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Landscape Message: March 23, 2018

March 23, 2018
Issue: 
1

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

Welcome to the 2018 season! The Landscape Message will be updated bi-weekly in March. The next message will be posted on April 6. 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, click on the section headings below to expand the content:


Scouting Information by Region

Environmental Data

The following data was collected on or about March 21, 2018. Total accumulated growing degree days (GDD) represent the heating units above a 50° F baseline temperature collected via our instruments for the 2018 calendar year. This information is intended for use as a guide for monitoring the developmental stages of pests in your location and planning management strategies accordingly.

Region/Location

GDD

Soil Temp
(°F at 4" depth)

Precipitation
(inches, rainfall equivalent)

Time/Date of Readings
2017 Total 2018 Current   Sun Shade Since 1/1 Since 3/1

Cape Cod

2799 3.5 34 - 15.29 5.03 3:00 PM 3/21

Southeast

2399 6 33 32 13.70 rain
(61.7 snow)
7.5 rain
(31.5 snow)
12:30 PM 3/21

North Shore

2855 14 - - 10.29 1.71 9:45 AM 3/21

East

3104 28.5 32 35 15.62 6.28 1:15 PM on 3/21

Metro West

2689 13.5 - - 8.16 3.58 6:00 AM 3/21

Central

2757 22 - - 9.73 2.80 3:30 PM 3/21

Pioneer Valley

2873 15 35 34 8.96 1.59 10:00 AM 3/21

Berkshires

2543 15 - - 11.64 2.60 11:00 AM 3/21

AVERAGE

2752 15 - - 11.68 4.07 -

n/a = information not available

Phenology

Indicator Plants - Stages of Flowering (BEGIN, BEGIN/FULL, FULL, FULL/END, END)
PLANT NAME (Botanic/ Common) CAPE S.E. N.S. EAST METRO W. CENT. P.V. BERK.
Hamamelis x intermedia (Witchhazel hybrids) Full Full Full Full Full Full Full/End Full
Hamamelis mollis (Chinese Witchazel) Full Full Full Full Full Full Full/End *
* = no activity to report/information not available

Regional Notes

Cape Cod Region (Barnstable)

General Conditions: December began with average conditions but finished with an extremely cold stretch that started on December 26 and lasted thru January 7. During this time temperatures were well below normal staying in the single digits and teens for much of the time. Many locations on the upper cape saw below zero temperatures during this period. The lack of snow cover during the cold stretch resulted in soil temperatures as low as 24° F, far below normal, Cape soils rarely go below 32° F for significant stretches. The remainder of January was average. February was milder than usual giving folks false sense of an early spring, even though the sun rarely showed itself. March began mild turned colder and to date has averaged colder than February. Precipitation has been abundant in February and March with official reading for Barnstable at over 15 inches, some areas recording as much as 18 inches of precipitation. There has also been a string of nor’easters in March. The first nor’easter March 2 & 3 had really strong winds and heavy rains, 90+ mph winds were recorded on more than one location on the Cape. The third nor’easter on March 13 brought blizzard conditions including strong winds (70-80mph) and heavy snow. The storms have caused extensive beach erosion and widespread power outages. Currently there is snow cover on the ground.

Month Average Temp High Temp Low Temp
December 32.4° F 57° F 12/6 5° F 12/29
January 30.8° F 57° F 1/13 1° F 1/7
February 39° F 56° F 2/21 8° F 2/3
March 36° F 58° F 3/1 17° F 3/18

Pests/Problems: The primary landscape problem is the damage caused by the recent nor’easters with downed trees, limbs, and branches. Evergreens primarily pitch pine were blown over at the base while deciduous trees suffered more breakage. Cleanup will likely last well into the spring, especially considering more strong storms are expected. The other major problem is winter injury, the cold stretch in late December and early January resulted in widespread winter injury on needled and broadleaved evergreens. I would expect to see additional winter injury symptoms show up through spring and into early summer, especially on plants that are at the northern reaches of their hardiness zone.

