Landscape Message: April 7, 2023

UMass Extension's Landscape Message is an educational newsletter intended to inform and guide Massachusetts Green Industry professionals in the management of our collective landscape. Detailed reports from scouts and Extension specialists on growing conditions, pest activity, and cultural practices for the management of woody ornamentals, trees, and turf are regular features. The following issue has been updated to provide timely management information and the latest regional news and environmental data.

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Scouting Information by Region

Environmental Data

The following data was collected on or about April 5, 2023. Total accumulated growing degree days (GDD) represent the heating units above a 50ºF baseline temperature collected via regional NEWA stations (http://newa.cornell.edu) for the 2023 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.

MA Region/Location	GDD		Soil Temp (°F at 4" depth)		Precipitation (Gain since last report)	Time/Date of Readings
	Gain since last report	2023 Total	Sun	Shade
CAPE	5	14	48	45	1.63	12:00 PM 4/5/2023
SOUTHEAST	6	19	52	45	1.01	3:00 PM 4/5/2023
NORTH SHORE	4	8	48	42	0.96	4/5/23
EAST	6	19	48	43	1.23	4:00 PM 4/5/2023
METRO	4	9	47	44	0.94	6:30 AM 4/5/2023
CENTRAL	4	7	45	42	1.32	7:30 AM 4/5/2023
PIONEER VALLEY	4	5	48	43	1.87	1:00 PM 4/5/2023
BERKSHIRES	5	5	46	43	1.45	8:30 AM 4/5/23

Phenology

Indicator Plants - Stages of Flowering (BEGIN, BEGIN/FULL, FULL, FULL/END, END)
PLANT NAME (Botanic / Common)	CAPE	S.E.	N.S.	EAST	METRO W.	CENT.	P.V.	BERK.
Cercis canadensis (redbud)	*	*	*	*	*	*	*	*
Amelanchier spp. (shadbush, serviceberry)	*	*	*	*	*	*	*	*
Magnolia stellata (star magnolia)	Begin	Begin/full	*	Begin/full	*	Begin	Begin	*
Forsythia x intermedia (border Forsythia)	Begin	Begin	*	Begin	*	Begin	Begin	*
Pieris japonica (Japanese Pieris)	Begin	Begin	Begin	Begin	Begin	Begin	Begin	Begin
Cornus mas (Cornelian Cherry Dogwood)	Begin	Full/End	Begin/Full	Begin	Begin	Begin	Begin/Full	Begin/Full
Acer rubrum (red maple)	Begin/Full	Full	Full	Full/End	Full/End	Full/End	Full/End	Full
Acer saccharinum (Silver Maple)	End	Full/End	Full/End	Full/End	Full/End	Full/End	Full/End	Full/End
* = no activity to report/information not available

Regional Notes

Cape Cod Region (Barnstable)

General Conditions:

The average temperature from March 22 thru April 4 was 44ºF with a low of 25ºF on April 3 and a high of 65ºF on April 4th.   Daytime highs have been in the 40s and 50s with nighttime lows in 30s and 40s, frequently below 32ºF in the upper and mid Cape. We have experienced a fairly even number of sunny, cloudy and partly cloudy days.  Minor precipitation occurred on many days, totalling just under two inches for the entire period.  

Blooming herbaceous plants include Glory of the Snow (Chionodoxa sardensis), daffodil (Narcissus spp.), Lenten Rose (Helleborus spp.) and Hyacinth (Hyacinthus orientalis).   Blooming woodies include Witch Hazel (Hammelis x intermedia).  Swelling buds of many woody species have appeared and new herbaceous plant shoots are emerging.  

Pests/Problems:

Much of the problems seen during the period include winter injury on broadleaved and needled evergreens.  Insects or damage observed during the period include hemlock wooly adelgid on hemlock (Tsuga canadensis) and spruce spider mite damage on Alberta spruce (Picea glauca ‘Conica’).  Diseases seen during the period include black knot on black cherry (Prunus serotina) and white pine needle disease on white pine (Pinus strobus). 

Weeds including bittercress (Cardamine hirsuta), mouse-ear cress (Arabidopsis thaliana), chickweed (Stellaria media) and fig buttercup (Ficaria verna) are in bloom.  The invasive bush honeysuckles (Lonicera spp.) are obvious in the woods at this time with green buds rapidly expanding ahead of most other species. 

Rabbit damage to nearly emerging herbaceous shoots is noticeable in many landscapes.

Southeast Region (Dighton)

General Conditions:

The weather has been typical for the season since the last report on March 24th. Day temperatures have been in the 40s to the 60s with a high of 64ºF on April 4th. Nights were still frosty with a low of 22ºF on the 31st. It's been breezy with wind gusts as high as 16 mph on the 22nd. There was rain on March 23rd, 24th, and April 4th. The herring are running. Spring peepers can be heard along wetlands at dusk. 

Plants in flower; Acer rubrum (swamp red maple), A. saccharinum (silver maple), Chionodoxa  (glory-of-the-snow), Cornus mas (Cornelian cherry), Forsythia x intermedia,  Hyacinthus orientalis (Dutch hyacinth), Magnolia stellata (star magnolia), Muscari armeniacum (grape hyacinth), Narcissus (daffodils), Pieris japonica (Japanese andrometer), Phlox stolonifera (creeping phlox), Populus deltoides (eastern cottonwood), Ulmus americana (American elm), Salix babylonica (weeping willow), S. discolor (American pussywillow), S. gracilistyla 'Melanostyla' (black pussywillow), Scilla siberica (Siberian squill), Vinca minor (myrtle).

Plants currently observed to be flowering include; Acer rubrum (swamp red maple), A. saccharinum (silver maple), Cardamine hirsuta (hairy bittercress), Chionodoxa (glory-of-the-snow), Eranthis hyemalis (winter aconite), Galanthus (snowdrop), Hamamelis mollis (Chinese witch hazel), Narcissus (daffodil), Salix discolor (American pussy willow), S. gracilistyla 'Melanostachys' (black pussy willow), Scilla siberica (Siberian squill), Ulmus americana (American elm). Spring peepers are active.

Pests/Problems:

Black flies are biting. Second-instar deer ticks potentially carry Lyme disease and are currently seeking hosts. Hairy bittercress and dandelions bloom on lawns. Green buds of invasive honeysuckle barberry, and multi-flora rose are visible.

North Shore (Beverly)

General Conditions:

The weather since the last reporting period has been variable, with an average temperature of 42ºF. A minimum of 25ºF was recorded on March 20 with a high of 63ºF on April 1. Soils are moist despite modest precipitation. Approximately 0.96 inches of rainfall was recorded at Long Hill during this period. Woody plants observed in emerging or full bloom cornelian cherry dogwood (Cornus mas), goat willow (Salix caprea), anise Magnolia (Magnolia salicifolia), February Daphne (Daphne mezereum), fragrant Viburnum (Viburnum farreri) and red maple (Acer rubrum) and cedar. Early flowering plants and bulbs include: hellebores (Helleborus orientalis), Siberian squill (Scilla siberica), puschkinia (Puschkinia libanotica), and daffodil (Narcissus spp.) 

