Landscape Message: June 21, 2019

HAPPY SUMMER SOLSTICE!

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 June 19, 2019. Total accumulated growing degree days (GDD) represent the heating units above a 50° F baseline temperature collected via our instruments for the 2019 calendar year. This information is intended for use as a guide for monitoring the developmental stages of pests in your location and planning management strategies accordingly.

MA Region/Location	GDD		Soil Temp (°F at 4" depth)		Precipitation (1-Week Gain)	Time/Date of Readings
	1-Week Gain	2019 Total	Sun	Shade
CAPE	104	453	67	63	2.18	12:00 PM 6/19
SOUTHEAST	101.5	520.5	66	60	2.50	12:00 PM 6/19
NORTH SHORE	100	518	63	58	1.12	9:30 AM 6/19
EAST	106.5	585.5	71	65	0.85	5:00 PM 6/19
METRO	98.5	539	64	61	1.22	5:30 AM 6/19
CENTRAL	95	571.5	60	58	1.20	8:30 AM 6/19
PIONEER VALLEY	100	590	69	62	0.95	1:00 PM 6/18
BERKSHIRES	72	512	66	60	1.73	6:45 AM 6/19
AVERAGE	100	536	66	61	1.47	-

n/a = information not available

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.
Ligustrum spp. (privet)	Begin	Begin	Begin/Full	Begin	Begin/Full	*	Begin/Full	*
Catalpa speciosa (northern Catalpa)	Begin	Begin	Begin/Full	Begin/Full	Begin/ Full	Full	Full	Begin
Syringa reticulata (Japanese tree lilac)	Begin	Begin/Full	Begin/Full	Begin/Full	Begin/Full	Full	Full	Begin/Full
Philadelphus spp. (mockorange)	Full	Full	Full	Full	Full	Full/End	Full	Full
Hydrangea anomala petiolaris (climbing Hydrangea)	Full	Full	Full	End	*	End	End	Full
Kalmia latifolia (mountain-laurel)	Begin/Full	Begin/Full	Begin/Full	Begin/Full	Full	Full	Full	Full
Cotinus coggygria (common smokebush)	Full	Full	*	*	Full/End	Begin	Full	Full
Cornus sericea (red osier dogwood)	Full	Full	Full	*	Full/End	Begin	Full	Full
Chionanthus virginicus (fringe tree)	Full	Full	Full/End	End	Full/End	Full/End	Full/End	Full/End
Cornus kousa (kousa dogwood)	Full	Full	Full	Full/End	Full/End	Full	Full	Full
Kolkwitzia amabilis (beautybush)	Full/End	Full	Full/End	Full/End	Full/End	Full/End	End	Full
Weigela florida (old fashioned Weigela)	Full/End	Full	Full/End	Full/End	Full/End	Full/End	End	Full/End
* = no activity to report/information not available

Regional Notes

Cape Cod Region (Barnstable)

General Conditions: The average temperature over the period from June 12 - June 19 was 64˚F with a low of 51˚F on June 13 and high of 77˚F on June 15. Precipitation fell on 4 days during the period totaling 2.18 inches. Topsoil moisture is adequate (excessive on some soils) and subsoil moisture is adequate. Overall, the period was dominated by cloudy days and high relative humidity.

Pests/Problems: Lecanium scale female adults continue to lay eggs. Lecanium scale adults (4-9mm hemispherical humps) can be found concentrated on twigs of oak, sweet gum and black gum. Some trees with high populations are showing twig dieback, chlorotic growth, and reduced sized leaves. Other insects or damage seen during the period include eastern tent caterpillar damage on black cherry, rose slug sawfly larvae and damage on rose, Viburnum leaf beetle larvae and damage on Viburnum, four-lined plant bug damage on shasta daisy, azalea lacebug on PJM Rhododendron and white spotted sawyers are active. Disease symptoms and signs seen over the period include anthracnose on sycamore (some trees are still completely denuded of leaves), spot anthracnose on dogwood, anthracnose on oak, anthracnose on maple, brown rot on ‘Kwanzan’ cherry, black spot on roses, azalea leaf and flower gall on azalea, tip dieback on Leyland cypress (Pestalotiopsis? Phyllosticta?), Iris leaf spot on bearded Iris, daylily leaf streak on daylily, powdery mildew on Monarda (seems early) and red thread in turf. Slugs, earwigs, and bunnies are causing damage. Weeds in bloom include black medic (Medicago lupulina), cypress spurge (Euphorbia cyparissias), white clover (Trifolium repens), hawkweed (Hieracium pratense) and multiflora rose (Rosa multiflora). Summer annual weeds continue to germinate.

