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Landscape Message: May 1, 2020

May 1, 2020
Issue: 
3

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.

Happy May Day! While operations at the University of Massachusetts Amherst have been significantly reduced in response to the COVID-19 pandemic, UMass Extension has developed a listing of resources for commercial horticulture operations in Massachusetts to help keep you informed and aware of relevant policies and best practices for landscapers, turf managers, arborists, nurseries, garden centers, and greenhouse producers.

For our COVID-19 Information and Support for Landscapers, Nurseries, Turf Managers, Garden Centers, Arborists, and Greenhouse Operations in Massachusetts, go to https://ag.umass.edu/landscape/news/covid-19-information-support-for-landscapers-nurseries-turf-managers-garden-centers.

The Landscape Message will be updated weekly in May. The next message will be posted on May 8. To receive immediate notification when the next Landscape Message update is posted, be sure to join our e-mail list.

To read individual sections of the message, click on the section headings below to expand the content:


Scouting Information by Region

Environmental Data

The following data was collected on or about April 29, 2020. Total accumulated growing degree days (GDD) represent the heating units above a 50° F baseline temperature collected via our instruments for the 2020 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
(1-Week Gain)

Time/Date of Readings

1-Week Gain

2020 Total

Sun

Shade

CAPE

0

14.5

45

43

2.70

10:00 AM 4/29

SOUTHEAST

0

22.5

58

46

0.80

2:30 PM 4/29

NORTH SHORE

0

40.0

49

43

0.45

4:00 PM 4/29

EAST

0

53.5

58

48

1.31

5:00 PM 4/29

METRO

0

34.0

41

40

1.26

6:30 AM 4/29

CENTRAL

0.5

33.5

45

40

1.26

12:00 PM 4/29

PIONEER VALLEY

0

19.0

56

45

0.74

3:00 PM 4/29

BERKSHIRES

0

14.5

42

41

0.79

8:15 AM 4/29

AVERAGE

0

29.0

49

43

1.16

-

n/a = information not available

Phenology

Indicator Plants - Stages of Flowering (BEGIN, BEGIN/FULL, FULL, FULL/END, END)

PLANT

CAPE

SE

NS

EAST

METRO

CENT

PV

BERK

Malus spp. (crabapple)

*

Begin

*

*

*

*

*

*

Amelanchier spp. (shadbush, serviceberry)

Begin

Begin

Begin

Full/End

Begin

Begin

Begin/Full

*

Rhododendron ‘P.J.M.’

Full

Full

Full

Full/End

End

Full

Full

Begin/Full

Pyrus calleryana (Callery pear)

Full

Full/End

Full

Full/End

Full

Full

Full

*

Rhododendron mucronulatum (Korean Rhododendron)

*

*

*

End

End

End

End

Full

* = no activity to report/information not available

Regional Notes

Cape Cod Region (Barnstable)

General Conditions: The average temperature over the period from April 22 - April 29 was 43˚F with a high of 59˚F on April 25 and a low of 31˚F on April 23. For the month of April so far, there was only one day that topped 60˚F, reaching 61˚F on April 7. The same number of days (1) topped 60˚F in January, with 64˚F on January 12. Most of the period was cool and cloudy, with few days suitable for field work. During the period, 2.7 inches of precipitation fell with most of it coming overnight on April 26. Top soil moisture and sub soil moisture is adequate to excessive.

Pests/Problems: The cool temperatures have greatly slowed plant development and allowed for longer than normal blooms for plants like Forsythia. Pests to keep an eye out for include Lecanium scale on woody ornamentals. High populations of Lecanium scale are widespread across the Cape. Look for the small (1-1.5mm) reddish brown oval scales on last year’s woody growth. The presence of whitish scale indicates bio control at work, likely an entomopathogenic fungi. (See images of both brown and white scale in last week’s report.) Also, keep an eye out for fall cankerworm which is very similar in appearance to winter moth caterpillars (see Insect report below). There were isolated areas of defoliation from fall cankerworm last year on the upper Cape. Other insects or diseases seen over the period include; white Prunicola scale on lilac, rose slug sawfly adults on rose, black knot on Prunus, winter burn on boxwood, and freeze damage to Hosta. Weeds in bloom include bittercress (Cardamine hirsuta), mouse-ear cress (Arabidopsis thaliana), fig buttercup/lesser celandine (Ficaria verna /Ranunculus ficaria), whitlow grass (Draba verna), and speedwell (Veronica spp). Dandelions (Taraxacum officinale) and common violet (Viola papilionacea) are just beginning to flower. Rabbits are mowing down perennials. Keep yourself protected from ticks.

White Prunicola scale on lilac, the yellow/orange are adult females. Rose slug sawfly adult on rose, searching for ovipositing site.

