Landscape Message: April 23, 2021

The following data was collected on or about April 21, 2021. Total accumulated growing degree days (GDD) represent the heating units above a 50° F baseline temperature collected via regional NEWA stations for the 2021 calendar year. This information is intended for use as a guide for monitoring the developmental stages of pests in your location and planning management strategies accordingly.

MA Region/Location	GDD		Soil Temp (°F at 4" depth)		Precipitation (2-Week Gain)	Time/Date of Readings
	2-Week Gain	2021 Total	Sun	Shade
CAPE	10.5	31	54	48	1.68	12:00 PM 4/21
SOUTHEAST	17	47	62	53	1.50	3:00 PM 4/21
NORTH SHORE	23.5	56	53	49	0.79	10:00 AM 4/21
EAST	32	69	60	55	2.25	4:00 PM 4/21
METRO	31	64.5	46	45	1.35	6:00 AM 4/21
CENTRAL	36	71	49	45	0.83	7:30 AM, 4/21
PIONEER VALLEY	43.5	79	52	47	2.63	12:00 PM 4/21
BERKSHIRES	31	49	49	44	2.29	8:00 AM 4/21
AVERAGE	28	58	53	48	0.72	_
n/a = information not available

See MA drought status as of April 20 here: https://droughtmonitor.unl.edu/CurrentMap/StateDroughtMonitor.aspx?MA

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.
Cercis canadensis (redbud)	*	*	*	Begin	Begin	*	Begin	*
Amelanchier spp. (shadbush, serviceberry)	Begin	Full	*	Begin/Full	Begin/Full	Begin/Full	Full	Begin
Pyrus calleryana (Callery pear)	Begin	Full	*	Full	Full	Full	Full	Begin/Full
Magnolia soulangiana (saucer Magnolia)	Begin/Full	Full	Full	Full	Full	Full	Full	Full
Prunus serrulata (Japanese flowering cherry)	*	*	Full	Full	Full	Full	Full	Full
Rhododendron 'P. J. M.'	Begin/Full	Full	*	Full	Full	Begin/Full	Full	Full
Forsythia x intermedia (border Forsythia)	Full	Full	Full	Full	Full	Full	Full	Full
Rhododendron mucronulatum (Korean Rhododendron)	*	*	*	Full	Full	Full	Full	Full
Magnolia stellata (star Magnolia)	Full/End	Full	Full	Full/End	Full/End	Full/End	Full	Full
Pieris japonica (Japanese Pieris)	Full	Full	*	Full	Full	Full	Full	Full
* = no activity to report/information not available

General Conditions: The period from April 7 – April 21 had an average temperature of 47˚F with a high of 67˚F on April 20 and a low of 34˚F on April 14; some low-lying areas had frost on April 14. The period had more cloudy days than sunny days, ending with a good stretch from April 18 to April 21 with highs in the 50-60s and sunny. The primary precipitation event was on April 16 which provided 1.68 inches in Barnstable, some locations received close to 2 inches. Some snow fell on April 16 and briefly could be seen as a dusting in the upper Cape area. Plants seen in bloom include hellebore, daffodil, Hyacinth, grape Hyacinth, Pulmonaria, Pachysandra and flowering quince. The earliest peaches are starting to open and apples are in tight cluster.

Pests/Problems: I spotted my first winter moth caterpillar for the season this past week in the shoots of a rose. These caterpillars are very tiny (3-4mm) and difficult to see without magnification when they first emerge. Winter moth populations are not expected to cause defoliation, but holes are likely to be seen in the leaves of host plants. Apples and blueberries grown for production are likely to require some winter moth management. Fall cankerworm has caused some small patches of defoliation the last couple of years, so keep on the lookout for these areas in the next couple of weeks.

Lecanium scale is still present in high numbers in some locations and in other locations appear to be under control by entomopathogenic fungi. Scout for lecanium scale (see photos) to determine whether treatment is necessary, the time to target this insect with dormant oil is upon us.

A recent visit to an area hard hit by black oak gall wasp (Zapatella davisae) many years back yielded several trees with the characteristic swellings and visible signs of the insect in last season’s twig growth. Hemlock woolly adelgid egg masses can easily be spotted at this time. Dieback as a result of last season’s drought is widespread on rhododendrons in unirrigated landscapes. The drought is likely to result in attacks by secondary pests such as bark beetles, borers and fungi on weakened plants.

It is an easy time to spot some of our invasive shrubs as they tend to leaf out just a little earlier than many of our native shrubs, particularly noticeable are the bush honeysuckles. Bush honeysuckle is easy to pull at this time of year when soils are moist. The invasive plant, fig buttercup (Ficaria verna) is in full bloom. Other weeds seen in bloom include hairy bittercress, whitlow grass, Arabidopsis, chickweed, speedwell, common violets and some dandelions. Lawns continue to green-up. Forsythia is in full bloom so now is the time to apply pre-emergent herbicides for crabgrass control. Rabbits are active. Don’t forget to protect yourself from deer ticks.

General Conditions: The weather has been windy and variable. Despite some passing sleet and snow flakes we have been unusually frost-free. The sunny days are inspiring all of us "covid shut-ins" with spring fever. Let's hope that trend continues with no further surprises. It seems we are already behind on rainfall. My town, Dighton, has imposed an outdoor watering ban, effective May 1st. There's irony in being surrounded by wetlands, and still being short on water. That's something to contemplate on Earth Day and improve upon in each home and yard (rain barrels). Lawns are green and growing fast. Asparagus spears are yielding first harvests. Along with plants the insects are emerging. Bumble bees, cabbage moths and very annoying black flies are about. Many of the songbirds are busy nesting. Hummingbirds are back.