Southeast Region (New Bedford)

There are no regional notes this week.

North Shore (Beverly)

General Conditions: This reporting period was relatively cool for this time of year. Day temperatures were in the low 70s and night temperatures in the mid-50s to the low 60s except on Saturday, June 15 when day temperatures climbed to 80˚F. At Long Hill, approximately 1.12 inches of rainfall was recorded. There is lush growth and lawns and gardens are looking good as a result of periodic rain showers during this period. Trees and shrubs are putting on new growth. Woody plants seen in bloom include: Tulip tree (Liriodendron tulipifera), Chinese tree lilac (Syringa pekinensis), Stewartia (Stewartia rostrata), bigleaf Magnolia (Magnolia macrophylla), privet (Ligustrum spp.), Kousa dogwood (Cornus kousa), Lemoine Deutzia (Deutzia lemoinei), slender Deutzia (Deutzia gracilis), magician Deutzia (Deutzia magicien), Japanese snowbell (Styrax japonicus), beautybush (Kolkwitzia amabilis), and mountain laurel (Kalmia latifolia). Herbaceous plants in bloom include: Peonies (Paeonia spp.), redleaf rose (Rosa glauca), Virginia rose (Rosa virginiana), Baptisia (Baptisia australis), spiderwort (Tradescantia spp.), leopard’s bane (Doronicum spp.), meadowsweet (Filipendula ulmaria), catmint (Nepeta spp.), geranium (Pelargonium spp.), Aruncus (Aruncus dioicus), Allium (Allium spp.) and ox-eye daisy (Leucanthemum vulgare).

Pests/Problems: Oak shothole leafminer damage was observed on oaks. (Please see pest alert in the June 14 Landscape Message). Cedar-quince rust (Gymnosporangium clavipes) was observed on serviceberry (Amelanchier spp.). This rust infects cedar/junipers and a wide range of rosaceous hosts. Avoid planting susceptible cedar and juniper varieties near susceptible rosaceous plants. Rose slug sawfly damage was observed on roses. For a light infestation, a forceful spray of water out of a garden hose can provide control by knocking off and killing many of the soft-bodied larvae. Multiflora rose (Rosa multiflora) continues to bloom and is easy to identify. Weeds in the landscape continue to flourish. Take measures to control weeds before they set seed. Mosquitoes and ticks are very active. Protect yourself with insect repellent when working outdoors, especially at dawn and at dusk.

 

 

 

 

 

 

East Region (Boston)

General Conditions: The region has had moderate temperatures this past week. High temperatures ranged from 58-82˚F, averaging 73˚F. Low temperatures ranged from 50-63˚F, averaging 57˚F. We received 0.85” of precipitation with 0.63” of that falling on June 13. We have a total of 1.77” of precipitation thus far for June. We gained 106.5 GDDs for a total of 585.5 GDDs base 50˚F for 2019. Plants are thriving and putting on new growth. There is an abundance of color throughout the landscape as many perennials, shrubs and trees are flowering.

Pests/Problems: Unwanted vegetation is also thriving under these favorable growing conditions. There has been an abundance of Virginia creeper (Parthenocissus quinquefolia) seedlings germinating in mulched beds. Dodder (Cuscuta spp.) has begun attaching its parasitic tendrils to available plant material. Japanese knotweed (Fallopia japonica) has reached six feet tall. Cedar quince rust is prevalent on serviceberry (Amelanchier spp.) fruit. The Hydrangea leaftier moth caterpillar (Olethreutes ferriferana) has been sewing up the leaves of Hydrangea with a preference for ‘Annabelle’. Squirrels have been maliciously stripping the unripe fruit off cherry and peach trees.

Metro West (Acton)

General Conditions: We welcome the summer season in this week’s report with a gain of 98.5 GDD during this recording period and a total of 1.22” of rain. The historical monthly average rainfall for June is 3.93” and 2.90” of rain has been recorded for this month so far but it’s not over yet! Much is in bloom at this time of the year, including the following woody plants: Buddleia spp. (butterfly-bush), Catalpa speciosa (northern Catalpa), Chionanthus retusus (Chinese fringe tree), C. virginicus (fringe tree), Cornus kousa (Kousa dogwood), C. x rutgersensis 'Ruth Ellen' (Rutgers hybrid dogwood), Cornus sericea (red twig dogwood), Cotinus coggygria (common smokebush), Crataegus spp. (hawthorn), Kalmia latifolia (mountain laurel), Kolkwitzia amabilis (beautybush), Leucothoe axillaris (coast leucothoe), Ligustrum spp. (privet), Liriodendron tulipifera (tulip tree), Philadelphus coronarius (sweet mock orange), Physocarpus opulifolius (common ninebark), P. opulifolius 'Summer Wine' (summer wine ninebark), Potentilla fruiticosa (Potentilla), Rhododendron spp. (Rhododendron/azalea), Rosa spp. (rose), R. rugosa (rose), R. 'Knockout' (knockout family of roses), Rubus spp. (blackberry, bramble, raspberry), Spiraea prunifolia (bridal wreath), Syringa reticulata (Japanese tree lilac), Tilia cordata (littleleaf linden). Viburnum dentatum (arrowwood Viburnum), and Weigela florida (old fashioned Weigela).

