Landscape Message: September 3, 2021

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.

The Landscape Message will be updated bi-monthly in September. The next message will be posted on September 17. To receive immediate notification when the next Landscape Message update is posted, be sure to join our e-mail list 

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Scouting Information by Region

Environmental Data

The following data was collected on or about September 1, 2021. Total accumulated growing degree days (GDD) represent the heating units above a 50° F baseline temperature collected via regional NEWA stations for the 2021 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 2-Week Gain	Time/Date of Readings
	2-Week Gain	2021 Total	Sun	Shade
CAPE	352.5	2266.5	73	69	0.30	12:00 PM 9/1
SOUTHEAST	345.5	2316	75	71	3.30	3:00 PM 9/1
NORTH SHORE	349.5	2399.5	70	67	3.14	10:00 AM 9/1
EAST	349.5	2427.5	71	67	2.44	4:00 PM 9/1
METRO	333.5	2284.5	68	66	4.90	6:00 AM 9/1
CENTRAL	334	2341.5	69	62	4.18	10:00 AM 9/1
PIONEER VALLEY	335.5	2365.5	74	69	5.44	11:00 AM 9/1
BERKSHIRES	294.5	1973.5	72	66	4.72	7:15 AM 9/1
AVERAGE	337	2297	72	67	3.55	_
n/a = information not available

As of 8/31, there were still varying degrees of drought on most of the Cape and the Islands: https://droughtmonitor.unl.edu/CurrentMap/StateDroughtMonitor.aspx?MA

Phenology

Indicator Plants - Stages of Flowering (BEGIN, BEGIN/FULL, FULL, FULL/END, END)
PLANT NAME (Botanic / Common)	CAPE	S.E.	N.S.	EAST	METRO W.	CENT.	P.V.	BERK.
Heptacodium miconioides (seven-son flower)	Begin/Full	*	Begin/Full	Begin	Begin	Begin/Full	Begin	*
Clematis paniculata (sweet autumn clematis)	Begin/Full	Begin/Full	Full/End	Begin	Begin	*	Full/End	Begin
Polygonum cuspidatum (Japanese knotweed)	Full	Full	Full	Full	Full	Full	Full	Full
Hydrangea paniculata (panicle hydrangea)	End	Full/End	Full/End	Full/End	Full/End	Full/End	Full/End	Full/End
Hibiscus syriacus (rose-of-Sharon)	End	End	Full/End	Full/End	Full/End	Full/End	Full/End	Full/End
* = no activity to report/information not available

Regional Notes

Cape Cod Region (Barnstable)

General Conditions: The average temperature during the period from August 18 thru September 1 was 75˚F with a low of 60˚F on Aug. 28 and a high of 91˚F on Aug. 25. Overall, the period has been warm with daytime highs primarily in the 80s and lows around 70˚F and a relatively even mixture of cloudy, partly cloudy/sunny, and sunny days. During the period just over a quarter inch of precipitation fell over several small precipitation events leaving soil moisture still very short. As of September 2, the US Drought monitor ( https://droughtmonitor.unl.edu/CurrentMap/StateDroughtMonitor.aspx?MA ) had listed parts of the Cape in various categories from Abnormally Dry to Severe Drought, though I assume that will change with rainfall from the remnants of Ida.  Woody plants seen in bloom during the period include rose of Sharon, chaste tree, crape myrtle, mimosa, summersweet, butterfly bush, panicle hydrangea, and seven sons tree. Herbaceous plants seen in bloom include echinacea, hosta, Russian sage, achillea, boneset, Joe-pye weed, garden phlox, blacked eyed Susan, balloon flower, hardy hibiscus, autumn joy sedum, many goldenrods, and some asters.

Pests/Problems: Insect pests or damage observed during the period include daylily leafminer on daylily, euonymus scale on euonymus, black turpentine beetle damage on pitch pine, pine tip moth on pitch pine, chilli thrips on hydrangea, white prunicola scale on lilac, azalea lacebug on azalea, andromeda lacebug on andromeda, and eriophyid mites on beach plum. Disease symptoms or signs observed during the period include powdery mildew on numerous herbaceous and woody plants, black spot on rose, aster yellows on echinacea, cercospora leaf spot on hydrangea, guignardia leaf blotch on horse chestnut, leaf spot on river birch, rust and defoliation on callery pear, apple scab and cedar apple rust on crabapple, and slime flux on maple. Weeds and wildflowers in bloom include carpetweed, prostrate spurge, Pennsylvania smartweed, birdsfoot trefoil, yellow toadflax, Queen Anne’s lace, goldenrod, horseweed, pilewort, mugwort, ragweed, pigweeds, crabgrass and perennial sowthistle.

Southeast Region (Dighton)

General Conditions: Tropical storms and high humidity have predominated over the past two weeks. Due to regular rains, even unirrigated lawns are green and our lawn customers credit us. Some years you can't win, some years you can't lose. Thank goodness we are on the cusp of the transition to fall weather. Among the plants currently in flower, I've noticed: Ambrosia artemisiifolia (ragweed), Artemisia vulgaris (mugwort), Buddleja davidii (butterfly bush), Campsis radicans (trumpet vine), Chenopodium album (lamb's quarters), Clematis paniculata (autumn clematis), Clethra alnifolia (summersweet), Eragrostis spectabilis (purple lovegrass), Eupatorium perfoliatum (common boneset), Eutrochium purpureum (Joe-pye-weed), Franklinia alatamaha (Franklin tree), Helianthus tuberosus (Jerusalem artichoke), Hemerocallis (daylilies), Hibiscus syriacus (rose of Sharon), Hosta plantaginea (plantain lily), Hydrangea paniculata (panicled hydrangea), Hylotelephium telephium (formerly in the genus Sedum, stonecrop 'Autumn Joy'), Impatiens capensis (jewelweed), Lagerstroemia (crepe myrtle), Miscanthus sinensis (silvergrass), Oenothera biennis (evening primrose), Phlox paniculata (garden phlox), Phragmites australis (common reed), Reynoutria japonica (Japanese knotweed), Rosa, (rose), Rudbeckia hirta (black-eyed Susan), Salvia yangii (Russian sage), Setaria pumila (yellow foxtail), Soldigo spp. (goldenrod), and Symphyotrichum cordifolium (common blue wood aster/heart-leaf aster).

Pests/Problems: Diseases observed in the landscape were powdery mildew on phlox and lilac, late blight on tomato, and dollar spot rampant on irrigated lawns. Northern masked chafers are still active, and the predominant life stage this time of year are typically the 3rd instar larvae.

