The 2025 season brought another year of dramatic swings in weather, pest pressures, and plant health challenges across Massachusetts. From early spring leaf-out and erratic rainfall to the rapid rise of several invasive insects, homeowners saw firsthand how quickly the landscape can change. This annual review highlights the most important Massachusetts pest and plant health trends of 2025—and what they mean for your trees, shrubs, and outdoor spaces moving forward.

Trends in Weather

Weather patterns in 2025 continued the irregular trends we’ve seen in recent years. Spring arrived early and brought warmer, wetter conditions that accelerated leaf-out but also created ideal environments for foliar diseases. Summer was hot with sporadic, intense rainfall that often failed to replenish soil moisture. By early fall, much of the region experienced moderate drought, and many ornamental trees and shrubs showed signs of stress as a result.

Because rainfall rarely arrives when plants need it most, supplemental watering remains one of the most effective ways to support plant health. Smaller perennials may show drought stress within days, whereas trees—thanks to their larger biomass and energy reserves—may not display symptoms until months or even years after the initial stress period. Since we cannot control weather-related stressors, it becomes even more important to manage the ones we can: selecting plants suited to their site, choosing pest- and disease-resistant varieties, supplementing water during dry periods, and addressing significant insect and disease pressures before they compound.

According to the Blue Hill Observatory, the region received 42.31 inches of precipitation through October 2025, which is 2.20 inches above the long-term average. Monthly rainfall varied widely:

• May was the eighth-wettest May on record at 7.62 inches, nearly 4 inches above normal.
• July and October also saw significantly above-average rainfall.
• January, February, June, and August were notably dry, each 1.5–2.3 inches below typical levels.

This variability reflects yet another year of unpredictable precipitation, with alternating periods of excess moisture and short-term drought—conditions that continue to influence plant health across the landscape.

Insects: Up & Coming

Box Tree Moth:

MDAR Invasive Pest Dashboard

The box tree moth (Cydalima perspectalis) has expanded its range on Cape Cod this past year and has also been found in Brookline.  The moth’s larvae feed on boxwood leaves, causing defoliation. Several overlapping generations are expected to occur per year, with an estimated 1-5 generations possible from May to September. Green caterpillars with black-and-white stripes skeletonize leaves and form webbing on branches.  Severe infestations may cause branches to brown and plants to die.

To protect your boxwoods, monitor regularly for infestations.  Small infestations may be controlled with selective pruning.  As this pest continues to spread itself around regular spraying may become necessary to manage this pest.  Boxwoods also regularly suffer from boxwood psyllid, boxwood leafminer, and spider mites, as well as diseases like boxwood blight, Volutella and leafspots and winter injury.  Depending on the situation, replacement with alternative plants such as Japanese holly may be an option.  If you suspect a box tree moth infestation, call us and report it to MDAR to help track and control its spread. https://massnrc.org/pests/report.aspx

(Damage caused by box tree moth caterpillar feeding viewed on plants in Barnstable County, MA in 2023. Photo courtesy of Russ Norton, Cape Cod Cooperative Extension.)

Spotted Lanternfly:

Spotted lanternfly is spreading fast across the state.  Some of the newest established populations have now been in the Seekonk and Attleboro area.  There have been several other sightings of individuals throughout the state, but no established populations were found associated with them.  Spotted lanternfly is particularly problematic for grapes and fruit trees because of the damage to fruit and productivity.  In the landscape, however, they are more of a nuisance for a wide variety of shrubs and trees.  The primary concern is the high numbers and density of insects and the mess they make by their feeding.  As sucking insects, they will produce lots of honey dew (liquid insect poop) and black sooty mold that will then grow on the sugary excrement.  Everyone should be on the lookout for this pest since continued spread is very likely.  If any life stages of this insect are found in Massachusetts, it should be reported here: https://massnrc.org/pests/slfreport.aspx .

2025 Spotted Lanternfly

2024 Spotted Lanternfly

Scales and Bagworms:

Other insects that we have seen on the rise but are not newly introduced are bagworms and magnolia scale.  Magnolia scale was very prevalent this year and seems to be more and more prevalent each year.  This is a large, white, soft scale that looks like a white lump on twigs and branches.  Infestations become very obvious late into the summer when copious amounts of honeydew lead to black sooty mold, as well as flies, bees, and wasps.  This is a difficult scale insect to eradicate once a tree is infested, but over time, a combination of systemic and spray applications can manage it.  Annual treatment will likely be needed for long-term management to keep the scale from coming back.

Bagworm is another insect that has become much more common in recent years.  These caterpillars use parts of the plants they are feeding on to build a bag around themselves, acting as protection and camouflage.  Arborvitae, juniper, and cedar are among the most common plants typically fed on, but wide varieties of plants, including deciduous plants, could be hosts. A few of these caterpillars can be easily overlooked, but as the population increases, they can easily defoliate trees and permanently damage evergreens, creating large dead areas or killing the plant.