Southeast Region (Dighton)

General Conditions: We had rainstorms, frequent showers and record low daytime temperatures throughout most of the week. Ice was in the birdbath some mornings. A couple of sunny days in the 50's were glorious. The following plants are flowering: Amelanchier canadensis, Viburnum carlesii, tulips, daffodils, Narcissus spp., Muscari armeniacum, Scilla, Trillium grandiflorum, Leucojum aestivum, Lunaria annua, Forsythia, Magnolia stellata, M. x soulangeana, crabapple, Acer rubrum, A. platanoides, Prunus persica, P. subhirtella, P. cerasifera, violets, pansies, Poa annua, ground ivy, chickweed, dandelion, Lamprocapnos spectabilis, Pulmonaria, and Chaenomeles.

Pests/Problems: Tick activity is high at this time. Adult deer ticks (black-legged ticks) have been active in Massachusetts for at least 6 weeks according to TickReport https://www.tickreport.com/. Nymphal ticks should be active in Massachusetts any day now. Ticks pass through the egg, larval, nymph and adult stages. Nymphs will have already taken a blood meal and have the chance of passing on a pathogen, such as the bacteria that causes Lyme disease. In Massachusetts, TickReport finds that roughly 26% of nymphs are infected. It is critical to protect yourself against deer tick nymphs, especially since they are smaller and may be more easily missed. Cedar rust galls are swollen and should produce telial horns and spores with rains in the coming week. Chickweed seed is germinating faster than it can be hoed.

North Shore (Beverly)

General Conditions: Unseasonably cool temperatures persisted during this reporting period. Day temperatures were in the mid-40s to mid-50s and night temperatures were in the mid-30s to high 30s. Cloudy weather and rain showers were the norm for most of the days during this reporting period. At Long Hill approximately 0.45 inches of rain fell between 4/22 and 4/29. Gardeners and landscapers are busy doing spring cleanup. Soils are moist and suitable for planting. Woody plants that are beginning to bloom or continue to bloom include: serviceberry (Amelanchier arborea), weeping Higan cherry (Prunus subhirtella), mountain Pieris (Pieris floribunda), Japanese Pieris (Pieris japonica), star Magnolia (Magnolia stellata), Callery pear (Pyrus calleryana), Eastern leatherwood (Dirca palustris), Spicebush (Lindera benzoin) and Forsythia (Forsythia spp.). Spring flowering herbaceous plants seen in full bloom include: daffodils (Narcissus spp.), bloodroot (Sanguinaria canadensis), Pachysandra (Pachysandra terminalis), Vinca vine (Vinca minor), tulips (Tulipa spp), bleeding heart (Lamprocapnos spectabilis), dollar plant (Lunaria annua), forget me not (Myosotis scorpioides), trout lily (Erythronium americanum), barrenwort (Epimedium spp.) and lungwort (Pulmonaria spp.)

Pests/Problems: Extremely invasive, non-native fig buttercup/lesser celandine (Ficaria verna /Ranunculus ficaria) is in full bloom and thriving, sadly, outcompeting other wildflowers and native plants. Dandelions are also flowering. Ticks are active and it is important to protect yourself with a repellent when working outdoors. If you find a tick on yourself or a pet, send the tick to UMass Laboratory of Medical Zoology for identification and testing for tick borne pathogens. For details go to: https://www.tickreport.com/

Native trout lily (Erythronium americanum. (photo: Dan Bouchard, Long Hill)

East Region (Boston)

General Conditions: The last week of April has been wet, windy and cold. We received precipitation on 4 of the past seven days adding 1.31” for a total of 6.36” for April as of the 29th. Overnight lows averaged 35.5˚F as we continue to receive light frosts. It has been unusually cool with four days this week not getting out of the 40’s. We have gained no GGDs over the last week. Grass is greening up and the landscape continues to develop. Several noteworthy plants in bloom include; Brunnera macrophylla (false forget-me-not), Epimedium spp. (barrenwort), Leucojum aestivum (summer snowflake), and the underutilized native Xanthorhiza simplicissima (yellowroot).

Pests/Problems: Dandelions are flowering in unmanaged turf. Garlic mustard rosettes have begun to flower. Lesser celandine/fig buttercup (Ficaria verna/ Ranunculus ficaria) continues to invade moist locations. Japanese knotweed is rapidly gaining height. Hemlock wooly adelgid cottony egg masses are visible in abundance on untreated hemlock.

