Landscape Message: April 5, 2024

UMass Extension's Landscape Message is an educational newsletter intended to inform and guide Massachusetts land care professionals in the management of our collective landscape. Detailed reports from scouts and Extension specialists on growing conditions, pest activity, and cultural practices for the management of woody ornamentals, trees, and turf are regular features. The following issue has been updated to provide timely management information and the latest regional news and environmental data. 

Welcome to Landscape Message #2 for the 2024 growing season.  The next message will be published in two weeks, on April 19.  To receive immediate notification when the next Landscape Message update is posted, be sure to join our e-mail list 

To read individual sections of the message, scroll down to see the different section headings. The collapsible headings are unavailable while we undergo a software upgrade.

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Scouting Information by Region

Environmental Data

The following data was collected on or about April 3, 2024. Total accumulated growing degree days (GDD) represent the heating units above a 50ºF baseline temperature collected via regional NEWA stations (http://newa.cornell.edu) for the 2024 calendar year. This information is intended for use as a guide for monitoring the developmental stages of pests in your location and planning management strategies accordingly.

MA Region/Location	2024 Growing Degree Days		Soil Temp (°F at 4" depth)		Precipitation (Gain in inches since last report)	Time/Date of Readings
	Gain since last report	2024 total	Sun	Shade
CAPE	0	1	43	43	3.82	12:00 PM 4/3/2024
SOUTHEAST	2	6	46	43	5.20	3:00 PM 4/3/2024
NORTH SHORE	0	0	44	41	2.90	10:00 AM 4/3/2024
EAST	0	2	45	42	3.59	4:00 PM 4/3/2024
METRO	0	2	42	40	2.08	6:30 AM 4/3/2024
CENTRAL	0	1	41	41	5.21	8:00 AM 4/3/2024
PIONEER VALLEY	0	3	46	44	3.72	1:00 PM 4/3/2024
BERKSHIRES	0	0	42	39	3.26	9:00 AM 4/3/2024
AVERAGE	0	2	44	42	3.72	-
n/a = information not available

 

US Drought Monitor:  No change from our report from two weeks ago... in Massachusetts, only Nantucket island has an official drought designation at this time, classified as D1 (Moderate Drought).  State map as of Thursday 4/4: https://droughtmonitor.unl.edu/CurrentMap/StateDroughtMonitor.aspx?MA

Phenology

Indicator Plants - Stages of Flowering (BEGIN, BEGIN/FULL, FULL, FULL/END, END)
PLANT NAME (Botanic / Common)	CAPE	S.E.	N.S.	EAST	METRO W.	CENT.	P.V.	BERK.
Prunus serrulata (Japanese flowering cherry)	*	*	*	*	*	*	Begin	*
Magnolia stellata (star Magnolia)	*	Begin	*	*	*	Begin	Begin	*
Forsythia x intermedia (border Forsythia)	Begin	Begin	Full	Begin	*	Begin	Begin/Full	Begin
Pieris japonica (Japanese Pieris)	Full	Full	Full	Full	Full	Begin	Full	Begin
Cornus mas (Cornelian cherry dogwood)	Full	Full	Full	Full	Full	Full	Full	Full
Acer rubrum (red maple)	Begin/Full	Full	Full	Full/End	Full/End	Full	Full/End	Full
Acer saccharinum (silver maple)	Full/End	Full	Full/End	Full/End	Full/End	Full/End	Full/End	Full/End
* = no activity to report/information not available

Regional Notes

Cape Cod Region (Barnstable)

General Conditions:

The average temperature for the period from March 20 thru April 3 was 41ºF with a high of 60ºF on March 31 and a low of 24ºF on March 22. Overall the period was cloudy and cool. Nearly 4 inches of precipitation fell during the period with the majority coming on March 23, 28 & 29.

The cool weather slowed the advancement of plant development. Herbaceous plants seen in bloom during the period include hellebore (Helleborus orientalis), Siberian squill (Scilla siberica), daffodils (Narcissus spp.), and hyacinths (Hyacinthus spp.). Woody plants seen in bloom include elms (Ulmus spp.) and willows (Salix spp.).

Pests/Problems:

Insects or insect damage seen during the period include black turpentine beetle damage to pitch pine and boxwood leafminer damage on boxwood. Disease symptoms or signs observed during the period include the pink sporulation of coral-spot nectria canker and red thread in lawns.