North Shore (Beverly)

General Conditions: This reporting period began with a rainstorm that dropped most of the rainfall that was received between 8/18 and 9/1. A total of 3.14 inches of rainfall were recorded at Long Hill with 2.62 inches recorded on August 20. Daily air temperatures were variable. Day temperatures ranged from low 70s to low 90s and night temperatures ranged from low 60s to low 72s. The daily average air temperature was 75°F with a maximum air temperature of 93°F recorded on August 26 and minimum air temperature of 62°F recorded on August 29. Woody plants seen in bloom include: butterfly bush (Buddleia davidii), Russian daphne (Daphne x transatlantica), Franklin tree (Franklinia alatamaha), seven-son flower (Heptacodium miconioides), rose-of-Sharon (Hibiscus syriacus), and sweet autumn clematis (Clematis paniculata). Herbaceous plants seen in bloom include: Joe-pye weed (Eutrochium purpureum), garden phlox (Phlox paniculata), hostas (Hosta spp.), ‘Autumn Joy’ stonecrop (Hylotelephium telephium, formerly in the genus Sedum), black-eyed Suasn (Rudbeckia hirta), New England aster (Symphyotrichum novae-angliae), Japanese anemone (Anemone x hybrida) and coneflower (Echinacea spp.). Various kinds of annuals are also contributing color to the landscape.

Pests/Problems: Deer browsing damage was observed on some perennials. Powdery mildew continues to be prevalent on some lilac varieties and on garden phlox. Crabgrass and other weeds such as prostrate spurge (Euphorbia maculata), horseweed (Conyza canadensis), ragweed (Ambrosia artemisiifolia) and Japanese knotweed (Reynoutria japonica, syn. Fallopia japonica, Polygonum cuspidatum) are thriving in the landscape. Canada goldenrod (Solidago canadensis) is in full bloom and is providing a lot of color on roadsides and meadows. Mosquitoes have slowed down but they are still active at dawn and dusk. Ticks are still very active.

East Region (Boston)

General Conditions: August 2021 joined July 2021 with record breaking rainfall for the month; we received 10.47 inches and 3.81 inches respectively for a total of 14.28 inches over those two months. We received 2.44 inches over the past two-week reporting period mainly from remnants of Tropical Storms Fred and Henri. We also experienced excessive heat and humidity from August 23 thru the 27 with overnight temperatures averaging 70˚F. Perennial borders continue to attract pollinators. Heptacodium miconioides (seven-son flower) is just coming into bloom.

Pests/Problems: Soils are saturated. Today, September 1, we are expecting significantly more from the remnants of Tropical Storm Ida. Excessive soil moisture is a concern, and neglecting to control supplemental irrigation systems is an ongoing issue exacerbating the problem. Powdery mildew is rampant throughout the garden. Japanese knotweed (Reynoutria japonica, syn. Fallopia japonica, Polygonum cuspidatum) is in full bloom, so the timing to treat managed sites is now. (See the Weed section below.) Pokeweed (Phytolacca americana) can be seen in full fruit along roadsides. Ragweed is in full bloom distributing pollen throughout the landscape.

Metro West (Acton)

General Conditions: The summer season is winding down with the Labor Day holiday approaching and with day length shortening. Currently, we are at 13:07 hours of daylight with sunrise at 6:12 and sunset at 7:19 and days are getting noticeably shorter every day. This area experienced its fourth heatwave of the summer and the second for this month with temperatures recorded at 90°, 92°, and 91°on the 25^th, 26^th, and 27^th respectively. Plants are heavy with fruit, seed, berries, and nuts. For August, the historical monthly average precipitation is 3.72” and a grand total of 6.34” of rain was recorded for the month this year. Observed in some stage of bloom these past two weeks were the following woody plants: Buddleia spp. (butterfly-bush), Clethra alnifolia (summersweet), Heptacodium miconioides (seven-son flower), Hibiscus syriacus (rose-of-Sharon), Hydrangea paniculata (panicle hydrangea) and its many cultivars including 'Tardiva', Potentilla fruiticosa (shrubby cinquefoil), Rosa spp. (rose), R. 'Knockout' (“Knockout” family of roses), and Styphnolobium japonicum (Japanese pagoda tree). Woody vines observed in bloom include Campsis radicans (trumpet vine) and Clematis paniculata (sweet autumn clematis). Contributing even more color and interest to the landscape are some flowering herbaceous plants including: Alcea rosea (hollyhock), Achillea millefolium (yarrow), Asclepias syriaca (common milkweed), A. tuberosa (butterfly weed), Aster spp. (New England aster, New York aster, smoother aster, white wood aster), Boltonia asteroides (Bolton’s aster), Chelone lyonii (pink turtlehead), Cichorium intybus (chicory), Coreopsis sp. (tickseed), C. verticillata (threadleaf coreopsis), Daucus carota (Queen Anne's lace), Echinacea purpurea (coneflower) and its many cultivars, Eutrochium purpureum (Joe Pye weed), Gentiana makinoi var. ‘Royal Blue’ (gentian), Hemerocallis var. 'Stella D'Oro', (daylily), Hosta spp. (plantain lily), Hibiscus moscheutos (swamp mallow), Kirengeshoma palmata (yellow wax bells), Lamium maculatum (dead nettle), Leucanthemum sp. (shasta daisy), Liatris spicata (spike gayfeather), Lysimachia clethroides (gooseneck loosestrife), Lythrum salicaria (loosestrife), Patrinia gibbosa (patrinia), Salvia yangii (previously known as Perovskia atriplicifolia, Russian sage), Phlox carolina (Carolina phlox), P. paniculata (garden phlox), Physostegia virginiana (obedient plant), Platycodon grandiflorus (balloon flower), Rudbeckia fulgida var. sullivantii 'Goldsturm' (black eyed Susan), Hylotelephium telephium (formerly in the genus Sedum, ‘Autumn Joy’ stonecrop/sedum), Hylotelephium sp. (‘Rosy Glow’ sedum/stonecrop), Senna marilandica (wild senna), Solidago spp. (goldenrod), and Tanacetum vulgare (tansy).

Pests/Problems: Due to tropical storms, there were 3 separate weather alerts for this area in the past two weeks warning of potential tornados. Thankfully, there was only limited damage reported in Clinton, Marlboro, and Stow. Powdery mildew was observed on Cornus florida (flowering dogwood), Hamamelis (witch hazel), Monarda (bee balm), Phlox, and Syringa (lilac).

