Landscape Message: August 9, 2024 (2024)

UMass Extension's Landscape Message is an educational newsletter intended to inform and guide Massachusetts land care 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.

Welcome to Landscape Message #15 for the 2024 growing season. We are now in the bi-weekly phase of the annual schedule, however the next message is an exception and will be posted a bit later than normal, on Monday, August 26. To receive immediate notification when the next Landscape Message update is posted, be sure to join our e-mail list

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In This Issue

Scouting Information by Region

Environmental Data

Phenology

Regional Notes

Woody Ornamentals

Diseases

Insects and Other Arthropods

Landscape Weeds

Additional Resources

Scouting Information by Region

Environmental Data

The following data was collected on or about August 7, 2024. Total accumulated growing degree days (GDD) represent the heating units above a 50ºF baseline temperature collected viaregionalNEWA stations (http://newa.cornell.edu) for the 2024 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.

US Drought Monitor: Improvement on the drought front for this message. At this time, just small sections of northern Berkshire and Franklin counties, northern Middlesex county, and the northern 2/3 of Essex county are classified as "D0 - Abnormally Dry" (about 9% of the state's area in total). State map as of Thursday 8/8: https://droughtmonitor.unl.edu/CurrentMap/StateDroughtMonitor.aspx?MA

Phenology

Regional Notes

Cape Cod Region (Barnstable)

General Conditions: The average temperature for the period was 73ºF with a high of 90ºF on August 1 and a low of 57ºF on July 28. From July 24 thru July 30, temperature highs were near 80ºF with lows primarily in the 60s. From July 30 through August 5 was a hot stretch with highs in the upper 80s and lows in the mid 70s and with dew points in the 70s making it generally uncomfortable. Approximately 1 inch of precipitation occurred during the period, with the majority coming on July 28, but minuscule amounts fell on several other days. Soil moisture remains short.

Herbaceous plants seen in bloom include purple coneflower (Echinacea purpurea), black eyed Susan (Rudbeckia hirta), Russian sage (Salvia yangii), balloon flower (Platycodon grandiflorus), purple Joe-Pye weed (Eutrochium purpureum), and hardy hibiscus (Hibiscus moscheutos). Woody plants seen in bloom include sourwood (Oxydendrum arboreum), hydrangea (H. macrophylla & H. paniculata), mimosa (Albizia julibrissin), and abelia (Abelia x grandiflora).

Pests/Problems: Beware of box tree moth.Since box tree moth damage can happen fast, scout weekly. In recent weeks driving around the upper Cape, the sight of dead boxwoods in landscapes has become increasingly common as a result of box tree moth. Box tree moth will continue to be active and spread.

Insects or insect damage observed during the period include pine tip moth damage on pitch pine, hibiscus sawfly damage on hibiscus, four-lined plant bug damage on panicle hydrangea, chilli thrips damage to big leaf hydrangea, fall webworm on several deciduous woody plants, euonymus scale on Japanese holly, leafhopper damage to dahlia, sycamore lace bug damage on sycamore, two-spotted spider mites on numerous herbaceous and woody plants, some lingering Japanese beetles feeding on various ornamentals, and chinch bug damage in turf.

Disease symptoms or signs observed during the period include powdery mildew on numerous hosts, beech leaf disease on beech, venturia leaf spot on poplar, cedar apple rust on crabapple, pear trellis rust on Bradford pear, cercospora leaf spot on bigleaf hydrangea, septoria leaf spot on Rudbeckia, foliar nematode on hosta, guignardia leaf spot on horsechestnut, bacterial leaf spot on rose of Sharon, and tipblight on juniper.

Other issues observed in the landscape include scorch on dogwoods, rabbit damage to annuals and perennials, and damage to perennials from slugs and snails.

Weeds seen in bloom during the period include carpetweed (Mollugo verticillate), spotted spurge (Euphorbia maculata), spotted knapweed (Centaurea stoebe), lambsquarters (Chenopodium album), and tansy ragwort (Jacobaea vulgaris).

Southeast Region (Dighton)

General Conditions:

Since our last report on Wednesday, July 24th through August 7th, the south coast experienced its highest temperatures in the afternoons of Tuesday, August 1st to Thursday, August 3rd, reaching a sweltering 90ºF. Rain showers occurred on the morning of Monday, July 29th. There were evening thunderstorms on Saturday, August 3^rd, and Sunday, August 4th, and rain on Tuesday, August 6th, leading to cooler temperatures. Over the past two weeks, temperatures have averaged around 73ºF. The lowest temperature was 60ºF on Wednesday, August 7th. Total rainfall was 2.28 inches. Humidity has been high, averaging 85%. The wind reached a maximum speed of 14 mph from the south-southwest and south on Thursday, July 30^th, and Friday, July 31st, respectively. The soil temperature in full sun was 74ºF while the temperature was 68ºF in shade at 3 PM August 7^th.

Among the plants flowering are Buddleia davidii (butterfly bush), Campsis radicans (trumpet vine), Clethra alnifolia (summersweet clethra), Hibiscus syriacus (rose-of-Sharon), Hydrangea paniculata (panicle hydrangea), Lythrum salicaria (loosestrife), Polygonum cuspidatum (Japanese knotweed), Sophora japonica (Japanese pagodatree), and Vitex agnus-castus (chaste tree).

Pests/Problems

Crabgrass is setting seed; yellow nutsedge and Japanese knotweed are flowering.

North Shore (Beverly)

General Conditions:

This two-week reporting period was hot and humid with scattered storms on some days. Temperatures during this period were in the low to high 80s during the day and low 60s to low 70s at night, with a temperature above 90ºF recorded on one day (August 1). The average daily temperature for this period was 75ºF with a maximum temperature of 90ºF and a minimum of 57ºF (recorded on July 28). After several weeks of little rainfall, much needed rainfall arrived during this period, with approximately 2.06 inches recorded at Long Hill.