Many of the invasive shrubs such as privet (Ligustrum spp.), multiflora rose (Rosa multiflora) and honeysuckle (Lonicera spp.) are easily spotted due to the tendency to leaf out earlier than many other species. Invasive fig buttercup (Ficaria verna) was seen in bloom as well as the weeds hairy bittercress (Cardamine hirsuta), chickweed (Stellaria media), mouse-ear cress (Arabidopsis thaliana), henbit (Lamium spp.), speedwell (Veronica spp.) and common groundsel (Senecio vulgaris).

Southeast Region (Dighton)

General Conditions:

Over the past two weeks, commencing from March 20th, the highest temperature reached was 59°F on Sunday afternoon, March 31st, with the lowest recorded temperature being 24°F on Monday morning, March 22nd. The average temperature during this period stood at 42°F. On Saturday, March 23rd, the maximum sustained wind recorded was 21 mph, with gusts exceeding 40 mph. Precipitation occurred on seven days, accumulating to a total of 5.2 inches, resulting in saturated soils. Vernal pools and streams are at capacity, and the Taunton River has reached flood stage, prompting warnings across Bristol County. Additionally, forecasts predict an additional half-inch or more of rain in the next two days, accompanied by wind speeds gusting up to 65 mph.

Plants currently in flower include Acer rubrum (swamp red maple), Acer saccharinum (silver maple), Cornus mas (Cornelian cherry dogwood), Forsythia intermedia (border Forsythia), Magnolia stellata (star Magnolia) and Pieris japonica (Japanese andromeda).

Pests/Problems:

The combination of high humidity, saturated soils, and flooded root zones is likely to lead to issues with plantings, particularly in low, poorly drained areas.

Warnings have been issued regarding flooding on roadways, and drivers are advised to avoid crossing flooded areas on account of the risks involved.

Furthermore, ticks are present in high numbers and actively seeking hosts. It is recommended to take appropriate precautions, such as wearing insect repellent and conducting thorough examinations after outdoor activities

North Shore (Beverly)

General Conditions:

This past winter was very mild with minimal snowfall. There was a significant amount of rainfall in March. The total precipitation for March was 8.50 inches. The month of March was unseasonably mild with temperatures averaging 40°F. The minimum temperature was 17℉ recorded on March 1 and the maximum temperature was 57℉ recorded on March 31. April has begun with unseasonably low temperatures. The average daily temperature for these first three days of April was 40°F with a maximum of 49°F recorded on April 1 and minimum temperature of 31°F recorded on April 3. The weather forecast for the next few days as of this writing calls for a nor’easter that will bring significant amounts of precipitation and strong winds. The cooler weather is slowing down the blooming of some of the plants that flower during this time of year. Woody plants observed in bloom include Cornelian cherry dogwood (Cornus mas), goat willow (Salix caprea), winter honeysuckle (Lonicera x purpusii), February daphne (Daphne mezereum), winter hazel (Corylopsis ‘Winterthur’), Farrer viburnum (Viburnum farreri), Japanese pieris (Pieris japonica) and red maple (Acer rubrum). Early spring flowering plants seen in bloom include: hellebores (Helleborus orientalis), Siberian squill (Scilla siberica), Puschkinia (Puschkinia libanotica), glory of the snow (Chionodoxa), snowdrops (Galanthus spp.), daffodil (Narcissus spp.), and early, white woodland ‘Tommy’ crocus (Crocus tommasinianus).

Pests/Problems:

Fungal leaf spots were observed on mountain laurel (Kalmia latifolia). Management practices for leaf spots involve raking and removal of infected fallen leaves in the fall, removal of infected leaves during the winter months, and thinning mature shrubs for better air circulation. Some deer browsing damage has been observed on young Taxus plants and on leaves of emerging tulips.

East (Boston)

General Conditions:

It was a wet March and precipitation has already begun to accumulate in April. There is a wind/rain weather advisory for a storm approaching as I write on April 3^rd. Over the past two weeks, the average daytime temperature was 47℉, with a high of 59℉ on March 31^st. Overnight lows averaged 34℉ with a low temperature of 24℉ on March 22^nd. We received precipitation on 8 of the preceding 14 days totaling 3.59 inches. March ended with 6.75 inches of total precipitation and no snowfall. We are above average for the yearly historical surplus to date. The cooler temperatures have slowed down plant activity and likely preserved many Magnolia blooms from the pending storm. Some plants currently in bloom include: Cornus mas (Cornelian cherry dogwood), Helleborus spp. (Hellebores), Narcissus spp. (daffodil), Pieris japonica (Japanese pieris), Prunus spp. (early flowering cherry), and Viburnum x bodnantense (fragrant Viburnum). The unusual herbaceous perennial Petacites hybridus (butterbur) is flowering.