Southeast Region (Hanson)

General Conditions: The cold weather that began at the end of 2017, continued into January with some cold, windy days in the single digits and below 0 degrees F. (-9 on Jan. 2nd). We also saw a few days at 50 and 60 degrees, but overall a very cold month. February was warmer with a few days in the 50’s with a high of 67 degrees on February 21. Coming into March, we celebrated March 1st at 60 degrees. Snow wise, not a bad winter overall as far as total amounts, however, the storms that we did see were problematic. A winter storm on January 4, brought high winds and high wind gusts and 13 inches of heavy snow, with considerable damage to trees and shrubs. February brought some rainy days and light snow, but no significant snow events. However, March 2-3, brought 4.35 inches of rain and 16 inches of heavy wet snow with 30-40 mph winds and higher wind gusts. In Plymouth County many towns saw trees uprooted, due to the saturated soils and high winds. Power lines went down, homes were flooded and power outages lasted several days. White pines were probably the main tree species responsible for falling on homes, utility wires and vehicles. Several spruce, red cedar and /or Chamaecyparis were also uprooted or observed “listing to port”. Forsythia, and other shrubs were slammed to the ground. Broken tree limbs and debris littered the ground. January 13th brought another nor’easter with high winds and 16 inches of snow and more power outages, flooding and downed trees.

The early cold weather killed off the buds of many cold sensitive plants like Hydrangea macrophylla and Corylopsis spicata. In Hanson, the cold weather also delayed the flowering of witchhazels, which did not start to bloom until the 3rd week in February. Snow drops and winter aconites had just started to bloom in early March when they were covered by snow. Hellebores and winter honeysuckle, which usually begin bloom February, were not in bloom as of March 18.

Pests/Problems: Winter moth populations were down last fall and it is expected that winter moth numbers will be very low this spring. The number of winter moth eggs is very low in Hanson, MA, so low that there appear to be no eggs on the banded trees that are used to monitor winter moth. However, we always need to be cautious, as there may be pockets of winter moth that may cause damage. Blueberry and apples growers need to remain vigilant as winter moth caterpillars may cause significant damage to those crops, even in low numbers.

Gypsy moth caterpillars may be a problem in some areas this year, especially in areas where the numbers were high last year; time and monitoring will tell. For more information on winter moth and gypsy moth, see the Insect Section of the Landscape Message below.

Now is a good time to monitor hemlocks for hemlock wooly adelgid. Look for the tiny, white, cotton ball-like egg masses, especially towards the outer branch tips.

In many areas last year, Rododendron, Azalea, and Pieris showed signs of serious damage from lacebugs. Monitor those plants now and make a note to include those plants in a management plan later in the season. Unless managed, lacebugs may weaken plants where they do not survive.

Reports have come in from gardeners and hikers who reported that they found deer ticks on themselves and their pets, after working in the yard or hiking on those warm days in January and February. Remember that deer ticks may be active any day that the weather is above freezing.

Damage from voles to the crowns of hosta, Solomon’s Seal and Epimedium was observed. Look for exposed, chewed crowns and cover them with soil.

Deer have been heavily browsing rhododendrons, hollies and other plants.

Some good news, we have had sufficient snow and rain this winter to alleviate the dry soil conditions facing Plymouth County late last summer into the fall. It appears that Plymouth County is no longer facing drought conditions: https://www.drought.gov/drought/states/massachusetts

North Shore (Beverly)

General Conditions: The year 2017 ended very cold and the year 2018 also started off very cold with average air temperatures in the single digits and teens with strong cold winds. The wind chill temperatures were -20s F for some days in January. The second half of January was less cold with average temperatures going up to the 20s and lower 30s and a few days of lower 40s. The area also experienced a few snow snow storms during the month of January. February temperatures were milder with average air temperatures up in to the 30s and low 40s. There was no significant snowfall experienced in the month of February. The weather pattern changed in the month of March with temperatures going down to the low 30s and mid 20s. The cold temperatures are still lingering. The change in the weather pattern also brought a nor'easter every week with significant snowfalls. One nor’easter brought in a snow storm with very heavy snow that caused widespread damage to trees and shrubs in the region.

Pests/Problems: The snow storm in the first week of March caused a lot of broken tree branches and fallen trees in the area. Tree service professionals and homeowners are busy removing fallen trees and pruning off broken tree limbs and damaged shrubs. Deer browsing damage is widespread especially on young yews (Taxus sp.). The deer seemed to like Carolina rhododendron at Long Hill. They completely damaged the Carolina rhododendron and did not touch the other rhododendrons. Winter damage is also being observed on some plants especially those exposed to cold winter winds.