Woody vines in bloom are: Clematis spp. (Clematis), Lonicera sempirvirens (trumpet honeysuckle), and Wisteria spp. (Wisteria). Contributing even more color and interest to the landscape are some flowering herbaceous plants including: Achillea millefolium (yarrow), Ajuga reptans (bugleweed), Alchemilla mollis (lady’s mantle), Allium spp. [ornamental flowering onion, including A. giganteum (giant onion)and A. schoenoprasum (chives)], Amsonia hubrichtii (Arkansas blue star), Aquilegia vulgaris (columbine), Aruncus aethusifolius (dwarf goat's beard), A. dioicus (goat’s beard), Baptisia australis (false blue indigo), Campanula persicifolia (peach-leafed bell flower), C. takesimana ‘Elizabeth’ (bellflower), Clematis recta 'Purpurea' (clematis), Chrysogonum virginianum (green and gold), Coreopsis spp. (tickseed), Dianthus deltoides (maiden pink), Dicentra eximia (fringed bleeding heart), Digitalis purpurea (foxglove), Geranium cantabrigiense 'Biokovo' and 'Cambridge' (hardy cranesbill), Geranium maculatum (wild geranium), G. macrorrhizum (bigroot geranium), G. sanguineum (bloody cranesbill), Hemerocallis 'Stella D'Oro' (daylily), Hemerocallis spp. (daylily), Heuchera spp.(coral bells), Iris germanica (bearded Iris), I. sibirica (Siberian Iris), I. versicolor (blue flag Iris), Leucanthemum x superbum (shasta daisy), Lilium spp. (lily), Lupinus 'Russell Woodfield Hybrids' (lupine), Lychnis coronaria (rose campion), Nepeta spp. (ornamental catmint), Oenothera macrocarpa (Ozark sundrops), Paeonia spp. (peony), Penstemon digitalis 'Husker Red' (beardtongue), Phlox divaricata (Canadian phlox), Primula spp. (primrose), Salvia nemerosa (Salvia), Saponaria ocymoides (rock soapwort), Stachys byzantina (lamb’s ear), Tradescantia spp. (spiderwort), Thymus praecox (thyme), Veronica spp. (speedwell), and Vinca minor (periwinkle).

Pests/Problems: Branches are heavy and hanging low with foliage and/or flowers that are also compounded with the weight of the rain. Observed in the landscape this past week was fall webworm feeding on elm and anthracnose on sycamore. Rosa multiflora, an aggressive invasive vine remains in full bloom and is very easy to detect with its abundant white flowers and is seen growing in and amongst other trees and shrubs planted and/or in the wild landscape.

Central Region (Boylston)

General Conditions: Beautiful conditions for the past week prevailed. With highs in the 70’s, lows in the 60’s and humidity, we creep toward the point of needing the air conditioner. We had light precipitation here which kept beds and new plantings moist - no need to be watering either vegetable or flower gardens. Summer flowers are starting to break bud on Hydrangea and Spirea, while vibrant kousa dogwoods, Baptisia, and mountain laurel are in full swing.

Pests/Problems: Multiflora rose (Rosa multiflora) are currently in bloom, an excellent time to begin removal while easy to identify. Chances are if it’s vivacious, healthy, without insect damage and has clusters of white flowers, it is multiflora rose. Gypsy moth caterpillars were spotted turning witch hazel foliage into swiss cheese. Gypsy moth is still prevalent on most trees. Mosquitoes continue to be abundant, seeking refuge in the forest then coming out as soon as the wind dies down and a bit of shade presents itself. Don’t forget the natural bug spray!

