Landscape Message: September 7, 2018

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.

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

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Scouting Information by Region

Environmental Data

The following data was collected on or about September 5, 2018. Total accumulated growing degree days (GDD) represent the heating units above a 50° F baseline temperature collected via our instruments for the 2018 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	2018 Total	Sun	Shade
CAPE	340	2313	74	69	0.00	5:00 PM 9/5
SOUTHEAST	325.5	2430.5	75.9	69.5	0.00	4:30 PM 9/5
NORTH SHORE	358	2429.5	75	70	0.10	10:00 AM 9/5
EAST	342.5	2613	74	68	0.38	2:30 PM 9/5
METRO	302	2380	73	68	0.49	5:45 AM 9/5
CENTRAL	338.5	2480.4	68	64	0.84	7:00 AM 9/5
PIONEER VALLEY	335.5	2536.5	80	72	0.43	4:00 PM 9/5
BERKSHIRES	288	2217	72	68	0.11	9:30 AM 9/5
AVERAGE	329	2425	74	69	0.29
n/a = information not available

Drought conditions update: Viewing the map via the link below, dated September 6, shows Massachusetts is experiencing level D0 - 'Abnormally Dry' - throughout Cape Cod, Martha's Vineyard and Nantucket. Half of Bristol and almost all of Plymouth Counties are also labeled D0.  The rest of the state is free of any category of drought.
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	Begin	Begin	Begin	Begin	Begin	Begin	Begin
Clematis paniculata (Sweet Autumn Clematis)	Begin/Full	Begin	Begin/Full	Begin	Begin/Full	Begin	Begin/Full	Begin
Polygonum cuspidatum (Japanese Knotweed)	Full	Full	Full	Full	Full	Full	Full	Full
Styphnolobium japonicum (L.) Schott (Japanese Pagoda tree)	End	End	End	Full/End	Full/End	Full/End	Full/End	Full/End
Buddleia davidii (Butterfly Bush)	Full/End	Full/End	Full/End	Full/End	Full/End	*	Full/End	Full/End
* = no activity to report/information not available

Regional Notes

Cape Cod Region (Barnstable)

General Conditions: The average temperature over the last two weeks was 73°F with a high of 91°F on August 29 and a low of 53°F on August 24. Conditions have been warmer than average for the period. No precipitation fell during the period. The US Drought monitor has listed the Cape and parts of Southeastern MA as 'Abnormally Dry' since the beginning of August. Thunderstorms and rain showers that had been hit or miss in early August have been nonexistent over the last two weeks. Topsoil moisture conditions are very short and subsoil moisture conditions are short. The combination of hot temperatures and lack of rain fall has stressed some plants and has been problematic for fall turf renovation.

Pests/Problems: Insects or insect damage observed over the last two weeks include: sunflower moth (Homoeosoma electellum) on purple coneflower, tobacco budworm on petunia, chinch bug damage to turf, Lecanium scale on oak, two-spotted spider mites on butterfly bush, chilli thrips on Hydrangea, white pine weevil (Pissodes strobe) damage on white pine, turpentine beetle (Dendroctonus terebrans) on pitch pine, two-spotted spider mite on annuals and herbaceous perennials, Andromeda lacebug (Stephanitis takeyai) on Japanese Andromeda, azalea lacebug (Stephanitis pyrioides) on azalea, sycamore lacebug (Corythucha ciliate) on sycamore, daylily leafminer (Ophiomyia kwansonis) damage on daylily, and dogwood sawfly on dogwood. Diseases visible over the last week include leaf spot on Hydrangea, downy mildew on garden Impatiens, foliar nematodes on Japanese Anenomes, powdery mildew on the usual (just about everything), leaf spots (Septoria) on red twig dogwood, daylily leaf streak on daylily, Kabatina blight (possible Phomopsis as well) on eastern red cedar, leaf spot on birch, tar spot on Norway maple, black spot on rose, and cedar apple rust on crabapple. Weeds in bloom include purslane (Portulaca oleracea), prostrate spurge (Euphorbia maculate), redroot pigweed (Amaranthus retroflexus), lambsquarters (Chenopodium album), carpetweed (Mollugo verticillata), beggarticks (Bidens frondosa), copperleaf (Acalypha spp), prickly lettuce (Lactusa serriola), mugwort (Artemisia vulgaris), ragweed (Ambrosia artemisiifolia), smartweed (Polygonum spp.), and horseweed (Conyza canadensis). Rabbits are still abundant.

Southeast Region (Acushnet)

General Conditions: Since the last landscape message two weeks ago, we have had no rain. Hazy, hot and humid temperatures have been pretty overwhelming. With highs in the 80s to 90s and lows in the 70s, it’s been quite uncomfortable. Most of the landscape looks rather green in spite of it all, but with a closer look you can see how dry the soil is and the effects of this on many plants. Annuals, perennials, trees and shrubs that have not been watered during this period are in a sad state. Rose of Sharon (Hibiscus syniacus) flowers are starting to fade. Currently in full bloom are the show stopping Hydrangea paniculata, many different, lovely varieties of roses, and butterfly bush (Buddleia spp.) still flowering nicely. Beginning to show some beautiful color are sweet autumn Clematis (C. paniculata), seven sons flower (Heptacodium miconiodes), Sedum 'Autumn Joy' (Stonecrop), and ornamental grasses. Invasive Japanese knotweed is in full flower right now (see weed report below). Russian sage (Perovskia atriplicifolia), garden phlox (Phlox paniculata), black eyed Susan (Rudbeckia), and coneflower (Echinacea) are still blooming. Wild cucumber (Echinocystis lobata) is pretty draped in the trees. It almost looks a bit like the sweet autumn Clematis at first glance, but there are some interesting differences (see photo).