Woody plants seen in bloom include panicle hydrangea (Hydrangea paniculata), summersweet clethra (Clethra alnifolia), chaste tree (Vitex agnus-castus), butterfly bush (Buddleia davidii), Chinese scholar tree (Styphnolobium japonicum), rose-of-Sharon (Hibiscus syriacus), silk tree or mimosa (Albizia julibrissin), and harlequin glorybower (Clerodendrum trichotomum).

Some herbaceous plants seen in bloom include milkweed (Asclepias spp.), globe thistle (Echinops ritro), garden phlox (Phlox paniculata), purple coneflower (Echinacea purpurea), black-eyed Susan (Rudbeckia spp.), hostas (Hosta spp.), cranesbill (Geranium spp.), fairy candles (Actaea racemosa), yarrow (Achillea millefolium), Joe-Pye weed (Eutrochium dubium), Japanese anemone (Anemone x hybrida), fleece flower (Fallopia aubertii), summer flowering roses (Rosa spp.), and an assortment of annuals.

Pests/Problems:

The population of rabbits seems to be very high this year. They are causing a lot of damage to some annual and perennial plants in the landscape, especially plants in pots and planters.

Powdery mildew continues to be observed on garden phlox and susceptible lilacs. Some of the susceptible crabapple tree varieties are dropping leaves due to apple scab disease damage on the leaves. High pH induced iron deficiency symptoms (interveinal chlorosis) continue to be seen on some plants like blueberries and azaleas.

Weeds are thriving due to moist soil and warm temperatures. Remember that ticks and mosquitoes are still very active. Protect yourself with insect repellent when working outdoors especially at dawn and dusk.

East (Boston)

General Conditions:

We have received welcome precipitation over the past two weeks. We accumulated 1.45 inches, the majority falling over several rain events beginning July 31^st through August 6^th. Daytime temperatures averaged 84ºF with a high of 94ºF on August 1^st. Overnights remained hot and humid, averaging 67ºF until August 5^th, when we received relief from the high humidity. We have reached 1995 growing degree days (base 50). The landscape is looking refreshed from the recent rains.

Some plants in bloom include; Buddleia davidii (butterfly bush), Hibiscus moscheutos (hardy hibiscus), Oxydendron arboreum (sourwood), Phlox paniculata (garden phlox), Tetradium daniellii (Korean evodia), and Vernonia fasciculata (common ironweed).

Pests/Problems:

July was hot and dry. We received 1.67 inches of precipitation for the entire month, with 0.33 inches of that falling on July 31^st. Established trees and shrubs were showing signs of stress before the recent rains. Early leaf drop was observed on Amelanchier canadensis (serviceberry), Betula spp. (birch), and Malus spp. (apple).

Signs of powdery mildew have been observed on Amelanchier spp. (serviceberry), Phlox paniculata (garden phlox), and Syringa spp. (lilac).

Metro West (Acton)

General Conditions:

We are now in the second half of summer. During this two-week reporting period, this area experienced its fourth heat wave of the summer... a 3-day run beginning on August 1^st and ending on the 3^rd with temps recorded at 93°, 95°, and 91°, respectively. In my last message, I reported that there were 11 days this summer with temperatures recorded in the 90s. The number has increased to a total of 16 days, with 3 in June, 9 in July, and 4 in August. For July, the historical monthly average precipitation is 4.07”, and only 1.92” of rain was recorded. The historical monthly average rainfall for the month of August is 3.72” and as of the 6^th, 0.66” of rain has been recorded so far. Observed in some stage of bloom, at this time, are the following plants: Asclepias tuberosa (butterfly weed), Kirengeshoma palmata (yellow wax bells), Physostegia virginiana (obedient plant), Solidago spp. (goldenrod), Patrinia gibbosa (patrinia), and Veronicastrum virginicum (Culver’s root).

Pests/Problems:

Despite the recent rain, the continued lack of any substantial and steady rain continues to be a concern for our trees and shrubs in the landscape, especially compounded with the hot and humid weather. Signs of plant stress are apparent, including premature leaf drop, fall color, and flagging.

Central Region (Boylston)

General Conditions:

August is finally here, and summer has shown no signs of slowing down. With temperatures averaging 83.1ºF (highest being 92.7ºF on August 5th), nights have dropped as low as 60.3ºF (on July 28^th). Max precipitation was 0.59 inches on August 6^th, although 0.75 is expected for the 7^th, which would contribute to the average of 2.29 inches over the nearly 2-week span. The air has been holding onto a lot of moisture, as has the soil.

Some plants that can be seen blooming currently are panicle hydrangeas (Hydrangea paniculata), sweet pepperbush (Clethra alnifolia), great lobelia (Lobelia siphilitica), mountain mint (Pycnanthemum spp), nodding onion (Allium cernuum), rose mallow hibiscus (Hibiscus moscheutos), Joe-Pye weed (Eutrochium spp.), and goldenrod (Solidago spp.).

Pests/Problems:

A pest that can be seen in numbers at this time in the season are oleander aphids (Aphis nerii). These non-native pests are mostly spotted on butterfly weed (Asclepias tuberosa) and other milkweeds (Asclepias spp.).

Purple loosestrife (Lythrum salicaria) is not only flowering roadside and in gardens, but is continuing to be found in early stages throughout different landscapes.

Again, another problem that hasn’t tamed its presence are yellow jacket (Vespula spp.) ground nests, as well as paper wasp (Polistes fuscatus) and bald-faced hornet (Dolichiovespula maculate) hanging nests.

Pioneer Valley (Amherst)

General Conditions:

There was some relief from the high temperatures over this past reporting period, but the thick blanket of oppressive humidity stubbornly persisted. Dew points regularly crested in the middle to upper 70s in the afternoon, a trend that would have been unfathomable just a decade ago. Over the past few years, July has become the month of new heat and rainfall records, and this year’s iteration continued to break new ground. According to the Northeast Regional Climate Center, July ‘24 was one of the top five hottest months ever recorded at numerous New England weather stations. For Hartford, our Connecticut Valley neighbor to the south, July ’24 now ranks as the hottest month of all time.

