UMass Extension Landscape Message #12
May 22, 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 May and June this newsletter will be updated weekly. The next update will be available on May 29, 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 weather has remained on the cool side, with damp conditions prevailing overall for this reporting period.  Plant growth continues on a slow pace, with spring bloomers remaining in bloom for a long time due to the cool, moist conditions.  Lawns are lush and green, and soil moisture levels are good for planting and transplanting.  Pests/Problems:   Cicadas remain just below the soil surface, waiting for some warm weather to arrive before coming out en masse.  Winter moth caterpillars are actively feeding. Overall populations appear down, but clusters of high population numbers remain.  Infested trees are showing some foliar damage, but no defoliation has been seen to date.  Roses seem to be a preferred host this year.  Eastern tent caterpillar nests are getting large and are quite visible.  Lily leaf beetles are laying eggs.  Overall, these populations also appear to be low this year.  Dog ticks are active.  We have not yet seen the nymph stage of the deer tick.  Cutworm caterpillars are active in perennial and vegetable beds, as well as in turf.  It is a good year for spring weeds.  Bracts of native Cornus florida are spotted and deformed, possibly due to Botrytis or Elsinoe cornii.  Apple scab is beginning to show up on susceptible crabapples.

Southeast Region (Hanson) – General Conditions: Cool, sunny weather has been the norm this past week with just enough well-spaced rain to keep plants looking great.  It is a wonderful spring!  Hanson received 1.1 inches of rain, and soils are moist.  Wisteria, Fothergilla, flowering dogwood, azaleas, early rhododendrons, Exochorda racemosa (pearlbush), Daphne x burkwoodii 'Carol Mackie', Euonymous alatus, barberry, doublefile viburnums, Rutgers hybrid dogwoods, lily of the valley, Helleborus foetidus, Vinca, Pulmonaria, Trillium, Corydalis lutea, Euphorbia polychroma, Primula, Brunnera macrophylla, Ajuga, bleeding heart, Phlox subulata, Phlox divaricata, Phlox stolonifera, sweet woodruff, columbine, Draba, Arisaema, Dicentra eximia, and Solomon's seal are in full bloom. Pests/Problems: We've had reports of high density winter moth caterpillars in areas of Brockton, Hull and on a few trees in West Bridgewater, so there are definitely 'hot spots' of winter moth caterpillar in Plymouth County.  If you are observing high numbers of winter moth caterpillars in areas where you are, please let Bob Childs or me know.  Today, I observed winter moth caterpillars feeding on the seeds inside the samaras (fruit) of silver and Norway maple, and they did not (at this time) appear to be feeding extensively on the foliage. Curious.  Gypsy moth caterpillars and forest tent caterpillar populations appear to be down.  Again, if you are seeing high numbers of these two caterpillars, please let us know.  Eastern tent caterpillar webs are expanding.  Hemlock woolly adelgid, lily leaf beetles, boxwood psyllid, wasps and hornets, carpenter bees, mosquitoes, blackflies, aphids, and ticks are all active.  Buttercups, wild mustard, ground ivy, chickweed, veronica, violets, and dandelions are in full bloom.  Beneficial insects are active.  Barberry and burning bush, two Massachusetts invasive plants, are in bloom.  If future potential seed dispersal is of concern to clients who may not wish to remove and destroy the plants, an alternative may be to prune or shear plants now to remove flowers.  Seed production will be interrupted, and plants will grow and fill in nicely while producing fewer seeds.

East Region (Boston) – Pests/Problems: Cool and pleasant.  Breezy as well! Pests/Problems: Annual weeds such as lambsquarters have begun to grow more rapidly, but may still be at the stage where they are easy to manually remove.  Crabgrass is germinating as well.

Metro West (Waltham) – General Conditions: Continuing to warm up during the day, but some nights are remaining rather cool.  Pests/Problems:  Forest tent caterpilllars are about one inch long.

Metro West (Hopkinton) – General Conditions: Nights continue to be cool, holding the flowers on some of the early flowering trees and shrubs.

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

Pioneer Valley Region (Amherst) - General Conditions: Lawns maintain their green and lush growth.  Seeds planted in early May are beginning to take root, leaf out, and fill in dead areas.  Likewise, gardens are growing well with plentiful blooms of iris, bleeding heart, columbine, and tulips.  Deciduous trees continue to leaf out well with the expanding light green candles on pine, spruce, and yew.  Pests/Problems:  London planetrees are recovering well with new foliage growth on branches nipped by early morning freezing temperatures earlier this month.  There is loss of slightly distorted green leaves on the ground under green ash foliage infected with ash anthracnose.  The orange-red gelatinous fruiting structures of cedar-apple and quince rust are becoming more prominent on infected junipers. 