Pests/Problems:

Some deer browsing has been observed on some plants. Winter burn has been observed on Cryptomeria and on some broad-leaved evergreens such as boxwood (Buxus spp.) and some rhododendrons and azalea (Rhododendron spp.). Fungal leaf spot of mountain laurel was observed on some shrubs in the landscape. Cultural practices that promote plant vigor such as proper watering, fertilizing, properly timed hygiene tasks such as pruning, raking and removing fallen leaves in the fall will help manage this disease. 

East Region (Boston)

General Conditions:

The past two weeks have brought cold mornings and sunny afternoons, with daytime temperatures averaging 53ºF with a high of 63ºF on April 1 and a daytime low of 42ºF on March 25. Overnight lows averaged 35ºF with a hard frost and low of 25ºF on March 31. The overnight low of 47ºF combined with the daytime high of 61ºF on March 23 resulted in our first 4 Growing Degree Days of the season. We received 1.23 inches of precipitation over this two week reporting period. Total precipitation for March was 4.55 inches. Blooming spring bulbs and other highlights include: Crocus spp. (spring crocus), Iris histrioides ‘Katharine Hodgkin’ (dwarf iris), Narcissus spp. (daffodil) and Puschkinia scilloides (striped squill). Cornus mas (Cornelian cherry dogwood) and Magnolia Stellata (star magnolia). Hamamelis x intermedia (witch hazel hybrids) and Helleborus spp. (Hellebores) continue to flower. Acer spp. (maple) and Populus spp. (poplar) are distributing pollen.

Pests/Problems:

The extreme temperature swing overnight on March 28 caused some early blooming Magnolia spp. petals to turn brown. The winter annual, hairy bittercress (Cardamine hirsuta) continues to flower. Winter burn on Buxus spp. (boxwood) and Prunus laurocerasus (cherry laurel) in unprotected locations is extensive. Garlic mustard (Alliaria petiolata) seed has germinated in disturbed soils. 

Metro West (Acton)

General Conditions:

Spring’s arrival brought fairly typical conditions, including a range of warm and cool temperatures, frost, a snow flurry, blustery days, and rain. Temperatures of note included highs of 65ºF recorded on April 1st and 4th with a low of 21ºF recorded on March 31st. Snow flurries briefly passed through the area on March 25th, leaving no accumulation. According to NOAA, the 20-year monthly average rainfall for March is 3.76” and the total recorded for the month was 4.4”.  The average monthly rainfall for the month of April is 4.15” and as of the 4th, 0.34”of rain has been recorded so far. Buds are swelling on several woody plants including Forsythia spp. (forsythia), Syringa spp. (lilac) and Viburnum spp.

Pests/Problems: 

Soils are saturated and rivers, lakes, and pond water levels are high. Let’s hope for many more long and soaking April showers to get us all through this growing season. 

Central Region (Boylston)

General Conditions:

Weather has been typical for this time of year, with daytime high temperatures varying from mid-30’s to mid-60’s. Overnight low temperatures were still dropping consistently below freezing, and even into the mid-20’s. We have not had a good soaking rain for some time, but we saw several rainy days amounting to over an inch of rain during the reporting period. It still feels like very early spring, with only early season bulbs like Scilla luciliae (Glory of the Snow) and its cousin S. siberica (Siberian squill), and daffodils (Narcissus spp.) in bloom throughout the region. Soils are moist, but not overly saturated. 

Pests/Problems:

Deer browse still occurring in the garden. Ticks are active. Garlic mustard (Alliaria petiolata), an invasive plant species in our region, is actively growing. Second year plants will bolt soon, but it’s best to learn to ID first year plants as basal rosettes to pull them long before they get to flowering stage. Sarcococca hookeriana (sweet box) is showing evidence of cold damage from the -13ºF temperatures in early February. This marginally hardy low-growing evergreen shrub in the boxwood family has made it through several winters without any evidence of damage from cold temperatures, but that one night was likely too much for this shrub to withstand. 

Pioneer Valley (Amherst)

General Conditions:

Spring is slowly taking shape in the Pioneer Valley. Over the past two weeks there has been a mixture of mild, sunny days and cool to cold nights. High temperatures continue to climb into the 50s and 60s, and long-term forecasts predict temperatures in the 70s by next week. We are likely to experience at least a few more sub-freezing low temperatures as April continues. Buds on numerous trees and shrubs are swelling or starting to break with rosaceous hosts (serviceberry, cherries, crabapple), American elms and Japanese maples at the top of the list. Forsythias are just starting to flower in certain pockets around the valley and before long the spectacle of spring color will begin. Soils remain moist to wet from several scattered showers. However, at this time of year the uppermost soil surface can quickly dry out with the lack of foliage, bright sun and strong spring winds. The USGS has produced a detailed report on the hydrologic drought of 2022 with interesting details about how groundwater and rivers/streams were impacted in the region (https://pubs.usgs.gov/sir/2023/5016/sir20235016.pdf). 

One lingering issue from the mid-March nor’easter is bent and deformed branches on landscape conifers. Arborvitaes, yews, pines and other conifers with upright or long, pliable branches were damaged by the extremely heavy, wet snow. To be clear, the branches remain intact but simply no longer remain upright. Tying the branches to correct their orientation can be performed, but it must be done with care to avoid long-term damage. Use soft rope or rubber insulated wire to tie up drooping branches and consider using a soft rag as a buffer between the rope/wire and the bark. Using a more abrasive material may damage the bark as trees sway in the wind. The rope or insulated wire must be removed in subsequent years, once the branch has stiffened, to avoid girdling injury. The chorus of peepers is getting very strong in wetland areas and a variety of insects are slowly starting to appear. Turfgrasses are starting to green up in many landscapes and the forecasted warming should accelerate growth.

Pests/Problems:

Continue to scout for and address winter injury, when possible. Winter burn on boxwood is often scattered in the upper canopy and affected branches have pale brown to tan-colored leaves. Rabbits are a major nuisance right now, eating spring bulbs and nibbling other newly emerging plants. Most deer repellents will also deter rabbits. Now is a good time to prune dead twigs and branches from landscape trees and shrubs prior to leaf out. Scout for cool season spider mite (southern mite and spruce spider mite) activity on broadleaf evergreens and conifers. Once apple and crabapples leaf out, apple scab infections will soon follow. This is a good time to prune out interior canopy branches and suckers that do not receive direct sunlight. Foliage on these canopy parts are often the first to become diseased and the removal of suckers improves airflow through the canopy and general aesthetics. 

Berkshire Region (Great Barrington)

General Conditions:

The fluctuating conditions between sub-normal and well above normal temperatures that have characterized much of this winter and early spring continued through the recent scouting period. While the high temperature at North Adams reached 61ºF on March 22, Pittsfield and Richmond reached 68ºF and 70ºF , respectively, on April 4th. Lowest temperatures at the 3 sites all occurred on March 31. It was 20ºF at both North Adams and Pittsfield, and 19ºF at Richmond. Precipitation, year to date, is about 1.5 inches above normal. About 1.5 inches of snow fell at this site in West Stockbridge on March 29. In deeply shaded spots, or areas where snow piled high, there are still some remnants of the 2-foot snowfall on March 14/15. Winds on April 1 gusted up to 50MPH, resulting in much damage to trees. For the most part, soils are moist but, except for the heaviest soils, conditions are favorable for digging and planting of dormant trees and shrubs, as well as dividing and planting many herbaceous perennials. Growth of turfgrass has begun on many sites. Buds on deciduous trees and shrubs are beginning to swell but none are leafing. What is putting on a show now are the colorful flowers of crocus (Crocus spp.), snowdrops (Galanthus spp.), and scilla (Scilla lucilia). Turfgrass at many sunny sites and on good quality soils is beginning to grow but slowly.