Nearly all our landscape and forest plants can handle the heat without issue, provided there’s ample rainfall. Thankfully, most of the valley has fared well with precipitation this summer, save for western Hampden County where totals were below average last month. In fact, most of the Commonwealth experienced below-average rainfall in July. A cooling trend has developed at the time of writing and a heavy dose of rain is forecasted as the remnants of tropical storm Debby moves through the Northeast.

The nighttime soundscape has reached its peak with cicadas, katydids, crickets and grasshoppers trying to outcompete one another with mating calls. There’s also a tremendous amount of late season color with herbaceous perennials in full bloom.

Pests/Problems:

The beech leaf disease nematode (Litylenchus crenatae ssp. mccannii) is starting to migrate from infested leaves to buds in greater numbers. Populations of adult nematodes will increase over the next several weeks as populations peak around early September across the region. Rainfall helps to facilitate migration, as the nematode requires a film of water to move across plant surfaces. Unfortunately, the BLD nematode can also tolerate dry periods during this migratory period.

Honey locust plant bug (Diaphnocoris chlorionis) damage is visible now and for some trees viewed across Hampshire County, there is significant canopy browning.

Scattered crabapples are starting to appear very thin due to apple scab (Venturia inaequalis). These are usually trees with a profusion of interior canopy suckers. Pruning and removal of these suckers not only improves the tree’s appearance, but also helps to increase airflow through the canopy. Most importantly, it reduces the volume of foliage in full shade, where apple scab can readily develop and spread. Cedar-apple rust foliar lesions are very abundant on some apple and crabapple cultivars right now. The circular, reddish-orange spots can coalesce on highly susceptible trees and result in premature leaf shedding. This past spring, the disease was prolific on eastern redcedar (Juniperus virginiana). The spores produced on redcedar then dispersed to infect apple/crabapple. A similar but distinct rust disease, cedar-quince rust, is causing symptoms on infected serviceberries (Amelanchier). Specifically, gall-like stem cankers are girdling shoots, resulting in browning leaves and canopy dieback. Stem and branch cankering pathogens like Phom*opsis and Botryosphaeria are widespread due to the regular rainfall. The anthracnose pathogen Colletotrichum is also having a good year and has been regularly encountered on an array of trees and shrubs.

Berkshire Region (West Stockbridge)

General Conditions: After a hot and dry stretch of 5 days from July 24 through the 28th, the weather in the Berkshires took a turn to wet weather. At most sites, rain fell on 7 of the 10 days from July 29 to August 7. Total rainfall for the last two-week scouting period amounted to 2.50 inches in North Adams, 4.11 inches in Pittsfield, 4.26 inches in West Stockbridge, and 4.69 inches in Richmond. As a result, soils are currently quite moist. However, the previous stretch of hot and dry weather did take its toll on many plants. The highest daily temperature for the period was 86ºF on August 1 in Pittsfield, 88ºF on August 1 and 2 in North Adams, and 89ºF on August 2 in Richmond.

Nevertheless, flowers abound in most landscapes. Turfgrass growth has been vigorous, as has been that of weeds in lawns and gardens.

Pests/Problems: The hot and wet conditions of late have taken their toll on many plants. Plant diseases are quite common, especially foliar diseases. An assortment of such diseases, including apple scab, cedar apple rust, yellow streak on day lilies, black spot on roses, and anthracnose on hawthorn, among others, have scarred the appearance of a wide range of plants. Many plants, especially roses and crabapples, have also lost a considerable amount of foliage due to disease infections. Another problem observed this week was stem canker on a dogwood (Cornus florida) trunk. This has resulted in the dieback of affected branches or the loss of most leaves.

Insect pest populations on plants have generally been low. Even the number of Japanese beetles appeared fewer than usual. On the other hand, slugs and snails abound with the frequency of rain and have chewed holes in the leaves of many low growing plants such as hostas. Ticks and mosquitoes are plentiful and threatening because of being vectors for diseases which threaten the health of humans. Weather conditions this summer have also favored weed growth, many of which are now setting seed, thus requiring much attention as to their removal.

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, and Anna Petrie, 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, pathogens, or problems of interest seen in the UMass Extension Plant Diagnostic Lab, a select few:

Target canker (also known as Neonectria canker), caused by Neonectria ditissima, on European hornbeam (Carpinus betulus). The tree is over 10 years old and one of several at a residential property. It resides in a raised bed at the top of a hill, exposed to full sun in well-drained, sandy soils with no supplemental irrigation. For several years, branch and trunk cankers have developed in a longitudinal pattern with splitting and cracking bark (see photo). Target canker is most often found on birch (Betula) in southern New England, but Neonectria ditissima has a broad host range among deciduous hardwoods. This fungal pathogen is also part of the beech bark disease complex. Some trees can harbor numerous, large cankers and yet the canopy can still appear healthy overall.

Phom*opsis blight (Phom*opsis juniperivora) on Daub’s Frosted Chinese juniper (Juniperus chinensis ‘Daub’s Frosted’). This popular cultivar is a low and spreading shrub with yellow-colored new growth and bluish-green older needles. This specimen was planted against a pool house in full sun. The submitted branch segments exhibited a serious shoot and needle dieback with symptomatic tissue appearing light to dark brown in color. After a brief incubation, black spore-bearing structures (pycnidia) ruptured through the infected needles to disperse large masses of clear spores. Phom*opsis blight can be a serious disease of junipers, regardless of species and cultivar. The disease has been widespread in 2024, likely due to the abundant precipitation over the past two growing seasons.