Among the many plants in flower I've noticed the following: Acer platanoides (Norway maple), A. rubrum (swamp red maple), Alliara petiolata (garlic mustard), Amelanchier canadensis (shadblow, serviceberry), Betula populifolia (grey birch), Cardamine hirsuta (hairy bittercress), Chaenomeles spp. (flowering quince), Forsythia x intermedia (border Forsythia), Hyacinthoides hispanica (wood Hyacinth), Lamium amplexicaule (henbit, deadnettle), Leucojum aestivum (giant snowbell), Lindera benzoin (spicebush), Lunaria annua (honesty, money plant), Magnolia soulangeana (saucer Magnolia), M. stellata (star Magnolia), Muscari spp. (grape Hyacinth), Narcissus spp. (daffodil), Pieris japonica, (Japanese Andromeda), Phlox subulata (creeping Phlox), Prunus cerasifera (plum), P. persica (peach), Prunus x subhirtella (Higan cherry), Pulmonaria spp. (lungwort), Pyrus spp. (pear), Rhododendron 'P.J.M.', Scilla siberica (Siberian squill), Stellaria media (chickweed), Taraxacum officinale (dandelion), Trillium grandiflorum (great white Trillum), Tulipia spp. (tulip), Viburnum carlesii (Korean spice Viburnum), Vinca minor (periwinkle) and Viola tricolor (Johnny-jump-up, wild violet). Unfortunately, the invasive, non-native plant Ficaria verna (lesser celandine, fig buttercup) is in bloom and outcompeting native ground covers.

Pests/Problems: Scouts report that what may be early emerging deer tick nymphs (usually active in May) are being encountered at this time. Their bodies are approximately 2mm in diameter and you don't have to be in "the brush" to pick them up. If you have been anywhere outdoors, take time to check your clothing immediately, then check your entire body sans clothing as soon as possible. Black flies are abundant and aggressive.

General Conditions: Winter hazels, hellebores and Siberian squill are finishing their bloom now. Among herbaceous plants seen in full bloom are daffodils and bloodroot. Tulips, Epimedium spp. and Lindera benzoin (spicebush) are beginning to bloom.

Pests/Problems: Many people do not realize that recent rain events fall far short of the amount of precipitation we need to relieve this region and most of the state from the continuing “abnormally dry” or “mild drought” conditions. https://droughtmonitor.unl.edu/CurrentMap/StateDroughtMonitor.aspx?MA .  Along with ticks, black flies and mosquitoes are biting.

General Conditions: Over the past two weeks we experienced extreme daytime high temperatures of 77˚F on the 10th and 74˚F on the 20th, while only reaching 40˚F on the 16th. As of April 11, 2021 was on record as the seventh driest first quarter of any calendar year. A spring nor’easter came through on the 16th. We received rain, sleet, a couple of inches of wet snow followed by more rain. In the end, we received 2.2 inches of beneficial precipitation over the course of three days. Turf is greening, spring bulbs continue to emerge and many trees and shrubs are coming into bloom. There is an abundance of color throughout the landscape.

Pests/Problems: Garlic mustard (Alliaria petiolata) seedlings have germinated while second year rosettes are flourishing. Ficaria verna (lesser celandine) has begun flowering. Japanese knotweed has recently emerged and is rapidly gaining in height. Norway maples (Acer platanoides) are in full bloom above as their first-year seedlings are developing in any available space below.

General Conditions: Happy belated Earth Day! Much has happened within the past two weeks since the last report. On April 13^th this area was declared in a moderate drought. Fortunately, since then, we received some precipitation in the form of rain and heavy wet snow. Lawns are greening up and growing especially with the recent rain; leaves and flower buds are expanding; and day length is increasing daily. As of Wednesday, April 21^st, we are at 13 hours and 40 minutes. The average rainfall total for the month of April is 4.16” and I have recorded 1.84” of rain in this area for this month so far. The landscape is filled with color and observed in some stage of bloom this past week were the following woody plants: Amelanchier spp. (shadbush, serviceberry), Cercis canadensis (redbud), C. canadensis ‘Alba’ (white flowering redbud), Chaenomeles speciosa (common flowering quince), Cornus mas (Cornelian cherry dogwood), C. officinalis (Japanese Cornelian cherry), Forsythia spp., Lindera benzoin (common spicebush), Magnolia x loebneri 'Merrill', (Merrill Magnolia), M. x soulangeana (saucer Magnolia), Pieris japonica (Japanese Pieris), Prunus spp. (cherry), Pyrus spp. (pear), Rhododendron mucronulatum (Korean Rhododendron), and R. 'P. J. M.' (PJM Rhododendron).

Contributing even more color and interest to the landscape are some flowering herbaceous plants and spring ephemerals including: Anemone pulsatilla (pasque flower), A. nemorosa (wood anemone), Asarum europaeum (European ginger), Brunnera macrophylla (alkanet), Caltha palustris (marsh marigold), Chionodoxa luciliae (glory of the snow), Crocus spp., Dicentra canadensis (squirrel corn), D. cucullaria (Dutchman's breeches), D. eximia (fringed bleeding heart), D. spectabilis (old fashioned bleeding heart), Epimedium versicolor 'Sulphureum' (yellow flowering barrenwort), Erythronium americanum (yellow trout-lily), Helleborus niger (Christmas rose), Hepatica spp. (liver leaf), Hyacinthus spp. (Hyacinth), Mertensia virginica (Virginia bluebells), Muscari spp. (grape Hyacinth), Narcissus spp. (daffodil), Omphalodes verna (blue-eyed Mary), Pachysandra procumbens (Allegheny spurge), Petasites japonicus (Japanese butterbur), Primula spp. (primrose), Pulmonaria longifolia (lungwort), P. rubra (salmon colored lungwort), Puschkinia libanotica (striped squill), Sanguinaria canadensis (bloodroot), S. canadensis 'Multiplex' (double bloodroot), Scilla siberica (Siberian squill), Tulipa spp. (tulip), Vinca minor (periwinkle), Viola spp. (violet), and Waldsteinia fragaroides (barren strawberry).

Pests/Problems: With the recent rain and snow within the past week, soils are saturated but let’s hope for many more long and soaking April showers. Despite the recent rain and snow, precipitation totals for this area continue to be below monthly averages. As of April 13^th, the Drought Management Task Force declared this area in a moderate drought. Acer platanoides (Norway maple) is in full bloom. This invasive tree is hard to miss now that it is in bloom and its flowers are a bright yellowish-green and are easily seen on trees found growing almost everywhere. Continuing to flourish everywhere in the landscape is the basal foliage of Alliaria petiolata (garlic mustard). Other weeds seen in bloom but without the invasive tendency of the previous two mentioned are: Draba verna (spring whitlow grass), Glechoma hederacea (ground ivy) and Lamium purpureum (purple deadnettle), Stellaria media (common chickweed), and Taraxacum officinale (dandelion). Ticks are active so continue to monitor yourself and others.