Pests/Problems: Mushrooms and slime molds have been seen, and watering with the humid weather can be the cause in some areas. Ticks are still pretty active. Hot temperatures and still waters are a breeding ground for mosquito larvae so don’t forget to dump any standing water. Wasps are very active; be aware of paper-like nests or activity coming from holes leading from underground yellow jacket nests. Beetles are still active, as well as earwigs, slugs and snails. I've inserted a photo of an Ailanthus webworm moth found in the field. Larvae create webs on leaves and branches of the tree of heaven (Ailanthus tree). They resemble beetles when not in flight. Magnolia scale, spider mites, powdery mildew, fungus, tar spot on Norway maple, and marginal leaf scorch are present. Cedar apple rust is on apples (Malus) and rust is also on ornamental pears. 

 

 

 

North Shore Region (Beverly)

General Conditions: The weather conditions during this reporting period continued to be hot and humid except for a few days in the middle of the reporting period. Day temperatures ranged from low 80s to mid-80s, with temperatures above 90 degrees recorded on three days. This two-week period was also very dry. Rainfall occurred only on one day at the beginning of this period when a quick rain shower passed through the area. Approximately 0.10 inches of rainfall was recorded at Long Hill. Woody plants seen in bloom include: butterfly bush (Buddleia davidii), blue mist shrub (Caryopteris x clandonensis), Russian Daphne (Daphne x transatlantica), Franklin tree (Franklinia alatamaha), seven-son flower (Heptacodium miconioides), rose-of-Sharon (Hibiscus syriacus), sweet autumn Clematis (Clematis paniculata), trumpet vine (Campsis radicans) and crepe myrtle shrub (Lagerstroemia spp.). Herbaceous plants seen in bloom include: bush clover (Lespedeza thunbergii), garden phlox (Phlox paniculata), Hostas (Hosta spp.), autumn joy Sedums (Sedum spp.), Rudbeckia (Rudbeckia hirta), New England aster (Symphyotrichum novae-angliae), morning glory (Ipomoea purpurea), Japanese Anemone (Anemone x hybrida) and water lily (Nymphaea odorata). Different kinds of annuals are also contributing color in the landscape.

Pests/Problems: Because of dry conditions during the past two weeks, some plants are starting to show signs of drought stress such as wilting, premature leaf drop and early fall color. Powdery mildew was observed on some lilacs and Phlox. Other diseases observed include tar spot on Norway maple, black spot on roses, cedar apple rust on crabapple and powdery mildew on flowering dogwood. Pests observed include azalea lace bug on azalea, aphids on Rudbeckia and spider mites on some annuals and perennials. Remember that mosquitoes and ticks are still active at dawn and dusk. Protect yourself with insect repellent when working or walking in the woods at dawn or dusk

East Region (Boston)

General Conditions: The end of summer has been hot and humid, reaching 96°F on August 29, tying the highest temperature of the year last recorded on July 3. Temperatures have fluctuated over the last two weeks, with highs that ranged from 71°F to 96°F, averaging 85°F. Low temperatures ranged from 55°F to 77°F, averaging 64°F. We have experienced three days with highs in the 90s and have gained 342.5 GDDs, for a total of 2613 GDDs. Rainfall has been sparse; over the last two weeks, we’ve received only 0.38 inches of precipitation, falling on August 28 and bringing the August total to 4.23 inches. Plants in bloom include: Albizia julibrissin (mimosa), Asclepias syriaca (common milkweed), A. tuberosa (butterfly weed), Buddleia spp. (butterfly bush), Campsis radicans (trumpet vine), Clematis paniculata (sweet autumn Clematis), Coreopsis spp. (tickseed), Daucus carota (Queen Anne's lace), Echinacea purpurea (coneflower), Eupatorium purpureum (Joe Pye weed), Heptacodium miconioides (seven-son flower), Hibiscus moscheutos (swamp mallow), H. syriacus (rose-of-Sharon), Hosta spp. (Hosta), Hydrangea macrophylla ‘Bailmer’ (‘Endless Summer’ Hydrangea), H. paniculata (panicle Hydrangea), Panicum virgatum (switchgrass), Perovskia atriplicifolia (Russian sage), Phlox paniculata (garden phlox), Physostegia virginiana (obedient plant), Platycodon grandiflorus (balloon flower), Rudbeckia hirta (black-eyed Susan), Sedum ‘Autumn Joy’ (stonecrop), Solidago spp. (goldenrod), and Styphnolobium japonicum (Japanese pagoda tree).

Pests/Problems: The lack of rain has left soils dry; weeding has resulted in dusty conditions. Powdery mildew continues to dominate throughout the landscape at this time of year. Lythrum salicaria (purple loosestrife) is in full bloom. Digitaria spp. (crabgrass) continues to thrive, getting larger every day and its fruits have formed as seeds are maturing. Cynanchum louiseae (black swallow wort) seed has matured; pods are splitting open and releasing its wind-borne seed. Euphorbia maculata (prostrate spurge) fruit has matured, dropping seed.