Canopy dieback caused by Cytospora canker (Cytospora chrysosperma) on a mature weeping willow (Salix babylonica). The 35-year-old tree has been present at the site for 22 years. It resides in an open landscape close to a saltwater bay with full sun in a clay-loam soil mix that is moderately well-drained. The root zone is dominated by moss and several large surface roots are visible. This year, a shoot tip dieback developed in the canopy and a cankering disease was suspected by the managing arborist. The symptoms were not present in previous years. The submitted shoots exhibited several symptoms associated with fungal cankering, which included: (i) brown and wilted foliage, (ii) twigs with dark-colored bark and oozing sap, and (iii) darkly stained vascular tissue. Upon microscopic analysis, numerous erumpent pycnidia were present on the diseased twigs (see photo). From these spore-bearing structures, clear tendrils of spores are produced, which are blown and splashed to nearby twigs to initiate new infections.

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

Insects and Other Arthropods

Invasive Updates:

• Asian Longhorned Beetleis still present in Worcester, Shrewsbury, Boylston, West Boylston, and parts of Holden and Auburn, MA. If you suspect you’ve found this insect or the damage it causes, please report it to the Asian Longhorned Beetle Eradication Program office in Worcester, MA at 508-852-8090 or toll free at 1-866-702-9938.

Now is the time to monitor for adult Asian longhorned beetles! The USDA APHIS considers August "Tree Check Month", so get out there and look at those maples! When in doubt about the identity of a longhorned beetle, always report it.For more information, visit this article: USDA APHIS Asks for Help Looking for Asian Longhorned Beetle by Checking Trees.

To report an Asian longhorned beetle find online or to compare it to common insect look-alikes, visit the Asian Longhorned Beetle Report page from the MA Department of Agricultural Resources.

• Box Tree Moth has been detected in the following Massachusetts communities: Bourne, Sandwich, and Barnstable. A map of these locations is available at MDAR’s Invasive Pest Dashboard. If you believe you have found this insect, please take a photo, note your location, and report it immediately to the MA Department of Agricultural Resources using their Report a Pest Form. Box tree moth caterpillars were reported to be active at certain locations on Cape Cod, MA as of the week of April 19th. C.L. Fornari reports on 6/8/2024 that box tree moth pupae are present at a location in Sandwich, MA at this time (see photos).These pupae are likely the overwintered caterpillars that were actively feeding in April which will give rise to the next generation of adults.

Adult box tree moths have been reported arriving at blacklight traps on Cape Cod, MA as of 6/24/2024 and by others monitoring the same area the week prior. A new generation of box tree moth caterpillars for the 2024 season was reported by C.L. Fornari on Cape Cod as of 7/18/2024. It remains important to monitor boxwood for this pest.

The USDA APHIS has announced a new quarantine for box tree moth in Massachusetts and Ohio, and has expanded existing quarantines in Michigan and New York. This includes conditions for interstate movement of regulated Buxus species. This quarantine includes the entire Commonwealth of Massachusetts. The federal order states:

“Boxwood plants may only be moved interstate from a quarantined area from an establishment operating under a compliance agreement, and only if accompanied by a certificate issued by a State Agricultural Authority certifying that the requirements of this Federal Order and the compliance agreement have been met. These requirements will prevent producers and distributors of boxwood from moving infested plants interstate. State Agricultural Authorities may prescribe additional safeguards and protocols.

All other regulated articles of boxwood, including plant parts, pieces, cuttings, clippings, debris, and any portion of the plant, alive or dead, except for decorative purposes, are prohibited from movement.”

MDAR has recently sent a notice to boxwood growers in Massachusetts of the following:

"Effective May 22, 2024, the USDA has issued a Federal Order establishing a quarantine for the entire state of Massachusetts. In an effort to restrict the movement of box tree moth,boxwoods (Buxus spp.) may no longer be exported from Massachusetts except by an establishment operating under a compliance agreement (CA) to be issued by MDAR.Anyone wishing to register for a CA must go to the Massachusetts Department of Agricultural Resources box tree moth pageand click on the EXPORTS link, and fill out the form. An MDAR staff person will follow up within one week. Please note that the quarantine does NOT restrict in-state sales, movement within the state, or import of boxwoods into Massachusetts. If you have any further questions, please feel free to contact either MDAR (taryn.lascola@mass.gov) or USDA (203-741-5641)."

To read the full announcement of the box tree moth quarantine for Massachusetts from MDAR, please visit the Massachusetts Introduced Pests Outreach Blog.

Need information about monitoring and trapping box tree moth?Check out this newly available t from UMass Extension.

• Elm Zigzag Sawfly has been detected in the following Massachusetts communities: Tyringham, Washington, Williamsburg, Amherst, Great Barrington, New Ashford, Dalton, Chesterfield, Holyoke, Hinsdale, Granby, Greenfield, Westfield, Chester, Deerfield, Becket, Sunderland, Williamstown, and Windsor. A map of these locations can be found on the MA DCR Forest Health Program Elm Zigzag Sawfly page. If you believe you have found this insect, please take a photo, note your location, and report it immediately using MA DCR’s Massachusetts Elm Zigzag Sawfly Reporting Form. Felicia Hubacz, MA DCR, reports elm zigzag sawfly larvae actively feeding in the Becket, MA population as of 5/28/2024. UMass Extension observed tiny elm zigzag sawfly feeding in the Windsor, MA population on 5/31/2024 (see photos).

Elm zigzag sawfly feeding continues to be very apparent on infested trees. Look for the diagnostic zigzag feeding pattern on elm leaves, as well as the more cryptic defoliation that occurs as the zigzags coalesce (see photos). Please report any suspicious defoliation of elm to the previous reporting link.