General Conditions: Spring has definitely felt pretty typical in the Central Region, with a good mix of high and low temperatures, a bit of snow, but unfortunately too little rain. For this reporting period, we did experience high temperatures well into the 60’s and 70’s, as well as consistent night time low temperatures in the 30’s. A heavy wet snowstorm on Friday, April 16 brought three inches of mush that certainly helped to counteract the limited precipitation we have seen this spring. But, according to the US Drought Monitor, most of the region is abnormally dry, with moderate drought conditions across the northern part of the region. Much is in bloom across the landscape including early and mid-season spring bulbs like daffodils, tulips, and Hyacinths. Our early minor bulbs like Siberian squill are still holding strong thanks to the cooler temperatures. Many of our early spring blooming native species are flowering now, including bloodroot (Sanguinaria canadensis), wood poppy (Stylophorum diphyllum), and Dutchman’s breeches (Dicentra cucullaria). Spring blooming Magnolias are winding down, but cherries are in full bloom across the region. Lawns are actively growing now. Most have required at least one mowing at this point in time.

Pests/Problems: Nothing of note, aside from the lack of precipitation. Obviously, given the cold night time temperatures, it’s still too early in the season to plant tender annuals or to move houseplants outdoors. Ticks are very active, as are mosquitoes.

General Conditions: Spring is chugging along full steam ahead in the Pioneer Valley, with an array of woody plants in bloom and many trees pushing new growth. It’s hard to find any tree or shrub on the UMass campus that isn’t in some stage of flowering or new growth (catalpa aside). Hemlock buds are breaking and pine candles are elongating with mugo and Japanese white ahead of eastern white and limber. The bursting of new growth and increased student activity on campus makes for hopeful times. The first half of April was unseasonably warm and dry throughout southern New England, described in detail here. In the valley, from 4/3 through 4/10 we experienced bright sun and high temperatures in the mid-60s to lower 70s. Since 4/11, conditions have been much more variable, with a heavy dose of cloudy skies, cooler temperatures and rain. The biggest weather event of this reporting period was the late season nor’easter that soaked the region on 4/15 and 4/16. Total rain accumulation (no snow) at the Easthampton gauge was >2.5”. The precipitation was badly needed after several dry and sunny weeks, low humidity and persistent winds. Prior to the soaking, the last significant rainfall (i.e. >0.5”) took place on 3/28. The long duration April nor’easter resulted in several inches of accumulating snow in the hill towns, as temperatures peaked in the low to mid-30s on 4/16. As a result, soil moisture is high as we enter the prime period for spring transplanting. When transplanting trees and shrubs, especially from pots, it’s critical that the roots be properly disentangled and reoriented. This is the best and likely only chance to reset the bad habits that have formed inside of containers. This process can be difficult and some level of root loss and damage is to be expected. Roots above the natural flare and those that will become girdling roots in the years ahead should be pruned out. A bonsai root hook can be a very helpful tool in sorting out the particularly tangled specimens. Poor root form typically does not produce visible symptoms in the canopy for many years to decades. But once trees are mature, these girdling and circling roots may not be correctable. We’re still not out of the woods when it comes to a spring frost, so carefully watch the forecast for nightly lows. That said, according to the long-term forecast, as we enter the last week of April, low temperatures will hover in the 40s and highs will consistently peak in the 60s and 70s. Turf grasses are rapidly greening now that soil temperatures in full sun have reached 50°F. Many residential lawns are getting close to needing their first cut, if they haven’t had one already.

Pests/Problems: The drought-busting rain from the nor’easter relieved the drying soil conditions that were becoming a concern. There are reports of high overwintering survival for the hemlock woolly adelgid. Inspect landscape trees and treat accordingly. White pines with brown needles are scattered across the forest and landscape at this time. May is the month when symptoms of white pine needle damage become most conspicuous. Needles infected last season will turn brown and are prematurely shed from the canopy, peaking around the time when new growth is emerging (late May to early June). As trees and shrubs are flushing new growth, dead shoots and branches are becoming more apparent. Prune and discard these dead parts now, as cankering fungi can be actively dispersing spores on mild and wet days. New and succulent stems can be susceptible to cankering infections. Japanese knotweed is actively growing with shoots reaching 1’ tall already. Other invasive plants like honeysuckle and multiflora rose are also actively growing. White grubs are active and migrating towards the soil surface with the warming temperatures. Gnats, mosquitoes and wasps have been abundant during the warmer days.

General Conditions: If one thing is certain at this time of year, it is the dramatic shift in weather conditions. Temperature wise, the two-week scouting period began with 3 consecutive days reaching the 70 degree mark, as recorded at the Pittsfield Airport. The high for the period was 73˚F on April 10^th. From that point on, daily temperatures rotated every few days from the 40s to the 50 or 60s and back to the 40s. Low temperatures for the period were 33˚F on the 15^th and 16^th at the Pittsfield Airport, 32˚F in Richmond, and 33˚F in North Adams. Those two days were also the wettest. Precipitation fell not only as rain but also as snow. Snowfall varied considerably from the valleys to the higher elevations. Here in West Stockbridge, snowfall amounted to about 3 or 4 inches. Rain mixed with snow during the day on April 16^th and by evening most of the snow had melted, at least at the lower elevations. Total precipitation over the two days amounted to nearly 2 inches or more in most locations. Soils are moist but workable as of the morning of April 21. Perhaps spurred by the warmth of 70-degree temperatures and sufficient soil moisture, the landscape has burst into color with the blossoms of early flowering azaleas, cherries, and Magnolias, with the lingering yellow brilliance of Forsythia. Crabapple flower buds are just about ready to open. Growth of turfgrass has also accelerated and mowing has begun at many sites.

Pests/Problems: Despite some warm days, pest development has been slow. Spruce spider mite was found on dwarf Alberta spruce. The larvae of boxwood leaf miner are very active and numerous when observed by cutting open the epidermis of boxwood leaves. The hatching of eastern tent caterpillars is associated with the timing of Forsythia bloom. However, numerous crabapple trees, a favored host of the caterpillars, were examined on April 21 but no caterpillars were evident as yet. Black-legged tick numbers remain very high and tick attachments and bites have occurred on most everyone working in landscapes or simply taking their dogs for walks. Wasps are also common now. Japanese beetle grubs can be seen in the upper two inches of soil. Weed development, including the ubiquitous dandelion, is thriving at this time. High wind events have been common this year and continue to appear periodically, causing much tree damage. Winds are especially fierce as this report is being compiled on April 21.