Metro West (Acton)

General Conditions: Labor Day has come and gone, which usually marks the end of summer by bringing with it cooler temperatures; however, temperatures have been recorded into the 90s since, and the weather outside is oppressive. During this past two-week reporting period, there was just one rain event when 0.49” of rain was recorded on the 29^th, bringing the total precipitation for the month to 6.91”, which far surpasses the historical August monthly average rainfall of 3.72”. September’s average rainfall is 3.77” and there has not been any precipitation recorded for the month so far. In some stage of bloom at this time are the following woody plants: Albizia julibrissin (silk tree), Buddleia spp. (butterfly bush), Heptacodium miconioides (seven-son flower), Hibiscus syriacus (rose-of-Sharon), Hydrangea paniculata (panicle Hydrangea and its many cultivars including 'Tardiva'), Potentilla fruiticosa (Potentilla), Rosa 'Knockout' (the Knockout family of roses) and Styphnolobium japonicum (Japanese pagoda tree). Two woody vines in bloom are 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: Achillea millefolium (yarrow), Asclepias syriaca (common milkweed), A. tuberosa (butterfly weed), Aster spp. (New England Aster, New York Aster, smoother Aster, white wood Aster), Astilbe spp. (false Spirea), Boltonia asteroides (Bolton’s Aster), Chelone lyonii (pink turtlehead), Coreopsis spp. (tickseed), Daucus carota (Queen Anne's lace), Echinacea purpurea (coneflower and its many cultivars), Eupatorium purpureum (Joe Pye weed), Geranium sanguineum (cranesbill Geranium), Hemerocallis spp. (daylily), Hibiscus moscheutos (swamp mallow), Hosta spp. (plantain lily), Kirengeshoma palmata (yellow wax bells), Leucanthemum spp. (Shasta daisy), Liatris spicata (spike gayfeather), Lythrum salicaria (loosestrife), Patrinia gibbosa (Patrinia), Perovskia atriplicifolia (Russian sage), Phlox carolina (Carolina Phlox), Phlox paniculata (garden Phlox), Physostegia virginiana (obedient plant), Platycodon grandiflorus (balloon flower), Rudbeckia fulgida var. sullivantii 'Goldsturm' (black-eyed Susan), Sedum ‘Rosy Glow’ (Stonecrop), Senna marilandica (wild Senna), and Solidago spp. (goldenrod).

Pests/Problems: Let’s hope that we receive more rain now that the fall planting season is upon us. We’ve been in a dry spell for two weeks. Observed in the landscape these past two weeks were browning and leaf drop on Acer platanoides (Norway maple) due to tar spot and/or anthracnose and leaf blotch on Aesculus sp. (horsechestnut). Powdery mildew is on Cornus florida (dogwood), Hamamelis (witch hazel), Monarda (bee balm), Phlox, and Syringa (lilac). Cedar Apple Rust is on Amelanchier spp. (serviceberry) and Crataegus spp. (hawthorn).

Central Region (Boylston)

General Conditions: As the end of meteorological summer approaches, you wouldn’t know it by the number of days nearing or over 90° F. Along with the heat, the fact that only 0.84” of rain has fallen over the last few weeks has left plants in non-irrigated areas showing some stress symptoms such as leaf drop, leaf scorch, and mid-day wilting. Trees, shrubs and vines in bloom include: Calluna vulgaris spp. and cvs. (heather), Clerodendron trichotomum (harlequin glorybower), Clethra acuminata (mountain pepperbush), C. alnifolia (summersweet, almost at an end), C. barbinervis (Japanese Clethra), Styphnolobium japonicum (Japanese pagoda tree, coming to an end), Hydrangea aspera (rough-leaved Hydrangea), H. macrophylla ‘Bailmer’ (‘Endless Summer’ Hydrangea), H. paniculata (panicle Hydrangea), H. quercifolia (oak-leaf Hydrangea), H. serrata ‘Bluebird’ (mountain Hydrangea) and Clematis cvs. (Clematis vines) - in particular, C. heracleifolia var. davidiana (tube Clematis), C. ‘Rooguchi’, and C. terniflora (sweet autumn Clematis). The following perennials and bulbs are in bloom: Ageratina altissima ‘Chocolate’ (white snakeroot), Anemone japonica ‘Pamina’ and ‘Robustissima’(Japanese Anemones), Anemonopsis macrophylla (false Anemone), Angelica gigas (purple parsnip), Echinacea spp. and cvs. (coneflower), Eupatorium purpureum (Joe Pye weed), Galtonia candicans (summer Hyacinth), Geranium ‘Gerwat’ (Geranium Rozanne), Indigofera amblyantha (Chinese indigo), Kniphofia ‘Jade Green’ (red hot poker plant), Phlox paniculata (garden phlox), Rudbeckia fulgida var. sullivantii ‘Goldsturm’ (brown-eyed Susan), Rudbeckia subtomentosa ‘Henry Eilers’ (sweet coneflower), Senna marilandica (wild Senna), Solidago spp. and cvs. (goldenrod), Stenanthium gramineum (eastern featherbells), Vernonia noveboracensis (ironweed), and Veronicastrum virginicum (Culver’s root). Many ornamental grasses are flowering now as well, adding their beauty to the landscape. Some examples looking particularly good at this point are: Chasmanthium latifolium (northern sea oats), Calamagrostis x acutiflora ‘Karl Foerster’ (feather reed grass), Miscanthus cvs., Panicum virgatum and cvs. (switchgrass), and Pennisetum orientale ‘Karley Rose’ (Oriental fountain grass).