Pioneer Valley Region (Amherst)

General Conditions: Mild weather with scattered rain showers characterized this past reporting period in the Pioneer Valley as we reach the summer solstice and the zenith of day length. High temperatures were mostly below-average for the week, ranging from 62°F to 83°F, while low temperatures spanned 49°F to 66°F. Dew points were on the rise over this period, hovering in the lower to middle 60s from 6/16 through 6/19. This resulted in some humid and clammy, late June weather. The mild temperatures, high relative humidity and cloud cover with occasional rain, provides ideal conditions for many fungal and bacterial pathogens in the landscape. Despite the unsettled conditions, rainfall accumulations were not significant throughout much of the valley. Soil temperatures remained pretty much the same from the last reporting period. Soils remain fairly moist in most settings but the recent rainfall has not been sufficient to water newly transplanted trees and shrubs. Continue to provide supplemental water on a weekly basis. This is especially true for plants with a dense, fibrous root mass, such as Rhododendron, azalea and blueberry. The root mass can be so dense that water is not absorbed in the center of the mass, so ensure these plants are receiving a soaking irrigation until established. The long-term forecast calls for more scattered rain showers and increasing temperatures. The light but regular rain has been beneficial for lawns and turf grasses remain green and growing despite some browning.

Pests/Problems: The rain and cloudy weather with high humidity should allow apple scab to continue spreading within infected tree canopies. Leaf shedding of interior canopy leaves is starting to increase for trees monitored on the UMass campus. Scout for and treat for black vine weevils infesting Rhododendron. The half-moon-shaped notching on the leaf margins is the best indication of their presence. Also, prune out and discard Rhododendron leaves with brown leaf margins as they can harbor the fungus Pestalotiopsis (cause of grey leaf blight). The assemblage of strange and varied leaf aphids and eriophyid mites is on full display right now. These are mostly trivial pests but their actions are highly conspicuous. One in particular, the witchhazel cone gall aphid, was recently observed. These large, horned galls prominently protrude from the upper leaf surface. Sycamore continue the struggle to leaf out due to sycamore anthracnose. For many, they can’t remember a season when the disease was this destructive on American sycamore. Bacterial wetwood is fresh and streaming on select hardwoods, such as elm, poplar, and horsechestnut, among others. The streaming is most readily found on large basal cracks and seams. Oaks injured by the oak shothole leafminer continue to be seen throughout the Pioneer Valley. The damage is insignificant for many oaks but it’s also easy to find trees with serious leaf mining and blotching. While oak anthracnose is the disease most benefiting from the infection sites at this time, later in the season Tubakia leaf blotch may become more important. This late season foliar disease of oak was very abundant in 2018 due to the ample late season rain.

Berkshire Region (Great Barrington)

General Conditions: Another wet week but temperatures have moderated and both daytime and night time temperatures are near normal. For the most part this spring, rains have been frequent but not torrential. One of the heaviest rains fell on Sunday, June 16 when 1. 36 inches was measured. Noticeably, humidity is starting to build as temperatures are gradually increasing. Lightning bugs have made their appearance and bears are on the move as there have been numerous sightings of late, including in many home yards. Soil moisture remains high. Watering of turfgrass and landscape plantings has as yet not been needed. The forecast is for a warming trend but, again, with frequent showers at least over the next few days. Rosa multiflora dominates roadsides and field edges. With its abundant display of blooms, it stands out in the unmanaged landscape and it’s easy to understand why it is such an aggressive invasive species. Turfgrass has thrived to this point, no doubt benefitting from frequent rains and relatively cool temperatures.

Pests/Problems: Despite the rain, incidence of plant diseases has not been common, though that may change with increasing temperatures and humidity. Diseases observed include black spot and rose mosaic virus on the foliage of roses, apple scab and cedar apple rust on crabapples, and Weir’s spruce cushion rust which is now infecting this season’s needles on spruce. Azalea gall on Rhododendron was reported to this scout. Insects observed include linden aphid on silver linden (Tilia tomentosa), boxwood leaf miner adults, and imported willow leaf beetle adults. The waxy fibers of boxwood psyllids can be seen in cupped leaves of new growth on boxwood. Wilting shoots were found on “Black Lace” elderberry (Sambucus nigra), usually an indication of elderberry borer (Desmocerus palliatus), but no sign of the borers could be found. Slug population is high, most likely due to the wet weather. The slugs are devouring seedlings in gardens. Millipede population is also high and found in similar sites as the slugs. Mosquitoes are now very abundant as are deer ticks.

Regional Scouting Credits

• CAPE COD REGION - Russell Norton, Horticulture and Agriculture Educator with Cape Cod Cooperative Extension, reporting from Barnstable.
• SOUTHEAST REGION - Kristin McCullin, Horticulturist reporting from Haskell Public Gardens, New Bedford.
• 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 UMass Amherst.
• BERKSHIRE REGION - Ron Kujawski, Horticultural Consultant, reporting from Great Barrington.