• Emerald Ash Borer is well established across most of Massachusetts. A map of these locations from the MA Department of Conservation and Recreation is available.
• Jumping Worms are non-native earthworms that impact natural ecosystems. Available resources include a fact sheet about earthworms in Massachusetts and jumping worm FAQ’s. In August, adult jumping worm sightings typically increase due to the life cycle of these earthworms and their large and noticeable size at this time of year.
• Spotted Lanternfly now has established populations in the following locations in Massachusetts: Holyoke, Springfield, West Springfield, Agawam, Fitchburg, Worcester, Shrewsbury, Southborough, Ashland, Wellesley, Weston, Chelmsford, Grafton, Lawrence,Lynn, Wilbraham, Ludlow, and Chicopee,MA. The MA Department of Agricultural Resources reportedthat spotted lanternfly egg hatch hadbegun in Holyoke and Springfield, MA as of 5/14/2024. As of 7/19/2024, MDAR reports mostly 4th instar spotted lanternfly nymphs and a few adult spotted lanternflies active at known populations in the Connecticut River Valley.

In areas of the statewhere spotted lanternfly is present and has been observed through monitoring,the SLF Management Guide suggests management options for SLF nymphs and adults. Spotted lanternfly should not be managed using insecticides in locations where the insect has not been confirmed in the state. This may result in unnecessary, costly, and environmentally irresponsible applications. The first step in areas outside of the communities listed above for MA is to report SLF to MDAR (also see link below).

For homeowners now living with spotted lanternfly in Massachusetts, the MA Department of Agricultural Resources offers the following decision-making guides:
• Checklist for residents living in infested areas
• Checklist for businesses in infested areas
• Management guide for homeowners

If you believe you have found this insect, please take a photo, note your location, and report it immediately using theSpotted Lanternfly Report Form. Available resources include a map of spotted lanternfly locations in Massachusetts from the MA Department of Agricultural Resources, MDAR’s spotted lanternfly fact sheet, UMass Extension’s Spotted Lanternfly Management Guide, and an SLF InsectXaminer episode.

Medically Important Pests:

• Ticks are a serious public health concern and may be active in managed landscapes any time temperatures are above freezing.Encounters with deer ticks can increase in New England in April, October, and November; however, precautions should be taken year-round to prevent tick bite exposure. Available resources include tick information from Cape Cod Cooperative Extension, personal protective measures, and a list of potential tick testing resources. The New England Center of Excellence in Vector-Borne Diseases (NEWVEC) also provides the latest tick information and resources.
• Mosquitoes and the diseases they vector are also a serious public health concern in Massachusetts by summer. Available resources include Mosquito Repellents from the Department of Public Health and Prevent Mosquito Bites from the Centers for Disease Control and Prevention. The Massachusetts Department of Public Health tests for Eastern Equine Encephalitis (EEE) and West Nile Virus (WNV) from June to October. TheMassachusetts risk maps are currently available for both EEE and WNV.

As of August 6th, EEE has been detected in mosquito samples taken from Plymouth, Barnstable, and Essex counties in Massachusetts. The MA Department of Public Health now ranks certain communities at moderate risk (meaning there is EEE in mosquito populations in that area now) in these counties. Middleborough, Carver, and Plymouth, MA are ranked as high risk (meaning “conditions likely to lead to infection of a person with EEE are occurring in your area”). People living and working in these communities should take the precautions as suggested in the links above to protect themselves from mosquito bites.

As of August 6th, WNV risk has been increased to moderate (infection with WNV is likely or has already occurred) in many communities in the following Massachusetts counties: Norfolk, Plymouth, Bristol, Dukes, Middlesex, Worcester, Hampden, Essex, and Suffolk. Individuals in these areas should continue to take precautions to protect themselves from mosquito bites.

As of 8/6/2024 there have been 30 EEE positive and 116 WNV positive mosquito samples in MA. As of 8/6/2024, the MA Department of Public Health announced the first human case of West Nile virus and the first animal case of EEE in Massachusetts.

• Wasps/Hornets: Many wasps are predators of other arthropods, including pest insects such as certain caterpillars that feed on trees and shrubs. Adult wasps hunt prey and bring it back to their nest where young are being rearedas food for the immature wasps. A common such example are the paper wasps (Polistes spp.) who rear their young on chewed up insects. Paper wasps can sting, and will defend their nests, which are open-celled paper nests that are not covered with a papery “envelope”. These open-celled nests may be seen hanging from eaves or other outdoor building structures. Aerial yellow jackets and hornets create large aerial nests that are covered with a papery shell or “envelope”. Common yellow jacket species include those in the genus Vespula. Dolichovespula maculata is commonly known as the baldfaced hornet, although it is not a true hornet. The European hornet (Vespa crabro) is three times the size of a yellow jacket and may be confused for the northern giant hornet (Vespa mandarinia). The European hornet is known to Massachusetts, but the northern giant hornet is not. If you are concerned that you have found or photographed a northern giant hornet, please report it using the MA Department of Agricultural Resources Report Pest Sightings page. Some people are allergic to stinging insects, so care should be taken around wasp/hornet nests. Unlike the European honeybee (Apis mellifera), wasps and hornets do not have barbed stingersand therefore can sting repeatedly when defending their nests. It is best to avoid themand, if that cannot be done and assistance is needed to remove them, consult a professional.