Pests/Problems: Magnolia scale adult females are very visible at this time on Magnolia spp. and cvs. Dogwood sawfly have been noted on grey dogwood, Cornus sanguinea ‘Midwinter Fire’ and C. sericea ‘Bud’s Yellow’. Japanese beetles are still active. Budworms are being found on flowering perennials and annuals. Blister beetles were found on Clematis, Anemone japonica, and A. pulsatilla. Powdery mildew was noted on Syringa spp. (lilacs), Phlox paniculata (garden Phlox), and Monarda spp. and cvs. (bee-balm). Cedar-apple rust is on Malus (crabapple and apples).

Pioneer Valley Region (Amherst)

General Conditions: The calendar might say September, but it still feels like the peak of summer in the Pioneer Valley as we endure yet another, and hopefully the last, heat wave in 2018. If we weren’t shedding daylight at a rapid clip right now (we lost 38 minutes over this past reporting period), it really would feel like July never ended. September of 2017 was warm and dry and this year is starting out with much of the same. We haven’t had any precipitation since 8/22 and surface soils are dry. Subsurface soils, especially in shaded settings, remain fairly moist. This is a surprising turn of events after the deluge of rainfall we received from mid-July through mid-August. According to the Northeast Regional Climate Center, the northeast experienced one of the hottest, if not the hottest, August on record (http://www.nrcc.cornell.edu/services/blog/2018/09/04/index.html). Locally, high temperatures were ≥90°F for 12/31 (39%) days in August in both Springfield and Easthampton. Over the past two weeks, we’ve had a mixture of warm but comfortable days with beautifully cool nights in the lower to upper 50s. These days have contrasted sharply with our most recent, post-Labor Day weather; high temperatures in the 90s and dew points near 70°F sent the heat index well over 100°F. Many trees and shrubs bear the marks of a long growing season: tattered foliage with various spots, blotches and marginal scorching, stem and branch cankers, canopy dieback, mechanical wounds and a general ragged appearance. Some members of the green industry probably feel like many of these plants appear after this hot and humid summer. Even still, many trees and shrubs are doing what they do best, persisting through extreme weather and providing us with their beauty and quantifiable benefits like shade, stormwater capture, carbon sequestration and wind buffering.

Pests/Problems: With cool weather on the horizon, the spruce spider mite will require attention once more. Scout interior canopy branches on arborvitae, spruce, fir, hemlock, falsecypress and other conifers for the characteristic flecking damage. Treat with an appropriate miticide that will limit mortality of beneficial insects that prey on spider mites. Avoid unnecessary applications of imidacloprid to conifers that don’t need it, because that would reduce natural predators and allow spider mite populations to explode. For example, eastern hemlocks that don’t have hemlock woolly adelgid infestations should not be treated. Continue to scout for and prune dead canopy stems and branches as they appear. A reduction of inoculum now will mean reduced potential for new infections next season. Many late season foliar diseases are at or near their peak damage for the year, such as: Tubakia leaf blotch of oak, Entomosporium leaf spot of hawthorn and pear, apple scab on apple and crabapple and Septoria leaf spot of dogwood. Heat scorch is common on katsura and Stewartia at this time, especially young trees that have been recently transplanted. Keep these trees well-watered and hopefully with time they will adapt and suffer lower levels of scorch in the future. For trees suffering from moderate to severe cases of foliar disease, fall cleanups will help to reduce overwintering inoculum in the form of blighted and discarded leaves. If you are treating for Rhizosphaera needle cast on spruce and fir, the fall treatment window is upon us soon. This disease is especially difficult to control on landscape trees and fungicides should be used only on high-value trees. The root and butt rot pathogen Ganoderma sessile (varnish conk, previously G. lucidum) is actively producing new conks at the base of infected trees, especially oak and maple. Last season’s conks may still be present at the base and appear reddish-black in color. They stand in sharp contrast to the newly developing conks that have a cream-colored, amorphous shape when young, developing into a maroon-red, shelf-like conk that while annual is rubbery and tough. Continue to water newly transplanted trees and shrubs throughout the autumn season. Drought stress heading into the winter can make plants more susceptible to cold injury.

Berkshire Region (Great Barrington)

General Conditions: After weeks of frequent and heavy rains, the past monitoring period (August 22 – September 5) experienced very dry weather with only 0.11 inches of rain. Yet, soil moisture remained at a moderate level due to having been quite saturated by those heavy rains; the exception to an adequate soil moisture level was coarse textured soil low in organic matter content. Nevertheless, soils to be seeded to grass or where trees, shrubs, and perennials are to be planted should be irrigated a few hours prior to planting and again after planting. The biggest concern, weather wise, was the oppressive heat, especially on August 28 and 29 when temperatures were in the upper 80s and low 90s, with heat indexes in the upper 90s and low 100s throughout the county. After a few days of reprieve, the heat wave came back on September 3 and 4, again in the upper 80s and low 90s with oppressive humidity. Soil temperatures remain high for this time of year when nights are normally much cooler than has occurred lately. Despite the heat and recent dry conditions, the landscape remains lush with much color provided by late blooming perennials such as Japanese Anemone (Anemone x hybrid), monkshood (Aconitum fischeri), goldenrod (Solidago spp.), Joe-Pye weed (Eupatorium purpureum), New England Aster (Aster nova-angliae), Russian sage (Perovskia atriplicifolia), showy stonecrop (Sedum spectabile), and sweet autumn Clematis (Clematis terniflora). Hydrangea paniculata is the dominant flowering shrub in landscapes now. Japanese knotweed (Polygonum cuspidatum), a plant on the Massachusetts invasive plant list, is in full bloom and can be seen along roadsides and, oddly perhaps, in many home gardens.