East Region (Boston)

General Conditions: January began with record-setting cold temperatures. We experienced 13 consecutive daytime temperatures below 32° F from December 26th through January 7th with eight of those with highs in the teens including a six-day stretch from December 28th to January 2nd. A nor'easter on the 4th delivered 11.0 inches of snow. Temperatures warmed, reaching the low 60s on the 12th and 13th, as a warm front dropped over two inches of rain. Temperatures were up and down during the latter half of the month with precipitation falling mostly as rain. Overall, January temperatures were seasonal with excess precipitation; 14 inches of snow fell accounting for 5.3 inches of rain equivalent.

February was unusually warm; in contrast with January, we experienced only one day with temperatures below freezing. We again set records in February, this time not for the longest arctic cold stretch, but instead for record high temperatures as we hit 71°F and 74°F on the 20th and 21st respectively. Not only were records broken on both days, but it should be noted that Boston has only experienced February highs in the 70s on two occasions since records began in 1892, one of those occurred in 2017. Despite the warm temperatures, we did manage to receive 9.5 inches of snow, the largest event occurring on the 17th dropped 6 inches, all of which melted away by the 18th. Precipitation was consistent during the month with dry spells lasting no more than 3 days. As warm temperatures melted away the January snowfall, soils were saturated and very muddy. We received 4.04 inches of rain equivalent for the month. Warm conditions and lack of snow, more reminiscent of spring, made grass green up by just the slightest amount. Buds were swelling and cornelian cherry (Cornus mas) had just begun to open. With an average high of 46°F (more than 7 degrees above normal) and soils plenty moist, things were looking good for an early spring. There was such an abundance of moisture that the ponds were full and the swamp had overflown, blocking off foot access along one of the two paths.

March has been a different story so far. We welcomed meteorological spring (March 01), reaching temperatures of 62°F - that would be the last day temperatures were above 45°F. Over the last 19 days, highs have hovered between the mid-thirties and mid-forties. Three Nor'easters have impacted the area. The first on the 2nd dropped 2.63 inches of rain with gusts topping 52 mph, the 2nd on the 7th dropped 8.5 inches of snow and the 3rd on the 13th, dropped 17.6 inches of snow. A fourth is expected overnight on the 21st/22nd. With a strong sun angle, and temperatures in the 40s, much of the snow has melted on slope and open areas, while in other areas, snow depth remains at 8 inches. Where the snow has melted, snowdrops are beginning to flower, daffodil foliage is peeking up through the snow in some areas. While there are a couple of Siberian squill (Scilla siberica) in flower, these are mostly found around buildings and warmer protected areas. Currently in bloom, are red maple (Acer rubrum), silver maple (Acer saccharinum), American hazelnut (Corylus americana), beaked filbert (Corylus cornuta), Szechuan Filbert (Corylus heterophylla var. sutchuenensis), witch hazel cultivars (Hamamelis x intermedia), cultivar of Japanese witch hazel (Hamamelis japonica 'Tsukubana-kurenai'), black pussy willow (Salix gracilistyla var. melanostachys), and rosegold pussy willow (Salix gracilistyla).

Pests/Problems: Pilewort (Ficaria verna) began to emerge in February as temperatures were unseasonably warm and soils moist. Rabbit damage can be found throughout the collection, but mostly in protected areas, where it tends to be more difficult for avian predators to hunt. Prior to March, garlic mustard (Alliaria petiolata) rosettes were visible in bare ground as was wild garlic (Allium vineale). Winter burn damage on hemlock has been spotty. Of those trees affected, 40% damage has been observed, while other trees show no signs of winter burn. Low numbers of gypsy moth egg masses were found and removed during winter scouting. From the end of November to the end of December, we observed low numbers of winter moth flight; trap counts confirmed that winter moth populations are very low this year. Comparing trap counts from previous years, numbers of adults are at 2012-2013 levels. Adult mating was low as minimal egg masses were deposited on traps. After four years of heavy spring defoliations, reduced numbers of winter moth feeding will give plants a chance to recover. The three March nor'easters left significant damage; saturated soil and high winds associated with the first left almost 30 trees with either major damage or as complete losses. Snow associated with both the second and third nor'easter was heavy, causing a 2nd and 3rd round of damage to trees, although to a lesser extent. Branches are down throughout the area and crews have been busy with clean up.