Metro West (Acton)

General Conditions: Welcome to a New England spring! The rainy weather continued into this week with precipitation recorded for this area on six of the past seven days, bringing our total rainfall recorded for this month to 5.03” inches, thereby surpassing the April monthly average of 4.16”. Rain is in the forecast for the next couple of days so that number will surely climb. Weather certainly is typical and spring like with the fluctuating temperatures, windy days and nights, and rainy and/or grey damp days. This pattern has continued throughout the month and into the last week of April. For this past week, a high temperature of 66°F was recorded on the 25th and a low of 24°F was recorded on the mornings of the 22nd and 23rd. This morning, the29th, there was a thin layer of ice on my bird bath. With all that being said, lawns are greening up and growing and leaves and flower buds are expanding on trees and shrubs. The landscape is filled with color! Observed in some stage of bloom this past week were the following woody plants: Chaenomeles speciosa (common flowering quince), Cornus mas (Cornelian cherry dogwood), C. officinalis (Japanese cornelian cherry), Forsythia spp., Lindera benzoin (common spicebush), Magnolia x loebneri 'Merrill', (Merrill Magnolia), M. x soulangeana (saucer magnolia), M. 'Butterflies' (butterflies Magnolia), Pieris japonica (Japanese Pieris), Prunus spp. (cherry), Pyrus spp. (pear), Rhododendron mucronulatum (Korean Rhododendron), and R. 'P. J. M.' (PJM Rhododendron). Contributing even more color and interest to the landscape are some flowering herbaceous plants and spring ephemerals including: Anemone nemorosa (wood anemone), Asarum europaeum (European ginger), Caltha palustris (marsh marigold), Chionodoxa luciliae (glory of the snow), Crocus spp., Dicentra canadensis (squirrel corn), D. cucullaria (Dutchman's breeches), D. spectabilis (old fashioned bleeding heart), D. spectabilis ‘Alba’ (white old fashioned bleeding heart), Epimedium versicolor 'Sulphureum' (yellow flowering barrenwort), Helleborus niger (Christmas rose), Hyacinthus spp. (Hyacinth), Mertensia virginica (Virginia bluebells), Muscari spp. (grape Hyacinth), Narcissus spp. (daffodil), Omphalodes verna (blue-eyed Mary), Pachysandra procumbens (Allegheny spurge), Phlox subulata (moss Phlox), Primula spp. (primrose), Pulmonaria longifolia (lungwort), P. rubra (salmon colored lungwort), Puschkinia libanotica (striped squill), Sanguinaria canadensis (bloodroot), S. canadensis 'Multiplex' (double bloodroot), Scilla siberica (Siberian squill), Trillium erectum (red flowering Trillium), Tulipa spp. (tulip), Vinca minor (periwinkle) and Viola spp. (violet).

Pests/Problems: Soils are well saturated which could be an issue for planting and digging in some areas. Acer platanoides (Norway maple) is in full bloom. This invasive and allelopathic tree is hard to miss now that it is in bloom because its flowers are a bright yellowish-green and are easily seen on trees found growing almost everywhere. Continuing to flourish in too many places in the landscape is the basal foliage of Alliaria petiolata (garlic mustard). Other weeds seen in bloom but without the invasive tendency of the previously mentioned two are: Draba verna (spring whitlow grass), Glechoma hederacea (ground ivy), Lamium purpureum (purple deadnettle), Stellaria media (common chickweed), and Taraxacum officinale (dandelion).

Central Region (Boylston)

General Conditions: A real spring - long, cold and rainy. Temperatures during the reporting period were colder than we’ve grown accustomed to for late April, averaging in the 30’s and 40’s every day this week. The cooler temperatures have certainly prolonged flowering periods for some early spring blooms like daffodils and Siberian squill. Many Magnolia blossoms across the region were hit by a hard frost, turning flowers a lovely shade of brown. A sampling of what’s in bloom this week: Acer saccharum (sugar maple), Corydalis spp. (Corydalis), Geum fragarioides (barren strawberry), Houstonia caerulea (bluets), Hyacinthus (Hyacinth), Jeffersonia diphylla (twinleaf), Lindera benzoin (spicebush), Magnolia x soulangeana (saucer Magnolia), Plagiorhegma dubium (Asian twinleaf), Prunus spp. (flowering cherries), Sanguinaria canadensis (bloodroot), Stylophorum diphylla (wood poppy), and Vinca minor (myrtle).

Pests/Problems: The frequent rain has meant soils continue to be saturated and difficult to work for spring planting. Blackflies and ticks are abundant. Winter annual weeds like hairy bittercress and chickweed are spreading quickly. Garlic mustard (Alliaria petiolata) has begun to bolt and will flower soon.