Pests/Problems: The heat has caused some scorch on a few tree species, notably Amur cork tree (Phellodendron amurense). It may also be playing a factor in the appearance of leaf scorch on some trees adjacent to highways where salt applications in past winters may have damaged tree roots. It’s been a banner year for apple scab and cedar apple rust. There is an abundance of naked apple and crabapple trees due to severe infections of these diseases. Magnolia scale has been a prominent pest this year and all species and cultivars of Magnolia have been infested. The scale is now in the crawler stage. Though the scale appears on twigs, the foliage of Magnolia has been severely marred by sooty mold growing in the honeydew excreted by the scale. Tussock moth caterpillars, the hickory tussock moth caterpillar being the most commonly seen, are out and about feeding on the leaves of many different deciduous trees. However, this late in the year, this feeding is not of much concern. The bigger issue with tussock moth caterpillars is the itchy rash caused by contact with the prickly hairs on the insect. Best to avoid contact with the critters. A few adult Japanese beetles can still be found feeding on the foliage of susceptible plants but their numbers are few. Fall webworm continues to be actively feeding on many trees and shrubs but control this late in the growing season may not be warranted. In fact, leaving these caterpillars alone now may enhance the population of their natural predators.

Regional Scouting Credits

• CAPE COD REGION - Russell Norton, Horticulture and Agriculture Educator with Cape Cod Cooperative Extension, reporting from Barnstable.
• SOUTHEAST REGION - Jacqueline Hoyle, MCH, reporting from Acushnet.
• 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 Arnold Arboretum, Jamaica Plain.
• METRO WEST REGION - Julie Coop, Forester, Massachusetts Department of Conservation & Recreation, reporting from Acton.
• CENTRAL REGION  - Dawn Davies, Interim Horticulture Manager, reporting from Tower Hill Botanic Garden, Boylston.
• PIONEER VALLEY REGION - Nick Brazee, Plant Pathologist, UMass Extension Plant Diagnostic Lab, reporting from UMass Amherst.
• BERKSHIRE REGION - Ron Kujawski, Horticultural Consultant, reporting from Great Barrington.

Woody Ornamentals

Diseases

Recent pests and pathogens of interest seen in the UMass Extension Plant Diagnostic Lab:

Foliar anthracnose, caused by Colletotrichum, on sycamore maple (Acer pseudoplatanus). Tree is 60-years-old and was planted in a landscape with a highly restricted rooting zone near the coast. Over the past several years, marginal browning and premature leaf shedding has developed during the summer. The tree also has some sap stains on the trunk, possibly indicating decay or a trunk cankering pathogen is present. Drip irrigation is provided and the tree receives full sun.

Infestation of the white peach scale (Pseudaulacaspis pentagona) and stem cankering caused by Phomopsis on mulberry (Morus sp.). Tree is 8” in diameter and lives in full sun with sandy soils and no supplemental irrigation. The dieback exhibited by the tree appeared similar to desiccation and both the scale infestation and stem cankering infection were advanced. The white peach scale has a broad host range and at times can go undetected until populations are high.

Heat scorch on katsura (Cercidiphyllum japonicum). Tree is approximately 10- to 12-years-old and has been present at the site for two seasons. It receives full sun and is provided with drip irrigation. The top half of the canopy developed marginal leaf scorch this season and the symptoms, although less severe, did develop last season as well. Heat scorch is common for katsura that are recently transplanted even when adequate water is provided to the tree. While some opportunistic foliar pathogens sometimes expand the marginal browning, most trees appear to tolerate the scorch and with time adapt to the site conditions. As our climate continues to warm, katsura may require more shaded settings to thrive in the landscape.

Marssonina leaf blotch caused by Marssonina coronaria (also known as Diplocarpon mali) of espalier apple (Malus domestica). Tree is roughly 20-years-old and was planted in full sun. Soils are moist and deep at the site and the tree is regularly pruned to maintain form. In July, leaves began to develop yellow-colored spots and blotches and were prematurely shed from the canopy. While yellowing and shedding is also characteristic of apple scab, the pattern of spotting and blotching is less uniform and more irregular from Marssonina. This season, espalier apples have also been seriously blighted by cedar-apple rust, as many espalier cultivars appear to be highly susceptible to infection.

Pear trellis rust, caused by Gymnosporangium sabinae, of Bradford pear (Pyrus calleryana). Three pears were planted in 2004 in a residential landscape approximately 10’ apart from one another. Creeping junipers were planted underneath the trees along a slope and receive some supplemental water from overhead irrigation. This year, large red-colored spots developed on the foliage (see photo) beginning in July which had not been observed in previous years. The large spots have coalesced and foliage has been shedding prematurely from the canopy. Pear trellis rust is similar to other Gymnosporangium rusts in that the fungus requires a rosaceous host (in this case, ornamental or orchard pear) and Juniperus to complete its life cycle. While widespread in Europe, the disease was first detected in the northeast U.S. in 2011 (New York) and in New England in 2012 (Connecticut). The creeping junipers are experiencing a serious tip dieback as well but this can be attributed to infections by Phomopsis juniperovora and a species of Botryosphaeria s.l., in addition to the rust pathogen. Most Juniperus species tolerate rust infections with only minor damage, save for cedar-quince rust infections which can be damaging.