Metro West (Acton)

General Conditions: This winter certainly will be one referenced for years to come! Most notable were the high temperatures recorded on February 20th and 21st with highs of 71° and 75° recorded bringing an early mud season to the area and the back to back to back Nor’easters experienced in less than two weeks in early March on the 2nd, 7th, and 13th. And let’s not forget the subzero temperatures that were recorded way back in late December and early January. On 10 occasions, below zero temperatures were recorded with the coldest reading on January 2nd with a -13!  As I write this message, the weather forecasters are predicting a 4th Nor’easter to hit this area later today, bringing with it heavy wet snow. Weather lore uses the following idiom to describe typical March weather: March comes in like a lion and goes out like a lamb! After this month it may be more appropriate to alter the idiom and write: March comes in like a lion and goes out like a lion! Also, let’s not forget that the first day of spring was just yesterday on the 20th. Other than the Hamamelis spp. (Witch Hazel) in bloom, one would never suspect it and would think that it was a typical mid-winter day

Pests/Problems: At present, the Acton area is covered with a thick blanket of snow due to the recent nor’easters. Snowdrops seen weeks ago and just ready to bloom are now buried in snow. Also buried are downed branches and/or portions of trees making it difficult if not downright impossible for storm clean up. Uprooted wind thrown trees and trees with hangers and breaks of all sizes, some exposing heartwood, others are not, are scattered throughout the landscape. Shrubs, such as Forsythia, Hamamelis (Witch Hazel), Philadelphus (Mock Orange), Physocarpus (Nine Bark), and Viburnum are flattened by the weight of the snow.

Central Region (Boylston)

General Conditions: The beginning of January was marked by penetrating cold with subzero nighttime temperatures and even deeper windchill factors. February was milder than normal with record-breaking warmth on the 20th and 21st, allowing witch hazels (Hamamelis cvs), early crocus (Crocus tommasinianus) and snowdrops (Galathus nivalis) to bloom.  March took a turn in the opposite direction and returned to a colder, snowier pattern than normal with three nor'easters providing nearly constant snow cover throughout the month. Wet and heavy March snow caused significant tree and shrub damage throughout the region, though the higher elevations in Central Mass escaped the worst of the damage. 

Winter injury began showing up in February on evergreens like Rhododendrons, Hemlock (Tsuga canadensis), some Hollies (Ilex sp.), and Dwarf Alberta spruce (Picea glauca 'Conica').

Some plants are retaining more foliage than normal, Japanese Maples (Acer palmatum) and  Ironwood (Parrotia persica), for example, never shed their leaves in the fall, and much of it still remains.

Pests/Problems: Heavy deer and vole pressure due to persistent snow.

Pioneer Valley Region (Amherst)

General Conditions: Happy spring and welcome back to the Landscape Message. The 2018 growing season is upon us and I am very eager to plant some trees and shrubs, as I know many of you are as well. Winter’s cold grip is still lingering, but the Pioneer Valley has fared far better this month compared to the other regions of Massachusetts, outlined below. 2018 started with bitterly cold temperatures throughout the northeast. During a 12-day stretch from 12/27/17 through 1/7/18, the average low temperature was -2° F with a maximum low temperature of -15° F on 1/7. Harsh winds were also present at this time, sending wind chill values into the -20s and even -30s. Suffice to say, it was really cold. Conditions then moderated with intermittent snow storms as the doldrums of winter rolled on. Temperatures in late February and early March fooled us into thinking we may have an early spring. Between 2/14 and 2/28, we experienced nine days with high temperatures above 50° F. Furthermore, on 2/20 and 2/21, highs in Northampton reached 71° F and 80° F, respectively. Spring-flowering witchhazels exploded into bloom and bees were visible collecting pollen at their flowers! However, since the first week of March the mercury has been trending steadily downward, with a low temperature of 18° F on 3/20, the first day of spring. Overall, temperatures during the first half of March were 2-6 °F above normal, especially in Franklin County, according to the Northeast Regional Climate Center. Many snow lovers in the tri-county region often bemoan the infamous “snow holes” that form over the Connecticut River Valley and this recent trend of nor’easters only cemented this view. While the Berkshires and Worcester County eastward were inundated with fresh snow this March, the valley has received only minor accumulations. Soils in many landscape settings thawed during the late February warm-up and have been frost free ever since. However, moisture levels are very high at this time, rendering most soils less than ideal for planting right now. Red/silver maple and elm buds are swollen and a large silver maple on the UMass campus was in full bloom on March 9, but most of the early blooming trees are not in flower yet.