Central Region (Boylston)

General Conditions: August ended with wildly inconsistent weather, somehow befitting the way the rest of the summer months were this year. T.S. Henri was a bit of a dud here in the central region, bringing far less rain and wind than expected, but the small system that ran through the area prior to Henri had quite an impact. Nearly 2.5 inches of rain, most of which fell over the course of about an hour, continued the summer pattern of several days of intense heat sandwiched between substantial precipitation. We saw another above average month of precipitation, with more than 5 inches of rain in August. We also experienced several tornado warnings and had 3 separate tornadoes touch down in the region. Far less rain than the month of July, but most of it fell during this two-week reporting period. Soils are still consistently waterlogged across the region. There is much in bloom throughout the garden, but our annual display of fall wildflowers is just beginning. Goldenrods (Solidago spp.) and asters like New England aster (Symphyotrichum novae-angliae) are showing color that will carry through to the end of the growing season and complement the spectacular foliage display that is right around the corner.

Pests/Problems: There are still remarkably few pest and disease issues in the garden. Slugs and snails continue to be very active. Mosquito populations are high and getting worse. Ragweed is in full bloom and causing that annual hay fever so many of us experience at this time of year.

Pioneer Valley Region (Amherst)

General Conditions: As we transition into the autumn season with the arrival of September, this past reporting period saw a return of the heavy rainfall that dominated most of July. After a parched start to August, the latter half was anything but dry. The remnants of two tropical storms (Fred and Henri) saturated the Pioneer Valley yet again. Tropical storm Fred barreled through the tri-counties during the morning hours of 8/19. While short-lived, the storm produced heavy downpours that resulted in >1.5” of accumulation. Only a few days later, Henri lumbered across southern New England for two days (8/23–24), and while ultimately weaker than predicted, the system still produced >3” of accumulation. The two storms (essentially three storms if you consider the two waves of Henri) produced more than 4.5” of rainfall over a six-day period. A blistering four-day stretch of heat ensued, from 8/24–27, with dew points in the low to mid-70s. While ambient air temperatures just barely cracked the threshold (90°F) for an official heat wave from 8/25–27 (our fourth of the summer), heat index values at Barnes Airport were well above 100°F on 8/26 and 8/27. Isolated thunderstorms passed southward on 8/27, ushering in a brief end of month reprieve from the heat on 8/28. But the dew points were back on the rise by 8/30, when strong thunderstorms roiled from the west. Whether it was sunny and dry or cloudy and wet, there was one constant throughout almost the entire second half of August; unbearably high humidity. At the time of writing, the remnants of Hurricane Ida are predicted to dump upwards of 4” of rain across the valley.

On the positive side, the deep, late season watering has been beneficial for the majority of landscape trees and shrubs. After a summer of intense heat and drought in 2020, it’s remarkable how differently this season has progressed. It’s been similar to how 2016–17 unfolded, when a major summer drought was followed by a summer of plentiful rainfall. With the abundance of rain in July and August, the need for supplemental irrigation has been significantly reduced at times. For trees that were regularly irrigated or those on poorly-drained soils, symptoms of excessive soil moisture may be visible at this time. This can manifest as yellowing/browning of foliage, premature leaf shedding, brown-colored blisters developing on the underside of the foliage (edema) and canopy dieback. There’s still plenty of color in the landscape, with asters, goldenrod, late hostas, lilies, black-eyed Susan, sedums and hydrangea producing a varied array. While it’s easy to find worn and tattered trees in the landscape, some (e.g. hemlock, maple and oak) are still producing new growth given the abundance of rain. Many trees and shrubs are allocating resources to new root production and this is a good time for transplanting.

Pests/Problems: A large number of Norway maples in Hampshire County have foliage that is scorched, curled and prematurely shedding. The symptoms appear similar to drought stress, but after >16” of rain in July and August that is highly unlikely. The symptoms could be caused by maple anthracnose, which has been widespread this season. Overall, it’s been a quiet year for giant tar spot on Norway maple. Red oaks continue to exhibit shoot tip dieback scattered throughout the canopy. These blighted shoots retain brown leaves, which are directly next to healthy shoots. In many cases, these trees have lecanium scale infestations along with Diplodia stem/branch cankering. This continues to be a good season for Ganoderma sessile conk production. Large masses of fruiting bodies can be found on infected hardwoods in the landscape, such as the former state champion fernleaf beech (Fagus sylvatica ‘Asplenifolia’) on the UMass campus (pictured below). Late season foliar diseases continue to appear but these pathogens cause little overall harm as growth is mostly complete for the season. Lily leaf beetle larvae and adults are still active and lacebug activity on deciduous azaleas continues. Bees, wasps and hornets are still very active and mosquito populations remain high. Crabgrass is growing fast and setting seed right now.

Berkshire Region (Great Barrington)

General Conditions: Rain was once again a prominent feature of Berkshire weather this summer. According to data gathered at the Pittsfield Airport, the area is now (through 8/31) about 6.25 inches above the norm for rainfall for the year and about 11.5 inches above the amount of last year at this time. Rainfall over the past two weeks has certainly contributed to the well above normal precipitation. Rainfall amounts from August 17 through the 31^st were: North Adams = 3.43 inches; Pittsfield = 3.93 inches; Richmond = 3.50 inches; and here at this site in West Stockbridge, rainfall for the two week reporting period amounted to 4.72 inches with the largest amount, 2.90 inches, falling over the two days of August 22 and 23. Now, September is getting off to a wet start, having to deal with the remnants of hurricane Ida as it moves through New England. Needless to say, soils have been moist through the month of August though not as saturated as they were in July. With a ten day forecast calling for mostly sunny days, soils should remain moist but not saturated. Coupled with cooler temperatures, weather conditions should be ideal for planting nursery stock and/or for digging and transplanting existing plant materials in managed landscapes. Temperatures are forecast to be much more comfortable than they were during the past two weeks when most days were hot and humid. Turfgrass will respond to the moist and cooler conditions by accelerating its growth rate. As such, the beginning of September is an ideal time for fertilizer applications to turfgrass.

Pests/Problems: Plant pest pressures seem to be minimal at this time. There are still some Japanese beetles lingering about but there is little apparent feeding damage to plants by this beetle. On the other hand, diseases are more prevalent, in particular foliar diseases, e.g. powdery mildew on Monarda. Many woody plants are dropping their disease infected leaves. Most notable are apple and crabapple trees, many of which are nearly naked. Other trees and some shrubs are showing pre-mature fall color, perhaps an indication of foliar disease, stem cankers, or root decay relating to long periods of soil saturation. Herbaceous perennials have not been immune to foliar diseases though it seems it has been to a lesser extent. Most weeds are now setting seed and weed management should be a primary focus at this time of year. One critter that is particularly abundant is the Asian jumping worm, a.k.a. crazy worm, snake worm. They have spread very rapidly through this region and appear in very high numbers, whether it be in cultivated sites, i.e. vegetable gardens and annual flower beds, or in forests, lawns, or managed landscapes. Mosquito counts are also very high and most annoying to anyone working in the outdoors. Another pest issue becoming more prominent as we head into the latter parts of the year is mouse and vole related problems. The critters are not only feeding on plant materials, notably bulbs and tubers as well as melons and squash in vegetable gardens, but they are building nests in machinery and chewing on rubber tubing and plastic coated wiring. It would be wise to routinely examine mowers and other equipment for evidence of nesting material and gnawing of wiring.