• CAPE COD REGION - Russell Norton, Horticulture and Agriculture Educator with Cape Cod Cooperative Extension, reporting from Barnstable.
• SOUTHEAST REGION - Brian McMahon, Arborist, reporting from the Dighton area.
• NORTH SHORE REGION - Geoffrey Njue, Green Industry Specialist, UMass Extension, reporting from the Long Hill Reservation, Beverly.
• EAST REGION - Kit Ganshaw & Sue Pfeiffer, Horticulturists reporting from the Boston area.
• METRO WEST REGION – Julie Coop, Forester, Massachusetts Department of Conservation & Recreation, reporting from Acton.
• CENTRAL REGION - Mark Richardson, Director of Horticulture reporting from Tower Hill Botanic Garden, Boylston.
• PIONEER VALLEY REGION - Nick Brazee, Plant Pathologist, UMass Extension Plant Diagnostic Lab, reporting from Amherst.
• BERKSHIRE REGION - Ron Kujawski, Horticultural Consultant, reporting from Great Barrington.

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

• Dieback of Dark American arborvitae (Thuja occidentalis ‘Nigra’) caused by an infestation of the arborvitae leafminer (Argyresthia thuiella) and subsequent needle and shoot blight caused by Pestalotiopsis and Phyllosticta. Screening row of mature arborvitaes, approximately 15-years-old, that were planted in 2014. The tree spacing is tight, common for arborvitaes, and they receive a mixture of sun and shade with irrigation from lawn sprinklers. Last year, the homeowner noticed dieback in the most heavily shaded area of the hedge. The dieback has since been observed throughout the entire row of trees in 2021. The ALM infestation appeared to be severe, based on the submitted sample. The damaged tips were then colonized by two fungal pathogens that are common on arborvitae. The tight spacing, partial shade and lawn sprinklers likely contributed to the needle and shoot blight outbreak.
• Needle blight and canopy browning of Japanese black pine (Pinus thunbergii) caused by Septorioides strobi. The tree is approximately 15-years-old and has been present at the site for ten years. It resides in a lawn area between a parking lot and street, receiving full sun in predominantly sandy soils. The tree is pruned annually to maintain a pom-pom topiary. This season, extensive browning was observed throughout the canopy and the submitted needles were blighted at the tips. Upon closer inspection, black-colored pads of fungal tissue were found swelling from the blighted needle sections. Clear spore masses extruded from the pads after a brief incubation. Septorioides is better known as a needle blight pathogen of eastern white pine, but can attack a wide array of two- and three-needle pines.
• Severe infestation of the Cryptomeria scale on balsam fir (Abies balsamea) and Canaan fir (A. balsamea var. phanerolepis). Numerous trees, approximately eight-years-old, growing at a Christmas tree farm. Overhead irrigation is provided and soils vary from clay-based to sandy. Scattered trees across the farm exhibited a mottled yellowing on the upper needle surface. On the underside of the needles (abaxial surface), a very severe infestation of this non-native armored scale pest was immediately visible. The Cryptomeria scale continues to spread north and west in Massachusetts, based on previously diagnosed samples that originated from the southeastern portion of the Commonwealth.
• Dieback of eastern hemlock (Tsuga canadensis), due in part to stem cankering by Phomopsis. Mature hemlock in a full sun setting with a confined root zone. Symptoms of dieback include yellowing/browning needles, premature needle shedding and stunted growth. The symptoms were observed in summer of 2020 and later last season the tree was fertilized and treated for the hemlock woolly adelgid and elongate hemlock scale. The submitted branch segments had numerous blighted shoot tips and fine twig mortality. This is often a symptom of Phomopsis stem cankering on eastern hemlock. While this fungus is common on declining trees, several predisposing stresses must first weaken the tree, making them susceptible to attack.
• Decline of eastern white pine (Pinus strobus) caused by Diplodia sapinea. Several white pines at a residential property, all with diameters less than ~15”. Some of the trees have died while others appear fairly healthy. Heavy resin flow was observed on the trunks with sunken lesions and bark discoloration. A large submitted section of the symptomatic bark showed that Diplodia was the causal agent. While more typically a pathogen of two- and three-needle pines, D. sapinea can be an important contributor to decline for eastern white pines stressed by drought and needle blight diseases.

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

Insects and Other Arthropods

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

*Ixodes scapularis adults have been active all winter, as they typically are from October through May, and “quest” or search for hosts at any point when daytime temperatures are above freezing. Engorged females survive the winter and will lay 1,500+ eggs in the forest leaf litter beginning around Memorial Day (late May). 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 .

The UMass Laboratory of Medical Zoology is currently unable to accept samples for tick testing at this time. The Center for Agriculture, Food, and the Environment provides a list of potential tick identification and testing alternatives here: https://ag.umass.edu/resources/tick-testing-resources

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

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

Invasive Insects & Other Organisms Update:

• Spotted Lanternfly: (Lycorma delicatula, SLF) is not known to be established in Massachusetts landscapes at this time. However, due to the great ability of this insect to hitchhike using human-aided movement, it is important that we remain vigilant in Massachusetts and report any suspicious findings. Spotted lanternfly reports can be sent here: https://massnrc.org/pests/slfreport.aspx .

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

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

Now is a great time to provide copies of these BMP’s to employees, customers, family, and friends! The more eyes we have out there looking for spotted lanternfly, the better. Spotted lanternfly egg masses overwinter, and are laid by these insects on just about any flat surface. Use the above BMP’s as a guide to help you inspect certain items coming from CT, DE, MD, NC, NJ, NY, OH, PA, WV, and VA.