Pests/Problems: The arctic blast that pummeled the northeast to start the New Year has resulted in widespread injury on broad-leaved evergreens. Rhododendron, azalea, andromeda, holly, among others are exhibiting burn symptoms at this time. Symptoms appear as diffuse bronze- to brown-colored patches scattered across the leaf surface, wilting and branch dieback. Recently transplanted shrubs were particularly hard hit, as the shock of transplant inhibited cold acclimation. Once temperatures are consistently warm in May, many opportunistic fungal pathogens will colonize these blighted plant parts and further the dieback. Identify shoots that are unlikely to grow out of the injury and prune them. If the damage is minor to moderate, closely monitor the foliage to determine if a foliar pathogen has established and treat accordingly. Many mature plants will simply grow out of the injury but younger plants may need extra care, such as supplemental water during extended dry periods this summer. Winter burn on hemlock is common throughout the region. Symptoms of winter burn on eastern hemlock can range from localized to widespread needle browning in the canopy. The damage tends to develop on the needle tips at first and then spreads towards the base. However, at times it can occur sporadically across the needle. Widespread needle browning in the canopy can result in serious canopy dieback on landscape trees. The injury is often the result of exposure to extreme cold temperatures and harsh winds. Another way that hemlocks can suffer winter burn is through transpiration during the winter months. Sections of the canopy facing the sun are warmed during bright, sunny winter days, especially when reflective snow cover is present. The warming induces transpiration from the needles. However, since the soil and roots are frozen, water that is transpired from the needles cannot be replaced, leading to drying and desiccation. Hemlocks suffering from drought stress may be predisposed, as drought stress is known to inhibit cold acclimation as trees prepare for the dormant season. Additionally, abnormally warm autumn weather can also delay cold acclimation, making hemlocks more susceptible to cold injury. As a shallow rooted tree, hemlocks can be particularly susceptible to drought and thrive in forests with a thick layer of organic matter that buffers against soil drying. Recently transplanted trees and those suffering from disease or insect issues (e.g. hemlock woolly adelgid or elongate hemlock scale) can also be at higher risk for winter burn. Continue to scout for and prune cankered stems and branches. Apple scab was severe in many locations in 2017, meaning that high levels of overwinter inoculum may be present. Pruning crabapples and apples to remove interior canopy shoots under heavy shade will remove some of the most susceptible plant parts and improve air flow through the canopy, which promotes drying of the leaves.

Berkshire Region (Great Barrington)

General Conditions: The New Year began with bitterly cold weather with high temperatures only in the single digits on January 1 (6º F) and January 6 (4º F). Several nights had low temperatures below zero, bottoming on January 7 at minus 10º F. Despite several stretches of below normal cold temperatures since the beginning of the year, there were some unusually warm temperatures: 61º F (1/12), 63º F (2/20), and 73º F (2/21). With the current run of colder than normal temperatures in March, it would seem that, overall, this has been a colder than normal winter. Yet, the number of heating degree days is well below normal: 5585 (actual) versus 6076 (normal), as measured in Pittsfield. Snowfall this winter season is well above normal levels. As of March 20, total snowfall at the Great Barrington monitoring site is 88.3 inches for the season, about 40 inches above average. In Central Berkshire County, season to date snowfall total is 102 inches, well above the average season to date of 54 inches. Recent snowfalls have been mostly of the heavy, wet type. The snowstorm of March 2 resulted in some power outages and numerous downed branches. The storm of March 7 -9 dumped 18.5 inches of snow, Besides Hamamelis x intermedia, the only plants in bloom are snowdrops (Galanthus) though they are currently under a snow cover of about 1-2 feet.