Verticillium wilt of sugar maple (Acer saccharum 'Legacy'). Approximately 20 trees growing together at a nursery plantation, among hundreds, are symptomatic at this time. The trees are 10-years-old and have been present at the site for three years. Yellowing and browning of upper canopy foliage began in mid-summer and has intensified in recent weeks, despite heavy rainfall in the region during July and August. Supplemental water is provided to the trees as needed. Distinctive green-colored vascular staining was present when the bark was stripped from declining shoots and pitting was also clearly visible when cross-sectional discs were cut. The pathogen was readily cultured from this symptomatic material. The trees were to be immediately pulled and burned with an emphasis on collecting all of the dead foliage. Verticillium produces resting structures, known as microsclerotia, in dead plant parts, which allow it to persist for long periods of time when it becomes established at a site. Desiccated leaves harboring the fungus can be readily dispersed as they fall, spreading the fungus to nearby sites where it can colonize new, susceptible hosts.

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

Insects

Upcoming insect-related training:

• Space is still available for the upcoming Emerald Ash Borer Field Day! Please join UMass Extension at Mass Audubon’s Arcadia Wildlife Sanctuary (Easthampton, MA) on Tuesday, September 11, 2018 from 8:30 AM – 1:00 PM. Register now, as space is limited to 60 participants: https://ag.umass.edu/landscape/events/emerald-ash-borer-field-day .

This educational program is entirely devoted to the invasive, exotic emerald ash borer (EAB; Agrilus planipennis) that has been present in Massachusetts since 2012. This wood-boring/jewel beetle threatens all of our native North American ash tree species (Fraxinus spp.), including white and green ash which are not only an important part of our forest component in western and other areas of Massachusetts, but also are popularly planted street trees in our urban forests. Chionanthus virginicus, the white fringe tree, has also been found to be infested by this insect in other areas of the United States.

The morning will be spent on quick presentations from Rick Harper, UMass Extension Associate Professor and Tawny Simisky, UMass Extension Entomologist, Nicole Keleher of the MA Department of Conservation and Recreation, and Phil Lewis of the USDA’s Animal and Plant Health Inspection Service. Topics will include an overview of our ash tree resource and EAB basics, an update on the status of EAB in Massachusetts, and treatment options for protecting ash trees from EAB. In the afternoon, attendees will have the opportunity to join the speakers outside at the Arcadia Wildlife Sanctuary to view real emerald ash borer damage/infestations in the field. Participants will also have the chance to participate in a trapping demonstration. Mollie Freilicher, MA DCR Community Action Forester, will also join us outside for a sample tree inventory demonstration.

This program is recommended for all communities in Massachusetts, especially but not limited to those now struggling with EAB. Arborists, tree wardens, urban foresters, municipal officials, landscapers, land managers, landowners, and tree enthusiasts are encouraged to attend. The cost of registration is a reduced $25.00 per person, thanks to funding support provided by the Massachusetts Department of Conservation and Recreation and meeting space provided by Mass Audubon. Morning snacks and coffee will be provided. Driving instructions to the Arcadia Wildlife Sanctuary can be found on the web page mentioned above. Three pesticide contact hours for categories 35, 36, and Applicators License are available, and are valid for equivalent categories in all New England states. ISA, MCA, MCH, MCLP, and SAF credits requested.

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

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

The regulated area for Asian longhorned beetle is 110 miles² encompassing Worcester, Shrewsbury, Boylston, West Boylston, and parts of Holden and Auburn. If you believe you have seen damage caused by this insect, such as exit holes or egg sites, on susceptible host trees like maple, or believe you have captured or taken a photo of an adult insect, 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 .

• Deer Tick/Blacklegged Tick: Ixodes scapularis adult females, following a blood meal, can lay a single egg mass (up to 1500 – 2000 eggs) in mid-late May, and then the female deer tick perishes. Larvae emerge from the eggs later in the summer. Larvae are tiny and six-legged. Prior to feeding, they are not known to be able to transmit disease. After feeding, the larvae drop from their host and molt, re-emerging the following spring as nymphs. Nymphs (from last year’s overwintering cohort) are active from May-August. Nymphs are eight-legged and about the size of the head of a pin. These tiny nymphs typically attach to small mammal hosts; however, they will readily feed on people and pets. Nymphs are capable of carrying Lyme disease, human Babesiosis, human Anaplasmosis, and deer tick virus. For images of all deer tick life stages, along with an outline of the diseases they carry, visit: http://www.tickencounter.org/tick_identification/deer_tick .

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

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

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

You can also follow TickReport on Twitter @TickReport for timely updates from the Laboratory of Medical Zoology, including the latest tick and tick-borne disease related research.

• Emerald Ash Borer: (Agrilus planipennis, EAB) 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 most recently, 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. Positive identification of an EAB-infested tree may not be possible with these signs individually on their own.

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

• 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. (Ladybugs have already started entering homes in Hampshire County in small numbers, observed the week of 9/3/2018.) While such invaders do not cause any measurable structural damage, they can become a nuisance especially when they are present in large numbers. 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 shore 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 July depending on climate. Fall webworm caterpillars were reported for 2018 previously in the Pioneer Valley Region report and expanding webs were seen the week of 7/4/18 in Chesterfield, MA. 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.