Woody Ornamentals

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

Diseases

Infestation of the boxwood leafminer (Monarthropalpusi flavus) on littleleaf boxwood (Buxus microphylla). Plants are three-years-old and were transplanted nine months ago at a residential property. Yellow-colored spots developed on the upper surface of the foliage this spring, a distinct symptom of leafminer infestation. Leaf mining injury, exit holes and pupal cases were abundant on the underside of the foliage (see photo). Because these boxwoods were transplanted in autumn of 2018, the plants were purchased with an established infestation of this common boxwood pest.

Needle yellowing and branch dieback of a two-needle pine (most likely a mugo; Pinus mugo) caused by Cenangium ferruginosum and Septorioides strobi. Several hard pine samples have been submitted to the lab this season harboring Cenangium, which is considered an uncommon pathogen on the landscape. This fungus produces large and distinctive fruiting bodies known as apothecia that rupture through infected stems and branches (see photo). What is perplexing about the higher number of samples this season is that Cenangium most often attacks drought-stressed pines and moisture was ample in 2017 and 2018. Winter injury may be the predisposing stress facilitating disease development. This tree is approximately 10-years-old and did not show symptoms of cankering and needle blight in previous years.

Birch anthracnose, caused by the fungal pathogen Ophiognomonia. Four large birch (Betula sp.) in a residential landscape prematurely shedding a large volume of leaves. According to the managing landscaper, the customer is rather annoyed with the mess of falling leaves at this time. Trees are approximately 35-years-old and have a limited rooting zone. Shade is abundant which is helping to facilitate the anthracnose outbreak. Several species of Ophiognomonia can be responsible for birch anthracnose and little is known about the virulence of individual species by host. While not as common as maple or oak anthracnose, birch anthracnose can result in significant leaf shedding in the right setting, as is the case here.

Lower branch dieback of white spruce (Picea glauca) due to Stigmina needle cast and Rhizosphaera needle cast. The tree is 25-years-old and has been present at the site for 15 years. Tree is part of a dense, double row of evergreens that serve as a screen at a residential property. As a result, the lower branches are heavily shaded and have been declining in recent years. The upper canopy appears healthy but the soils are poorly drained. When Stigmina and Rhizosphaera co-occur, significant needle shedding can ensue. No stem cankering pathogens were found but may be present in other areas of the canopy.

Branch tip dieback throughout the canopy of a weeping cherry (Prunus sp. 'Pendula') due to brown rot (Monilinia fructicola) and stem cankering from Botryosphaeria. Tree is approximately 35-years-old and resides in a full sun setting. Brown rot has been very abundant this year, establishing on the flowering parts of cherry and then progressing into the shoot tips. Secondary stem cankering fungi like Botryosphaeria are very common on cherry and numerous samples are submitted to the lab each year.

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

Insects

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

• Gypsy Moth:(Lymantria dispar) host plants include but are certainly not limited to oak (favored), maple, birch, poplar, elm, witch hazel, and many others. Gypsy moth caterpillars typically begin to pupate at this time in Massachusetts. Pupation should be observed and adults may begin to appear by next week or the beginning of July. Once pupation occurs, the insect will no longer feed for the current season, and management is no longer necessary or feasible. Adult moths do not feed. Caterpillars were still seen resting in hidden areas on trees in Amherst, MA on 6/19/19.

The adult male gypsy moth is brown with black markings and highly feathered antennae. Adult male gypsy moths can fly. The adult female gypsy moth is white with black markings and straight, threadlike, black antennae. In Massachusetts, female gypsy moths do not fly (in other parts of the world, certain types of gypsy moths have females capable of flight). After the adults mate, the female moths will begin to lay the egg masses (tan/brown and spongy) which will overwinter.

• 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 .