Stylophorum diphyllum, wood poppy Sanguinaria canadensis, bloodroot Sanguinaria canadensis 'Multiplex', double-flowered bloodroot Narcissus 'Sunnyside Up', split-cup daffodil Prunus x subhirtella 'Autumnalis', higan cherry Lindera benzoin, spicebush Jeffersonia diphylla, twinleaf Houstonia caerulea, bluets

 

 

 

 

 

 

Erythronium 'Pagoda', trout lily

 

 

 

Pioneer Valley Region (Easthampton)

General Conditions: Another week of fickle weather in the Pioneer Valley as we close out the fourth month of the year. One third of 2020 has now passed and based on the current state, good riddance. Overall, this past reporting period featured below-average temperatures with cloudy skies and scattered rain showers on 4/24 and 4/26–27. But we did also experience some bright sun and temperatures in the mid-60s on 4/28 and 4/29. A typical mixed bag of spring weather in southern New England. The long-term forecast shows a general warming trend and May often has some of the nicest weather of the year, so there’s much to look forward to. While the deep, vibrant green of spring is starting to take hold in certain pockets of the landscape, plant development continues to only slowly advance. High temperatures have been acceptable for leaf and shoot development, especially when the sun is out, but low temperatures continue to approach freezing. With a few mild nights, plants should really begin to pop with new growth. Buds on hemlock, yew and spruce continue to swell and slowly break. Junipers are pushing new growth and pine candles are slowly elongating. Flowering cherry, purple PJM Rhododendron, Norway maple, Bradford pear and flowering quince are producing the brunt of the color right now. For some cities and towns, the streets are flooded with Bradford pears and Norway maples in flower. Those are unfortunate choices for widespread planting, but mature trees have value regardless of species. Some Forsythias still appear in full flower, continuing the strong year these plants have had. Honeysuckle, privet, hawthorn and crabapple/apple foliage is developing at a strong pace. Turf grasses are greening beautifully and many lawns are now under regular mowing cycles. The spring winds were nowhere near as ferocious this past week as they were in mid-April. The windy spring weather and wet soils can easily dislodge newly transplanted trees and shrubs. While there are many ways to stake trees, using materials specifically designed for plants like rubber insulated wire or Velcro straps can help plants avoid injury while they are violently whipped around this time of year. The wonderful and exceptionally loud chorus of spring peepers is one of the best sounds of spring.

Pests/Problems: Pest and pathogen activity still remains low at this time with the cold nighttime temperatures. But it’s still a great time to identify and prune blighted shoots and stems from trees and shrubs. As buds swell and slowly break, it’s becoming easier to identify what’s alive and what isn’t. If you really scour the landscape, it’s easy to find plants worthy of the time. Winter-related injuries, like shoot tip dieback on Viburnum, grey leaf blight of Rhododendron and needle browning on dwarf Alberta spruce have been observed. Rust galls are visible and sporulating on Juniperus species at this time. These galls can be pruned out if one is attempting to control the various rust diseases that are associated with juniper and rosaceous hosts. Mosquitoes and black flies have started to appear but aren’t bad yet.

Berkshire Region (Great Barrington)

General Conditions: Yo-yo weather which has been so characteristic for the past several months continued during the past week as a few days were sunny and close to the seasonal normal or were damp and well below the normal temperature. Daytime temperature reached a high of 63˚F on April 25. The night time low during the same time span was 28˚F on the morning of April 23. Precipitation for the month of April, up to April 29, was 0.11 inches above normal, as recorded at Pittsfield Airport. However, total precipitation for the year-to-date is 1.67 inches below normal and 2.67 inches less than last year at this time. Currently, soils are saturated, except for sites with gravely soil. Snow fell in the higher elevations during the overnight hours of Sunday, April 26, but quickly disappeared after daybreak on Monday. With the exception of spring bulbs and other early blooming herbaceous plants, development of woody plants has been slow. Forsythia, star Magnolia (Magnolia stellata), cherry (Prunus spp.) and Pieris floribunda are among the species still in bloom. Turfgrass is growing rapidly now and the mowing season is underway.

Pests/Problems: One consequence of the relatively mild winter is the minimal amount of winter injury to evergreens. There is certainly much less than observed last year. Pest occurrence is still quite low. However, the population of black-legged ticks (deer ticks) is high and the frequency of tick attachment to those working in the landscape is likewise high. Bees and wasps are active, as are mosquitoes and gnats.

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 Tower Hill Botanic Garden, Boylston.
  • PIONEER VALLEY REGION - Nick Brazee, Plant Pathologist, UMass Extension Plant Diagnostic Lab, temporarily reporting from Easthampton.
  • BERKSHIRE REGION - Ron Kujawski, Horticultural Consultant, reporting from Great Barrington.

Woody Ornamentals

Diseases

The UMass Plant Diagnostic Lab remains closed at this time to sample submission. Once the lab is allowed to reopen and resume activities, we will share this information immediately.

As noted in the Barnstable County report, oak Lecanium scale populations remain high this year. Scale feeding on stems and small branches can facilitate infection by stem cankering fungi. For oak (Quercus spp.), members of Botryosphaeria s.l. are of primary concern. One member of this group, Diplodia, has been associated with serious branch and trunk cankers of oak throughout the northeast. As oak buds continue swell and break, the location of dead shoots and branches is more evident in the canopy. Botryosphaeria s.l. infections result in a multitude of small cankers that coalesce to girdle stems. The small, black-colored fruiting bodies can often be observed after they have ruptured through the bark. A combination of scale feeding and stem cankering can cause problems for oaks already stressed by prior defoliation, wood boring insects and root disease (specifically Armillaria). Oaks are durable and long-lived trees but unfortunately are preferred by many insect pests and fungal pathogens. If possible, prune and discard cankered stems and branches from the canopy to reduce pathogen inoculum. Systemic fungicides are more likely to have utility against Botryosphaeria s.l. but be mindful of potential resistance development.