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, reporting from Amherst.
• BERKSHIRE REGION - Ron Kujawski, Horticultural Consultant, reporting from Great Barrington.

Woody Ornamentals

Diseases

White pine management field tour at Bear Brook State Park (Allenstown, NH) on 9/16 & 9/17. Topics will include white pine health and low-density white pine management. Program details and registration information can be found here: https://extension.unh.edu/event/2021/09/low-density-white-pine-management

Recent pests and pathogens of interest seen in the UMass Extension Plant Diagnostic Lab https://ag.umass.edu/services/plant-diagnostics-laboratory:

• Brown needle spot, caused by Lecanosticta acicola, on Austrian pine (Pinus nigra ‘Frank’). This is a slow-growing, fastigiate cultivar of P. nigra with a dense, tight canopy. The tree is approximately 15-years-old and has been present at the site for three years. The site conditions include full sun, drip irrigation in heavy soils. The tree was treated earlier this season for sawflies. This summer, serious needle browning and shedding developed in the canopy. The northwestern side of the canopy is heavily infected but the symptoms are scattered throughout other portions of the canopy as well. Submitted shoots had needles brown, desiccated tips and scattered, dark-colored spots (pictured). Spore masses of Lecanosticta were readily found on blighted needle tips, illustrating this pathogen’s ability to sporulate throughout the growing season when conditions allow.
• Pestalotiopsis needle blight on giant sequoia (Sequoiadendron giganteum). The tree is young, less than 10-years-old and has been present on the site for three years. The tree resides in a shaded setting without any supplemental irrigation. This summer, it exhibited dead and dying shoot tips. Submitted shoots had tips that were pale brown and desiccated. Drought stress from 2020 and a lack of sunlight are likely contributors to disease development. Giant sequoias can do well in New England if provided with full sun and well-drained soils. Pestalotiopsis is a common needle and stem blight pathogen on trees and shrubs in the Cupressaceae, occurring most often on arborvitae, juniper and cryptomeria.
• Fire blight, caused by Erwinia amylovora, on apple (Malus domestica) and pear (Pyrus communis). Small, home orchard composed of over ten apple and pear trees, planted along an 8’ brick wall with full sun and well-drained, loamy soils. Last year, symptoms of fire blight developed (blackened leaves and shoot tips) and symptoms intensified in 2021. Following the fire blight infection, the stems were subsequently colonized by the cankering pathogen Phomopsis. This pattern of secondary colonization is common on trees infected by fire blight and should influence decisions on management. For commercial orchards, it’s believed that pruning of stems and branches killed by fire blight should take place during the dormant season in winter, to avoid further spread of the bacterium. However, when the dead material is left in the canopy for the season (fire blight infections take place in May), cankering fungi like Botryosphaeria and Phomopsis readily establish, furthering the dieback and spreading to adjacent portions of the canopy. For landscape trees and home orchards, pruning of dead material as soon as it appears is recommended.
• Dieback of Norway spruce, caused by needle blight (Rhizosphaera kalkhoffii and Stigmina lautii), spruce bud scale (Physokermes piceae) and Phomopsis stem cankering (Phomopsis sp.). The tree is believed to be >60-years-old (~50’ tall and 30” dbh) and resides at a residential site that is adjacent to a wetland, with full sun and wet soils. The tree was pruned two years ago to remove branches overhanging the home and this side of the tree has appeared weak over the past two seasons. Chronic health problems for mature Norway spruce often include some kind of environmental stress, such as drought, or perhaps in this case excessive soil moisture. In many cases, a complex of insect pests and disease-causing fungi are present.
• Powdery mildew of London planetree (Platanus × acerifolia) caused by Erysiphe platani. Several planetrees (15’ tall and 3-4” in diameter) were transplanted in 2020 to create a hedgerow. This year, the canopies exhibited undersized, distorted and blighted foliage. Powdery mildew of planetree can be a damaging disease for young and recently planted trees dealing with transplant shock. Conditions this season were excellent for many powdery mildew fungi, with persistent stretches of the high humidity required for spore germination and mycelial growth across the surface of the leaf. Given their size, the trees can be readily treated to reduce disease severity next season. Once established, the disease should result in only minor injury.
• Leaf and stem blight on Catawba rhododendron (Rhododendron catawbiense) caused by Phytophthora. The plant is >25-years-old and has been present at the site for at least 15 years and drip irrigation is provided. The plant receives mostly shade under a mixed canopy of overstory trees in an urban, residential garden. In July of this year, symptoms of Phytophthora blight developed in the canopy. Symptoms included blighted shoot tips, stem cankering and leaf spots/blotches on the foliage. There is a tremendous diversity of native and non-native Phytophthora species in the region. When flooded soil conditions develop after heavy rains, the pathogen can readily sporulate and spread, causing a range of disease symptoms, spanning: fine root rot, lower trunk rot (crown rot), stem cankering, shoot blight, leaf spots/blotches and leaf blight. Ericaceous plants like rhododendron are common hosts for Phytophthora.
• Septoria leaf spot and Botryosphaeria cankering (suspected) on red-twigged dogwood (Cornus alba ‘Sibirica’). The plants are young, five to seven-years-old, and were transplanted three years ago. The homeowner described the symptoms as leaf yellowing, spots and stem dieback. Unfortunately, only foliage was submitted and no stem or branch material. Septoria leaf spot was found on the foliage (pictured), which is a common, mid- to late season disease for dogwoods. Subsequent inquiry and submitted photos strongly suggested stem and branch cankering from Botryosphaeria. Again, this is a common disease for the shrub dogwoods. The stems were blackened, desiccated and progressively dying from the tips to base. Two plants on opposite sides of the property were diseased. The site is close to the ocean and irrigation is provided via overhead sprinklers, likely facilitating disease development and spread.
• Partial canopy dieback of Chinese juniper (Juniperus chinensis ‘Hetzii’) caused by transplant shock, needle blight (Pestalotiopsis) and a minor bagworm (Thyridopteryx ephemeraeformis) and armored scale infestation (Carulaspis). The tree is 20-years-old and was delivered to a nursery five months ago. Soon after delivery of the tree, symptoms of canopy dieback started to develop. The root ball is irrigated daily with approximately 20 gallons of water and the tree experiences a mix of sun and shade. Bagworm is increasingly becoming an important pest of trees like juniper in New England as its range expands northward.