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

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

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

For a map of known, established populations of SLF as well as detections outside of these areas where individual finds of spotted lanternfly have occurred (but no infestations are present), visit: https://nysipm.cornell.edu/environment/invasive-species-exotic-pests/spotted-lanternfly/

The spotted lanternfly is considered native to China, India, and Vietnam. It has been introduced as a non-native insect to South Korea and Japan, prior to its detection in the United States. In South Korea, it is considered invasive and a pest of grapes and peaches. The spotted lanternfly has been reported feeding on over 103 species of plants, according to new research (Barringer and Ciafré, 2020) and when including not only plants on which the insect feeds, but those that it will lay egg masses on, this number rises to 172. This includes, but is not limited to, the following: tree of heaven (Ailanthus altissima) (preferred host), apple (Malus spp.), plum, cherry, peach, apricot (Prunus spp.), grape (Vitis spp.), pine (Pinus spp.), pignut hickory (Carya glabra), sassafras (Sassafras albidum), serviceberry (Amelanchier spp.), slippery elm (Ulmus rubra), tulip poplar (Liriodendron tulipifera), white ash (Fraxinus americana), willow (Salix spp.), American beech (Fagus grandifolia), American linden (Tilia americana), American sycamore (Platanus occidentalis), big-toothed aspen (Populus grandidentata), black birch (Betula lenta), black cherry (Prunus serotina), black gum (Nyssa sylvatica), black walnut (Juglans nigra), dogwood (Cornus spp.), Japanese snowbell (Styrax japonicus), maple (Acer spp.), oak (Quercus spp.), and paper birch (Betula papyrifera).

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

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

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

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

• Emerald Ash Borer: (Agrilus planipennis, EAB) Since the New Year, the Massachusetts Department of Conservation and Recreation has confirmed at least 22 new community detections of emerald ash borer in Massachusetts. To date, 11 out of the 14 counties in Massachusetts have confirmed emerald ash borer. (The remaining counties where EAB has yet to be detected are Barnstable, Dukes, and Nantucket counties.)A map of these locations and others previously known across the state may be found here: https://ag.umass.edu/fact-sheets/emerald-ash-borer .

This wood-boring beetle readily attacks ash (Fraxinus spp.) including white, green, and black ash and has also been found developing in white fringe tree (Chionanthus virginicus) and has been reported in cultivated olive (Olea europaea). Adult insects of this species will not be present at this time of year. Signs of an EAB infested tree may include (at this time) D-shaped exit holes in the bark (from adult emergence in previous years), “blonding” or lighter coloration of the ash bark from woodpecker feeding (chipping away of the bark as they search for larvae beneath), and serpentine galleries visible through splits in the bark, from larval feeding beneath. Blonding on EAB infested ash has been particularly noticeable this winter in certain areas of Hampshire and Berkshire counties. Trees have been so heavily fed upon by woodpeckers that this change in the color of ash tree bark can be seen even while driving. (Monitoring for EAB this way is not recommended while operating your vehicle.) Particularly striking photos of blonding on ash caused by pileated woodpeckers were shared with UMass Extension from Lee, MA, courtesy of Cindy Packard on 2/13/2021. It is interesting to note that woodpeckers are capable of eating 30-95% of the emerald ash borer larvae found in a single tree (Murphy et al. 2018). Unfortunately, despite high predation rates, EAB populations continue to grow.

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

• Winter Moth: (Operophtera brumata) data since 2017 has indicated that the winter moth population in eastern Massachusetts has been on the decline while the percent of winter moth pupae parasitized by Cyzenis albicans has increased! This is excellent news, as it is data supporting the evidence that winter moth populations have decreased while the parasitic fly, C. albicans, has become established at many locations in New England. Dr. Joseph Elkinton’s laboratory at UMass Amherst has released this biological control of winter moth since 2005 and conducted the rigorous sampling required to determine where the insect has established and what its impact on the winter moth population has been at multiple sites in eastern MA. More information about the Elkinton Lab’s research and the biological control of winter moth can be found here: https://www.fs.fed.us/foresthealth/technology/pdfs/FHAAST-2018-03_Biology_Control_Winter-Moth.pdf

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

For blueberry growers in eastern Massachusetts concerned about winter moth, please visit this recent update from Heather Faubert, University of Rhode Island: https://web.uri.edu/ipm/2021/04/april-22-winter-moth-update/

• Gypsy Moth: (Lymantria dispar) thanks to the gypsy moth caterpillar killing fungus, Entomophaga maimaiga, the recent outbreak of gypsy moth in Massachusetts has come to an end! Most locations in Massachusetts will not see damaging or even noticeable populations of this insect in 2021. Gypsy moth has been in Massachusetts since the 1860's. This invasive insect from Europe often goes unnoticed, thanks to population regulation provided by the entomopathogenic fungus, E. maimaiga, as well as a NPV virus specific to gypsy moth caterpillars. (And to a lesser extent many other organisms, including other insects, small mammals, and birds who feed on gypsy moth.) However, if environmental conditions do not favor the life cycle of the fungus, outbreaks of gypsy moth caterpillars are possible. (Such as most recently from 2015-2018, with a peak in the gypsy moth population in 2017 in Massachusetts.)

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

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

The regulated area for Asian longhorned beetle is 110 miles² encompassing Worcester, Shrewsbury, Boylston, West Boylston, and parts of Holden and Auburn. If you believe you have seen damage caused by this insect, such as exit holes or egg sites, on susceptible host trees like maple, please call the Asian Longhorned Beetle Eradication Program office in Worcester, MA at 508-852-8090 or toll free at 1-866-702-9938.

To report an Asian longhorned beetle find online or compare it to common insect look-alikes, visit: http://massnrc.org/pests/albreport.aspx or https://www.aphis.usda.gov/pests-diseases/alb/report .

• White Spotted Pine Sawyer (WSPS): Monochamus scutellatus adults can emerge in late May throughout July, depending on local temperatures. This is a native insect in Massachusetts and is usually not a pest. Larvae develop in weakened or recently dead conifers, particularly eastern white pine (Pinus strobus). However, the white spotted pine sawyer looks very similar to the invasive Asian Longhorned Beetle, Anoplophora glabripennis, ALB. ALB adults do not emerge in Massachusetts until July and August. Beginning in July, look for the key difference between WSPS and ALB adults, which is a white spot in the top center of the wing covers (the scutellum) on the back of the beetle. White spotted pine sawyer will have this white spot, whereas Asian longhorned beetle will not. Both insects can have other white spots on the rest of their wing covers; however, the difference in the color of the scutellum is a key characteristic. See the Asian longhorned beetle entry above for more information about that non-native insect.
• Jumping Worms: In recent years, public concern about Amynthas spp. earthworms, collectively referred to as “jumping or crazy or snake” worms, has dramatically increased. University researchers and Extension groups in many locations in the US are finding that these species cause not only forest ecosystem disturbances, but may also negatively impact soil structure and reduce plant growth in gardens and managed landscapes. They do this by voraciously devouring the organic layer of the soil while feeding very close to the soil surface, unlike other species of earthworms. In woodland areas, they can quickly eat all of the leaf litter on the forest floor. Jumping worms also leave a distinct grainy soil full of worm castings. The soil becomes granular and may look like dried coffee grounds.