Pests/Problems

Damage from deer and rabbit browsing is evident on woody shrubs throughout the landscape. Winter annuals in bloom include: Cardamine hirsuta (hairy bittercress), Capsella bursa-pastoris (shepherd’s purse), and Stellaria media (common chickweed). The invasive Ficaria verna (lesser celandine) has emerged in moist locations. First year rosettes of the invasive biennial Alliaria petiolata (garlic mustard) continue to green up along roadsides and woodland edges.

Metro West (Acton)

General Conditions:

Spring arrived just over two weeks ago and brought with it weather that has been fairly typical for spring, including a range of warm and cool temperatures, frost, a snow flurry, blustery days, and lots of rain. Today and tomorrow’s forecast continue this weather pattern with the possibility for snow, strong winds, rain, and flooding. The monthly average rainfall for March is 4.62” and the total recorded for the month was 6”. The average monthly rainfall for the month of April is 4.43” and as of the 2nd, 0.24” of rain has been recorded so far. Galanthus spp. (snowdrops) are already past bloom and buds are swelling on several woody plants including Forsythia sp. (forsythia), Syringa sp. (lilac), and Viburnum spp.

Pests/Problems:

Soils are saturated, and rivers, lakes, and pond water levels are high; erosion from rain, downed branches and twigs from strong wind gusts, and rodent damage to lawns and plants are some of the things that have been observed out in the landscape.

Central Region (Boylston)

General Conditions:

Though spring is upon us, the next few days will feel more like late winter with potential snow and ice, up to 4 to 8 inches of snow and winds gusts up to 55 mph. In the last couple of weeks, the weather has been very rainy, including cold mornings and warmer days with persistent winds. Average precipitation within this short period of time was 5.21 inches, one single day (3/23/2024) being 2.78 inches. Many spring bulbs are in full bloom and early flowering trees and shrubs are showing off. Red maples (Acer rubrum) are finally in full bloom, which seems to be a bit behind compared to other locations. Pussy willows (Salix discolor) are having a full bloom moment as well, as well as white forsythia (Abeliophyllum distichum). The yellow Forsythia x intermedia is not too far behind.

Pests/Problems:

Soils have stayed consistently saturated with all the heavy rain, creating some soil erosion. Winds have created a lot of damage on trees as well. Rabbit/deer damage seen on early buds and foliage, especially on species that are emerging earlier compared to previous years.

Pioneer Valley (Amherst)

General Conditions:

After a stretch of bright sun and mild temperatures supercharged plant development in mid-March, a round of cold spring weather swept across the Pioneer Valley. High temperatures in the 30s and 40s dominated much of this past reporting period until the Easter holiday weekend when temps rose to the mid-50s. Many trees and shrubs across the landscape have swollen buds and those that are flushing new growth are doing so very slowly with the cold nights. Crabapple, viburnum and larch have expanding leaves and shoots on the UMass campus with Japanese maples close behind. Scattered flowering cherries in warm microclimates are in full bloom. Cornelian cherry dogwood (Cornus mas) seem to be having an extended flowering period with the cool temperatures. But the current star of spring has been Japanese andromeda (Pieris japonica), which are really having an incredible bloom this year. With the mild winter, we can expect other flowering trees and shrubs that can be injured by cold temperatures (e.g. rhododendron and redbud) to also have a stellar display this spring. Turfgrasses have noticeably greened up but are not uniformly green just yet. Hairy bittercress (Cardamine hirsuta), among many other weeds, are rapidly growing and flowering on untreated lawns.

Soils remain moist due to recent rain and cool temperatures but on clear, sunny days with gusty winds and low humidity, it doesn’t take long for the uppermost soil surface to dry out. Overall, this is an ideal time for transplanting. Getting root systems disentangled and properly oriented before soil temperatures increase can help ease the shock of transplant. As tree and shrub canopies grow and spread over time, it may become increasingly difficult to string trim and mow around these plants. In these cases, removal of the turfgrass to accommodate the widening canopy should be performed. This will reduce or eliminate physical injuries and soil compaction from lawn care equipment and accommodate the expanding root zone. Turfgrasses can be more easily removed when dormant before new root development begins. Care should be taken to avoid excessive damage to the root system and the exposed soil should be covered in mulch or wood chips.