Pests/Problems: Deer have taken to browsing on woody plants in a big way this winter. Though the most heavily browsed plants are such favorites as common yew (Taxus) and arborvitae (Thuja), deer have not been quite as fussy of late due to the deep snows which make movement about the landscape very difficult. Deer have frequently taken to marching down driveways and walkways in order to get at shrubbery on people’s yards. Besides deer browsing, damage to trees and shrubs, weighed down by heavy snows, is the most common landscape problem now. In addition to outdoor issues, the emergence in homes by insects such as the Multicolored Asian Lady Beetle is a common complaint.

Regional Scouting Credits

  • CAPE COD REGION - Russell Norton, Horticulture and Agriculture Educator with Cape Cod Cooperative Extension, reporting from Barnstable.
  • SOUTHEAST REGION - Deborah Swanson, UMass Extension Horticulturist for Plymouth County - Retired, reporting from Hanson.
  • NORTH SHORE REGION - Geoffrey Njue, Green Industry Specialist, UMass Extension, reporting from the Long Hill Reservation, Beverly.
  • EAST REGION - Kit Ganshaw & Sue Pfeiffer, Horticulturists, reporting from the Arnold Arboretum, Jamaica Plain.
  • METRO WEST REGION – Julie Coop, Forester, Massachusetts Department of Conservation & Recreation, reporting from Acton.
  • CENTRAL REGION  -  Joann Vieira, Horticulturist, reporting from Princeton.
  • PIONEER VALLEY REGION - Nick Brazee, Plant Pathologist, UMass Extension Plant Diagnostic Lab, reporting from UMass Amherst.
  • BERKSHIRE REGION - Ron Kujawski, Horticultural Consultant, reporting from Great Barrington.

Woody Ornamentals

Diseases

Winter burn of landscape conifers and broad-leaved shrubs is the biggest concern right now. Numerous eastern hemlock samples have been submitted with varying levels of needle browning and branch dieback. In addition, western redcedar (Thuja plicata) and Oriental spruce (Picea orientalis) samples with winter burn have been submitted. Scouting for conifers that are marginally hardy in our region (e.g. Blue Atlas cedar and Japanese Cryptomeria) have indicated burn on these trees as well, depending upon the specific location and exposure.

New or updated UMass Extension Tree and Shrub Disease Fact Sheets for 2018 (http://ag.umass.edu/landscape/fact-sheets/diseases):

1. Stigmina Needle Cast

2. Phomopsis Canker

3. Armillaria Root and Butt Rot

4. Botryosphaeria Canker

5. Phytophthora Bleeding Canker

6. Phytophthora Root and Crown Rot

7. Root and Butt Rot Pathogens of Oak (Quercus spp.)

8. Tar Spot of Maple

9. Tubakia Leaf Blotch

10. Sycamore Anthracnose

11. Oak Anthracnose

12. Guignardia Leaf Blotch

13. Verticillium Wilt

14. Diplodia Blight

15. Black Knot of Prunus

16. Coral-Spot Nectria Canker

17. Spruce Needle Rust

18. Rhabdocline Needle Cast

19. Ploioderma Needle Cast

20. Wetwood & Slime Flux

21. Oak Leaf Blister

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

Insects

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

  • Winter Moth: (Operophtera brumata) The winter moth population is at a record low! The 2018 outlook concerning winter moth caterpillar population numbers in Massachusetts is very positive for those of you in the eastern areas of the state accustomed to dealing with damaging populations of this insect. Dr. Joseph Elkinton, Professor of Environmental Conservation at the University of Massachusetts, Amherst, MA, has excellent news: data from his lab’s research locations in eastern Massachusetts suggest that this invasive pest’s population size is at an all-time low. In fact, the 2017 winter moth population was the lowest they have seen since studying and working toward the biological control of this insect for the past 13 years. The populations of winter moth are so low in Massachusetts at this time, that Dr. Elkinton’s lab and scouts for UMass Extension’s Landscape Message are having a very difficult (to impossible) time locating winter moth eggs to monitor egg color change, development, and hatch for the 2018 season. Heather Faubert, with the University of Rhode Island, reports far fewer winter moth eggs present at the locations she typically monitors. To date (as of 3/21/18) she has not reported winter moth egg color change or hatch at her locations in Rhode Island, Connecticut, or the two sites she has in Massachusetts.