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

Insects

Interesting Beneficial Insect:

• Tiger Bee Fly: Xenox tigrinus is a true fly in the Family Bombyliidae (the “bee” flies). These are relatively large flies (1/2 – ¾ of an inch in length) with distinct markings on their wings. Because it is so noticeable, UMass Extension has received a couple of reports of this insect in recent weeks. Xenox tigrinus is a parasite of the larvae of carpenter bees. This insect may be found hovering around wooden fences, rooves or other wooden surfaces on homes, and any manner of wooden structures that may support carpenter bee populations. The females of this species will lay their eggs in places where carpenter bees have laid their eggs. Once the fly eggs hatch, and the tiger bee fly larvae will eat the larvae of the carpenter bee. Despite its name, the tiger bee fly does not have the ability to sting or bite. They mimic bees as a defense against their own predators. Xenox tigrinus should be considered a beneficial insect, as it helps regulate populations of carpenter bees which are capable of causing damage to wooden structures, particularly those that are not painted or stained.

Insects and Other Arthropods of Medical Importance:

• Mosquitoes: The first human case of WNV has been detected in 2021 in Middlesex County, according to the Bureau of Infectious Disease and Laboratory Sciences. WNV positive mosquito samples have been identified in Barnstable, Bristol, Essex, Franklin, Hampden, Hampshire, Middlesex, Norfolk, Plymouth, Suffolk, and Worcester Counties. WNV risk levels have increased to moderate for communities in the Greater Boston area due to increasing WNV activity in mosquitoes. Please view the risk maps available here for updates: https://www.mass.gov/info-details/massachusetts-arbovirus-update .

According to the Massachusetts Bureau of Infectious Disease and Laboratory Science and the Department of Public Health, there are at least 51 different species of mosquito found in Massachusetts. Mosquitoes belong to the Order Diptera (true flies) and the Family Culicidae (mosquitoes). As such, they undergo complete metamorphosis, and possess four major life stages: egg, larva, pupa, and adult. Adult mosquitoes are the only stage that flies and many female mosquitoes only live for 2 weeks (although the life cycle and timing will depend upon the species). Only female mosquitoes bite to take a blood meal, and this is so they can make eggs. Mosquitoes need water to lay their eggs in, so they are often found in wet or damp locations and around plants. Different species prefer different habitats. It is possible to be bitten by a mosquito at any time of the day, and again timing depends upon the species. Many are particularly active from just before dusk, through the night, and until dawn. Mosquito bites are not only itchy and annoying, but they can be associated with greater health risks. Certain mosquitoes vector pathogens that cause diseases such as West Nile virus (WNV) and eastern equine encephalitis (EEE).

For more information about mosquitoes in Massachusetts, visit: https://www.mass.gov/service-details/mosquitoes-in-massachusetts .

There are ways to protect yourself against mosquitoes, including wearing long-sleeved shirts and long pants, keeping mosquitoes outside by using tight-fitting window and door screens, and using insect repellents as directed. Products containing the active ingredients DEET, permethrin, IR3535, picaridin, and oil of lemon eucalyptus provide protection against mosquitoes.

For more information about mosquito repellents, visit: https://www.mass.gov/service-details/mosquito-repellents and https://www.cdc.gov/mosquitoes/mosquito-bites/prevent-mosquito-bites.html .

• Deer Tick/Blacklegged Tick: Check out the archived TickTalk with TickReport webinars available here: https://ag.umass.edu/landscape/education-events/ticktalk-with-tickreport-webinars  .

*Ixodes scapularis - We are now in the time of year when deer tick larvae and nymphs are frequently encountered. Larvae may be encountered in April, but in some locations may peak in their activity in August, while still being encountered through November. Nymphs are encountered from April through July, peaking in June. Nymphs are again present in October and November. For images of all deer tick life stages, along with an outline of the diseases they carry, and their timing of activity, visit: http://www.tickencounter.org/tick_identification/deer_tick .

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

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

*Note that deer ticks (Ixodes scapularis) are not the only disease-causing tick species found in Massachusetts. The American dog tick (Dermacentor variabilis) and the lone star tick (Amblyomma americanum) are also found throughout MA. Each can carry their own complement of diseases, including others not mentioned above. Anyone working or playing in tick habitats (wood-line areas, forested areas, and landscaped areas with ground cover) should check themselves regularly for ticks while practicing preventative measures.

• 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 reared, as food for the immature wasps. A common such example are the paper wasps (Polistes spp.) who rear their young on chewed up insects. They may be seen searching plants for caterpillars and other soft-bodied larvae to feed their young. 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, however these insects sometimes find the most interesting locations to construct their nests. These photos taken on 8/15/2021 show a paper wasp nest that was located at the end of a cannon at a town memorial park in Hampshire County, MA. So expect these nests in the oddest of locations to avoid being stung! 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 Asian giant hornet (Vespa mandarinia). The European hornet is known to Massachusetts, but the Asian giant hornet is not. If you are concerned that you have found or photographed an Asian giant hornet, please report it here: https://massnrc.org/pests/report.aspx . Paper wasps and aerial yellowjackets overwinter as fertilized females (queens) and a single female produces a new nest annually in the late spring. Nests are abandoned at the end of the season. Queens start new nests, lay eggs, and rear new wasps to assist in colony/nest development.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 stingers, and therefore can sting repeatedly when defending their nests. It is best to avoid their nests, and if that cannot be done and assistance is needed to remove them, consult a professional.

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

Invasive Insects & Other Organisms Update:

• Box Tree Moth: Cydalima perspectalis is native to East Asia. It has become a serious invasive pest in Europe, where it continues to spread. The caterpillars feed mostly on boxwood, and heavy infestations can defoliate host plants. Once the leaves are gone, larvae consume the bark, leading to girdling and plant death. The box tree moth is not currently known to be established in Massachusetts, however the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) is urging professionals and citizens to report any suspicious insects.

To report suspected box tree moth life stages or damage to boxwood in Massachusetts, please visit: https://massnrc.org/pests/pestreports.htm .

Females lay eggs singly or in clusters of 5 to more than 20 eggs in a gelatinous mass on the underside of boxwood leaves. Most females deposit more than 42 egg masses in their lifetime. They typically hatch within 4 to 6 days. Pupae typically first appear in April or May and are present continuously through the summer and into the fall, depending on the local climate and timing of generations. Adults first emerge from the overwintering generation between April and July, depending on climate and temperature. Subsequent generations are active between June and October. Adults typically live for two weeks after emergence. The exact timing of the life cycle of this insect in Massachusetts is not currently known.