• Gypsy Moth: Lymantia dispar adult activity is at an end for the 2018 season. The Massachusetts Department of Conservation and Recreation (DCR) has released preliminary numbers for the total acres defoliated by gypsy moth caterpillars in 2018. MA DCR officials estimate that approximately 161,000 acres were defoliated by gypsy moth in 2018. This pales in comparison to the over 923,000 acres of defoliation due to gypsy moth estimated in 2017. (We can thank Entomophaga maimaiga for the population decrease between last year and the beginning of this year.) The acreage number for 2018 is a rough estimate at this time, as state officials are still working on confirming that gypsy moth was responsible for the defoliation they saw from the air, by visiting these locations on the ground to determine that gypsy moth caterpillars were the cause of the defoliation seen. Once final numbers and a map of the 2018 defoliation becomes available, this information will be highlighted in the Landscape Message.

One worrisome note is that Entomophaga maimaiga does not seem to have been as active in the gypsy moth population in 2018 as it was in 2017. This allowed many healthy adult moths to mate and females to lay egg masses that will overwinter and provide us with a population of caterpillars in 2019. More information can be found in the August issue of Hort Notes, which is available here under “Trouble Maker of the Month”: https://ag.umass.edu/landscape/newsletters/hort-notes/hort-notes-2018-vol-298 .

• 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.

• Spotted Lanternfly: (Lycorma delicatula, SLF) is not known to occur in Massachusetts. This insect is a member of the Order Hemiptera (true bugs, cicadas, hoppers, aphids, and others) and the Family Fulgoridae, also known as planthoppers. This insect is a non-native species first detected in the United States in Berks County, Pennsylvania and confirmed on September 22, 2014. Until November 2017, this invasive insect was only known to Pennsylvania. It has now been reported from Delaware (November 20, 2017), New York (November 29, 2017), and Virginia (January 10, 2018). The most recent detection of the spotted lanternfly outside of Pennsylvania is an established population in New Jersey as reported by the New Jersey Department of Agriculture on July 17, 2018.

The Delaware Department of Agriculture announced the finding of a single female spotted lanternfly in New Castle County in the Wilmington, Delaware area. At this time, officials in Delaware note that it is unclear if this individual was an accidental hitchhiker, or evidence of an established population in the state. For more information about the find in Delaware, visit: https://news.delaware.gov/2017/11/20/spotted-lanternfly-confirmed-delaware/ . The New York State Department of Agriculture and Markets reported on November 29, 2017 the finding of a single dead individual spotted lanternfly in the state from earlier in the month. A single dead specimen was confirmed at a facility in Delaware County, New York, which is located south-west of Albany. The NYS Dept. of Agriculture and Markets states that this dead individual may have come in on an interstate shipment. For more information about the find in New York, visit: https://www.agriculture.ny.gov/AD/release.asp?ReleaseID=3637 . Virginia Cooperative Extension announced the finding of a spotted lanternfly population in Frederick County, Virginia, on January 10, 2018. It was noted that at the location in Virginia, numerous adult lanternflies and egg masses were discovered, in addition to more at another site approximately 400 yards away. For more information about the find in Virginia, visit: https://ext.vt.edu/agriculture/commercial-horticulture/spotted-lanternfly.html . Most recently, the New Jersey Department of Agriculture reports spotted lanternfly has been confirmed in portions of Warren County, NJ on July 17, 2018. For more information about the find in New Jersey, visit: https://www.nj.gov/agriculture/news/press/2018/approved/press180717.html .

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

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

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

• Two-marked Tree Hopper: The Enchenopa binotata species complex is now thought to be made up of very closely related Enchenopa spp. that are morphologically very similar but separated by the different host plants that they are found on. These particular treehoppers are found on black walnut, wafer ash (Ptelea trifoliata), and Viburnum. These insects will feed on the host plants with piercing-sucking mouthparts and drink plant juices from the leaves and petioles. Leaves will become shiny and sticky with their excrement. Eggs continue to be laid by adult females, using saw-like ovipositors to insert them into plant stems, at a location observed in Amherst, MA as of 9/5/18. Eggs are covered with a vivid white, sticky, frothy material that protects them but can easily be mistaken for a scale insect. (Particularly when the adult is not present nearby.) These treehoppers, whether by their feeding activity or egg laying behavior into plant stems, are not considered to be damaging pests (even when high in numbers) and therefore management is generally not required.

• Viburnum Leaf Beetle: Pyrrhalta viburni is a beetle in the family Chrysomelidae that is native to Europe, but was found in Massachusetts in 2004. Viburnum leaf beetle egg hatch was observed in Boston, MA on 5/4/2018. By early to mid-June, Viburnum leaf beetle larvae crawl down the host plant, enter the soil surface, and pupate. This typically occurs when the larvae are just under ½ inch in length. After pupation, by early-July, adult beetles will emerge from the soil and begin feeding on Viburnum foliage again prior to mating and laying eggs. Viburnum leaf beetle adults were very active in Amherst, MA, (observed on 8/6/18) spending their days mating and feeding. Adult females are laying the eggs that will overwinter in pits chewed in host plant stems (toward the terminals) and covered with a cap of chewed bark. 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. Larvae, where they are present, may be treated with a product containing spinosad. 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/ .