Pests/Problems:

Beech buds continue to swell and all eyes will be on the newly developing leaves to determine if any of the various treatments reduced beech leaf disease (BLD) incidence and severity. Arbotect 20-S (thiabendazole hypophosphite) was given a 24c label for use against BLD. Root flare injections can be performed on a biennial basis once leaves are fully developed for the season. The lack of very cold weather this winter led to excellent overwintering survival for the hemlock woolly adelgid (Adelges tsugae). Dormant oil can be used to treat both the adelgid and the elongate hemlock scale (Fiorinia externa) but will not be as effective as the systemic insecticide dinotefuran. Heavy rains over the winter and spring have washed away mulch and soil across the landscape, exposing surface roots in some cases. Despite the mild winter, winter burn on rhododendron and other broadleaved evergreens is still present in scattered locations. Scout for spruce spider mite on spruce and arborvitae so that miticide treatments can be made before significant damage takes place. Spider mites can be readily dislodged from needles during heavy rain, so periods of wet weather can suppress populations. Spruce needle rust is becoming visible on blue spruce needles. Symptoms appear as yellow to orange foliar lesions that will swell and rupture, releasing orange-colored spores. Scout for and protect the terminal leaders on white pines and Norway spruce in full sun for white pine weevil. Trees that are roughly 10–20’ tall are particularly susceptible to attack.

Berkshire Region (West Stockbridge)

General Conditions:

The yo-yo type weather pattern continued over the past 2 weeks. There were days with warm temperatures followed by dramatic temperature drops the next day. North Adams experienced a high temperature of 58℉ on April 1^st and that was not an April Fool's joke. Low temperature in the north County site was 19℉ on March 25. Pittsfield had a high temperature of 54℉ on April 1 while Richmond experienced 53℉ on that day. Low temperatures for those two sites were 18℉ at Pittsfield Airport on both the mornings of March 22 and 24, and 15℉ in Richmond on March 24. Rainfall totals for the two-week period from March 23 to April 2 were: 2.68 inches at North Adams, 3.36 inches in Pittsfield, and 3.26 in Richmond. The heaviest rains at each site fell on March 23. It was actually a mix of rain, sleet, and wet snow. The biggest problem over the past two weeks and one which is continuing today, April 3 on into April 4, is the occurrence of high winds with gusts between 50 and 60 mph. This has resulted in power outages in many communities.

The arrival of some mild temperatures, along with plenty of soil moisture has prompted growth of turfgrass but not yet to the point of requiring mowing. Spring flowering bulbs are putting on a show. A few trees and shrubs are displaying flowers, but the numbers are still small. With no frost in soils and plenty of soil moisture, yet not muddy except for poorly drained sites, soil conditions have favored the planting of dormant woody plants.

Pests/Problems:

Pest infestations are still very limited. The most common occurrence remains to be black-legged ticks, also called deer ticks (Ixodes scapularis). Evidence of past mite infestations, i.e. stippling on leaves, can be found on many evergreen shrubs. Browsing by deer and rabbits is still high but with grass greening up, deer can often be seen grazing on the grass. Voles also remain active and damage to young trees and woody shrubs' stems is common. Their tunnels and pathways in turfgrass are also frequently observed. The warming soils have brought, without a doubt, the most serious damage in landscapes which is that caused by the high wind gusts. There have been numerous trees and branches brought down by recent very high wind gusts. Such gusts are currently taking place today, April 3^rd, and are expected to continue through April 4^th. Cutworms were found in the upper 4 inches of soil. Surprisingly, some Jumping worms (Amynthus spp.) were observed in soils exposed to full sun.

Regional Scouting Credits

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

Woody Ornamentals

Diseases

Recent pests, pathogens, or problems of interest seen in the UMass Extension Plant Diagnostic Lab, a select few:

Decline and death of a leatherwood (Dirca palustris) due to poor root form and root decay by Armillaria. The plant was approximately eight years old and was transplanted to a shaded landscape several years ago. As a forest understory shrub native to the northeast, leatherwood can tolerate low light settings. The soil at the site is heavy and does not drain well during years with abundant rainfall (such as 2021 and 2023). In late summer of 2023, the plant exhibited symptoms of decline, including leaf wilting and premature leaf shedding. Branch samples submitted to the lab at that time did not reveal any insect pests or foliar/cankering pathogens. The plant subsequently died and the lower trunk and root flare with primary roots was recently submitted for analysis. Examination of the roots revealed very poor root development with circling and tangled primary roots. In addition, approximately 2/3 of the roots were decayed by Armillaria. The wood was bleached, stringy and easily peeled apart in sheets. It can be challenging to collect root samples to confirm the presence of a root decay pathogen when the goal is to restore vigor to a stressed and weakened plant.