The Massachusetts Department of Agricultural Resources (MDAR) recently reported that the U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) has confirmed the presence of box tree moth in the continental United States and is taking action alongside state partners and industry to contain and eradicate the invasive pest that was imported on nursery plants shipped from Ontario, Canada. For a recent press release regarding this insect from the MA Department of Agricultural Resources, visit: https://www.mass.gov/news/state-agricultural-officials-urge-public-to-inspect-boxwood-shrubs-for-box-tree-moths .

Between August 2020 and April 2021, a nursery in St. Catharines, Ontario shipped boxwood (Buxus species) that may have been infested with box tree moth to locations in six states—25 retail facilities in Connecticut, Massachusetts, Michigan, New York, Ohio, and South Carolina—and a distribution center in Tennessee. At this time, the pest has been identified in three facilities in Michigan, one in Connecticut, and one in South Carolina, and APHIS is working with state plant regulatory officials to determine whether other facilities may be impacted. For more information, visit: https://www.aphis.usda.gov/aphis/newsroom/stakeholder-info/sa_by_date/sa-2021/sa-05/box-tree-moth .

• Spotted Lanternfly: (Lycorma delicatula, SLF) is not known to be established in Massachusetts landscapes 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 .

The Massachusetts Department of Agricultural Resources has recently released spotted lanternfly Best Management Practices for Nurseries and Landscapers: https://massnrc.org/pests/linkeddocuments/MANurseryBMPs.pdf

And Best Management Practices for Moving Companies and the Moving Industry: https://massnrc.org/pests/linkeddocuments/SLFChecklistMovingIndustryMA.pdf

Now is a great time to provide copies of these BMP’s to employees, customers, family, and friends! The more eyes we have out there looking for spotted lanternfly, the better. Use the above BMP’s as a guide to help you inspect certain items coming from CT, DE, MD, NC, NJ, NY, OH, PA, WV, and VA.

UMass Extension is teaming up with UMass Amherst’s Department of Environmental Conservation, the USDA APHIS, and the Massachusetts Department of Agricultural Resources to monitor for the spotted lanternfly in Massachusetts. A team including members of UMass Extension’s Landscape, Nursery, and Urban Forestry Program, Extension’s Fruit Program, Stockbridge School of Agriculture, and the Department of Environmental Conservation at UMass, Amherst are undertaking a nine-month integrated research and extension project to develop effective tools to detect the spotted lanternfly.

The researchers associated with this project (Dr. Joseph Elkinton, Dr. Jeremy Andersen and Dr. Jaime Pinero) will be working with Dr. Miriam Cooperband of the USDA APHIS lab on Cape Cod to identify and evaluate airborne attractants that can improve the ability to detect SLF in traps. Dr. Cooperband has identified several attractant lures released from host plants of SLF. She is currently working on pheromones produced by SLF that may be much more attractive. The UMass team will help her conduct field tests of these new lures, while also assisting the Massachusetts Department of Agricultural Resources (MDAR) in monitoring for SLF in Massachusetts. UMass Extension Entomologist, Tawny Simisky, will periodically report on progress made during the course of this project. For more information, please visit: https://ag.umass.edu/cafe/news/looking-for-spotted-lanternfly-recent-invasive-arrival .

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.

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/ .

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 feeding on over 103 species of plants, according to new research (Barringer and Ciafré, 2020) and when including not only plants on which the insect feeds, but those that it will lay egg masses on, this number rises to 172. This includes, but is not limited to, 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 .

• Emerald Ash Borer: (Agrilus planipennis, EAB) in 2021 alone, the Massachusetts Department of Conservation and Recreation has confirmed at least 28 new community detections of emerald ash borer in Massachusetts. To date, 11 out of the 14 counties in Massachusetts have confirmed emerald ash borer. (The remaining counties where EAB has yet to be detected are Barnstable, Dukes, and Nantucket counties.)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). Signs of an EAB infested tree may include D-shaped exit holes in the bark (from adult emergence), “blonding” or lighter coloration of the ash bark from woodpecker feeding (chipping away of the bark as they search for larvae beneath), and serpentine galleries visible through splits in the bark, from larval feeding beneath. It is interesting to note that woodpeckers are capable of eating 30-95% of the emerald ash borer larvae found in a single tree (Murphy et al. 2018). Unfortunately, despite high predation rates, EAB populations continue to grow.

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: https://massnrc.org/pests/eabreport.htm .

• Lymantria dispar: (Formerly Gypsy Moth; LD) Professionals working in parts of Berkshire County (ex. Alford, Great Barrington, Richmond, Sheffield, South Egremont, and Williamstown) as well as NY and CT report being deluged with questions from property owners looking to manage Lymantria dispar caterpillars in 2022 following expanding populations of this insect in those areas this season. Here is some information to help with those discussions:

In high populations of Lymantria dispar (formerly gypsy moth), scraping egg masses can be a futile effort. When populations are high, caterpillars can blow in from surrounding forested areas onto your property (next spring) even after an egg mass scraping effort is undertaken. Additionally, on large trees, female moths can lay their egg masses in areas that are not practical/safe to reach. However, if you do try to remove egg masses from high value specimen trees this fall and winter, be sure to scrape them into a can of soapy water. If scraped onto the ground, they may still hatch next spring.

A good plan would be to have an arborist come monitor the property and surrounding area this fall/winter once Lymantria dispar females are completely done laying eggs. (Additional egg mass survey information will also be available for Massachusetts through the Department of Conservation and Recreation once surveys are complete for 2021, here: ( https://www.mass.gov/guides/lymantria-dispar-gypsy-moth-in-massachusetts ). If there are large numbers of egg masses on your property and in the woods nearby, consider applying reduced risk insecticides next spring to protect high-value specimen trees from defoliation next year, especially if they could become hazardous if they were to decline. (Ex. trees near the home, garage, etc.) Applications would be made following 90-100 GDD's, after eggs have hatched, and caterpillars have settled to feed. Egg hatch begins roughly around the first week in May in MA, however this timing may depend upon spring temperatures. Special care should also be taken to protect trees that were defoliated this year, as two consecutive years of defoliation are often very stressful even for mature trees. Young trees/new plantings should be protected as well.

After caterpillars hatch, and once they settle to begin feeding (when they are approximately 3/4 inch in length or less), they are very susceptible to applications of the reduced risk insecticide known as Bacillus thuringiensis Kurstaki. This is a soil dwelling bacterium that is lethal to the caterpillars if they ingest it on the leaves. Another reduced risk option is the active ingredient spinosad (also derived from a soil dwelling bacterium). Spinosad should not be applied to plants in bloom, as it is toxic to pollinators - but that toxicity goes away once the product dries (in about 3 hours). Chlorantraniliprole is another reduced risk active ingredient that can be applied to the leaves of susceptible hosts when caterpillars are young and just beginning to feed.