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

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

Additional resources can also be found here:

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

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

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

Spring Scouting & Preparation for Upcoming Tree & Shrub Insects & Mites:

• Bagworm: Thyridopteryx ephemeraeformis is a native species of moth whose larvae construct bag-like coverings over themselves with host plant leaves and twigs. This insect overwinters in the egg stage, within the bags of deceased females from last season. Eggs may hatch and young larvae are observed feeding around mid-June, or roughly between 600-900 GDD’s. Now is the time to scout for and remove and destroy overwintering bags. In certain areas across MA in 2020, increased populations of bagworms were observed and reported, particularly in urban forest settings and managed landscapes. More information can be found here: https://ag.umass.edu/landscape/fact-sheets/bagworm
• Balsam Twig Aphid: Mindarus abietinus overwinters as a silvery colored egg on host plant twigs. Eggs hatch just prior to budbreak and nymphs feed for a period of time on the undersides of last season’s needles before molting into a wingless stem mother. Stem mothers move to buds just as they open and give “live birth” to second generation nymphs. These second generation nymphs are the most damaging, feeding on new needles as they elongate, causing distortion and stunting. Excessive amounts of honeydew may be produced and cause needles to stick together. Foliar applications, if needed, may be made between 30-100 GDD’s, base 50°F on warm days before budcaps loosen. Inspect the twigs, near the base of needles of Balsam fir, Fraser fir, and other true firs for overwintering eggs and eventually the needles for feeding nymphs. This insect may be most problematic in Christmas tree production. In landscapes, many natural enemies can provide adequate management of this insect.
• Boxwood Leafminer: Monarthropalpus flavus partly grown fly larvae overwinter in the leaves of susceptible boxwood. Yellowish mines may be noticeable on the undersides of leaves. This insect grows rapidly in the spring, transforming into an orange-colored pupa. After pupation, adults will emerge and white colored pupal cases may hang down from the underside of leaves where adults have emerged. Adults may be observed swarming hosts between 300-650 GDD’s, or roughly the end of May through June. Most cultivars of Buxus sempervirens and B. microphylla are thought to be susceptible. If installing new boxwoods this spring, resistant cultivars such as ‘Vardar Valley’ and ‘Handsworthiensis’ are good choices at sites where this insect has been a problem.
• Boxwood Mite: Eurytetranychus buxi overwinter as tiny eggs on boxwood leaves and hatch mid-spring. These mites are tiny (about the size of a period) and difficult to detect. Feeding may cause plants to appear off-color. If management is deemed necessary, the timing for treatment may be between 245-600 GDD’s or roughly the beginning of May.
• Boxwood Psyllid: Psylla buxi feeding can cause cupping of susceptible boxwood leaves. Leaf symptoms/damage may remain on plants for up to two years. English boxwood may be less severely impacted by this pest. Eggs overwinter, buried in budscales, and hatch around budbreak of boxwood. Eggs may hatch around 80 GDD’s. Foliar applications may be made between 290-440 GDD’s. However, the damage caused by this insect is mostly aesthetic. Therefore, no management may be necessary.
• Cankerworms: Alsophila pometaria (fall cankerworm) and Paleacrita vernata (spring cankerworm) are often confused for winter moth (Operophtera brumata). Cankerworm populations in eastern MA, particularly on areas of Cape Cod, were confused for winter moth in 2019. Spring cankerworm adults are active in February and March, and fall cankerworm adults are active in late November into early December. During these times, both species lay eggs. These native insects most commonly utilize elm, apple, oak, linden, and beech. Eggs of both species hatch as soon as buds begin to open in the spring. Caterpillars occur in mixed populations and are often noticeable by mid-May in MA. Young larvae will feed on buds and unfolding leaves. There are two color forms (light green and dark) for caterpillars of both species. Like winter moth, they will drop to the soil to pupate. This usually occurs in June. Fall cankerworm larvae have three pairs of prolegs (one of which is small so it is sometimes referred to as ½) and spring cankerworm have two pairs. (Winter moth caterpillars also have 2 pairs of prolegs.) If populations are large and damage is noticeable on hosts, reduced risk insecticides such as Bacillus thuringiensis Kurstaki or spinosad may target larvae between 148-290 GDD’s.
• Cooley Spruce Gall Adelgid: Adelges cooleyi is a native insect that has a complex life cycle. It has at least five different morphological forms, and requires 2 years and two hosts to complete its normal life cycle. Galls (pineapple shaped/cone-like and at the tips of twigs) are produced on Colorado blue spruce, Engelmann, Sitka, and Oriental spruce and cause needle injury (yellow spots and distortion) to Douglas-fir. Immature females overwinter on spruce near twig terminals. In the early spring, females mature into stem mothers and lay hundreds of eggs on lateral terminals. Upon egg hatch, nymphs migrate to new spring growth and feed at the base of growing needles. Immatures can be targeted on spruce between 22-81 GDD’s (mid-late April). On Douglas-fir, dormant oil applications should be made immediately before budbreak to avoid phytotoxicity. Follow all label instructions.