Grey leaf blight of Rhododendron is caused by the fungal pathogen Pestalotiopsis. The fungus is opportunistic and not considered overly aggressive, often advancing on foliage suffering from winter burn. But Pestalotiopsis is a known endophyte, meaning it can infect the plant and avoid detection for a period of time. While much of the leaf remains healthy, the best practice is to prune out these leaves to physically remove the pathogen. Performing these regular sanitation prunes can help prevent a larger outbreak.

Grey leaf blight of rhododendron, caused by Pestalotiopsis. Grey leaf blight of rhododendron, caused by Pestalotiopsis. Grey leaf blight of rhododendron, caused by Pestalotiopsis.

 

 

 

 

 

 

Winter injury on the lower canopy of a dwarf Alberta spruce (Picea glauca ‘Conica’).Winter injury on the lower canopy of a dwarf Alberta spruce (Picea glauca ‘Conica’).

 

 

 

 

 

 

Stone fruit trees (peaches, plums and cherries) are now flowering, leading to possible brown rot infections. Brown rot of stone fruits is caused by two species of Monilinia and both are capable of causing stem cankering and fruit rot on landscape and orchard trees. For landscape trees, shaded settings dramatically increase disease incidence and severity, especially morning shade. If fruit production is of primary importance, then pruning to provide maximum sunlight and airflow on the branches is required. This means that aesthetics have to take a back seat, but a properly sculpted peach or plum tree can provide landscape interest. There is a wider range of fungicides available for landscape trees if fruit will not be consumed. However, if fruit is intended for consumption, fungicide selection should be more careful. Iprodione (Rovral), mancozeb (Bravo Weather Stik), Captan and fenbuconzole (Indar) are used in orchards and provide good disease control along with cultural measures.

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

Insects

Insects and Other Arthropods of Public Health Concern:

  • Deer Tick/Blacklegged Tick: Check out the archived FREE TickTalk with TickReport webinars available here:https://ag.umass.edu/landscape/education-events/webinars . Previous webinars including information about deer ticks and associated diseases, ticks and personal protection, and updates from the Laboratory of Medical Zoology are archived at the link above.

The next live webinar will be held on May 13, 2020: “Ticks & Red Meat Allergies: The Latest Science”. Join TickReport, Dr. Stephen Rich, and Dr. Scott Commins as they explore the science behind red meat allergies caused by tick bites. Special guest Dr. Scott Commins, a leading physician and research scientist in the field of alpha-gal red meat allergies, will discuss this interesting phenomenon with Dr. Rich.

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. Deer tick nymphs (immatures) are also active, and may be encountered at this time, through August. Nymphs will have already taken a blood meal, and therefore can be infected with disease causing pathogens. It is important to protect yourself against ticks and be especially vigilant for tiny, difficult to see nymphs. For images of all deer tick life stages, along with an outline of the diseases they carry, visit: http://www.tickencounter.org/tick_identification/deer_tick .

Anyone working in the yard and garden on springtime cleanup and planting 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: http://www.tickencounter.org/prevention/protect_yourself .

Have you just removed an attached tick from yourself or a loved one with a pair of tweezers? If so, consider sending the tick to the UMass Laboratory of Medical Zoology to be tested for disease causing pathogens. To submit a tick to be tested, visit: https://www.tickreport.com/ and click on the blue “Order a TickReport” button. Results are typically available within 3 business days, or less. By the time you make an appointment with your physician following the tick attachment, you may have the results back from TickReport to bring to your physician to aid in a conversation about risk.

The UMass Laboratory of Medical Zoology does not give medical advice, nor are the results of their tests diagnostic of human disease. Transmission of a pathogen from the tick to you is dependent upon how long the tick had been feeding, and each pathogen has its own transmission time. TickReport is an excellent measure of exposure risk for the tick (or ticks) that you send in to be tested. Feel free to print out and share your TickReport with your healthcare provider.

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

  • 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 miles2 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 or https://www.aphis.usda.gov/pests-diseases/alb/report .