Pests/Problems:

As mentioned, high winds of late have added to the considerable amount of damage to trees and shrubs this year. Besides toppled trees and completely severed branches, many trees have cracked trunks and limbs. Deer ticks are prominent and many landscape professionals have reported tick bites. Among the safety precautions to take when working in landscapes is application of the repellent permethrin to clothing. Interestingly, after the 1.5-inch snow on March 29, numerous winter cutworms (Noctua pronuba) were seen atop the snow. Once the snow melted, the cutworms disappeared. Those not consumed by birds most likely borrowed into the soil. Emerald Ash Borer damage to white ash was observed. Initial attention was drawn to multiple ash trees by large patches of light-colored bark and by numerous holes caused by woodpeckers seeking the borers. Another observation during this scouting period was the blistered leaves on boxwood, indicating presence of Boxwood Leaf Miner. Browsing by deer, rabbits and voles is at a high level right now.

Regional Scouting Credits

• CAPE COD REGION - Russell Norton, Horticulture and Agriculture Educator with Cape Cod Cooperative Extension, reporting from Barnstable.
• SOUTHEAST REGION - Brian McMahon, Arborist, reporting from the Dighton area.
• NORTH SHORE REGION - Geoffrey Njue, Green Industry Specialist, UMass Extension, reporting from the Long Hill Reservation, Beverly.
• EAST REGION - Kit Ganshaw & Sue Pfeiffer, Horticulturists reporting from the Boston area.
• METRO WEST REGION – Julie Coop, Forester, Massachusetts Department of Conservation & Recreation, reporting from Acton.
• CENTRAL REGION - Mark Richardson, Director of Horticulture reporting from New England Botanic Garden at Tower Hill, Boylston.
• PIONEER VALLEY REGION - Nick Brazee, Plant Pathologist, UMass Extension Plant Diagnostic Lab, reporting from Amherst.
• BERKSHIRE REGION - Ron Kujawski, Horticultural Consultant, reporting from Great Barrington.

Woody Ornamentals

Diseases

Recent pests and pathogens of interest seen in the UMass Extension Plant Diagnostic Lab, a select few:

Foliar edema on rhododendron (Rhododendron sp.). This mature plant is believed to be over 40-years-old and resides in a residential landscape that may be a developed wetland. Soils are sandy and remain wet throughout the winter months. The plant does receive full sun and has not experienced this issue previously. Rhododendrons have fibrous root systems and are particularly sensitive to saturated soils. Symptoms of edema on broadleaf evergreens typically manifests as chlorotic spots and blotches on the surface of the foliage with brown-colored callus forming on the underside. When overwatering is the culprit, the issue can be remedied. However, when sites are naturally wet, corrective action is more challenging to accomplish.

Spruce needle rust (SNR), caused by Chrysomyxa weirii, on blue spruce (Picea pungens). The tree is approximately 10- to 15-years-old and resides in a shaded setting with compacted, dry soils composed of sand and clay. Blue spruce requires full sun to thrive and when grown in shade becomes diseased by various fungal pathogens. The tree has an overall “thin” appearance with lackluster growth. While Rhizosphaera needle cast was detected, the primary issue at present appeared to be needle rust. Orange spots surrounded by yellowing tissue were abundant on the needles. These orange spots are fungal pads that expand in late April and May, rupture the cuticle and release large volumes of pigmented spores. In many cases, SNR causes only aesthetic injury and does not represent a major threat to long-term health. This case appears to be more serious and given the poor growing conditions, it may contribute to further decline. While many rust fungi require two botanically unrelated plants to compete their life cycle (i.e. Juniperus and a rosaceous host), C. weirii infects only spruce.

Stunted and distorted shoots and needles on white fir (Abies concolor) due to herbicide exposure. The tree is mature, approximately 75-years-old, and resides in a full sun landscape with well-drained loam soils. The submitted branch segments revealed the 2022 needles were severely stunted and distorted while the shoots were also undersized. Older needles and shoots appeared largely normal with some distortion. There is an English ivy ground cover around the tree and the property has been largely unmaintained. The managing arborist did not know if any herbicides were used on the property or a neighboring property.

Severe infestation of the pine bark adelgid (PBA; Pineus strobi) and subsequent colonization by sooty mold fungi on an eastern white pine (Pinus strobus ‘Fastigiata’). The tree is young and was transplanted at the site 18 months ago. It was planted in a narrow bed close to a commercial building in full sun with drip irrigation. In late summer to early fall of last year, white cottony masses and black-colored growth was observed on the back of the tree. The PBA is a common pest of eastern white pine and other ornamental pines in the region. It uses a piercing and sucking mouthpart to extract fluids from infested stems. However, it is not considered a serious pest, even when populations are high. Sooty mold fungi often co-occur, growing on the honeydew excreted by the adelgids. The combination of the two is highly conspicuous and reduced aesthetics. If trees are otherwise healthy, they seem to tolerate PBA infestations without any symptom development. 

Report by Nick Brazee, Plant Pathologist, UMass Extension Plant Diagnostic Lab, UMass Amherst.

Insects and Other Arthropods

• Deer Tick/Blacklegged Tick: Ixodes scapularis adults have been active all winter, as they typically are from October through May, and “quest” or search for hosts at any point when daytime temperatures are above freezing. Engorged females survive the winter and will lay 1,500+ eggs in the forest leaf litter beginning around Memorial Day (late May). For images of all deer tick life stages, along with an outline of the diseases they carry, visit:https://web.uri.edu/tickencounter/species/blacklegged-tick/ .

Anyone working in the yard and garden should be aware that there is the potential to encounter deer ticks. The deer tick or blacklegged tick can transmit Lyme disease, human babesiosis, human anaplasmosis, and other diseases. Preventative activities, such as daily tick checks, wearing appropriate clothing, and permethrin treatments for clothing (according to label instructions) can aid in reducing the risk that a tick will become attached to your body. If a tick cannot attach and feed, it will not transmit disease. For more information about personal protective measures, visit: https://web.uri.edu/tickencounter/prevention/protect-yourself/ .

The Center for Agriculture, Food, and the Environment provides a list of potential tick identification and testing resources here: https://ag.umass.edu/resources/tick-testing-resources .

*In the news: UMass Amherst has now been designated as the location for the New England Center of Excellence in Vector-Borne Diseases (NEWVEC). This CDC (Centers for Disease Control and Prevention) funded center will work to reduce the risk of vector-borne diseases spread by ticks, mosquitoes, and other blood-sucking insects or insect relatives in New England:https://www.umass.edu/news/article/cdc-designates-new-england-center-excellence-vector-borne-diseases-umass-amherst . For more information and to contact NEWVEC, visit:https://www.newvec.org/ . To contact the center for more information about their Spring 2023 Project ITCH (“Is Tick Control Helping”), visit:https://www.newvec.org/itch . 