• Eastern Spruce Gall Adelgid: Adelges abietis is a pest of Norway spruce primarily, but occasionally damages other spruce species such as Colorado blue, white, and red spruce. This adelgid overwinters as a partially grown female, often referred to as a stem mother. This overwintering individual matures around bud break and lay 100-200 eggs. The eastern spruce gall adelgid may be targeted for management between 22-170 GDD’s, base 50°F (mid-April to early-May). This insect is non-native, and was introduced into the United States from Europe before 1900. Galls are small, sometimes pineapple shaped/variable, but produced on the basal portion of the shoots, such that the twig extends beyond the gall. Twig dieback may occur.
• Eastern Tent Caterpillar: Malacosoma americanum eggs overwinter on host plant twigs. Egg hatch typically occurs when wild cherry leaves begin to unfold and young caterpillars may emerge by late-April through the first two weeks in May (90-190 GDD’s). Susceptible hosts include cherry and crabapple. Other host plants whose leaves are fed upon by this native insect can include apple, ash, birch, willow, maple, oak, poplar, and witch-hazel. Prune off and remove egg masses from ornamental host plants by early spring. Eastern tent caterpillars are native to Massachusetts and have many associated natural enemies (parasites and predators) that help regulate populations. Unless these caterpillars are actively defoliating specimen trees in a landscaped setting, we can coexist with this particular herbivore native to our forests.
• Elongate Hemlock Scale: Fiorinia externa is found on eastern, Carolina, and Japanese hemlock, as well as yew, spruce, and fir. The elongate hemlock scale may overwinter in various life stages, and overlap of many developmental stages at any given time can be observed throughout much of the season. Dormant oil applications for this pest can occur according to label instructions in April, roughly between 7-120 GDD’s. Treatments for the crawler, or mobile, stage of this insect may be made in late May through mid-June, or between 360-700 GDD’s, base 50°F. Nitrogen fertilizer applications may make elongate hemlock scale infestations worse.
• Euonymus Scale: Unaspis euonymi is an armored scale that can be found on euonymus, holly, bittersweet, and pachysandra. This insect can cause yellow spotting on leaves, dieback, and distorted bark. Dormant oil applications can be made between 35-120 GDD’s or roughly from mid-April to early-May. For crawlers, early June timing is suggested between 533-820 GDD’s. (Eggs begin to hatch in early June.)
• European Pine Sawfly: Neodiprion sertifer overwinters in the egg stage. Eggs are laid by females the previous season by cutting slits in needles using their ovipositors and depositing 6-8 eggs in each of 10-12 needles. Egg hatch occurs from late-April to mid-May and caterpillars become active roughly between 78-220 GDD, base 50°F. The primary host in MA is Mugo pine but it can be found on Scots, red, jack, and Japanese red pine. It is also found on white, Austrian, ponderosa, shortleaf, and pitch pine when planted near the aforementioned species. This dark colored caterpillar feeds in tight groups and small numbers can be pruned or plucked out of host plants and destroyed. Spinosad products can be used whenever the caterpillars are actively feeding, usually by mid-May and when caterpillars are still small. Bacillus thuringiensis kurstaki is not effective against sawflies.
• Forest Tent Caterpillar: Malacosoma disstria egg hatch occurs between 192-363 GDD’s, base 50°F, by mid-late May and caterpillars may be active for at least 5-6 weeks following. Susceptible hosts whose leaves are fed on by this insect include oak, birch, ash, maple, elm, poplar, and basswood. This native insect has many natural enemies, including some very effective pathogens that typically regulate populations. However, outbreaks of this insect can occur on occasion.
• Hemlock Looper: Two species of geometrid moths in the genus Lambdina are native insects capable of defoliating eastern hemlock, balsam fir, and white spruce. Adult moths lay their eggs on the trunk and limbs of hosts in September and October, and eggs will hatch by late May or early June. (L. fiscellaria caterpillars may be active between 448-707 GDD’s.) Monitor susceptible hosts for small, inch-worm like caterpillars. Where populations are low, no management is necessary. Hemlock loopers have several effective natural enemies.
• Hemlock Woolly Adelgid: Adelges tsugae is present on eastern and Carolina hemlock. The overwintering hemlock woolly adelgid generation (sistens) is present through mid-spring and produces the spring generation (progrediens) which will be present from early spring through mid-summer. HWA, unlike many other insects, does most of its feeding over the winter. Eggs may be found in woolly masses at the base of hemlock needles beginning in mid-March. Each woolly mass is created by a female who may then lay 50-300 eggs. Eggs hatch and crawlers may be found from mid-March through mid-July. Infested trees may be treated with foliar sprays in late April to early May, using Japanese quince as a phenological indicator. Systemic applications may be made in the spring and fall, or when soil conditions are favorable for translocation to foliage. Nitrogen fertilizer applications may make hemlock woolly adelgid infestations worse.
• Imported Willow Leaf Beetle: Plagiodera versicolora adult beetles overwinter near susceptible hosts. Adult beetles will chew holes and notches in the leaves of willow once they become available. Females lay yellow eggs in clusters on the undersides of leaves. Larvae are slug-like and bluish-green in color. They will feed in clusters and skeletonize the leaves. Most plants can tolerate the feeding from this insect, and foliage will appear brown. Repeated yearly feeding can be an issue, in which case management of the young larvae may be necessary. Take care with treatment in areas near water.