The eggs of this insect, if they can be found, were laid by the females who emerged in November of 2017 and were active through the winter months (mainly November through December when temperatures are above freezing). Eggs are currently present in the landscape and hidden in cracks and crevices of bark or beneath lichen on host plants such as oak, maple, apple, blueberry, crabapple, etc. Eggs are tiny and green when first laid, but quickly turn a red-orange color soon after. At this time, anyone monitoring winter moth eggs will most likely see that they are orange in color. As the egg develops, it will turn a bright blue color, shortly prior to egg hatch. For more information about the life cycle and management of winter moth, please visit thisfact sheet: Winter Moth Identification and Management (https://ag.umass.edu/landscape/fact-sheets/winter-moth-identification-management).

Management of winter moth in 2018 may only be necessary for high-value agricultural crops (such as blueberry) or where managers are actively monitoring winter moth eggs and have observed numbers of eggs consistent with previous years when damage occurred. It is expected, however, that in most locations in eastern Massachusetts, a reprieve from damaging winter moth caterpillar populations will occur in 2018.

Winter moth is a non-native insect that was identified in Massachusetts for the first time in 2003 following persistent reports of defoliation in eastern areas of the state such as Cape Anne and on the North Shore near Cohasset, Hingham, and Rockland on the South Shore in the late 1990’s. For more detailed information about the history of this insect pest in North America and Massachusetts, please visit this fact sheet: Winter Moth in Massachusetts: History and Biological Control (https://ag.umass.edu/landscape/fact-sheets/winter-moth-in-massachusetts-history-biological-control).

This fact sheet also includes updates regarding the progress of the work of Dr. Joseph Elkinton’s laboratory group at the University of Massachusetts and their efforts towards the biological control of winter moth using Cyzenis albicans, a tachinid fly. The fly parasitizes the caterpillars of winter moth specifically. In other areas, such as Nova Scotia where winter moth was also problematic, this fly used for biological control has been successful in reducing winter moth to a non-pest. C. albicans has been released across 43 sites in Massachusetts and has been established in at least 32 of those locations as evidenced through the recovery of flies in winter moth in subsequent years. The Elkinton Lab now has data showing that at six of these locations, the fly populations have increased alongside an observed decrease in the winter moth population there. For more information about the progress of winter moth biological control in Massachusetts, visit the following article in Hort Notes found under “Trouble Maker of the Month”, here: https://ag.umass.edu/landscape/newsletters/hort-notes/hort-notes-2018-vol-292.

  • Gypsy Moth:(Lymantria dispar) The outlook for the 2018 season in regard to gypsy moth is significantly better than it would have been if Entomophaga maimaiga didn’t outbreak in the gypsy moth caterpillar population in late June of 2017. At that time, many dead caterpillars were seen hanging from tree trunks and branches, killed by the fungus, which was aided by the wet spring weather earlier in the year. Need a reminder of what that looked like? Go to: https://ag.umass.edu/landscape/news/gypsy-moth-caterpillars-dying-across-massachusetts. Unfortunately, prior to the fungal epizootic, gypsy moth caterpillars were able to defoliate over 923,000 acres across Massachusetts in 2017, according to the MA Department of Conservation and Recreation. For a map of where this occurred, visit: https://www.mass.gov/guides/gypsy-moth-in-massachusetts.

Egg masses laid by female moths in 2017 can be seen at this time. This is the stage of the insect that overwinters. Egg masses are “fuzzy” or hairy and brownish-tan in color. Each egg mass can hold up to 500-1000 eggs. These masses may be found on host plant trunks and branches such as oak (favored), maple, birch, poplar, and many others, but are also laid on inanimate objects including the surfaces of homes, outdoor furniture, camping equipment, firewood piles, etc. This may make the accidental movement of gypsy moth egg masses possible.

Egg hatch for this insect is also not yet upon us, and occurs after winter moth egg hatch. Gypsy moth egg hatch typically occurs between 90-100 growing degree days, using a base of 50°F and average temperatures. This is usually around the first week in May in Massachusetts, but variations in temperature may lead to early egg hatch in the last week in April. This can also coincide with serviceberry (Amelanchier) bloom. After egg hatch occurs, groups of tiny gypsy moth caterpillars may remain on their egg mass just before crawling to the canopy of their host plant, where they can disperse using a technique known as “ballooning”. Ballooning occurs when very young caterpillars spin a silken thread and catch the wind to blow onto a new host plant once the thread breaks. This method of dispersal can lead to host plants becoming defoliated that previously did not have egg masses directly on them, however egg masses may be present on nearby oaks, for example, and provide a local population of caterpillars.