Woody ornamental insect and non-insect arthropod pests to consider, a selected few:

Highlighted Invasive Insects & Other Organisms Update:

• Spongy Moth: Lymantria dispar egg masses will be seen overwintering on just about any flat surface, including host plants such as oak, but also fencing, buildings, steps, outdoor furniture, and more. The end of winter and start of spring is a good time to scout properties, particularly in areas of Berkshire County, MA and abutting locations in CT and NY that experienced elevated L. dispar populations in 2022. If large numbers of egg masses are seen, plan to monitor them between 90-100 growing degree days (roughly the first week in May, but this varies) to better time egg hatch and caterpillar emergence. The MA Department of Conservation and Recreation, Forest Health Program reports that winter counts of spongy moth egg masses are higher than hoped for in parts of Berkshire County coming into the spring of 2023. This may mean that spongy moth caterpillars will again be noticeable in these areas this year, despite seeing caterpillar die-off from the spongy moth killing fungus Entomophaga maimaiga last season. For more information from the Forest Health Program, visit: https://storymaps.arcgis.com/stories/b60f63199fa14805a8b9f7c82447a25b and look under the spongy moth navigation tab.

If egg masses are plentiful near high-value specimen trees in Berkshire County in 2023, consider applying the reduced risk insecticide Bacillus thuringiensis Kurstaki (Btk) to host plant leaves before caterpillars are over ¾ inch in length. Work with a licensed pesticide applicator and arborist to plan these applications, if necessary, especially if a high-value host plant was defoliated by this insect in 2021 or 2022.

Additionally, we’ve been asked about wrapping trees to prevent spongy moth caterpillars from accessing the canopy to feed. Here is some information. If you are interested in wrapping trees or shrubs with a sticky barrier to capture older, crawling spongy moth caterpillars, there are a few things to consider. 1) This will not prevent all caterpillars from accessing the tree to feed, nor is it a guarantee that no foliage will be eaten by them on the plant to which it has been applied. 2) This will not prevent the tiniest of caterpillars (newly hatched) from ballooning on the wind into tall trees and settling to feed. For example, this could mean that caterpillars will still have some access to the leaves following their dispersal in the spring. 3) Do not apply any sticky substances directly to the tree or shrub bark to avoid risk of injury to the plant. 4) Sticky bands will need to be monitored frequently throughout the growing season, particularly in mid-to-late May and especially June, to clean and replace them. If the bands become covered in dead caterpillars, living ones can crawl over the dead and still access the leaves of the tree. You do not have to hang the bands up now, but now is a good time to purchase necessary materials if you are interested in doing this on a few trees or shrubs in your yard. It is recommended that bands be placed on trees (and sticky material on the bands) once the caterpillars are approximately an inch in length. This may be approximately in early or mid-June. Bands should then be left up and changed frequently through July, until the caterpillars have pupated. This technique may work best with an engaged property owner that is willing and able to frequently check and help change the bands. For more information, visit: https://www.canr.msu.edu/resources/using-bands-to-protect-shade-trees-from-spongy-moth

The good news – homeowners in central and eastern Massachusetts will hopefully not have to worry too much about spongy moth this year. It may be undetectable in many central and eastern MA locations. MA DCR reports not seeing significant overwintering spongy moth egg masses in those locations. The primary area of concern includes parts of southwestern Berkshire County.

For more information about spongy moth, view the first episode of InsectXaminer, here: https://ag.umass.edu/landscape/education-events/insectxaminer .

Why did the common name for Lymantria dispar change recently? More information is available here: https://entsoc.org/news/press-releases/spongy-moth-approved-new-common-name-lymantria-dispar .

• Hemlock Woolly Adelgid: Adelges tsugae is present on eastern and Carolina hemlock. The overwintering hemlock woolly adelgid generation (sistens) is present through mid-spring and produces the spring generation (progrediens) which will be present from early spring through mid-summer. HWA, unlike many other insects, does most of its feeding over the winter. Hemlock woolly adelgid winter mortality (due to two significant regional cold snap events) is expected to be high for 2023. HWA that were most likely to survive these extreme cold events are those on lower host tree branches, if they were insulated by snow pack at the time. Determine if HWA are alive or dead on host plants before making chemical management decisions. This can be done quickly in the field by squishing overwintered HWA in their ovisacs between your thumb and forefinger and looking for a dark brown/blackish stain (from the hemolymph, or insect blood). If staining does not occur, the insect may have died and dried up. Test at least a few insects on at least a few branches to determine if any are alive. (Much more extensive examination may involve viewing at least 200 adelgids per site/location to calculate percent winter mortality.)

Eggs may be found in woolly masses at the base of hemlock needles beginning in mid-March. Each woolly mass is created by a female who may then lay 50-300 eggs. Eggs hatch and crawlers may be found from mid-March through mid-July. Infested trees may be treated with foliar sprays in late April to early May, using Japanese quince as a phenological indicator. Systemic* applications may be made in the spring and fall, or when soil conditions are favorable for translocation to foliage. Nitrogen fertilizer applications may make hemlock woolly adelgid infestations worse.

For more information, visit: https://ag.umass.edu/landscape/fact-sheets/hemlock-woolly-adelgid .

*Note: beginning July 1, 2022 systemic insecticides known as neonicotinoids (including imidacloprid) have become state restricted use for tree and shrub uses in Massachusetts. More information is available, here:https://www.mass.gov/service-details/pesticide-newsupdates

• Spotted Lanternfly: (Lycorma delicatula, SLF) is a non-native, invasive insect that feeds on over 103 species of plants, including many trees and shrubs that are important in our landscapes. It overwinters as an egg mass, which the adult female insect lays on just about any flat surface. Pictures of egg masses can be seen here:https://massnrc.org/pests/linkeddocuments/SLFChecklistForResidents.pdf
   

  Currently, the only established populations of spotted lanternfly in Massachusetts are in Fitchburg, Shrewsbury, Worcester, and Springfield MA. Therefore, there is no reason to be preemptively treating for this insect in other areas of Massachusetts. If you suspect you have found spotted lanternfly in additional locations, please report it immediately to MDAR here: https://massnrc.org/pests/slfreport.aspx . If you are living and working in the Fitchburg, Shrewsbury, Worcester, and Springfield, MA areas, please be vigilant and continue to report anything suspicious.

For More Information:

From UMass Extension:

*New*: Spotted Lanternfly Management Guide for Professionals:https://ag.umass.edu/landscape/fact-sheets/spotted-lanternfly-management

*Note that management may only be necessary in areas where this insect has become established in Massachusetts, and if high value host plants are at risk. Preemptive management of the spotted lanternfly is not recommended.

Fact Sheet:https://ag.umass.edu/landscape/fact-sheets/spotted-lanternfly

Check out the InsectXaminer Episode about spotted lanternfly adults and egg masses! Available here:https://ag.umass.edu/landscape/education-events/insectxaminer

From the MA Department of Agricultural Resources:

Fact Sheet and Map of Locations in MA:https://massnrc.org/pests/pestFAQsheets/spottedlanternfly.html

Spotted Lanternfly Management Guide for Homeowners in Infested Areas:https://massnrc.org/pests/linkeddocuments/SLFHomeownerMgmtGuide.pdf

• Asian Longhorned Beetle: (Anoplophora glabripennis, ALB) Look for signs of an ALB infestation which include perfectly round exit holes (about the size of a dime), shallow oval or round scars in the bark where a female has chewed an egg site, or sawdust-like frass (excrement) on the ground nearby host trees or caught in between branches. Be advised that other, native insects may create perfectly round exit holes or sawdust-like frass, which can be confused with signs of ALB activity.