The efficacy of systemic insecticides for the management of Lymantria dispar is not entirely understood. However, products containing azadirachtin, abamectin, or acephate are labelled for use against this insect. Of those, azadirachtin is a reduced risk insecticide. With regard to acephate, some research suggests that it is more effective at managing caterpillars feeding on smaller diameter trees than on larger trees (Dan Herms, Personal Communication).

LD 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 LD moth caterpillars. (And to a lesser extent many other organisms, including other insects, small mammals, and birds who feed on LD moth.) However, if environmental conditions do not favor the life cycle of the fungus, outbreaks of LD moth caterpillars are possible. (Such as most recently from 2015-2018, with a peak in the LD moth population in 2017 in Massachusetts.)

Check out Episode 1 of InsectXaminer to reminisce about the 2015-2018 outbreak of this insect and learn more about the fungus and the virus and how to recognize caterpillars that have been killed by these pathogens: https://ag.umass.edu/landscape/education-events/insectxaminer .

• 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 .

• Jumping Worms: In recent years, public concern about Amynthas spp. earthworms, collectively referred to as “jumping or crazy or snake” worms, has dramatically increased. University researchers and Extension groups in many locations in the US are finding that these species cause not only forest ecosystem disturbances, but may also negatively impact soil structure and reduce plant growth in gardens and managed landscapes. They do this by voraciously devouring the organic layer of the soil while feeding very close to the soil surface, unlike other species of earthworms. In woodland areas, they can quickly eat all of the leaf litter on the forest floor. Jumping worms also leave a distinct grainy soil full of worm castings. The soil becomes granular and may look like dried coffee grounds.

Unfortunately, there are currently no research-based management options available for these earthworms. So prevention is essential – preventing their introduction and spread into new areas is the best defense against them. Adult jumping worms can be 1.5 – 8 inches or more in length. Their clitellum (collar-like ring) is roughly located 1/3 down the length of the worm (from the head) and is smooth and cloudy-white and constricted. These worms may also wiggle or jump when disturbed, and can move across the ground in an S-shape like a snake. While the exact timing of their life cycle in MA might not be completely understood, their life cycle may be expected to go (roughly) something like this: they hatch in the late spring in 1-4 inches of soil, mature into adults during the summer and adults lay eggs sometime in August, and it is thought that their cocoons overwinter. (Adults perish with frost.) It is also worth noting here that jumping worms do not directly harm humans or pets.

For more information, listen to Dr. Olga Kostromytska’s presentation here: https://ag.umass.edu/landscape/education-events/invasive-insect-webinars

*NEW*: UMass Extension Fact Sheets:

Earthworms in Massachusetts – History, Concerns, and Benefits: https://ag.umass.edu/landscape/fact-sheets/earthworms-in-massachusetts-history-concerns-benefits 

Jumping/Crazy/Snake Worms – Amynthas spp.:

https://ag.umass.edu/landscape/fact-sheets/jumpingcrazysnake-worms-amynthas-spp

Suggested reading includes Dr. Kostromytska’s recent “Hot Topics” article in Hort Notes (including an identification guide), here: https://ag.umass.edu/landscape/newsletters/hort-notes/hort-notes-2021-vol-323

Additional resources can also be found here:

University of Minnesota Extension: https://extension.umn.edu/identify-invasive-species/jumping-worms

Cornell Cooperative Extension: http://ulster.cce.cornell.edu/environment/invasive-pests/jumping-worm

UNH Extension: https://extension.unh.edu/blog/invasive-spotlight-jumping-worms

Tree & Shrub Insects & Mites:

• Bagworm: Thyridopteryx ephemeraeformis is a native species of moth whose larvae construct bag-like coverings over themselves with host plant leaves and twigs. In certain areas across MA in 2020, increased populations of bagworms were observed and reported, particularly in urban forest settings and managed landscapes. More information can be found here: https://ag.umass.edu/landscape/fact-sheets/bagworm

These caterpillars develop into moths as adults. Their behaviors, life history, and appearance are interesting. The larvae (caterpillars) form “bags” or cases over themselves as they feed using assorted bits of plant foliage and debris tied together with silk. As the caterpillars feed and grow in size, so does their “bag”. Young, early instar caterpillars may feed with their bag oriented skyward, skeletonizing host plant leaves. As these caterpillars grow in size, they may dangle downward from their host plant, and if feeding on a deciduous host, they can consume the leaves down to the leaf veins. Pupation can occur in southern New England in late September or into October and this occurs within the “bag”. Typically, this means that the caterpillars could encounter a killing frost and die before mating could occur. However, in warmer areas of Massachusetts or if we experience a prolonged, warm autumn, it is possible for this insect to overwinter and again become a problem the following season. If the larvae survive to pupation, adult male moths emerge and are winged, able to fly to their flightless female mates. The adult male is blackish in color with transparent wings. The female is worm-like; she lacks eyes, wings, functional legs, or mouthparts. The female never gets the chance to leave the bag she constructs as a larva. The male finds her, mates, and the female moth develops eggs inside her abdomen. These eggs (500-1000) overwinter inside the deceased female, inside her bag, and can hatch roughly around mid-June in southern New England. Like other insects with flightless females, the young larvae can disperse by ballooning (spinning a silken thread and catching the wind to blow them onto a new host). While arborvitae and junipers can be some of the most commonly known host plants for this insect, the bagworm has a broad host range including both deciduous and coniferous hosts numbering over 120 different species. Bagworm has been observed on spruce, Canaan fir, honeylocust, oak, European hornbeam, rose, and London planetree among many others.

This insect can be managed through physical removal, if they can be safely reached. Squeezing them within their bags or gathering them in a bucket full of soapy water (or to crush by some other means) can be effective ways to manage this insect on ornamental plants. Early instar bagworm caterpillars can be managed with Bacillus thuringiensis var. kurstaki (Btk) but this is most effective on young bagworms that are approximately no larger than ¾ inch in length. As bagworms grow in size, they may also have behavioral mechanisms for avoiding chemical management. At this point in the season, physical removal (if possible) may be the best option. This will also preserve any natural enemies that would be found attacking this insect, such as certain parasitic wasps. It is also important to note that the bags from dead bagworms will remain on the host plant, so check the viability of the bagworms by dissecting their bags to avoid unnecessary chemical applications. Historically in Massachusetts, bagworms have been mostly a problem coming in on infested nursery stock. With females laying 500-1000 eggs, if those eggs overwinter the population can grow quite large in a single season on an infested host. Typically this insect becomes a problem on hedgerows or plantings nearby an infested host plant. Thyridopteryx ephemeraeformis is found from Massachusetts to Florida, and is typically a more significant pest in southern climates. However, in recent years (2019-2021), bagworm appears to be overwintering in successfully in certain locations in Massachusetts.