Tree & Shrub Insect & Mite Pest Suggested Scouting:

• Andromeda Lace Bug is most commonly encountered on Japanese andromeda, however other host plants may be impacted. Most activity from this insect occurs between late May through September, with several generations occurring per year. Both nymphs and adults feed on host plant leaf undersides and cause white/yellow-colored spots or chlorosis to occur on host plant leaf surfaces.
• Arborvitae Leafminer moths appear from mid-June to mid-July and lay their eggs. Eggs hatch and larvae enter the leaves where they feed, often unnoticed until January or February when browned leaf tips become more apparent. Feeding from this insect is sometimes confused for winter injury, and vice versa.
• Azalea Lace Bug is a pest of both deciduous and evergreen azaleas (Rhododendron spp.), however resistance has been reported in Rhododendron atlanticum, R. arborescens, R. canescens, R. periclymenoides, and R. prunifolium. The insects feed on host plant leaf undersides, and cause chlorosis on leaf surfaces. Azalea lace bugs are activethroughout the summer.
• Bagwormcaterpillar feeding is underway! A sample of emerald green arborvitae from Hampshire County was submitted to the UMass Plant DiagnosticLaboratory on 7/23/2024, filled with bagworm caterpillars. Browning of foliage was evident from their feeding. A population of this size can easily work its way down a hedge, defoliating the plants as they go. By August, caterpillars and their associated bags will be very large, and the defoliation and feeding damage on host plant leaves they can cause will be quite noticeable by then.
• Cryptomeria Scale first generation crawlers are present from approximately 600-800 GDD's and second generation crawlers are present from 1750-2130 GDD's. Look for discolored needles on susceptible host plants. Check the undersides of needles for the hardened scale covers and/or yellow crawlers. Crawlers present in June and August. Scout for scale insects on the underside of needles on the inside of bottom branches first. Scouting on overcast days may make it easier to see the symptoms caused by cryptomeria scale infestation. Yellow sticky cards can be placed in infested trees to aid in scouting for adult (winged) male emergence. Egg laying will begin soon after males are seen. Check scale covers for round exit holes left behind by natural enemies.
• Dogwood Borer 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 appears 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.
• Dusky Birch Sawfly second generation larvae may be present on various species of birch (Betula) at this time. Second generation adults may emerge by mid-July, laying eggs which will hatch and feeding larvae may be present until mid-September. While small trees may be defoliated by these feeding Hymenopteran caterpillars, in the majority of cases feeding by this insect rarely reaches levels where chemical intervention is necessary. Btk (Bacillus thuringiensis kurstaki) does not work on sawfly larvae.
• Euonymus Scale overwinters as a fertilized female. Eggs are laid beneath dark brown female scale covers in the early spring. Egg hatch occurs over a 2-3 week period, with crawlers present by early June. A second generation of crawlers may be present by mid-July, with adults present again in August and September. While Euonymus spp. host plants are preferred, additional host plants have been reported.
• Fall Home-Invading Insects: Various insects, such as ladybugs, boxelder bugs, seedbugs, and stink bugs will begin to seek overwintering shelters in warm places, such as homes, throughout the next couple of months. While such invaders do not cause any measurable structural damage, they can become a nuisance especially when they are present in large numbers. While the invasion has not yet begun, if you are not willing to share your home with such insects, now should be the time to repair torn window screens, repair gaps around windows and doors, and sure up any other gaps through which they might enter the home.
• Hickory Tussock Moth caterpillars are out and about, as is common this time of year. Lophocampa caryae is native to North America with caterpillars of this species found from July through September. These white, black and hairy caterpillars may be seen wandering landscapes. Hickory, walnut, hornbeam, and others are favored host plants, although these caterpillars may be seen on many other trees and shrubs. The hairy caterpillars themselves or their cocoons may cause dermatitis in sensitive individuals, especially children. Avoid handling and teach children to ask an adult first before picking up a hairy caterpillar. Typically does not require management.
• Japanese Beetle adults werereported active at the end of June in MA in 2024 (see scouting reports above). Adult beetles skeletonize the leaves of susceptible host plants, often feeding on roses, grapes, and shrubs first and moving to the foliage of trees as the season continues. Adults are typically active from late June to early August.

• Locust Borer adult beetles are typically active by early September until the first frost, often associated with goldenrod. Beetles are attractive – black with a series of yellow stripes throughout the body and approximately ½-1 inches long. Black locust (Robinia pseudoacacia) is the host of the wood boring larvae of this visually striking insect.

• Magnolia Scale reports to UMass Extension have increased as now is the time when adult female scales are large, covered in a white, waxy coating, and very noticeable. Nymphs will soon wander to the newest twigs of their host plants where they will settle to overwinter. When safe and practical to do so, such as on smaller trees, large female scales can be removed with a soft brush (without damaging the host plant bark). See link for more management options.

• Oak Skeletonizer populations have been noticeable in forested locations in the Williamsburg, MA area in recent years. A park tree in Ashfield, MA showed signs of the activity of this insect on 7/6/2024 as shown here. The oak skeletonizer is a native species of New England and elsewhere in the eastern United States and parts of Canada. Deciduous oaks and chestnut are hosts for this insect. Occasionally, this insect has a large outbreak population. For example, in 1971 in New York, trees were damaged by this insect by July and a second generation was found by September. In 1959 and 1960, two generations per year were observed in Michigan (Gibbons and Butcher, 1961).

  Foliage of the red oak group is skeletonized by this species. Leaves become translucent and eventually dry out. Heavily attacked foliage will appear lacey from the skeletonizing. Occasional outbreaks can cause damage over a large area, and repeated years of defoliation can cause a reduction in host plant growth. Occasionally, part of the tree crown may be killed by the activity of this insect. However, the oak skeletonizer is often found in low level, non-damaging populations and their presence can be tolerated.

  Visually monitor for the activity of this insect in late May or early June (first generation). Look for skeletonized host plant leaves and eventually the characteristic white, ribbed cocoons. Trees can tolerate this native insect and often chemical management is not necessary.

• Obscure Scale may be present on oak, chestnut, hickory, or pecan. Newly hatched crawlers may be active on infested stems and branches for a long period of time, roughly between mid-July through September. Because the scale coverings, even of dead scales, cling to the host plant bark, heavy infestations that have been present for multiple years may be detected any time of the year if the layered, encrusted scales are searched for. Take note if branches appear deformed or lumpy/misshapen.