The regulated area for Asian longhorned beetle is 110 square miles encompassing Worcester, Shrewsbury, Boylston, West Boylston, and parts of Holden and Auburn.  If you believe you have seen damage caused by this insect, such as exit holes or egg sites, on susceptible host trees like maple, please call the Asian Longhorned Beetle Eradication Program office in Worcester, MA at 508-852-8090 or toll free at 1-866-702-9938.

To report an Asian longhorned beetle find online or compare it to common insect look-alikes, visit: http://massnrc.org/pests/albreport.aspx orhttps://www.aphis.usda.gov/pests-diseases/alb/report .

• Emerald Ash Borer: (Agrilus planipennis, EAB) has been detected in at least 11 out of the 14 counties in Massachusetts.A map of these locations across the state may be found here:https://ag.umass.edu/fact-sheets/emerald-ash-borer . Additional information about this insect is provided by the MA Department of Conservation and Recreation, here:https://storymaps.arcgis.com/stories/b60f63199fa14805a8b9f7c82447a25b .

This wood-boring beetle readily attacks ash (Fraxinus spp.) including white, green, and black ash and has also been found developing in white fringe tree (Chionanthus virginicus) and has been reported in cultivated olive (Olea europaea). Signs of an EAB infested tree may include D-shaped exit holes in the bark (from adult emergence), “blonding” or lighter coloration of the ash bark from woodpecker feeding (chipping away of the bark as they search for larvae beneath), and serpentine galleries visible through splits in the bark, from larval feeding beneath. It is interesting to note that woodpeckers are capable of eating 30-95% of the emerald ash borer larvae found in a single tree (Murphy et al. 2018). Unfortunately, despite high predation rates, EAB populations continue to grow. However, there is hope that biological control efforts will eventually catch up with the emerald ash borer population and preserve some of our native ash tree species for the future.

• Winter Moth: (Operophtera brumata) data since 2017 has indicated that the winter moth population in eastern Massachusetts has been on the decline while the percent of winter moth pupae parasitized by Cyzenis albicans has increased! Dr. Joseph Elkinton’s laboratory at UMass Amherst has released this biological control agent of winter moth since 2005 and conducted the rigorous sampling required to determine where the insect has established and what its impact on the winter moth population has been at multiple sites in eastern MA.

The take-home point? Do not worry about winter moth this spring! In fact, management of this insect in landscaped settings will likely not be necessary in most locations. Blueberry growers may still, on the other hand, be interested in scouting and continuing to monitor for this insect, as only very low numbers of winter moth caterpillars might be tolerated in that system. In recent years, it is worth-while to note that some areas on the Cape and other locations in eastern MA have reported noticeable native cankerworm populations in the spring, which are often confused for winter moth. Read more about cankerworms in the spring scouting list below.

• Jumping Worms: Amynthas spp. earthworms, collectively referred to as “jumping or crazy or snake” worms, overwinter as eggs in tiny, mustard-seed sized cocoons found in the soil or other substrate (ex. compost). The tiny, impossible to remove cocoons will overwinter and provide a population of these earthworms in the 2023 season.

For More Information:

UMass Extension Fact Sheets:

• Earthworms in Massachusetts – History, Concerns, and Benefits: https://ag.umass.edu/landscape/fact-sheets/earthworms-in-massachusetts-history-concerns-benefits
• Jumping/Crazy/Snake Worms – Amynthas spp.: https://ag.umass.edu/landscape/fact-sheets/jumpingcrazysnake-worms-amynthas-spp
• A Summary of the Information Shared at UMass Extension’s Jumping Worm Conference in January 2022: https://ag.umass.edu/news-events/highlights/jumping-worms-conference
• Invasive Jumping Worm Frequently Asked Questions (Over 70 Questions and their Answers): https://ag.umass.edu/landscape/fact-sheets/invasive-jumping-worm-frequently-asked-questions

Spring Scouting Suggestions & Preparation for Upcoming Tree & Shrub Insects (Native and Invasive):

• Bagworm:Thyridopteryx ephemeraeformis is a native species of moth whose larvae construct bag-like coverings over themselves with host plant leaves and twigs. This insect overwinters in the egg stage, within the bags of deceased females from last season. Eggs may hatch and young larvae are observed feeding around mid-June, or roughly between 600-900 GDD’s. Now is the time to scout for and remove and destroy overwintering bags. More information can be found here:https://ag.umass.edu/landscape/fact-sheets/bagworm
• Balsam Twig Aphid: Mindarus abietinus overwinters as a silvery colored egg on host plant twigs. Eggs hatch just prior to budbreak and nymphs feed for a period of time on the undersides of last season’s needles before molting into a wingless stem mother. Stem mothers move to buds just as they open and give “live birth” to second generation nymphs. These second generation nymphs are the most damaging, feeding on new needles as they elongate, causing distortion and stunting. Excessive amounts of honeydew may be produced and cause needles to stick together. Foliar applications, if needed, may be made between 30-100 GDD’s, base 50°F on warm days before budcaps loosen. Inspect the twigs, near the base of needles of Balsam fir, Fraser fir, and other true firs for overwintering eggs and eventually the needles for feeding nymphs. This insect may be most problematic in Christmas tree production. In landscapes, many natural enemies can provide adequate management of this insect.
• Boxwood Leafminer: Monarthropalpus flavus partly grown fly larvae overwinter in the leaves of susceptible boxwood. Yellowish mines may be noticeable on the undersides of leaves. This insect grows rapidly in the spring, transforming into an orange-colored pupa. After pupation, adults will emerge and white colored pupal cases may hang down from the underside of leaves where adults have emerged. Adults may be observed swarming hosts between 300-650 GDD’s, or roughly the end of May through June. Most cultivars of Buxus sempervirens and B. microphylla are thought to be susceptible. If installing new boxwoods this spring, resistant cultivars such as ‘Vardar Valley’ and ‘Handsworthiensis’ are good choices at sites where this insect has been a problem. For more information, visit: https://ag.umass.edu/landscape/fact-sheets/boxwood-leafminer
• Boxwood Mite: Eurytetranychus buxi overwinter as tiny eggs on boxwood leaves and hatch mid-spring. These mites are tiny (about the size of a period) and difficult to detect. Feeding may cause plants to appear off-color. If management is deemed necessary, the timing for treatment may be between 245-600 GDD’s or roughly the beginning of May.
• Boxwood Psyllid: Psylla buxi feeding can cause cupping of susceptible boxwood leaves. Leaf symptoms/damage may remain on plants for up to two years. English boxwood may be less severely impacted by this pest. Eggs overwinter, buried in budscales, and hatch around budbreak of boxwood. Eggs may hatch around 80 GDD’s. While foliar applications may be made between 290-440 GDD’s, the damage caused by this insect is mostly aesthetic. Therefore, typically, management is not necessary. For more information, visit: https://ag.umass.edu/landscape/fact-sheets/boxwood-psyllid .
• Cankerworms: Alsophila pometaria (fall cankerworm) and Paleacrita vernata (spring cankerworm) are often confused for winter moth (Operophtera brumata). Cankerworm populations in eastern MA, particularly on areas of Cape Cod, were confused for winter moth in 2019. Spring cankerworm adults are active in February and March, and fall cankerworm adults are active in late November into early December. During these times, both species lay eggs. These native insects most commonly utilize elm, apple, oak, linden, and beech. Eggs of both species hatch as soon as buds begin to open in the spring. Caterpillars occur in mixed populations and are often noticeable by mid-May in MA. Young larvae will feed on buds and unfolding leaves. There are two color forms (light green and dark) for caterpillars of both species. Like winter moth, they will drop to the soil to pupate. This usually occurs in June. Fall cankerworm larvae have three pairs of prolegs (one of which is small so it is sometimes referred to as ½) and spring cankerworm have two pairs. (Winter moth caterpillars also have 2 pairs of prolegs.) If populations are large and damage is noticeable on hosts, reduced risk insecticides such as Bacillus thuringiensis Kurstaki or spinosad may target larvae between approximately 148-290 GDD’s.