• Boxwood Psyllid: Cacopsylla buxi produces cupping of the leaves of American boxwood. Nymphs, covered in long threads of wax, feed on newly developing leaves in the spring. As the cupped leaves form, nymphs are protected from horticultural oil and insecticidal soap applications. Nymphs use these sheltered areas to continue feeding until late May and early June. One generation occurs per year. Adults lay the overwintering eggs near bud scales in the early summer. Damage from previous feeding by the boxwood psyllid was observed on 6/12/19 in Boylston, MA. Cupped leaves could be found on Buxus spp.‘Green Gem’, but the extent of the distorted leaves on the plants was minimal. Most Buxus sempervirens cultivars are preferred and thus damaged, whereas English boxwoods rarely are damaged by the psyllid. However, the injury caused by this insect is primarily aesthetic. It is not typically as damaging as injury caused by the boxwood leafminer (Monarthropalpus flavus), the adult flies of which typically emerge in late May to early June between roughly 300-650 GDD’s. Eggs are laid in the upper side of the current season’s leaves and hatch in roughly 3 weeks. Larvae feed within the leaves, which may become yellow and spotted and drop prematurely. Over multiple seasons, twig dieback may occur. Partially grown larvae overwinter. This insect attacks most cultivars of Buxus sempervirens and B. microphylla. Buxus sempervirens ‘Vardar Valley’ is considered to be resistant to the boxwood leafminer. Mined leaves from the boxwood leafminer were observed on 6/12/19 in Boylston, MA. Leaf mines could be found on Buxus spp.‘Green Gem’, along with shed pupal “skins” stuck to the leaves, indicating that the adult fly had emerged.

• Cottony Taxus Scale: Pulvinaria floccifera, also referred to as the cottony Camellia scale, utilizes such hosts as Taxus, Camellia, holly, Hydrangea, Japanese maple, Euonymus, Magnolia, and jasmine, among others. Females have laid the long, narrow, white and fluted egg sac that makes them much more noticeable. Eggs will hatch over an extended period of 6 weeks and crawlers may be treated between 802-1388 GDD’s. This insect can cause the host to appear off-color. They also produce honeydew which promotes sooty mold growth. Dieback is not common with this insect. Target the underside of the foliage. Horticultural oil, neem oil, and insecticidal soaps may be used to manage these soft scales. Reduced risk options help preserve natural enemies.

• Deer Tick/Blacklegged Tick: Check out the archived FREE TickTalk with TickReport webinars available here: https://ag.umass.edu/landscape/education-events/webinars . The next live webinar will be held on October 9, 2019 with Dr. Stephen Rich of the UMass Laboratory of Medical Zoology. Previous webinars including information about deer ticks and associated diseases, American dog ticks and lone star ticks and associated diseases, ticks and personal protection, and updates from the Laboratory of Medical Zoology are archived at the link above.

Deer tick (Ixodes scapularis) nymphs (immatures) are active at this time, and may be encountered now through August. 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. The deer tick or blacklegged tick can transmit Lyme disease, human babesiosis, human anaplasmosis, and other diseases. Preventative activities, such as daily tick checks, wearing appropriate clothing, and permethrin treatments for clothing (according to label instructions) can aid in reducing the risk that a tick will become attached to your body. If a tick cannot attach and feed, it will not transmit disease. For more information about personal protective measures, visit: http://www.tickencounter.org/prevention/protect_yourself .

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

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

• Eastern Tent Caterpillar: Malacosoma americanum caterpillars have finished feeding. Adult moths typically appear by the end of June to early July.

• Elongate Hemlock Scale: Fiorinia externa is found on eastern, Carolina, and Japanese hemlock, as well as yew, spruce, and fir. Overlap of many developmental stages at any given time can be observed. Treatments for the crawler, or mobile, stage of this insect may be made in late May through mid-June, or between 360-700 GDD’s, base 50°F.

• Emerald Ash Borer: (Agrilus planipennis, EAB) Three additional communities have had emerald ash borer confirmed by the Massachusetts Department of Conservation and Recreation. This brings the 2019 count to 29 new communities added to the list of known areas where this insect occurs in the state. 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, 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 (at this time) 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: https://massnrc.org/pests/pestreports.htm.

• Euonymus Caterpillar: Yponomeuta cagnagella is of European origin and widespread in distribution throughout Europe. It was first reported in North America in Ontario in 1967. Euonymus caterpillars have mostly all pupated at a location being observed in Amherst, MA as of 6/17/19. The white, elongated and oval-shaped cocoons created by pupating caterpillars can be found within webs on branches and leaves, in the grass beneath infested host plants, and sheltered areas nearby. Adult moths are anticipated to begin to emerge within the next week or so.

The Euonymus caterpillars (larvae) feed in groups and envelop the foliage of the host plant in webs as they feed. Hosts include: Euonymus europaeus (tree form), E. kiautschovicus, E. alatus, and E. japonicus. Mature caterpillars are just under an inch in length, creamy yellow-gray in color with black spots and a black head capsule. By late June, these larvae pupate in white, oval-shaped cocoons which are typically oriented together vertically either on host plants or non-hosts in the area. Cocoons can be found in cracks and crevices, or webbed together leaves. The adult moth emerges in late June in most locations. The adult female secretes a gummy substance over her eggs which will harden, making them even more difficult to see. Eggs hatch by mid-August, at which time the tiny larvae prepare to overwinter beneath their eggshell-like covering. These larvae are inactive until the following year, when caterpillars group together to feed on newly emerging leaves, creating a mess of webs as they feed. There is one generation per year. Plants may be partially or entirely defoliated. Management of young, actively feeding caterpillars with Bacillus thuringiensis is possible if deemed necessary, however many species of Euonymus are considered invasive themselves.