• Oriental Beetleadults are active from mid-June through early August in Massachusetts. Adult activity occurs in the evening and at night, so the feeding they do on certain flowers (daisy, roses, phlox, and petunia) may not be seen by the observer.
• Pear Sawfly is an introduced (European) species that feeds on a wide variety of trees and shrubs, including pear, cherry, cotoneaster, crabapple, hawthorn, mountain ash, plum, and shadbush. Sawfly larvae feed on the leaves of their hosts, skeletonizing them at first and eventually leading to leaf browning and early leaf loss. A second generation of adult sawflies may emerge from pupal cells in the soil by August. Second generation larvae may feed on host plant leaves through September until they drop to the soil to overwinter as pupae.
• Pine Needle Scale can be a very serious pest of the needles of ornamental pines. Light infestations may go unnoticed and typically do not cause considerable damage. As a population increases, this scale insect feeds with piercing-sucking mouthparts to remove host plant fluids from the needles, causing them to eventually turn yellowish in color and possibly brown. Twigs and entire branches may eventually be killed. Lower branches typically die first. Depending upon geographic location, one or two generations of pine needle scales occur per year. If a second generation is present, second-generation crawlers are present by late July through September. Two generations per year occur in Massachusetts. More northerly locations may have a single generation per year.
• Pitch Mass Borer overwinters in the pitch mass found on the host plant. This insect tunnels beneath the bark, into the cambium. It may take up to two years for the pitch mass borer to mature. Pupation typically occurs by the end of May through June, in time for adult clearwing moth emergence in July and August.
• Redheaded Flea Beetle (Systena frontalis) has been identified as a native pest of nurseries in many locations in the eastern United States. Suspected redheaded flea beetle damage was seen on Ilex crenata 'Dwarf Pagoda' (Dwarf Pagoda Japanese holly) on 3/27/2024 that was purchased in Massachusetts but may have originated in NJ. While identification of this species of insect is uncertain based on host plant damage alone, it appears to be a reasonable and educated assumption. Redheaded flea beetles are known to feed on a wide variety of host plants. These include but are not limited to: cabbage, beans, beets, blueberries, and other agricultural crops as well as Physocarpus, Weigelia, Cornus, Forsythia, Itea, Hydrangea, and Ilex. Adult beetles are active and feed from approximately late-June to mid-September on the upper and lower leaf surfaces of their hosts. This can cause damage that looks like skeletonization and eventually holes in the leaves. Leaves appear covered in brown patches as in these photos. This damage was caused last season on this evergreen plant.
• Redheaded Pine Sawfly larvae feed on the outside of host plant needles. This results in shriveled, browned, and straw-like needles that remain attached to the hosts. Older caterpillars are capable of eating the entire needle. Feeding began in the spring and early summer, and can sometimes be extensive by the fall.Redheaded pine sawfly larvae were observed on 8/3/2024 in the Montague Sandplains (Montague and Franklin County, MA) by Dr. Paul Sievert, emeritus faculty of UMass Amherst. Parasitoid wasps possiblyin the genus Exenterus were observed interacting with the larvae (see photos).
• Sugar Maple Borer is a native pest of sugar maples in New England. Adult beetles are brightly colored with yellow stripes alternating with black. Adults may be confused with the previously mentioned locust borer. Adult sugar maple borers lay their eggs in sugar maple bark in late July and early August.
• Southern Pine Beetle has been trapped in Massachusetts since 2015. By 2022 and2023, southern pine beetle has reached outbreak conditions in small areas of the state, killing pitch pine (Pinus rigida), particularly on Martha’s Vineyard and Nantucket islands in MA.If you believe you have found infested pitch pine in Massachusetts, please report southern pine beetle using the Massachusetts Southern Pine Beetle Reporting Form from MA DCR.

• Tuliptree Aphid is a native North American insect that occurs wherever the tuliptree grows. Depending upon local temperatures, these aphids may be present from mid-June through early fall. There are several generations per year. The tuliptree aphid can cause reduced leaf size as a result of its feeding. These insects feed on their host plants with piercing-sucking mouthparts which they use to remove host plant fluids. Some leaves, especially those in the outer canopy, may turn brown or yellow and drop from infested trees prematurely.

  The most significant impact these aphids can have is typically the resulting honeydew, or sugary liquid excrement, which may be present in excessive amounts and coat leaves and branches, leading to sooty mold growth. This honeydew may also make a mess of anything beneath the tree, including sidewalks and parked cars. Ants, bees, wasps, and flies may be attracted to and feed on the honeydew. Management is typically not necessary, as this insect does not significantly impact the overall health of its host.

• Twospotted Spider Mite season is under way as warm temperatures rise! Populations on many different deciduous and some coniferous hosts may rise from 363-618 GDD's and again from 1300-2000 GDD's. Twospotted spider mites prefer hot, dry conditions in the summer and fall. Population increases and subsequent plant damage can occur under these conditions. Using piercing-sucking mouthparts, mites feed primarily on the underside of host plant leaves and remove fluids. This feeding causes graying or yellowing of the leaves. Necrotic spots can also occur in advanced stages of leaf damage. This may lead to a stippled/bleached appearance of leaves; on occasion, complete defoliation due to spider mite activity is possible under high populations. Twospotted spider mites also create a fine webbing which can be found on infested plants.

Magnification is needed to visually detect twospotted spider mites. At least a 10-15X hand lens is required. The undersides of host plant leaves can be examined for the mites themselves or their shed or cast skins, as well as the fine webbing left behind by spider mites. However, it may be easier to view twospotted spider mites when a branch that is suspected to be infested is shaken or struck over a white piece of paper.See previous link for more details.