• 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.
• Fall Webworm: Hyphantria cunea is native to North America and Mexico. It is now considered a world-wide pest, as it has spread throughout much of Europe and Asia. (For example, it was introduced accidentally into Hungary from North America in the 1940’s.) Hosts include nearly all shade, fruit, and ornamental trees except conifers. In the USA, at least 88 species of trees are hosts for these insects, while in Europe at least 230 species are impacted. In the past history of this pest, it was once thought that the fall webworm was a two-species complex. It is now thought that H. cunea has two color morphs – one black headed and one red headed. These two color forms differ not only in the coloration of the caterpillars and the adults, but also in their behaviors. Caterpillars may go through at least 11 molts, each stage occurring within a silken web they produce over the host. When alarmed, all caterpillars in the group will move in unison in jerking motions that may be a mechanism for self-defense. Depending upon the location and climate, 1-4 generations of fall webworm can occur per year. Fall webworm adult moths lay eggs on the underside of the leaves of host plants in the spring. These eggs hatch in late June or early July depending on climate. Young larvae feed together in groups on the undersides of leaves, first skeletonizing the leaf and then enveloping other leaves and eventually entire branches within their webs. Webs are typically found on the terminal ends of branches. All caterpillar activity occurs within this tent, which becomes filled with leaf fragments, cast skins, and frass. Fully grown larvae then wander from the webs and pupate in protected areas such as the leaf litter where they will remain for the winter. Adult fall webworm moths emerge the following spring/early summer to start the cycle over again. 50+ species of parasites and 36+ species of predators are known to attack fall webworm in North America. Fall webworms typically do not cause extensive damage to their hosts. Nests may be an aesthetic issue for some. If in reach, small fall webworm webs may be pruned out of trees and shrubs and destroyed. Do not set fire to H. cunea webs when they are still attached to the host plant.
• Hickory Tussock Moth: Lophocampa caryae is native to southern Canada and the northeastern United States. There is one generation per year. Overwintering occurs as a pupa inside a fuzzy, oval shaped cocoon. Adult moths emerge approximately in May and their presence can continue into July. Females will lay clusters of 100+ eggs together on the underside of leaves. Females of this species can fly, however they have been called weak fliers due to their large size. When first hatched from their eggs, the young caterpillars will feed gregariously in a group, eventually dispersing and heading out on their own to forage. Caterpillar maturity can take up to three months and color changes occur during this time. These caterpillars are essentially white with some black markings and a black head capsule. They are very hairy, and should not be handled with bare hands as many can have skin irritations or rashes (dermatitis) as a result of interacting with hickory tussock moth hairs. By late September, the caterpillars will create their oval, fuzzy cocoons hidden in the leaf litter where they will again overwinter. Hosts whose leaves are fed upon by these caterpillars include but are not limited to hickory, walnut, butternut, linden, apple, basswood, birch, elm, black locust, and aspen. Maple and oak have also been reportedly fed upon by this insect. Several wasp species are parasitoids of hickory tussock moth caterpillars.
• Lacebugs: Stephanitis spp. lacebugs such as S. pyriodes can cause severe injury to azalea foliage. S. rhododendri can be common on rhododendron and mountain laurel. S. takeyai has been found developing on Japanese andromeda, leucothoe, styrax, and willow. Stephanitis spp. lace bug activity should be monitored through September. Before populations become too large, treat with a summer rate horticultural oil spray as needed. Be sure to target the undersides of the foliage in order to get proper coverage of the insects. Certain azalea and andromeda cultivars may be less preferred by lace bugs.
• Magnolia Scale: Neolecanium cornuparvum is a soft scale that 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, looking as if they have been rolled in powdered sugar. By August, the adult female scale is fully developed, elliptical and convex in shape and ranging from a pinkish-orange to a dark brown in color. Adult females may also be covered in a white, waxy coating. By that time, the females produce nymphs (crawlers; living young; eggs are not “laid”) that wander the host before settling on the newest twigs to overwinter. In the Northeastern United States, this scale insect has a single generation per year.

On magnolia hosts, these large soft scales could either be Neolecanium cornuparvum, the magnolia scale, or Toumeyella liriodendri, the tuliptree scale. The tuliptree scale can be found both on magnolia and tuliptree hosts, whereas the magnolia scale is only known to magnolia. Differentiation between these two species of scale (on magnolia) can be difficult in the field.

• Viburnum Leaf Beetle: Pyrrhalta viburni is a beetle in the family Chrysomelidae that is native to Europe, but was found in Massachusetts in 2004. 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/ .

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

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

Weeds

The flowering period of Japanese knotweed, Polygonum cuspidatum, is right on time, so now is the time to begin your herbicide applications. Glyphosate-based herbicide products are the best choice for the control of Japanese knotweed. In areas near water, a formulation of glyphosate that is labeled for these areas should be used. Non-chemical products containing clove oil, citric acid, acetic acid or orange extract will not effectively control Japanese knotweed.

Common reed or phragmites, Phragmites australis, is starting to flower in New England, so now is the time to treat this invasive plant. Glyphosate-based herbicide products are the best choice for the control of common reed. In areas near water, a formulation of glyphosate that is labeled for these areas should be used.

Poison ivy can be treated now. Glyphosate or triclopyr are the best herbicides for poison ivy control. Triclopyr products should be selected over glyphosate products in areas where grasses need to be saved. Contact (Scythe^TM, Reward^TM) or the non-chemical/organic herbicide products will provide “burndown” activity only and will not adequately control poison ivy.

Many landscape trees commonly produce vegetative suckers at their trunk base. Suckers are commonly seen on crabapple, flowering cherry, flowering pear, plum, linden, maple and sometimes oak. Honey locust commonly produces vegetative sprouts along the entire length of its trunk. Pruning is effective but very time consuming. Another option would be to use the product Scythe^TM that contains pelargonic acid to remove these vegetative suckers and sprouts when they are very small. Very small means less than one inch in length or smaller. Pelargonic acid is a contact herbicide. If Scythe^TM is applied to small suckers and sprouts, the product will desiccate them and physical removal will not be required. Larger growth will first need to be physically removed and then Scythe^TM can be used as a maintenance program. Products that contain glyphosate should not be used as glyphosate is a translocated herbicide and injury to the whole plant is possible.

At this point in the season, summer annual weeds have become large. Many weeds have become very large and just spraying them will result in unsightly dead vegetation, so hand weeding may be necessary. However, spot spraying with a non-selective herbicide is usually a better strategy than hand-weeding because it does not break the mulch barrier. A determination on a site-by-site basis will need to be made.

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

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Diagnostic Services

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