Now (until before the last week in April) is a great time to scout the landscape and count the number of gypsy moth egg masses present not only on valuable landscape specimens that are hosts for this insect, but on nearby forested hosts such as oak which might provide sources of ballooning caterpillars. Egg mass counts can help us make decisions regarding whether or not to manage for this insect. Some individuals also use this opportunity to scrape egg masses into a container of soapy water, although this is time consuming and some egg masses will be missed.

Despite the fungal outbreak that swept through the 2017 caterpillar population, some lucky caterpillars survived to pupation and emerged as adult moths. (However, adults were present in far fewer numbers than would have existed without the fungus.) While it is very difficult to predict how much defoliation Massachusetts will see in 2018 due to gypsy moth caterpillar feeding, we can be certain that in areas where many egg masses are currently seen overwintering, pockets of defoliation could still occur in certain areas of the state this year. Thanks to the gypsy moth caterpillar-killing fungus, however, the population should be on the decline, but we cannot expect the caterpillars to disappear completely from Massachusetts landscapes this season.

  • Emerald Ash Borer: (Agrilus planipennis, EAB) A new community detection of emerald ash borer was confirmed last week by the Massachusetts Department of Conservation and Recreation in Hampshire County, MA. A map of this location and others 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 most recently, 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. Positive identification of an EAB-infested tree may not be possible with these signs individually on their own.

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

  • 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. These particular signs of damage from the beetle may be more visible at this time of year, when host trees such as maples are leafless. 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. Adult insects of this species will not be present at this time of year.

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.

  • Spotted Lanternfly: (Lycorma delicatula, SLF) is not known to occur in Massachusetts. This insect is a member of the Order Hemiptera (true bugs, cicadas, hoppers, aphids, and others) and the Family Fulgoridae, also known as planthoppers. This insect is a non-native species first detected in the United States in Berks County, Pennsylvania and confirmed on September 22, 2014. Until November, 2017, this invasive insect was only known to Pennsylvania. It has now been reported from Delaware (November 20, 2017), New York (November 29, 2017), and most recently in Virginia (January 10, 2018). The Delaware Department of Agriculture announced the finding of a single female spotted lanternfly in New Castle County in the Wilmington, Delaware area. At this time, officials in Delaware note that it is unclear if this individual was an accidental hitchhiker, or evidence of an established population in the state. For more information about the find in Delaware, visit: https://news.delaware.gov/2017/11/20/spotted-lanternfly-confirmed-delaware/. The New York State Department of Agriculture and Markets reported on November 29, 2017 the finding of a single dead individual spotted lanternfly in the state from earlier in the month. A single dead specimen was confirmed at a facility in Delaware County, New York, which is located south-west of Albany. The NYS Dept. of Agriculture and Markets states that this dead individual may have come in on an interstate shipment. For more information about the find in New York, visit: https://www.agriculture.ny.gov/AD/release.asp?ReleaseID=3637. Most recently, Virginia Cooperative Extension announced the finding of a spotted lanternfly population in Frederick County, Virginia, on January 10, 2018. It was noted that at the location in Virginia, numerous adult lanternflies and egg masses were discovered, in addition to more at another site approximately 400 yards away. For more information about the find in Virginia, visit: https://ext.vt.edu/agriculture/commercial-horticulture/spotted-lanternfly.html.

The spotted lanternfly is considered native to China, India, and Vietnam. It has been introduced as a non-native insect to South Korea and Japan, prior to its detection in the United States. In South Korea, it is considered invasive and a pest of grapes and peaches. The spotted lanternfly has been reported from over 70 species of plants, including the following: Tree of heaven (Ailanthus altissima), apple (Malus spp.), plum, cherry, peach, apricot (Prunus spp.), grape (Vitis spp.), pine (Pinus spp.) and others.

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

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

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

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

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

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

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

Plant of the Week

Betula nigra is a great choice for providing ornamental interest to the winter landscape:

https://extension.umass.edu/plant-identification/river-birch

Report by Mandy Bayer, Extension Assistant Professor of Sustainable Landscape Horticulture, UMass Stockbridge School of Agriculture


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Diagnostic Services

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

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