• Viburnum Leaf Beetle larvae may be found anywhere on the leaves and usually in groups. When young, larvae feed on the undersides of the leaves. As they grow larger, they may feed on the upper surface. Larval development may take approximately 8-10 weeks to completeand 3 larval instars are reported. Pupae are yellowish and are found in the soil beneath the host plant. Adults emerge around the middle of July and are brown, smaller than the largest larvae (approximately ¼ inch), and will also feed on the leaves. Adults are present in the landscape until the first hard frost.
• White Marked Tussock Moth is one of many native tussock moth species commonly encountered in the late summer and early fall. Avoid touching these caterpillars or their cocoons: they may cause allergic reactions, especially if their hairs come into contact with sensitive skin (ex. back, stomach, underside of arms) (Wagner, 2005). Contact dermatitis (itching) as a result of interacting with these insects has been reported from schools and daycares. Teach children how to identify and avoid handling cocoons and caterpillars. These caterpillars have urticating (irritating) hairs. Welts may appear on the skin within minutes, but subside the next day; however, itching can last for several days depending upon the sensitivity of the individual.
• White Prunicola Scaleis an armored scale that has been on occasion found in samples submitted to the UMass Plant Diagnostics Laboratory. Trunks and branches primarily of Japanese flowering cherry, lilac, and privet are infested by the white prunicola scale. Feeding may reduce tree vigorand foliage may yellow or become sparse. Two generations may occur per year in New England, with eggs/crawlers in early June and again in early August. However, under warmer conditions, three generations per year are possible.
• Yellow Poplar Weevilis also known as the sassafrass weevil, the magnolia leafminer, or the tulip tree leafminer. This insect, as all of these common names suggest, feeds on yellow poplar (tulip tree;Liriodendron tulipifera), sassafras (Sassafras albidum), magnolia (Magnolia spp.), as well as bay laurel (Laurus nobilis). Adult beetles lay eggs in the midribs of host plant leaves by May, after which the eggs hatch and larvae feed by creating blotch mines in the leaves. Larvae can be observed in May and June, and adults emerging to feed again by August, prior to overwintering in sheltered areas.

Beneficials/Non-Pests:

• Ichneumonid Wasps are one of the many wasp families that provide natural pest management services as parasitoids of pest insect species. They lay their eggs in or on the larvae of their hosts. The pest larvae then fails to developas the wasp egg hatches and the wasp larvae feeds on its host. One way to identify an adult ichneumonid wasp is to look for the horse head shape in the veins of the forewing. This is one way to distinguish an ichneumonid from a braconid wasp, another common family of parasitoids. The ichneumonid wasp seen here is associated with the redheaded pine sawfly, a pest of many species of Pinus.

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

Landscape Weeds

For information about identification of weeds noted below, check out UMass Extension's Weed Herbarium.

Crabgrass management in turf: Summer is chugging along and so is the growth and development of crabgrass in turf settings. As crabgrass grows and produces more tillers, options for effective control decrease. At this point of the season, most crabgrass is 5-tiller or larger. For the control of these large, several tiller crabgrass plants, managers should consider the use of quinclorac (Drive WLR8^TM or other post-patent product). Applications will require the addition of a high-quality MSO (ethylated seed oil) surfactant for effective control. The late season control of crabgrass with quinclorac still has the chance to stop flowering and the production of seed. Sometimes referred to as a “rescue application”, late season crabgrass control can also serve to get crabgrass out of the way in preparation for late summer and early fall overseeding.

English ivy (Hedera helix): In the last few weeks, I have received a couple of inquiries about whether English ivy (Hedera helix) is invasive in Massachusetts. These inquiries also ask about the best way to control English ivy. The Massachusetts Invasive Plant Advisory Committee (MIPAG) has not evaluated English ivy for invasiveness in Massachusetts. While this species is non-native, it would likely fall short of meeting some of the criteria that would make it designated as invasive, likely invasive, or potentially invasive. A full evaluation of this species would not likely show this plant to 1) demonstrate the potential for rapid and widespread dispersion and establishment, 2) have the potential to disperse over spatial gaps, and 3) exist in high numbers in natural plant communities and minimally managed habitats. MIPAG defines an invasive plant as a non-native species that can spread into native or minimally managed plant systems in Massachusetts. These plants cause economic or environmental harm by developing self-sustaining populations and becoming dominant and/or disruptive to those systems. Early during the evaluation of a plant species, a well-known nurseryman in Massachusetts coined the phrase “garden thug” which appropriately describes this plant species' behavior in New England. Management of a “garden thug” certainly can be justified in some situations. Initial research done in eastern Europe and repeated by Joe Neal at North Carolina State University showed that effective control was achieved with a postemergence application of glyphosate in the spring. Applications of a 41% glyphosate formulation at 4 to 5% should be applied when the new-season growth is 3 to 5 inches long and has 3 to 5 leaves. At least 2 or 3 years of a spring application will likely be required for complete control.

Japanese knotweed (Fallopia japonica): As we move into the middle of August, the application window for the best control of Japanese knotweed is quickly approaching. This application window starts at the first sign of floral structure development, continues through the flowering period, and ends before the first frost. Since knotweed commonly grows in wet areas or near streams, rivers, or wetlands, the management of this invasive plant may invoke 310 CMR 10.00 the Massachusetts Wetlands Protection Act. 310 CMR 10.00 regulates all activities in the resource areas identified in the act. Before any management activities can begin, the Conservation Commission in the municipality should be contacted to determine to what extent 310 CMR 10.00 might impact the project. Working within the constraints of 310 CMR 10.00 can take time, so now is the time to begin that process to allow for the treatment of Japanese knotweed in a timely manner.

Report by Randy Prostak, Weed Specialist, UMass Extension Landscape, Nursery, and Urban Forestry Program

Additional Resources

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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 thePlant DiagnosticLaboratoryweb site.

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 orders for Routine Soil Analysis (including optional Organic Matter, Soluble Salts, and Nitrate testing), Particle Size Analysis, Pre-Sidedress Nitrate (PSNT), Total Sorbed Metals, and Soilless Media(no other types of soil analyses available at this time). Checkfor 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 athttps://ag.umass.edu/resources/tick-testing-resources.

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