Canopy thinning and lower branch dieback of blue spruce (Picea pungens) due to needle blight (Rhizosphaera kalkhoffii and Stigmina lautii) and twig cankering (Phomopsis). Three spruce were planted in a row at a residential property and are approximately 20 years old. The trees are south facing but receive only part sun due to shading from nearby hardwoods. Soil drainage is described as moderate and there is a swamp nearby, indicating a high water table. Submitted branch segments had needles that were pale green to brown along with blighted twigs. This combination of needle blight and cankering fungi can be very destructive on blue spruce. The increase in annual precipitation in the Northeast due to climate change will only further promote disease development and spread on blue spruce.

Phyllosticta leaf blight (Phyllosticta sp.) on Japanese holly (Ilex crenata). The plants are approximately 15 years old and have been present at the site for 10 years. They are approximately 24” tall, planted along the foundation of a home with morning sun and afternoon shade. Over the past two years, shoots with brown leaves have appeared. Winter injury on Japanese holly was widespread in 2023, due to the arctic blast the area received in early February of that year. If the pathogen took advantage of a weakened and stressed plant, there could be higher levels of disease this year. Phyllosticta species are common on ornamental Ilex and each year the lab receives various hollies with leaf blotch and blight caused by this pathogen.

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

Insects and Other Arthropods

Invasive Updates:

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

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

• Box Tree Moth has been detected in the following Massachusetts communities: Bourne, Sandwich, and Barnstable. A map of these locations is available here. If you believe you have found this insect, please take a photo, note your location, and report it immediately here.
• Elm Zigzag Sawfly has been detected in the following Massachusetts communities: Becket, Chester, Windsor, and Williamstown. If you believe you have found this insect, please take a photo, note your location, and report it immediately here.
• Emerald Ash Borer is well established across most of Massachusetts. A map of these locations from the MA Department of Conservation and Recreation is available.
• Jumping Worms are non-native earthworms that impact natural ecosystems. Available resources include a fact sheet about earthworms in Massachusetts and jumping worm FAQ’s.
• Spotted Lanternfly now has established populations in the following locations in Massachusetts: Holyoke, Springfield, West Springfield, Agawam, Fitchburg, Worcester, Shrewsbury, Southborough, Ashland, Wellesley, Weston, and Chelmsford. If you believe you have found this insect, please take a photo, note your location, and report it immediately here. Available resources include a map of spotted lanternfly locations in Massachusetts from the MA Department of Agricultural Resources, MDAR’s spotted lanternfly fact sheet, UMass Extension’s Spotted Lanternfly Management Guide, and an SLF InsectXaminer episode.

Medically Important Pests:

• Ticks are a serious public health concern and may be active in managed landscapes any time temperatures are above freezing. Available resources include tick information from Cape Cod Cooperative Extension, personal protective measures, and a list of potential tick testing resources. The New England Center of Excellence in Vector-Borne Diseases (NEWVEC) also provides the latest tick information and resources.
• Mosquitoes and the diseases they vector are also a serious public health concern in Massachusetts by summer. Available resources include Mosquito Repellents from the Department of Public Health and Prevent Mosquito Bites from the Centers for Disease Control and Prevention. The Massachusetts Department of Public Health tests for Eastern Equine Encephalitis (EEE) and West Nile Virus (WNV) from June to October. Beginning in June, risk maps will be available here.