Berkshire Region (Great Barrington) - General Conditions: Very cool conditions continued this past week, slowing plant and pest development.  Cool, cloudy, wet, and windy weather for most of the period.  Soil moisture is high.  Pests/Problems:  Viburnum leaf beetle is now widely spread in South County.  Most recent report is from Lenox where it was found on V. lantana.  It has also been seen this year in Great Barrington and West Stockbridge on V. sargentii, V. nudum, and V. denatatum.

ENVIRONMENTAL DATA -

The following growing-degree-day (GDD) and precipitation data was collected for a one-week period, May 14, 2008 through May 20, 2008.  Soil temperature and phenological indicators were observed on May 20, 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
Deutzia spp. (Deutzia species)	*	*	begin	*	begin	*	*	*
Syringa meyeri (Korean Lilac)	*	*	begin	begin	begin	*	*	*
Spirea x vanhouttei (Vanhoutte Spirea)	full	*	full	*	begin	*	begin	begin
R. catawbiense (Catawba Rododendron)	full	b/full	begin	begin	*	b/full	begin	begin
Enkianthus. campanulatus (Redvein Enkianthus)	*	begin	begin	b/full	begin	full	b/full	*
Aesculus hippocastanum (Horsechestnut)	full	full	full	b/full	*	*	full	begin
Syringa vulgaris (Common Lilac)	b/full	full	full	full	full	full	full	full
Elaeagnus umbellata (Autumn Olive)	full	full	full	*	full	full	*	*
Leucothoe spp. (Fetterbush, Leucothoe)	*	*	full	*	*	full	*	*
Lonicera tatarica (Tatarian Honeysuckle)	full	full	f/end	full	full	full	full	full
Halesia spp. (Silverbell)	*	full	end	full	full	full	*	full
Cornus florida (Flowering Dogwood) – BRACTS	full	full	f/end	end	end	full	f/end	full
Cercis canadensis (Redbud)	full	full	f/end	end	end	full	f/end	full
Malus spp. (Crabapple)	full	full	end	end	end	full	end	full
Viburnum spp. (Early Fragrant Viburnums)	f/end	f/end	f/end	*	end	f/end	end	full
Chaenomeles speciosa (Floweringquince)	f/end	end	full	*	end	f/end	end	full
* = 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 - No reports this year of large numbers of this pest in MA have been received yet.  It is assumed that numbers are low and that this pest will be of little concern this year.
  
  
• Forest Tent Caterpillar - No reports this year of large numbers of this pest in MA have been received yet.  It is assumed that numbers are low and that this pest will be of little concern this year.
  
  
• Eastern Tent Caterpillar - Silken webs in the branch crotches of Malus and Prunus species are quite noticeable now.  This pest is occurring randomly throughout the state, and in some regions the numbers are significant once again this year.  In parts of southern NY state and across PA, this caterpillar is appearing in extremely large population numbers.  It is most likely too late in the season for a Bacillus thuringiensis Kurstaki product, but an insecticide that contains spinosad will still work very well. 
  
  
• Fall Cankerworm - Reports of this native caterpillar are just beginning to be received.  It is not yet clear just how widespread this pest will be this year in the state.  The thinking is that, once again, there will be random yet significant small pockets occurring throughout the state. 
  
  
• Winter Moth - Some areas in eastern MA (e.g., Hull and Weymouth) are experiencing large numbers of this introduced species this year, and damage is already noticeable.  Other areas in the eastern part of the state have winter moth but in lower numbers.  Now that the leaves have expanded from the buds, this pest can be treated with a product that contains spinosad or with one of the labeled pyrethroid insecticides.  This pest, which is extremely serious when occurring in large numbers, is now randomly dispersed throughout coastal regions of the state, and close inspection is required to know where it currently is and if controls are warranted.  It is not uncommon to find it in large numbers in one section of a town or neighborhood and not in an adjacent one.  Spot surveys have revealed various sizes of winter moth caterpillars active on the same tree(s), which suggests that the cool spring may have resulted in a staggered egg hatching of winter moth caterpillars. 
  
  
• Euonymus Caterpillar is active and attacks several different forms of euonymus; tree form is often the preferred host but others are susceptible.  This yellow caterpillar with black spots is “smooth-skinned” and initially appears sawfly-like, but closer inspection of the numbers of pairs of prolegs lets us know that it is in the lepidoptera and not the hymenoptera.  When occurring in large numbers, this caterpillar produces copious amounts of silk all throughout the plant.  Much defoliation can occur.  Treat the same as the other lepidoptera caterpillars; although, it may be too late for B.t. to be effective.  This pest overwinters as a young larva and resumes activity once the new foliage appears in the spring. 
  