  For more information, visit: https://ag.umass.edu/landscape/fact-sheets/fall-cankerworm and

• Cooley Spruce Gall Adelgid: Adelges cooleyi is a native insect that has a complex life cycle. It has at least five different morphological forms, and requires 2 years and two hosts to complete its normal life cycle. Galls (pineapple shaped/cone-like and at the tips of twigs) are produced on Colorado blue spruce, Engelmann, Sitka, and Oriental spruce and cause needle injury (yellow spots and distortion) to Douglas-fir. Immature females overwinter on spruce near twig terminals. In the early spring, females mature into stem mothers and lay hundreds of eggs on lateral terminals. Upon egg hatch, nymphs migrate to new spring growth and feed at the base of growing needles.

  Immatures can be targeted on spruce between 22-81 GDD’s (mid-late April).

  Immatures can be targeted on spruce between 22-81 GDD’s (mid-late April). On Douglas-fir, dormant oil applications should be made immediately before budbreak to avoid phytotoxicity. Follow all label instructions.
• Eastern Spruce Gall Adelgid:Adelges abietis is a pest of Norway spruce primarily, but occasionally damages other spruce species such as Colorado blue, white, and red spruce. This adelgid overwinters as a partially grown female, often referred to as a stem mother. This overwintering individual matures around bud break and lays 100-200 eggs.

  The eastern spruce gall adelgid may be targeted for management between 22-170 GDD’s, base 50°F (mid-April to early-May).

  The eastern spruce gall adelgid may be targeted for management between 22-170 GDD’s, base 50°F (mid-April to early-May).

  Egg hatch typically occurs when wild cherry leaves begin to unfold and young caterpillars may emerge by late-April through the first two weeks in May (90-190 GDD’s).

  This insect is non-native, and was introduced into the United States from Europe before 1900. Galls are small, sometimes pineapple shaped/variable, but produced on the basal portion of the shoots, such that the twig extends beyond the gall. Twig dieback may occur.
• Eastern Tent Caterpillar: Malacosoma americanum eggs overwinter on host plant twigs. Egg hatch typically occurs when wild cherry leaves begin to unfold and young caterpillars may emerge by late-April through the first two weeks in May (90-190 GDD’s). Susceptible hosts include cherry and crabapple. Other host plants whose leaves are fed upon by this native insect can include apple, ash, birch, willow, maple, oak, poplar, and witch-hazel. Prune off and remove egg masses from ornamental host plants by early spring. Eastern tent caterpillars are native to Massachusetts and have many associated natural enemies (parasites and predators) that help regulate populations. Unless these caterpillars are actively defoliating specimen trees in a landscaped setting, we can coexist with this particular herbivore native to our forests.
• Elongate Hemlock Scale: Fiorinia externa is found on eastern, Carolina, and Japanese hemlock, as well as yew, spruce, and fir. The elongate hemlock scale may overwinter in various life stages, and overlap of many developmental stages at any given time can be observed throughout much of the season. Dormant oil applications for this pest can occur according to label instructions in April, roughly between 7-120 GDD’s. Treatments for the crawler, or mobile, stage of this insect may be made in late May through mid-June, or between 360-700 GDD’s, base 50°F. Nitrogen fertilizer applications may make elongate hemlock scale infestations worse.

For more information, visit: https://ag.umass.edu/landscape/fact-sheets/elongate-hemlock-scale .

• Euonymus Scale: Unaspis euonymi is an armored scale that can be found on euonymus, holly, bittersweet, and pachysandra. This insect can cause yellow spotting on leaves, dieback, and distorted bark. Dormant oil applications can be made between 35-120 GDD’s or roughly from mid-April to early-May. For crawlers, early June timing is suggested between 533-820 GDD’s. (Eggs begin to hatch in early June.)
• European Pine Sawfly: Neodiprion sertifer overwinters in the egg stage. Eggs are laid by females the previous season by cutting slits in needles using their ovipositors and depositing 6-8 eggs in each of 10-12 needles.

Egg hatch occurs from late-April to mid-May and caterpillars become active roughly between 78-220 GDD, base 50°F. The primary host in MA is Mugo pine but it can be found on Scots, red, jack, and Japanese red pine. It is also found on white, Austrian, ponderosa, shortleaf, and pitch pine when planted near the aforementioned species.  This dark colored caterpillar feeds in tight groups and small numbers can be pruned or plucked out of host plants and destroyed. Spinosad products can be used whenever the caterpillars are actively feeding, usually by mid-May and when caterpillars are still small. Bacillus thuringiensis kurstaki is not effective against sawflies.

• Forest Tent Caterpillar: Malacosoma disstria egg hatch occurs between 192-363 GDD’s, base 50°F, by mid-late May and caterpillars may be active for at least 5-6 weeks following. Susceptible hosts whose leaves are fed on by this insect include oak, birch, ash, maple, elm, poplar, and basswood. This native insect has many natural enemies, including some very effective pathogens that typically regulate populations. However, outbreaks of this insect can occur on occasion.
• Hemlock Looper: Two species of geometrid moths in the genus Lambdina are native insects capable of defoliating eastern hemlock, balsam fir, and white spruce. Adult moths lay their eggs on the trunk and limbs of hosts in September and October, and eggs will hatch by late May or early June. (L. fiscellaria caterpillars may be active between 448-707 GDD’s.) Monitor susceptible hosts for small, inch-worm like caterpillars. Where populations are low, no management is necessary. Hemlock loopers have several effective natural enemies.
• Imported Willow Leaf Beetle: Plagiodera versicolora adult beetles overwinter near susceptible hosts. Adult beetles will chew holes and notches in the leaves of willow once they become available. Females lay yellow eggs in clusters on the undersides of leaves. Larvae are slug-like and bluish-green in color. They will feed in clusters and skeletonize the leaves. Most plants can tolerate the feeding from this insect, and foliage will appear brown. Repeated yearly feeding can be an issue, in which case management of the young larvae may be necessary. Take care with treatment in areas near water. 

Check out Episode 4 of InsectXaminer to see the imported willow leaf beetle in action: https://ag.umass.edu/landscape/education-events/insectxaminer

• Japanese Cedar Longhorned Beetle: Almost on an annual basis, UMass Extension receives questions about evidence of wood boring beetle attack on eastern redcedar and similar hosts, including but not limited to: American arborvitae, Atlantic white cedar, common juniper, false arborvitae, Hinoki cypress, Japanese cedar, Leyland cypress, and others. The culprit could be the Japanese cedar longhorned beetle (Callidiellum rufipenne) or our native cedar tree borer (Semanotus ligneus). C. rufipenne is discussed here. We recommend submitting samples of the damaged plant material and any insect life stages to the UMass Plant Diagnostics Laboratory: https://ag.umass.edu/services/plant-diagnostics-laboratory/tree-shrub-diagnostics-pinewood-nematode-assay .