• Imported Willow Leaf Beetle: Plagiodera versicolora adult beetles overwinter near susceptible hosts. A few adult imported willow leaf beetles were seen feeding on willow foliage in Chesterfield, MA on 5/11/19 and no mating or egg laying was seen at the time.By 5/22/19, it was very easy to spot adult imported willow leaf beetles feeding and mating, as well as the damage they cause to the leaves. Egg laying was also observed on 5/22/19. On 5/29/19, feeding adult beetles and clusters of eggs were still observed. No larvae were yet seen at this particular location at that time. However, by 6/2/19, clusters of eggs hatched and tiny, feeding imported willow leaf beetle larvae could be seen. These yellow-ish larvae skeletonize the leaf in groups. Larvae were observed feeding on Japanese pussy willow and corkscrew willow on 6/12/19 in Boylston, MA. Extensive skeletonization of leaves was occurring on the corkscrew willow, in particular, at this location. See Regional Reports above for further updates. Larvae are slug-like and bluish-green to yellow in color. They will feed in clusters and skeletonize the leaves. Most plants can tolerate the feeding from this insect, and foliage will appear brown. Repeated yearly feeding can be an issue, in which case management of the young larvae may be necessary. Take care with treatment in areas near water.

• Lace Bugs: Corythucha spp.and Stephanitis spp. lace bugs are active. Corythucha spp. utilize many hosts such as: hawthorn, cotoneaster, Amelanchier, quince, Pyracantha, various oaks, birch, maple, mountain ash, sycamore, hackberry, elm, walnut, butternut, basswood, etc. 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. Systemic insecticides applied after bloom have been reported as effective. Be aware of the implications this may have on pollinators attracted to these flowering plants when making management decisions. Certain azalea and Andromeda cultivars may be less preferred by lace bugs.

• Lily Leaf Beetle: Lilioceris lilii adults overwintered in sheltered places. Although adult beetles were not seen during the chilly weather on 5/13/19 in Amherst, MA, previously laid eggs were found on host plant foliage in this location. As of 5/21/19, egg hatch had occurred and larvae of various sizes could be seen feeding on foliage in groups. Smaller larvae skeletonize leaves, whereas larger larvae can eat the entire leaf.By 5/30/19, large lily leaf beetle larvae were observed eating entire leaves. Conditions were also favorable to see adults mating, and eggs could also still be found at this location on 5/30. On 6/3/19, adult lily leaf beetles, eggs, and larvae of various sizes were still seen on host plants. Susceptible hosts include Lilium spp. (Turk’s cap, tiger, Easter, Asiatic, and Oriental lilies) and Fritillaria spp. (Note: daylilies are not hosts.) Typically, in May, mating will occur and each female will begin to lay 250-450 eggs in neat rows on the underside of the foliage. If there are only a few plants in the garden, hand picking and destroying overwintering adults can help reduce local garden-level populations.

• Roseslugs: Although two species of sawfly are typically termed “roseslugs”, one in particular, Endelomyia aethiops, may be problematic on Rosa spp. in Massachusetts at this time. Larval roseslug sawflies were seen skeletonizing the upper leaf surfaces of Rosa spp. at a location in Boylston, MA on 6/12/19. These insects are native to the Northeast. The adult female sawfly inserts her eggs, one by one, into the edges of host plant leaves. These eggs hatch and the larvae feed through the end of June, skeletonizing upper leaf surfaces. Once the caterpillars are fully grown (approximately ½ inch in length), they drop to the ground to construct overwintering cells. Pupation occurs the following spring and adults emerge shortly thereafter. There is one generation per year. Btk will not manage sawflies, as they are members of the Hymenoptera, not the Lepidoptera.