  • White Spotted Pine Sawyer (WSPS): Monochamus scutellatus adults can emerge in late May throughout July, depending on local temperatures. This is a native insect in Massachusetts and is usually not a pest. Larvae develop in weakened or recently dead conifers, particularly eastern white pine (Pinus strobus). However, the white spotted pine sawyer looks very similar to the invasive Asian Longhorned Beetle, Anoplophora glabripennis, ALB. ALB adults do not emerge in Massachusetts until July and August. Beginning in July, look for the key difference between WSPS and ALB adults, which is a white spot in the top center of the wing covers (the scutellum) on the back of the beetle. White spotted pine sawyer will have this white spot, whereas Asian longhorned beetle will not. Both insects can have other white spots on the rest of their wing covers; however, the difference in the color of the scutellum is a key characteristic. See the Asian longhorned beetle entry above for more information about that non-native insect.
  • 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. In certain areas across MA in 2019, increased populations of bagworms were observed and reported. 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 soon 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 ‘Winter Gem’ are good choices at sites where this insect has been a problem.
  • 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. Foliar applications may be made between 290-440 GDD’s. However, the damage caused by this insect is mostly aesthetic. Therefore, no management may be necessary.
  • 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 were 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 (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 148-290 GDD’s.
  • 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). On Douglas-fir, dormant oil applications should be made immediately before budbreak to avoid phytotoxicity. Follow all label instructions.
  • Dogwood Borer: Synanthedon scitula is a species of clearwing moth whose larvae bore not only into dogwood (Cornus), but hosts also include flowering cherry, chestnut, apple, mountain ash, hickory, pecan, willow, birch, bayberry, oak, hazel, myrtle, and others. Kousa dogwood appear to be resistant to this species. Signs include the sloughing of loose bark, brown frass, particularly near bark cracks and wounds, dead branches, and adventitious growth. The timing of adult emergence can be expected when dogwood flower petals are dropping and weigela begins to bloom. Adult moth flights continue from then until September. Emergence in some hosts (ex. apple) appears to be delayed, but this differs depending upon the location in this insect’s range. Eggs are laid singly, or in small groups, on smooth and rough bark. Female moths preferentially lay eggs near wounded bark. After hatch, larvae wander until they find a suitable entrance point into the bark. This includes wounds, scars, or branch crotches. This insect may also be found in twig galls caused by other insects or fungi. Larvae feed on phloem and cambium. Fully grown larvae are white with a light brown head and approx. ½ inch long. Pheromone traps and lures are useful for determining the timing of adult moth emergence and subsequent management.
  • 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 lay 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). 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.
  • Emerald Ash Borer: (Agrilus planipennis, EAB) Since the New Year, the Massachusetts Department of Conservation and Recreation has confirmed at least 18 new community detections of emerald ash borer in Massachusetts. While the cities and towns with recent detections of EAB are too numerous to list here, they are in areas of Essex, Franklin, Hampshire, Middlesex, Norfolk, and Worcester counties. It is worthwhile to note that this was the first detection of EAB in Franklin County. A map of these locations and others previously known across the state may be found here: https://ag.umass.edu/fact-sheets/emerald-ash-borer .

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). Adult insects of this species will not be present at this time of year. Signs of an EAB infested tree may include (at this time) D-shaped exit holes in the bark (from adult emergence in previous years), “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. Positive identification of an EAB-infested tree may not be possible with these signs individually on their own.

For further information about this insect, please visit: https://ag.umass.edu/fact-sheets/emerald-ash-borer . If you believe you have located EAB-infested ash trees, particularly in an area of Massachusetts not identified on the map provided, please report here: http://massnrc.org/pests/pestreports.htm .

  • 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.
  • Fletcher Scale: Parthenolecanium fletcheri is a soft scale pest of yew, juniper, and arborvitae. Feeding scales, especially on yew, result in honeydew and sooty mold, needle yellowing, and at times, premature needle drop. There is one generation per year. Overwintered second instar nymphs can be targeted between 38-148 GDD’s, base 50°F. Nymphs develop and adult females lay eggs (on average 500-600) in May that hatch by June. Dead females conceal egg masses beneath. Crawlers migrate short distances to branches and may be concentrated on certain branches of a particular plant.
  • 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.
  • Gypsy Moth:(Lymantria dispar) thanks to the gypsy moth caterpillar killing fungus, Entomophaga maimaiga, the recent outbreak of gypsy moth in Massachusetts has come to an end! Most locations in Massachusetts will not see damaging or even noticeable populations of this insect in 2020. Gypsy moth has been in Massachusetts since the 1860's. This invasive insect from Europe often goes unnoticed, thanks to population regulation provided by the entomopathogenic fungus, E. maimaiga, as well as a NPV virus specific to gypsy moth caterpillars. (And to a lesser extent many other organisms, including other insects, small mammals, and birds who feed on gypsy moth.) However, if environmental conditions do not favor the life cycle of the fungus, outbreaks of gypsy moth caterpillars are possible. (Such as most recently from 2015-2018, with a peak in the gypsy moth population in 2017 in Massachusetts.)