The Japanese cedar longhorned beetle was first detected in Washington state in 1954. This wood boring beetle is found in conifers belonging to the cypress family. Primary hosts noted for this species include arborvitae, cypress, juniper, and cedar (Chamaecyparis). Adult beetles are small, approximately ¼ to ½ inch in length with long antennae (males have antennae that are slightly longer than their bodies; females have shorter antennae). The females have reddish brown elytra (hardened wings) and the males appear darker in color (shiny blue-black) with red visible on the “shoulders” of the beetle (just behind the thorax). There is one generation per year, although in colder locations it may take 2 years to complete its life cycle. Once the females emerge from their host, they begin to lay eggs in the cracks and crevices of bark during their 20-day life span. Each female lays approximately 20 eggs (Shibata, 1994). Eggs hatch within 2 weeks and the larvae bore beneath the bark, creating tunnels or galleries as they feed in the phloem and cambium layers of the tree or shrub. Larvae are cream colored with 3 pairs of thoracic legs and grow up to approximately ¾ inch in length. As many as 10 larvae may be found in a single arborvitae branch. When the larvae are mature, they enter the xylem where they pupate, which is suspected to occur in the fall. The Japanese cedar longhorned beetle is thought to overwinter as an adult within the host plant, and emerges early the next season in the spring (Hoebeke, 1999; Humphreys and Allen, 2000; Maier and Lemmon, 2000). However, depending upon geographic location, there is discrepancy between sources regarding the overwintering life stage of this insect.

The feeding damage from the larvae of this insect causes branch dieback which may not be noticed until the following spring after initial infestation. Other signs of this insect include frass found near galleries and splits in the bark and 1/8 inch, oval exit holes. Bark may appear puckered where larval mining occurs, and frass can be seen within the mines if they are exposed by splits in the bark. Frass-packed galleries occur in the cambium and xylem. Monitor for this insect, especially in Suffolk and Nantucket Counties in Massachusetts. May also be present elsewhere in the state. Look for branch dieback on susceptible hosts in the spring. Look for bark splits, galleries, frass, and oval exit holes. With caution and the proper tools, slice open dying branches to look for galleries in the cambium and xylem and also potentially expose larvae, pupae, or adult beetles. 

Borers may be preferentially attracted to stressed plants. Take precautions to avoid plant stress, such as proper planting and site selection. Prune out and destroy infested branches prior to adult emergence in the spring. In Japan, Shibata (1994) determined that approximately 53% of pre-adult Japanese cedar longhorned beetles succumb to disease or parasitism by a suite of natural enemies. Most of the larval mortality occurs due to (as of yet) unidentified diseases; some pupal mortality occurs due to disease as well. Before pupation, larvae are also killed by two important parasitoids - Doryctes yogoi and Ischnoceros sapporensis. Two species of parasitoids from the pupal cells of Japanese cedar longhorned beetles are also known - Baeacis semanoti and Rhimphoctona spp. (Invasive Species Compendium; CABI). The full impact of natural enemies on this insect in the United States is not completely understood.

• Lecanium Scales (Oak): Parthenolecanium quercifex overwinters as a second instar nymph on oak twigs. Females will begin feeding and mature in the spring, from mid-April to early May and eggs may be laid between late May and into June. Eggs hatch in June or early July and crawlers migrate to host plant leaves where they spend the summer and migrate as second instars back to host plant twigs in the fall. Mid-April to early-May (35-145 GDD’s) for dormant oil applications.
• Lily Leaf Beetle:Lilioceris liliiadults overwinter in sheltered places. As soon as susceptible hosts such as Lilium spp. (Turk’s cap, tiger, Easter, Asiatic, and Oriental lilies) and Fritillaria spp. break through the ground, the adult lily leaf beetles are known to feed on the new foliage. (Note: daylilies are not hosts.) Typically, in May, mating will occur and each female will begin to lay 250-450 eggs in neat rows on the underside of the foliage. If there are only a few plants in the garden, hand picking and destroying overwintering adults can help reduce local garden-level populations at that time.  

Check out Episode 3 of InsectXaminer to see the lily leaf beetle in action:https://ag.umass.edu/landscape/education-events/insectxaminer

• Magnolia Scale: Neolecanium cornuparvum overwinters as first instar nymphs which are elliptical, and dark slate gray in color and can usually be found on the undersides of 1 and 2 year old twigs. Nymphs may molt by late April or May and again by early June at which time the scales may be purple in color. Eventually nymphs secrete a white powdery layer of wax over their bodies. Dormant oils can be applied between 7-35 GDD’s targeting the overwintering nymphs. Avoid applications to opening buds or blooms.
  • For more information, visit: https://ag.umass.edu/landscape/fact-sheets/magnolia-scale .
• Pine Bark Adelgid: Pineus strobi overwinters as an immature which begins feeding during the first days of warm weather in the spring and begins secreting white wax over itself, which can eventually coat the entire trunk of infested trees. Egg laying may begin in April. This insect can be found on the trunk, branches, twigs, and the base of needles on new shoots. Spruce is a secondary host but this adelgid can repeatedly reproduce itself on pine. Wash off bark with a strong jet of water. If necessary, dormant oil applications can be made in mid-late April between 22-58 GDDs. Hosts include eastern white, Scots, and Austrian pines. This insect does little damage to healthy trees and can often be tolerated.
• Snowball Aphid: Neoceruraphis viburnicola eggs overwinter on viburnum twigs and buds. Eggs hatch and this aphid becomes active on certain species of viburnum roughly between 148-298 GDD’s or around redbud bloom. This insect is particularly noticeable on V. opulus, V. prunifolium, and V. acerifolia. Stem mothers, appearing blueish-white, can be found in curled up and distorted foliage. Damage caused by this insect pest is mostly aesthetic.
• Spruce Bud Scale: Physokermes piceae is a pest of Alberta and Norway spruce, among others. Immatures overwinter on the undersides of spruce needles, dormant until late March. By April, females may move to twigs to complete the rest of their development. Dormant oil applications may be made between 22-121 GDDs. Follow all label instructions, as oil may remove the bluish color from certain conifers. Mature scales are reddish brown, globular, 3 mm. in diameter, and found in clusters of 3-8 at the base of new twig growth. They closely resemble buds and are often overlooked. Crawlers are present around June.

• Spruce Spider Mite: Oligonychus ununguisis a cool-season mite that becomes active in the spring from tiny eggs that have overwintered on host plants. Hosts include spruce, arborvitae, juniper, hemlock, pine, Douglas-fir, and occasionally other conifers. This particular species becomes active in the spring and can feed, develop, and reproduce through roughly June. When hot, dry summer conditions begin, this spider mite will enter a summer-time dormant period (aestivation) until cooler temperatures return in the fall. This particular mite may prefer older needles to newer ones for food. When damaging spruce spider mite populations are known from last season, dormant oil applications can be made (when temperatures are appropriate according to label instructions) between 7-121 GDD’s, base 50°F (April). Magnification is required to view spruce spider mite eggs. Tapping host plant branches over white paper may be a useful tool when scouting for spider mite presence. (View with a hand lens.) Spider mite damage may appear on host plant needles as yellow stippling and occasionally fine silk webbing is visible.