Tree & Shrub Insect & Mite Pest Suggested Scouting:

• Bagworm is overwintering on Juniperus spp., Thuja spp., Quercus spp., Platanus spp., and others as 500-1000 eggs can be found in the bags of last season’s deceased females. Now is the time to remove and destroy overwintering bags of eggs prior to egg hatch at approximately 600 GDD’s (approx. mid-June).
• Balsam Twig Aphid overwinters as eggs on host plant bark, trunks, and branches (primarily Abies and Picea spp.). Eggs hatch roughly between 30-120 GDD’s, approximately April-May. Nymphs quickly mature into stem mothers, which produce 20-40 young (each) without laying eggs. These young feed on buds and tender needles, and cause most of their feeding damage during that time. Scout now for curled or stunted needles from feeding in prior years.
• Black Turpentine Beetle overwinters as an adult in the bark of its host plants. Adults may become active as temperatures rise, typically by mid-April to mid-May. Attacked host trees may ooze 1.6 inch diameter red or white masses of pitch from the lower 6 feet of the trunk. Pitch pine, eastern white pine, and other species of pine or spruce may be hosts for this insect. Frequently an issue on stressed trees in eastern Massachusetts. Favored by drought or flooding conditions.
• Boxwood Leafminer is overwintering as a partially developed larva within Buxus spp. leaves. Larvae will become active as temperatures warm, with pupae present by late April. Adult emergence occurs by mid-May, with pupal cases left behind clinging to leaves. Shake bushes in late April to detect flying adults. Resistant varieties of boxwood are available; see preceding link.
• Boxwood Mite feeds on upper and lower leaf surfaces of Buxus spp. hosts. Overwintered eggs hatch into larvae in the spring, which mature into nymphs and eventually adults. The entire life cycle takes approximately 18-21 days. Most feeding injury occurs in the spring and hosts may appear off-color.
• Boxwood Psyllid nymphs have overwintered within eggshells inserted between bud scales last summer. As soon as buds expand, nymphs will emerge and begin feeding on Buxus spp. developing buds and leaves. Upward cupping and yellowing of leaves can be a sign of previous or current season’s damage. Dormant season horticultural oil applications may be made in the spring, as temperatures and weather conditions allow.
• Cankerworms can be found feeding on similar host plants in the spring, despite fall and spring cankerworm being different species of insects. Spring cankerworm adult moths are active in February and March, laying masses of 100 or so eggs in the rough bark of larger branches or the trunk of the host plant. Fall cankerworm adults have already laid their masses of eggs on host plant branches and twigs, back in late November and early December of last year (sometimes the current year’s January). Egg hatch of both species will occur by approximately mid-May, with caterpillar feeding through roughly the end of June.
• Cooley Spruce Gall Adelgid typically overwinters as an immature female near spruce twig terminals. By early spring, this female matures into a stem mother which will lay hundreds of eggs on lateral terminals. Following egg hatch, nymphal feeding induces gall formation on spruce hosts. Green galls on spruce may be removed and destroyed. On Douglas fir, the Cooley spruce gall adelgid’s alternate host, look for woolly masses in the spring and distorted or crooked needles. Do not plant spruce and Douglas fir close together when possible.
• Eastern Spruce Gall Adelgid overwinters as a partially grown female, maturing into a stem mother by early spring. Stem mothers lay 100-200 eggs by budbreak. Eggs hatch and nymphs feed on the needles of their Picea spp. hosts. As green galls develop, prune out and destroy when possible.
• Eastern Tent Caterpillar overwintering eggs hatch in the spring and caterpillars emerge as cherry leaves begin to open. Look for groups of caterpillars feeding in silken tents at that time.
• Elongate Hemlock Scale is primarily a pest of hemlock and fir. Overwintered fertilized females or their eggs will become active with warming temperatures, with egg hatch generally occurring by the end of May or the beginning of June. At that time, crawlers will be present before they settle to feed on a needle. Colletotrichum fioriniae was observed on elongate hemlock scales in Lynnfield, MA on 2/23/2024 and again in Manchester, MA on 3/19/2024 by Richard Grant (see photos). C. fioriniae is an endophytic fungus that lives within the needles of hemlock. Up to 90% mortality can occur in elongate hemlock scale if this fungus invades the insect. Scales appear coated in a black material, looking similar to sooty mold (it is not sooty mold). This fungus was reported as active in elongate hemlock scale populations in western MA in 2023 as well.
• Euonymus Caterpillar tiny, overwintered larvae have spent their time beneath egg shells from last year. As temperatures increase in the spring, groups of caterpillars will begin feeding on newly emerging Euonymus spp. leaves. Additional resources include an InsectXaminer episode about euonymus caterpillar.
• Euonymus Scale overwinters as a fertilized female. Eggs are laid beneath dark brown female scale covers in the early spring. Egg hatch occurs over a 2-3 week period, with crawlers present by early June. While Euonymus spp. host plants are preferred, additional host plants have been reported.
• European Pine Sawfly eggs have overwintered in slits in last year’s needles. Egg hatch begins in approximately late-April and early May.
• Forest Tent Caterpillar egg masses overwinter and will hatch as leaves expand in the spring. Small caterpillars will search for expanding flower and leaf buds to begin feeding on.
• Hemlock Looper collectively refers to two species of geometrid (inchworm; looper) caterpillars. Overwintered eggs hatch by late May or early June, at which time young larvae begin their messy feeding on host plant needles. Hemlock and balsam fir are preferred hosts.
• Hemlock Woolly Adelgid has been favored this winter by the mild temperatures we’ve experienced in Massachusetts, according to the MA Department of Conservation and Recreation. Very little overwintering mortality has been measured at sites sampled across the state. Overwintered sistens generation females produce viable eggs in February and March.
• Imported Willow Leaf Beetle adults overwinter in loose bark or other sheltered areas near susceptible Salix and Populus spp. host plants. Once the host plant leaves emerge in the spring, adults will begin to feed and lay tiny, yellow eggs in clusters on leaf undersides. Additional resources include an InsectXaminer episode about imported willow leaf beetle
