/end	end	end	full	f/end	*
Acer rubrum (Red Maple)	end	f/end	end	*	full	f/end	full	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.  Small problematic populations often pop up somewhere unexpectedly.  Monitor for viable egg masses now and tiny ballooning caterpillars.
  
  
• Forest Tent Caterpillar - After occurring in large numbers through out 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 - Although 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 should have occurred throughout the range of this pest in eastern MA by now.  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.  They are small, oval and a light orange color and are often scattered on trunk bark.  As the embryos within the eggs near maturity, the eggs turn a deep blue color.  Upon hatching, the tiny larvae are carried upwards into the tree canopies mostly by air convection.  Once there, they seek swelling buds.  These tiny caterpillars then wriggle into the buds and begin to feed on foliage and flowers.  During years of high numbers, this pest can cause severe damage, especially if buds are slow to open due to cool weather.  Blueberries and apple trees can be sprayed with a dormant oil any time now (whenever the weather is conducive for oil sprays).  Once inside the buds, this caterpillar is very difficult to treat until the buds open and the larvae are exposed.  Work on the mass-rearing of 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 in eastern MA.  Last year, parasitized winter moth larvae were recovered on Cape Cod at a site where Cyzenis had been previously released.
  

Beetles:

• Lily Leaf Beetle - The bright red adults will be seen soon as they forage for newly emerging lilies.  Once found, the adults will begin feeding and mating.  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 pyrrethroid sprays, and they need to be administered at budbreak.
  
  
• 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.

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.  As homeowners begin to rake their yards this spring, they will notice 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 -

A follow up on spring applications of neonicotinoids − Apparently several people have wondered about some comments I made in the last message regarding the use of neonicotinoid products in the spring for white grub control.  I indicated that spring (meaning April or early May) applications of neonicotinoids probably would not reduce populations of white grubs already present in the turf.  I based those remarks on field trials that were conducted several years ago using imidacloprid (Merit™ and several other trade names now).

Imidacloprid was the first neonicotinoid to reach the turf market (more than 10 years ago).  More recently chlothianidin (available as Arena or in a combination product with bifenthin, sold as Aloft™) and thiamethoxam (Meridian™) have been registered in the turf market.  Both of these active ingredients are more soluble than imidacloprid and appear to be effective against a wider range of insect species.

I have talked with a few of my turf entomology colleagues who conduct many of the field trials that we all use to develop our recommendations.  Neither of them has conducted any trials where a neonicotinoid (whether imidacloprid, chlothianidin, or thiamethoxam) has been applied in the spring to target grubs that are present in the spring.  Neither have I.  So, at this point, there appear to be no data to confirm whether spring applications will control spring grubs.  I have always been a "show me" sort of person; so without data to back up a recommendation, I am reluctant to suggest treatment strategies that have not been tested.

However, studies conducted in Ohio involving September applications targeting large grubs showed that chlothianidin reduced grub populations quickly (about a week), while thiamethoxam reduced grub populations in about seven to 10 days, and imidacloprid took at least two weeks to achieve grub reduction.  (We conducted a smaller scale test in September a couple years ago that yielded very similar results against oriental beetles.)  It is tempting to extrapolate from those autumn field trials to project that spring applications of chlothianidin or thiamethoxam could control spring grubs, but the appropriate field studies apparently have not been "commissioned" by any of the companies.  Certainly I have not conducted those trials, and neither have three of my trusted colleagues.  Keep in mind that spring grubs are different, physiologically, than they were in the previous fall.  While they feed some in the spring, they are also beginning to prepare to pupate, so they may be a little less susceptible to chemical control. Certainly the "success" rate with fast acting products like trichlorfon (Dylox™) in the spring is usually quite a bit lower than it is when applied the previous late summer or fall.

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

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 1, 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.

DISCLAIMER. This message is intended for commercial use. UMass Extension assumes no liability for recommendations. It is the responsibility of the applicator to verify the registration status of any pesticide BEFORE applying it. Different states have different regulations as well. The use of trade names (™) does not imply endorsement. Similarly, there may be other products you prefer to use.

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