• Spotted Lanternfly: (Lycorma delicatula, SLF) is not known to occur in Massachusetts landscapes (no established populations are known in MA at this time). However, officials with the Massachusetts Department of Agricultural Resources (MDAR) urged residents to check plants for spotted lanternfly. On February 21, 2019 MDAR announced the discovery of a single dead spotted lanternfly adult at a private residence in Boston. As a result of this discovery, officials asked the public to check potted plants they purchase and report any suspicious insects. MDAR reports that this particular individual appeared to have been unintentionally transported this past December in a shipment of poinsettia plants originating from Pennsylvania. Officials also report that there is currently no evidence that this pest has become established in MA. For more information about this finding, please visit the MA Department of Agricultural Resources press release:https://www.mass.gov/news/state-agricultural-officials-urge-residents-to-check-plants-for-spotted-lanternfly .

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

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

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

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

• Taxus Mealybug: Dysmicoccus wistariae was spotted on Taxus in Amherst on 5/30/19, 6/3/19, and again on 6/19/19. This insect will produce honeydew that can lead to sooty mold growth, yellowing of needles, and sparsely foliated plants. Eventual dieback may be possible. This species is commonly associated with Taxus in New England, but can be occasionally found on dogwood, Rhododendron, Prunus spp., maple, Andromeda, and crabapple. These mealybugs are found on stems and branches and particularly like to congregate at branch crotches. Management may be targeted between 246-618 GDD’s. Horticultural oil and neem oil may be used according to label instructions.

• Viburnum Leaf Beetle: Pyrrhalta viburni is a beetle in the family Chrysomelidae that is native to Europe, but was found in Massachusetts in 2004. See Regional Reports above for updates regarding the activity of this pest. In Amherst, MA on 6/17/19, plants being monitored for the presence of this pest were devoid of feeding larvae. This is the time of year that Viburnum leaf beetle larvae, when they are approximately 10-11 mm. long, crawl down the shrub, enter the soil, and pupate. Once this occurs, feeding stops (pauses) until the adult beetles emerge in early July. At that time, adult beetles will resume feeding, mate, and the females will lay their eggs in pits they chew at the ends of twigs. Eggs overwinter. Adults may also migrate to previously not yet infested plants. 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 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/ .

• White Spotted Pine Sawyer (WSPS): Monochamus scutellatus adults can emerge now throughout July, depending on local temperatures. This is a native insect in Massachusetts and is usually not a pest. Larvae develop in weakened or recently dead conifers, particularly eastern white pine (Pinus strobus). However, the white spotted pine sawyer looks very similar to the invasive Asian Longhorned Beetle, Anoplophora glabripennis, ALB. ALB adults do not emerge in Massachusetts until July and August. Beginning in July, look for the key difference between WSPS and ALB adults, which is a white spot in the top center of the wing covers (the scutellum) on the back of the beetle. White spotted pine sawyer will have this white spot, whereas Asian longhorned beetle will not. Both insects can have other white spots on the rest of their wing covers; however, the difference in the color of the scutellum is a key characteristic. See the Asian longhorned beetle entry above for more information about that non-native insect.

• Woolly Apple Aphid: Eriosoma lanigerum may be found on apple, crabapple, hawthorn, mountain-ash, Pyracantha, and elm hosts. The primary (winter) host is elm, on which aphids infest emerging spring leaves, causing leaves to curl or close into stunted, rosette-like clusters found at twig tips. Woolly apple aphid was observed on elm on 6/3/2019 in Amherst, MA. Rosettes at this location are full of honeydew producing aphids.On apple and crabapple, this species of aphid colonizes roots, trunks, and branches in the summer and is commonly found near previous wounds or callous tissue. On roots, the aphids cause swelled areas which can girdle and kill roots. The aphids, when found in above ground plant parts such as elm leaves, are covered with white wax. Eggs are the overwintering stage on elm, which hatch in the spring in time for the nymphs to infest new elm foliage. Following a few generations on elm, the aphids will develop into a winged form, which will disperse and seek out apple and crabapple. Multiple generations will occur on these alternate hosts in the summer and by the fall, a winged form will return to elm and mated females will lay eggs near elm buds.

• Woolly Elm Aphid: Eriosoma americanum females lay a single egg in the cracks and crevices of elm bark, where the egg overwinters. Eggs hatch on elm in the spring as leaves are unfolding. A young, wingless female hatched from the egg feeds on the underside of leaf tissue. This female aphid matures and gives birth to 200 young, all females, without mating. These aphids feed, and the elm leaf curls around them and protects them. Curled leaves, due to the activity of the woolly elm aphid, were observed in Amherst, MA on 5/30/19. Opening these curled leaves revealed ample numbers of honeydew producing aphids within. By the end of June, winged migrants mature and find serviceberry hosts. Another set of females is produced. These new females crawl to and begin feeding on the roots of serviceberry. Multiple generations occur on the roots of serviceberry through the summer.

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

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

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

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