• Japanese Cedar Longhorned Beetle cause damage to arborvitae, cypress, juniper, and cedar (Chamaecyparis). Feeding damage from the larvae of this species causes branch dieback, which is typically not noticed until the springtime following the initial infestation. 1/8-inch oval exit holes, galleries beneath the bark (in the cambium and xylem), and frass may be signs of the activity of this insect. Take precautions to avoid host plant stress. May go unnoticed until a plant needs to be removed.
• Lecanium Scales, including most notably in Massachusetts, the oak lecanium, are soft scales that overwinter on host plant twigs as second instar immatures. In the spring, these immatures begin feeding and mature into hemispherical shaped adult females who lay their eggs by late May and into June. Between April and May, much honeydew (sugary excrement) may be produced by the active adult females.
• Lily Leaf Beetle, while not a pest of trees and shrubs, can be an important insect found in ornamental landscapes. As soon as lilies break through the ground in the spring, bright red overwintered adult beetles begin feeding on the foliage. This typically occurs in April, with adults mating and laying eggs by May; 250-450 eggs may be laid per female. Additional resources include an InsectXaminer episode about lily leaf beetle.
• Magnolia Scale overwinters as nymphs (immatures) found on 1 and 2-year old twigs of the host plant. Nymphs begin feeding as temperatures warm in the spring, molting once by late April or May and again by early June.
• Pine Bark Adelgid overwinters in an immature form which begins feeding again as springtime temperatures increase. This is the time when the insects begin secreting a white, waxy layer over their bodies. High populations can make the trunks of eastern white pine appear as if coated in snow. Typically, management is not necessary. Syringing (washing adelgids off the trunk of larger trees with a strong jet of water) is an option.
• Redheaded Flea Beetle (Systena frontalis) has been identified as a native pest of nurseries in many locations in the eastern United States. Suspected redheaded flea beetle damage was seen on Ilex crenata 'Dwarf Pagoda' (Dwarf Pagoda Japanese holly) on 3/27/2024 that was purchased in Massachusetts but may have originated in NJ. While identification of this species of insect is uncertain based on host plant damage alone, it appears to be a reasonable and educated assumption. Redheaded flea beetles are known to feed on a wide variety of host plants. These include but are not limited to: cabbage, beans, beets, blueberries, and other agricultural crops as well as Physocarpus, Weigelia, Cornus, Forsythia, Itea, Hydrangea, and Ilex. Adult beetles are active and feed from approximately late-June to mid-September on the upper and lower leaf surfaces of their hosts. This can cause damage that looks like skeletonization and eventually holes in the leaves. Leaves appear covered in brown patches as in these photos. This damage was caused last season on this evergreen plant.
• Snowball Aphid overwinters as an egg on the twigs and buds of Viburnum spp. hosts. Egg hatch occurs at the same time host plant buds are opening in the spring. Newly hatched aphids will begin to feed on and distort the newly developing leaves of their hosts. Aphids may be protected from contact insecticides within curled leaves.
• Southern Pine Beetle has been trapped in Massachusetts since 2015. By 2022 & 2023, southern pine beetle has reached outbreak conditions in small areas of the state, killing pitch pine (Pinus rigida). (Particularly on Martha’s Vineyard and Nantucket islands in MA.) If you believe you have found infested pitch pine in Massachusetts, please report southern pine beetle here.
• Spruce Bud Scale overwinters as an immature scale on the undersides of host plant needles. Once spring temperatures warm, the dormant scales become active by late March and in April female spruce bud scales move to host plant twigs. Adult females are reddish-brown and round, and usually found at the base of new twig growth.
• Spruce Spider Mite is a cool season mite which causes most of its feeding damage on coniferous hosts in the spring and fall. Monitor for discolored needles and the mites themselves. Monitoring for spruce spider mite can be done by shaking 3-4 branches over a white piece of paper and viewing mites with a hand lens.
• Tuliptree Scale is a soft scale pest of Liriodendron and Magnolia spp. among others. Second instar nymphs overwinter, begin feeding as temperatures warm in the spring, and mature into adults by the late spring/early summer.
• Viburnum Leaf Beetle overwinters on susceptible viburnum as eggs laid in pits chewed near the ends of twigs last season. These egg laying locations are covered with an oval-round cap. Prune out and destroy infested twigs prior to egg hatch in May.
• White Pine Aphid eggs overwinter in rows on the needles of their host plants. Egg hatch will occur as spring temperatures begin to warm. Aphids may feed on the needles, twigs, and small branches of their host plants.
• White Pine Weevil overwinters as an adult in the leaf litter in sheltered areas near host plants. As spring temperatures warm, adults fly to the leaders of Pinus and Picea spp. hosts where they mate, dig round holes in the bark, and deposit 1-5 tiny eggs in the cavity. Eggs hatch and the larvae tunnel as they feed, killing the previous season’s leader. Adult white pine weevils are active in March (through May), as soon as 7 GDD’s are reached.
• Woolly Apple Aphid overwinters as eggs in the cracks and crevices of Ulmus spp. host plants. As spring temperatures warm, these eggs hatch and stem mothers begin feeding on developing elm leaves. Their feeding and the feeding of the wingless nymphs they produce causes leaf distortion and a rosette to form on elm. If no elm is present, the aphids will complete their life cycle on apple year-round.
• Woolly Beech Leaf Aphid overwinters as eggs in host plant bark crevices near buds. At budbreak, eggs hatch and wool covered aphids begin feeding on host plant leaf undersides (Fagus spp.). Even though aphid populations may be very noticeable, they seldom require chemical management.
• Woolly Elm Aphid overwinters as eggs hidden in cracks and crevices of elm bark. As leaves unfold in the spring, eggs hatch and young aphids feed on the underside of elm leaf tissue. These aphids mature and give birth to hundreds of additional females. Feeding causes leaves to curl around the aphids. Curled leaves may also turn reddish brown.