• Yellowjackets: (Vespula spp. and Dolichovespula spp.) Often times, when we think that we have been “stung by a bee” the true culprit is some type of yellowjacket. Yellowjackets frequently interact with humans at the end of the summer due to a shift in their foraging behaviors. Early in the season, they can act as beneficial insects as they are predators of many pest insects such as caterpillars. These protein resources can be useful to them when rearing their young. Later in the season, they may switch to foods high in carbohydrates or sugars, including nectar and honeydew, but also some of our favorite items to pack during outdoor picnics or cookouts (soda and other sugary treats).

Unlike European honeybees (Apis mellifera), yellowjackets are capable of stinging multiple times (multiple stings from a single individual). This includes aerial yellowjackets such as the baldfaced hornet and other species in the genus Dolichovespula spp. European honeybees (the workers) can only sting once due to the fact that they have a barbed stinger/ovipositor. This causes the ovipositor to become stuck in the skin, tearing this structure free from the abdomen of the honeybee, thus killing the honeybee. Honeybees are often not aggressive and only attack when otherwise threatened. This may not be the case for yellowjackets.

Be on the lookout for their nests, and avoid. Baldfaced hornets and other aerial yellowjackets make aerial nests that are nearly completely covered with a papery shell (except for an opening for entrance/exit of the nest). These can be found in trees and shrubs located up off the ground. Some yellowjackets will also create subterranean nests or nest in cavities of trees, decayed stumps, or associated with buildings. If nests are in areas where these insects are unlikely to interact with humans, they can be left alone. These nests are not used again the following season, and by the first couple of hard frosts, all individuals will be gone. However, if they are close to homes/doorways, walkways, benches, etc. (high traffic areas) management may be necessary, especially if the homeowner/individuals using the property are allergic to stings.

Attempts to remove yellowjacket or baldfaced hornet nests should be made at night, or at least very early or very late in the day when temperatures are still cool, activity by the yellowjackets is likely to be low, and the individuals are likely to still be contained (largely) within the nest. Note that although the insects may not be terribly active, any disturbance to the nest/colony will change that. Wear protective clothing (long sleeves and pants tight around wrists and ankles and close-toed shoes or boots, at minimum). Many insecticides are labelled for use against yellowjackets and baldfaced hornets, including products that can be shot into the opening of the nest from many feet away. Note that agitated yellowjackets may leave the nest, looking for the source of aggravation (you), and will be ready to sting. Use extreme caution, and individuals who are allergic to stings should not attempt this. Hire a professional. Again, if the nest is in a location where interaction with people is unlikely, consider leaving it alone until a few hard frosts have hit, at which time the nest can be removed if desired.

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

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

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

Weeds

Japanese knotweed is in flower and now is the time to manage this invasive plant. Use a 2% spray solution of glyphosate sprayed to the initiation of spray drip. Japanese knotweed often grows near water and in these locations a glyphosate formulation that is labelled for these areas will need to be used. These areas may also need approval of the Conservation Commission as they may fall under the jurisdiction of the Massachusetts Wetland Protection Act. Do not use herbicide formulations that contain diquat (Reward) or tank-mixed pelargonic acid (Scythe) with the glyphosate. Diquat and pelargonic acid are contact herbicides and have the potential to decrease the efficacy of the systemic glyphosate. 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.

Poison ivy can be treated during the month of September. Glyphosate or triclopyr are the best herbicides for poison ivy control. Contact (Scythe, Reward) or the non-chemical/organic herbicide products will provide “burndown” activity only and will not adequately control poison ivy.

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 may need to be made.

Inspect areas of the landscape where new trees or shrubs, especially those that were field grown, have been planted early this season or last year. Look for perennial weeds that may be growing from the root ball. Canada thistle, mugwort, quackgrass, bindweed and horsenettle are some of the possible culprits. These weeds can be spot treated with glyphosate.

Many landscape trees commonly produce vegetative suckers at their truck base. Suckers are commonly seen on crabapples, pear, plum, linden, maple and sometimes oak. Honeylocust will also produce vegetative sprouts along the entire length of their truck. It these suckers or sprouts are not controlled, the landscape will be a contender for the “shabby landscape award”. Pruning is effective but very time consuming. Another option would be used the product Scythe 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 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 can be used as a maintenance program. Products that contain glyphosate should not be used, as glyphosate is a translocated (systemic) herbicide.

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

Plant of the Week

Enjoy the bright yellow stamens of this native grass, lovely in the landscape right now.  http://extension.umass.edu/plant-identification/indian-grass

Bridgit Litchfield reporting for Mandy Bayer

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Diagnostic Services

A UMass Laboratory Diagnoses Landscape and Turf Problems - The UMass Extension Plant Diagnostic Lab is available to serve commercial landscape contractors, turf managers, arborists, nurseries and other green industry professionals. It provides woody plant and turf disease analysis, woody plant and turf insect identification, turfgrass identification, weed identification, and offers a report of pest management strategies that are research based, economically sound and environmentally appropriate for the situation. Accurate diagnosis for a turf or landscape problem can often eliminate or reduce the need for pesticide use. For sampling procedures, detailed submission instructions and a list of fees, see Plant Diagnostics Laboratory

Soil and Plant Nutrient Testing - The University of Massachusetts Soil and Plant Nutrient Testing Laboratory is located on the campus of The University of Massachusetts at Amherst. Testing services are available to all. The function of the Soil and Plant Nutrient Testing Laboratory is to provide test results and recommendations that lead to the wise and economical use of soils and soil amendments. For complete information, visit the UMass Soil and Plant Nutrient Testing Laboratory web site. Alternatively, call the lab at (413) 545-2311.

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