Check out Episode 4 of InsectXaminer to see the imported willow leaf beetle in action: https://ag.umass.edu/landscape/education-events/insectxaminer

• Lecanium Scales (Oak): Parthenolecanium quercifex overwinters as a second instar nymph on oak twigs. Females will begin feeding and mature in the spring, from mid-April to early May and eggs may be laid between late May and into June. Eggs hatch in June or early July and crawlers migrate to host plant leaves where they spend the summer and migrate as second instars back to host plant twigs in the fall. Mid-April to early-May (35-145 GDD’s) for dormant oil applications.
• Lily Leaf Beetle: Lilioceris lilii adults overwinter in sheltered places. As soon as susceptible hosts such as Lilium spp. (Turk’s cap, tiger, Easter, Asiatic, and Oriental lilies) and Fritillaria spp. break through the ground, the adult lily leaf beetles are known to feed on the new foliage. (Note: daylilies are not hosts.) Typically, in May, mating will occur and each female will begin to lay 250-450 eggs in neat rows on the underside of the foliage. If there are only a few plants in the garden, hand picking and destroying overwintering adults can help reduce local garden-level populations at that time.

Check out Episode 3 of InsectXaminer to see the lily leaf beetle in action: https://ag.umass.edu/landscape/education-events/insectxaminer

• Magnolia Scale: Neolecanium cornuparvum overwinters as first instar nymphs which are elliptical, and dark slate gray in color and can usually be found on the undersides of 1 and 2 year old twigs. Nymphs may molt by late April or May and again by early June at which time the scales may be purple in color. Eventually nymphs secrete a white powdery layer of wax over their bodies. Dormant oils can be applied between 7-35 GDD’s targeting the overwintering nymphs. Avoid applications to opening buds or blooms.
• Pine Bark Adelgid: Pineus strobi overwinters as an immature which begins feeding during the first days of warm weather in the spring and begins secreting white wax over itself, which can eventually coat the entire trunk of infested trees. Egg laying may begin in April. This insect can be found on the trunk, branches, twigs, and the base of needles on new shoots. Spruce is a secondary host but this adelgid can repeatedly reproduce itself on pine. Wash off bark with a strong jet of water. If necessary, dormant oil applications can be made in mid-late April between 22-58 GDDs. Hosts include eastern white, Scots, and Austrian pines. This insect does little damage to healthy trees and can often be tolerated.
• Snowball Aphid: Neoceruraphis viburnicola eggs overwinter on viburnum twigs and buds. Eggs hatch and this aphid becomes active on certain species of viburnum roughly between 148-298 GDD’s or around redbud bloom. This insect is particularly noticeable on V. opulus, V. prunifolium, and V. acerifolia. Stem mothers, appearing blueish-white, can be found in curled up and distorted foliage. Damage caused by this insect pest is mostly aesthetic.
• Spruce Bud Scale: Physokermes piceae is a pest of Alberta and Norway spruce, among others. Immatures overwinter on the undersides of spruce needles, dormant until late March. By April, females may move to twigs to complete the rest of their development. Dormant oil applications may be made between 22-121 GDDs. Follow all label instructions, as oil may remove the bluish color from certain conifers. Mature scales are reddish brown, globular, 3 mm. in diameter, and found in clusters of 3-8 at the base of new twig growth. They closely resemble buds and are often overlooked. Crawlers are present around June.
• Spruce Spider Mite: Oligonychus ununguis is a cool-season mite that becomes active in the spring from tiny eggs that have overwintered on host plants. Hosts include spruce, arborvitae, juniper, hemlock, pine, Douglas-fir, and occasionally other conifers. This particular species becomes active in the spring and can feed, develop, and reproduce through roughly June. When hot, dry summer conditions begin, this spider mite will enter a summer-time dormant period (aestivation) until cooler temperatures return in the fall. This particular mite may prefer older needles to newer ones for food. When damaging spruce spider mite populations are known from last season, dormant oil applications can be made (when temperatures are appropriate according to label instructions) between 7-121 GDD’s, base 50°F (April). Magnification is required to view spruce spider mite eggs. Tapping host plant branches over white paper may be a useful tool when scouting for spider mite presence. (View with a hand lens.) Spider mite damage may appear on host plant needles as yellow stippling and occasionally fine silk webbing is visible.

Spruce spider mite populations may again build (with subsequent generations) in mid-late May (192-363 GDD’s) and again in late August to mid-September (2375-2806 GDD’s). Continue to scout for spruce spider mites by tapping branches over a white piece of paper or other white surface, then viewing them with a hand lens or other magnification. A general rule of thumb is that if 10 or more spruce spider mites are found per branch (in the absence of predatory mites), chemical management might be necessary (if you are also seeing roughly 10% of the foliage with stippling/discoloration). However, if you are finding light-colored and tear-drop shaped and fast-moving predatory mites, at a ratio of approximately 1 predatory mite: 10 spruce spider mites, these beneficial insect relatives may be able to help naturally keep spruce spider mite populations below damaging levels. It is important to also scout for predatory mites and beneficial insects (hoverfly larvae, lacewing larvae, and lady beetle larvae and adults) while scouting for spruce spider mites, because knowledge of the presence of these beneficial predators will impact your management decisions. Broad spectrum insecticides should not be used to manage spruce spider mites on host plants where predatory mites are present as these chemicals could kill the predatory mites and lead to a subsequent surge in spruce spider mite populations.

• Viburnum Leaf Beetle: Pyrrhalta viburni is a beetle in the family Chrysomelidae that is native to Europe, but was found in Massachusetts in 2004. Viburnum leaf beetle overwinters as eggs laid in capped pits on the newest growth of susceptible viburnum branches. Scout for overwintered eggs and prune out and destroy before they hatch. Egg hatch occurs in late-April to early-May as temperatures warm and foliage becomes available. Monitor for larvae in mid-May (80-120 GDD’s). This beetle feeds exclusively on many different species of viburnum, which includes, but is not limited to, susceptible plants such as V. dentatum, V. nudum, V. opulus, V. propinquum, and V. rafinesquianum. Some viburnum have been observed to have varying levels of resistance to this insect, including but not limited to V. bodnantense, V. carlesii, V. davidii, V. plicatum, V. rhytidophyllum, V. setigerum, and V. sieboldii. More information about viburnum leaf beetle may be found at http://www.hort.cornell.edu/vlb/ .
• White Pine Weevil: Pissodes strobi adults overwinter in sheltered locations in the leaflitter and become active very early in the spring, when daytime temperatures reach 50°F and before the bloom of forsythia (between 7-58 GDDs). Hosts include eastern white pine, Norway spruce, scotch, pitch, and red pine, blue spruce, and white spruce are also susceptible to white pine weevil damage. Adults will begin feeding on bark 7-10 inches below dormant terminal buds. Females will deposit eggs in terminal growth bark, and developing larvae will feed in leaders until they mature in July when pupation occurs in pupal chambers made of wood chips. Management in nurseries or Christmas tree production may be necessary. Target adults between 7-58 GDD’s.
• Woolly Elm Aphid: Eriosoma americanum females lay a single egg in the cracks and crevices of elm bark, where the egg overwinters. Eggs hatch on elm in the spring as leaves are unfolding. Aphids may be active from 121-246 GDD’s, base 50°F on elm. A young, wingless female hatched from the egg feeds on the underside of leaf tissue. This female aphid matures and gives birth to 200 young, all females, without mating. These aphids feed, and the elm leaf curls around them and protects them. By the end of June, winged migrants mature and find serviceberry hosts. Another set of females is produced. These new females crawl to and begin feeding on the roots of serviceberry. Multiple generations occur on the roots of serviceberry through the summer.

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

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