Hymenoptera Sawfly (Caterpillar) Larvae:

• European Pine Sawfly − This sawfly caterpillar is now active 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.  However, in the warmer regions, they may have already hatched.  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.  In Massachusetts the host plants are usually Exbury and Mollis varieties of deciduous azaleas.  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 several weeks, and mating pairs have been observed in the warmer regions (Amherst).   Eggs will appear soon 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 given that it is in CT, RI, VT, NH, ME, and NY state.  Inspect all viburnum plants brought into the region from those areas that already have this pest.  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 has been active for a few weeks, and its damage is starting to become noticeable.  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:

• Snowball Aphid remains actively feeding, but all of its injury has now occurred.  It will cease feeding by the end of May, but the curled and distorted foliage will remain on the host plant for the rest of the growing season.  Systemic imidacloprid may be helpful in reducing next year’s numbers on individual host plants, but time is running out for it to be translocated up to the foliage where this pest will be feeding for the next two to three weeks.
  
  
• Taxus Mealybug is 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 unsightly build-up 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 a horticultural oil spray or with one of the registered pyrethroid insecticides.
  
  
• 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 or the now-active mites; this 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 and immature mites.  Many spider mite species have now become active statewide, so 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.
  
  
• Clover Mites − A few calls have been received recently concerning this occasional pest.  Clover mites become active in the spring and feed on a wide range of host plants.  They are very small and usually go unnoticed.  However, they have the potential to invade homes and become a nuisance.  They do not bite people but their numbers, when occurring indoors, often causes alarm.  Preventing them from invading is the best overall strategy.  It is recommended that grass, weeds and other lush vegetation be kept 18-24 inches from the house around the foundation, especially on the sunnier sides.  It is claimed that clover mites will not cross over bare ground.  Many pesticide products are also labeled for the control of this mite.  As always, make sure that the recommended pesticides are labeled for use in your state and to always, read, understand and follow all labeled directions for use of such products.  Ohio Extension has a very informative fact sheet concerning this pest that can be obtained at the following web site:  http://ohioline.osu.edu/hyg-fact/2000/2095.html
  
  
• 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.  A horticultural oil spray at the summer rate (be careful of tender new foliage now emerging), systemic imidacloprid or systemic dinotefuran (Safari™), are all effective against this very serious pest.  (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.  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.  
  
  
• Cryptomeria Scale was found on Cape Cod last fall as well as in Rhode Island (not far from the MA border.  This was the first time that this scale has been found in MA.  Both finds were on Christmas trees in the nursery (plantation).  This scale attacks various conifers and has the potential to be a serious pest; our finds were both on fir.  Inspect needles for yellowing (stippling) and the presence of the scale on the needle undersides.  Treat with a horticultural oil if found.
  
  
• Honeylocust Plantbug - Now that the foliage of honeylocust has expanded from the bud, this pest is actively feeding, creating typical yellow stippling on expanded foliage.  However, the real serious damage occurs when it feeds heavily as the new foliage is just emerging from the bud.  In this case, the leaflets become heavily stunted, twisted and otherwise distorted.  Treatments include insecticidal soap sprays for the young nymphs or a labeled pyrethroid insecticide.  Systemic imidacloprid can also be effective, but it is too late in the year to achieve the necessary uptake in time to be effective for this season. 
  
  
• Boxwood Psyllid causes cupping of the new foliage that remains on the host plant for a year or more.  It does not result in yellow stippling injury.  Inspect susceptible boxwoods now for new cupped foliage and the white wax that is produced by the tiny psyllids.  Contact insecticides, such as soap and oils, may not provide good controls given that the pest is protected within the cupped foliage.  Certain pyrethroids are labeled for this pest.

Leaf Miners:

• Birch Leafminer − Populations of this potentially serious pest appear once again to be rather low in the state.  Where it is active, the larvae are now about half developed and injury is noticeable.  In most areas of the state now it may be too late for control measures.
  
  
• Inkberry Leafminer − This is one of the “Holly Leaf Miners” and is specific to inkberry.  Inspect now for browned foliage tips and then inspect more closely for the presence of mining within those browned tips, which will be hollow and contain a pupa.  Monitor for the emergence of the adult leaf miner flies  with yellow sticky cards.  Treat with a pyrethroid insecticide once the adults appear to break the cycle of reinfestation of the host plants.
  
  

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.

Miscellaneous Stuff:

• Ground Bees - Many calls have been received this year concerning solitary bees nesting in turf, which includes home lawns, parks, athletic fields and school grounds.  When these bees are prevalent, such as this year, they can cause alarm.  However, most of them are fairly docile and only sting (or in some cases, bite) when seriously provoked.  There are many types of these ground bees ranging from digger bees, mining bees, cicada killers, leaf-cutting bees, and others.  Overall, these bees appear more problematic than they actually are, and most will greatly subside in activity by early to mid June.  Occasionally, controls may be necessary, primarily on athletic fields where encounters between humans and bees may become significant and also where rare but very large numbers of these bees may soften the playing surface to the point of risking injury to players.  Ohio Extension has a very informative fact sheet on the topic which can be obtained at the following web site:   http://ohioline.osu.edu/hyg-fact/2000/2143.html

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

LANDSCAPE TURF

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 29, 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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