Missing gypsy moth already? Check out Episode 1 of InsectXaminer to reminisce about the 2015-2018 outbreak of this insect: https://ag.umass.edu/landscape/education-events/insectxaminer

  • 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.
  • 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. 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.
  • Honeylocust Plant Bug: Diaphnocoris chlorionis feeding results in tiny yellowish-brownish spots on leaves, leaf distortion, and in some cases, defoliation. (There are at least 7 species of plant bugs that feed on honeylocust, Gleditsia triacanthos.) There is one generation per year. Immatures and adults feed on foliage and light to moderately damaged foliage may persist throughout the growing season. Honeylocust plant bugs overwinter as eggs laid just beneath the bark surface of 2 and 3 year old twigs. Eggs hatch just after vegetative bugs of the host begin to open. Young nymphs crawl to the opening leaflets and begin feeding and the most significant damage occurs at that time, when the insect is hidden from view. Nymphs develop into adults around May-July. This insect can be targeted between 58-246 GDD’s, base 50°F.
  • 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.
  • 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.
  • Lilac Borer: Podosesia syringae is a clearwing moth pest of lilac, privet, fringetree, and ash. (It is also known as the ash borer, not to be confused with the emerald ash borer.) Adults mimic paper wasps. Larvae are wood-boring, and signs and symptoms include branch dieback, holes, and occasionally, sawdust-like frass accumulated on bark. Larvae bore into stems, trunks, and branches, chewing an irregularly shaped entrance hole. Peak adult moth flights may occur in the northern portion of this insect’s range in June and is usually over by August 1st. Pheromone traps can be used to time adult emergence. Adult females lay flattened, oval, and tan eggs that are deposited singly or in clusters on bark crevices, ridges, and sometimes smooth bark; but usually laid in or near wounds in the bark. On average, 395 eggs are laid by each female. After hatch, larvae chew into the bark and feed laterally and then vertically in phloem tissue. Larvae overwinter in tunnels in the final instar and resume feeding in the spring. Adults emerge through a round exit hole (4-5 mm. in diameter). This insectmay be targeted between 200-299 GDD’s, base 50°F.
  • Lily Leaf Beetle: Lilioceris lilii adults 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 this time. For more information about this insect, visit the newly updated fact sheet: https://ag.umass.edu/landscape/fact-sheets/lily-leaf-beetle .

Want to learn more about lily leaf beetle’s life cycle and learn to recognize adults, larvae, and eggs? Take 3 minutes to watch Episode 2 of InsectXaminer, here: 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.
  • 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.
  • Spotted Lanternfly: (Lycorma delicatula, SLF) is not known to occur in Massachusetts landscapes (no established populations are known in MA at this time). However, due to the great ability of this insect to hitchhike using human-aided movement, it is important that we remain vigilant in Massachusetts and report any suspicious findings. Spotted lanternfly reports can be sent here:https://massnrc.org/pests/slfreport.aspx

For a map of known, established populations of SLF as well as detections outside of these areas where individual finds of spotted lanternfly have occurred (but no infestations are present), visit: https://nysipm.cornell.edu/environment/invasive-species-exotic-pests/spotted-lanternfly/ This map depicts an individual find of spotted lanternfly at a private residence in Boston, MA that was reported by the MA Department of Agricultural Resources on February 21, 2019. More information about this detection in Boston, where no established infestation was found, is provided here: https://www.mass.gov/news/state-agricultural-officials-urge-residents-to-check-plants-for-spotted-lanternfly

This insect is a member of the Order Hemiptera (true bugs, cicadas, hoppers, aphids, and others) and the Family Fulgoridae, also known as planthoppers. The spotted lanternfly is a non-native species first detected in the United States in Berks County, Pennsylvania and confirmed on September 22, 2014.

The spotted lanternfly is considered native to China, India, and Vietnam. It has been introduced as a non-native insect to South Korea and Japan, prior to its detection in the United States. In South Korea, it is considered invasive and a pest of grapes and peaches. The spotted lanternfly has been reported from over 70 species of plants, including the following: tree of heaven (Ailanthus altissima) (preferred host), apple (Malus spp.), plum, cherry, peach, apricot (Prunus spp.), grape (Vitis spp.), pine (Pinus spp.), pignut hickory (Carya glabra), sassafras (Sassafras albidum), serviceberry (Amelanchier spp.), slippery elm (Ulmus rubra), tulip poplar (Liriodendron tulipifera), white ash (Fraxinus americana), willow (Salix spp.), American beech (Fagus grandifolia), American linden (Tilia americana), American sycamore (Platanus occidentalis), big-toothed aspen (Populus grandidentata), black birch (Betula lenta), black cherry (Prunus serotina), black gum (Nyssa sylvatica), black walnut (Juglans nigra), dogwood (Cornus spp.), Japanese snowbell (Styrax japonicus), maple (Acer spp.), oak (Quercus spp.), and paper birch (Betula papyrifera).