Beneficials/Non-Pests:

• Katydid Eggs (Orthoptera: Tettigoniidae) were spotted on 3/28/2024 in Amherst, MA on 2-year-old black birch (Betula lenta) planted in nursery beds (photo credit: Tim Mercer, UMass Amherst). Katydid eggs are frequently asked about once they are noticed by professionals and homeowners alike. These insects are very closely related to grasshoppers and crickets, but may be less likely to be found. Adult katydids are often green in color, although spectacularly some individuals may be pink! Their antennae are as long or longer than their bodies. Adult activity does not peak until approximately July through September. Adults can feed on leaves, pollen, and flowers but rarely damage plants. They overwinter as eggs laid on plant stems, in the soil, or on bark. These eggs may be mistaken for scale insects. However, the katydid is not considered a pest in managed landscape

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

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Additional Resources

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Diagnostic Services

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

Soil and Plant Nutrient Testing - The University of Massachusetts Soil and Plant Nutrient Testing Laboratory is located on the campus of the University of Massachusetts at Amherst. Testing services are available to all. The lab provides test results and recommendations that lead to the wise and economical use of soils and soil amendments. For more information, including current turn-around times, visit the UMass Soil and Plant Nutrient Testing Laboratory web site. The lab is currently accepting orders for Routine Soil Analysis (including optional Organic Matter, Soluble Salts, and Nitrate testing), Particle Size Analysis, Pre-Sidedress Nitrate (PSNT), Total Sorbed Metals, and Soilless Media (no other types of soil analyses available at this time). Check for current turnaround time. Please plan for the fact that date of receipt in the lab is affected by weekends, holidays, shipping time, and time for UMass Campus Mail to deliver samples to the lab.

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

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