• Viburnum Leaf Beetle: Pyrrhalta viburni is a beetle in the family Chrysomelidae that is native to Europe, but was found in Massachusetts in 2004. Viburnum leaf beetle overwinters as eggs laid in capped pits on the newest growth of susceptible viburnum branches. Scout for overwintered eggs and prune out and destroy before they hatch. Egg hatch occurs in late-April to early-May as temperatures warm and foliage becomes available. Monitor for larvae in mid-May (80-120 GDD’s). This beetle feeds exclusively on many different species of viburnum, which includes, but is not limited to, susceptible plants such as V. dentatum, V. nudum, V. opulus, V. propinquum, and V. rafinesquianum. Some viburnum have been observed to have varying levels of resistance to this insect, including but not limited to V. bodnantense, V. carlesii, V. davidii, V. plicatum, V. rhytidophyllum, V. setigerum, and V. sieboldii. More information about viburnum leaf beetle may be found athttp://www.hort.cornell.edu/vlb/ and here: https://ag.umass.edu/landscape/fact-sheets/viburnum-leaf-beetle .
• White Pine Weevil: Pissodes strobi adults overwinter in sheltered locations in the leaf litter and become active very early in the spring, when daytime temperatures reach 50°F and before the bloom of forsythia (between 7-58 GDDs). Hosts include eastern white pine, Norway spruce, scotch, pitch, and red pine, blue spruce, and white spruce. Adults will begin feeding on bark 7-10 inches below dormant terminal buds. Females will deposit eggs in terminal growth bark, and developing larvae will feed in leaders until they mature in July when pupation occurs in pupal chambers made of wood chips. Management in nurseries or Christmas tree production may be necessary. Target adults between 7-58 GDD’s.
• Woolly Apple Aphid:Eriosoma lanigerum may be found on apple, crabapple, hawthorn, mountain-ash, Pyracantha, and elm hosts. The primary (winter) host is elm, on which aphids infest emerging spring leaves, causing leaves to curl or close into stunted, rosette-like clusters found at twig tips. On apple and crabapple, this species of aphid colonizes roots, trunks, and branches in the summer and is commonly found near previous wounds or callous tissue. On roots, the aphids cause swelled areas which can girdle and kill roots. The aphids, when found in above ground plant parts such as elm leaves, are covered with white wax. Eggs are the overwintering stage on elm, which hatch in the spring in time for the nymphs to infest new elm foliage. Following a few generations on elm, the aphids will develop into a winged form, which will disperse and seek out apple and crabapple. Multiple generations will occur on these alternate hosts in the summer and by the fall, a winged form will return to elm and mated females will lay eggs near elm buds. These aphids are a favorite snack for insect predators such as the multicolored Asian lady beetle, Harmonia axyridis.

• Woolly Elm Aphid: Eriosoma americanum females lay a single egg in the cracks and crevices of elm bark, where the egg overwinters. Eggs hatch on elm in the spring as leaves are unfolding. Aphids may be active from 121-246 GDD’s, base 50°F on elm. A young, wingless female hatched from the egg feeds on the underside of leaf tissue. This female aphid matures and gives birth to 200 young, all females, without mating. These aphids feed, and the elm leaf curls around them and protects them. By the end of June, winged migrants mature and find serviceberry hosts. Another set of females is produced. These new females crawl to and begin feeding on the roots of serviceberry. Multiple generations occur on the roots of serviceberry through the summer.

Concerned that you may have found an invasive insect or suspicious damage caused by one? Need to report a pest sighting? If so, please visit the Massachusetts Introduced Pests Outreach Project:http://massnrc.org/pests/pestreports.htm .

Reported by Tawny Simisky, Extension Entomologist, UMass Extension Landscape, Nursery, & Urban Forestry Program

Turf

Insects

Winter cutworms

This year we have received multiple reports regarding winter cutworm larvae found on the snow or feeding. We have been monitoring the activity of winter cutworms at the UMass Joseph Troll Turf Research center and noted increased activity in March.

The winter cutworm (Noctua pronuba) has been introduced from Europe and is very cold tolerant relatively to other turf insect pests. The life cycle of this species in New England has not been studied, but according to past observationd (by Dr. Pat Vittum), adults ("yellow underwing moths") are expected to fly in mid- to late summer, and they will lay eggs in late August to late September. The caterpillars are active and feed through the winter if temperatures are above 40º F. Currently the caterpillars (Fig.1) are finishing up their feeding and development and getting ready to pupate. Even though we haven’t seen any significant damage to the turfgrass in New England, this species can be devastating to plants in the family Poaceae (Gramineae.. the grasses).

Please let me know (and send pictures) if you see any of these winter cutworms and associated damage. We are investigating their life cycle in New England and potential treatments.

Craneflies

Around this time the damage caused by common craneflies (Tipula oleracea) becomes apparent and at high densities, severe. In addition, predators will dig to feed on relatively large larvae. However, insecticide application is not very effective, now because of the size of the larvae. If damage must be stopped, fast acting contact insecticides can be used on high-value turf areas, followed by irrigation (1/4”). Often larvae come to the surface after treatments (Fig. 2). We expect early development and adult flight this year (mid-April), so some of the larvae might be pupating at this time.

 

Reported by Dr. Olga Kostromytska, Extension Assistant Professor and Turf Entomologist, UMass Stockbridge School of Agriculture

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Diagnostic Services

UMass Laboratory Diagnoses Landscape and Turf Problems - 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. Accurate diagnosis for a turf or landscape problem can often eliminate or reduce the need for pesticide use. For sampling procedures, detailed submission instructions and a list of fees, see Plant Diagnostic Laboratory

Soil and Plant Nutrient Testing - The University of Massachusetts Soil and Plant Nutrient Testing Laboratory is located on the campus of The University of Massachusetts at Amherst. Testing services are available to all. The lab provides test results and recommendations that lead to the wise and economical use of soils and soil amendments. For more information, including current turn-around times, visit the UMass Soil and Plant Nutrient Testing Laboratory web site. The lab is currently accepting new orders for Routine Soil Analysis (including optional Organic Matter, Soluble Salts, and Nitrate testing), Particle Size Analysis, Pre-Sidedress Nitrate (PSNT), and Soilless Media (no other types of soil analyses available at this time). See https://ag.umass.edu/services/soil-plant-nutrient-testing-laboratory/ordering-information-forms/turnaround-time-for-routine-soil-analysis for current turnaround time. Please plan for the fact that date of receipt in the lab is affected by weekends, holidays, shipping time, and time for UMass Campus Mail to deliver samples to the lab.

Tick Testing - The UMass Center for Agriculture, Food, and the Environment provides a list of potential tick identification and testing options at: https://ag.umass.edu/resources/tick-testing-resources.

Acknowledgements: UMass Extension gratefully acknowledges the support of the following funding sources for the production of the Landscape Message –

• The Massachusetts Nursery and Landscape Association Fund
• The Massachusetts Department of Conservation and Recreation, Award #ISADCR28219926UMA22A
• Stakeholders like you! The Landscape Message is partially supported by educational program user fees.