The adults and immatures of this species damage host plants by feeding on sap from stems, leaves, and the trunks of trees. In the springtime in Pennsylvania (late April - mid-May) nymphs (immatures) are found on smaller plants and vines and new growth of trees and shrubs. Third and fourth instar nymphs migrate to the tree of heaven and are observed feeding on trunks and branches. Trees may be found with sap weeping from the wounds caused by the insect’s feeding. The sugary secretions (excrement) created by this insect may coat the host plant, later leading to the growth of sooty mold. Insects such as wasps, hornets, bees, and ants may also be attracted to the sugary waste created by the lanternflies, or sap weeping from open wounds in the host plant. Host plants have been described as giving off a fermented odor when this insect is present.

Adults are present by the middle of July in Pennsylvania and begin laying eggs by late September and continue laying eggs through late November and even early December in that state. Adults may be found on the trunks of trees such as the tree of heaven or other host plants growing in close proximity to them. Egg masses of this insect are gray in color and look similar in some ways to gypsy moth egg masses.

Host plants, bricks, stone, lawn furniture, recreational vehicles, and other smooth surfaces can be inspected for egg masses. Egg masses laid on outdoor residential items such as those listed above may pose the greatest threat for spreading this insect via human aided movement.

For more information about the spotted lanternfly, visit this fact sheet: https://ag.umass.edu/landscape/fact-sheets/spotted-lanternfly .

  • 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 ununguis is 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 at http://www.hort.cornell.edu/vlb/ .
  • 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 are also susceptible to white pine weevil damage. 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.
  • 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! This is excellent news, as it is data supporting the evidence that winter moth populations have decreased while the parasitic fly, C. albicans, has become established at many locations in New England. Dr. Joseph Elkinton’s laboratory at UMass Amherst has released this biological control 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. More information about the Elkinton Lab’s research and the biological control of winter moth can be found here: https://www.fs.fed.us/foresthealth/technology/pdfs/FHAAST-2018-03_Biology_Control_Winter-Moth.pdf

The take-home point? Do not worry about winter moth this spring! In fact, management of this insect in landscaped settings likely will not be necessary in most locations. In recent years, it is worth-while to note that some areas on the Cape and other locations in eastern MA have reported noticeable cankerworm populations in the spring, which are often confused for winter moth. Read more about cankerworms in the spring scouting list below.

In landscape settings in eastern Massachusetts, it is best to wait until the leaves of susceptible hosts completely unfold and monitor for feeding caterpillars, prior to treatment, especially since populations in Massachusetts continue to be so low in many locations. Be sure that management of this insect is necessary by monitoring for damaging populations before making applications in landscape settings. For more information about the life cycle and management of winter moth, please visit thisfact sheet: Winter Moth Identification and Management ( https://ag.umass.edu/landscape/fact-sheets/winter-moth-identification-management ).

Winter moth is a non-native insect that was identified in Massachusetts for the first time in 2003 following persistent reports of defoliation in eastern areas of the state such as Cape Anne and on the North Shore near Cohasset, Hingham, and Rockland on the South Shore in the late 1990’s. For more detailed information about the history of this insect pest in North America and Massachusetts, please visit this fact sheet: Winter Moth in Massachusetts: History and Biological Control ( https://ag.umass.edu/landscape/fact-sheets/winter-moth-in-massachusetts-history-biological-control ).

  • 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 .

A note about Tick Awareness: deer ticks (Ixodes scapularis), the American dog tick (Dermacentor variabilis), and the lone star tick (Amblyomma americanum) are all found throughout Massachusetts. Each can carry their own complement of diseases. Anyone working in tick habitats (wood-line areas, forested areas, and landscaped areas with ground cover) should check themselves regularly for ticks while practicing preventative measures. Have a tick and need it tested? Visit the web page of the UMass Laboratory of Medical Zoology (https://www.tickreport.com/ ) and click on the blue Order a TickReport button for more information.

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


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Current Massachusetts and University policy have the effect of temporarily suspending most of the on-campus services that we provide, including but not limited to:

  • Soil and Plant Nutrient Testing Lab
  • Plant Disease Diagnostics Lab
  • Weed, Insect, Turfgrass, and Invasive Plant Identification

Until further notice, please do not send or deliver samples to the campus, as we cannot process them.

Diagnostic Services

A 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 Diagnostics Laboratory . No samples are being accepted at this time.

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 function of the Soil and Plant Nutrient 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 Nutrient Testing Laboratory web site. Alternatively, call the lab at (413) 545-2311. No samples are being accepted at this time.

At this time, the TickReport Risk Assessment and Passive Surveillance Program, which is not part of UMass Extension, remains open. Tick samples can continue to be submitted via https://www.tickreport.com . Please contact TickReport with further questions and updates on the status of their service.

Ticks are active any time that temperatures are above freezing! Remember to take appropriate precautions when working and playing outdoors, and conduct daily tick checks. UMass tests ticks for the presence of Lyme disease and other disease pathogens. Learn more