Pests:

Mosquitoes

Mosquitoes are going to be a problem at some point, no matter the weather, but this year, mosquitoes were actually a bit less.  This could have been due to the big fluctuation in rainfall discussed earlier, with short-term droughts.  The instances of mosquito-borne diseases were reduced this year overall.  This year, there were 451 positive West Nile Virus mosquito samples collected, but only 9 human cases of WNV, half the number as last year.  Eastern equine encephalitis was only found in 23 samples, with 0 human cases in the state.  Both WNV and EEE are spread when mosquitoes feed on infected birds that then bite people.  Infected mosquitoes also spread the viruses to other birds.

Mosquitos take about 2 weeks to develop.  Eggs will hatch within 2 days, larvae in a week or more, and another couple of days to pupate.  Mosquitoes lay their eggs in standing water. Limit the number of places around your home for mosquitoes to breed by draining or discarding items that hold water every couple of days, and check rain gutters and drains.  Aside from reducing breeding as much as possible, regular treatments can help to manage mosquito populations in your yard.

Ticks

Top, from left: The blacklegged or deer tick and American dog tick; bottom, from left: lone star tick and Asian longhorned tick Smith Collection/Gado/Getty Images; CDC

There are several kinds of ticks to be on the lookout for in Massachusetts.  Black legged ticks are the most common ticks and are the primary transmitter of Lyme disease.  Dog ticks are somewhat larger and less common to bite people.  Lone star ticks are more aggressive in seeking out hosts compared to the questing most ticks do, waiting for a host to brush past.  Lone star ticks are mostly isolated to Cape Cod and the islands at this point.  There is yet another new invasive tick species spreading, called the Asian longhorned tick.  Asian longhorned ticks have been primarily associated with livestock but can bite people and pets as well and do not need to mate to produce thousands of eggs.

The same precautions to avoid black legged ticks will help with these other species as well.  Aside from regular yard treatments, repellents containing DEET, picaridin, and oil of lemon eucalyptus can be used for both ticks and mosquitoes directly on skin or permethrin can be used to treat clothes.

The graphs below show that in 2025, the number of tick exposure visits were way up in the spring and early summer compared to the last few years.  The number of visits to Emergency Departments (ED) in any week related to exposure to ticks was over 0.6%, while the number of visits to EDs in any week were related to the diagnosis of a tick-borne disease was average. The 2025 data are shown compared to both the minimum and the maximum number of visits recorded over the few years. While tick activity usually increases in Spring and early Summer and then again in Fall, exact timing is dependent on weather.

Massachusetts Department of Public Health, Bureau of Infectious Disease and Laboratory Sciences. Tick Exposure and Tick-borne Disease Syndromic Surveillance Report, October 2025. http://www.mass.gov/eohhs/gov/departments/dph/programs/id/

This map shows the rate, per 10,000 total population, of ED visits by patients who had a visit related to a tick exposure, by Massachusetts county of residence, 2025 to date. Although there are differences in the rate of patient visits, this shows that people are exposed to ticks throughout all of Massachusetts and should take recommended steps to reduce the chance of being bitten.

Ticks can carry a number of different diseases at one time, not just Lyme disease.  Lyme disease (Ticks need to be attached to the skin for at least 24 hours to spread Lyme disease.), Babesiosis, and Anaplasmosis are fairly common.  Borrelia miyamotoi and Powassan virus are rare diseases spread by the black-legged tick.  Tularemia and Rocky Mountain spotted fever are rare diseases spread by dog ticks. Ehrlichiosis is a bacterial disease spread by the lone star tick, which has only been found in southeastern Massachusetts.

(Green: Lyme Disease, Blue: Babesiosis, Red: Human granulocytic anaplasmosis (HGA))

Massachusetts Department of Public Health, Bureau of Infectious Disease and Laboratory Sciences.

Tick-borne Disease Surveillance Summary, 2024.

https://www.mass.gov/lists/tick-borne-disease-surveillance-summaries-and-data

Plant Diseases:

Trees require moist, well-drained soils in order to thrive.  Conditions often found in residential landscapes, such as restricted root zones, soil compaction, sandy soils, and competition from surrounding trees and turfgrasses, drought, or even overwatering, contribute to decline.

Beech Leaf Disease

Beech leaf disease (BLD) is an important disease of European and American beech trees.  In just four years the disease has spread across the whole state.  The map shows how much the disease has spread in the last few years.  Unlike most other plant diseases that are caused by fungi, BLD is caused by a leaf-infecting nematode (a microscopic round worm).  Early signs of infection can be identified by dark banding between the leaf veins when looking at backlit leaves.  There are foliar spray treatments as well as trunk injection that may help manage this disease and keep old established beech trees healthy for longer.  Infection for only a few years may be enough to kill some trees.  This disease only adds to the more common Phytophthora bleeding cankers, and beech bark disease causing decline in beech trees.  It is worthwhile to begin treatment even with seemingly healthy trees to help reduce infection.

If you have seen any symptoms on your trees and shrubs that you think are not normal, let us know.  We would be happy to help identify the problem and recommend solutions to help manage your plants.

As 2025 comes to a close, one thing is clear: unpredictable weather and shifting pest populations continue to reshape plant health in Massachusetts. Staying ahead of these trends with early detection, consistent monitoring, and timely treatments can make all the difference in protecting your landscape. If you notice anything unusual in your trees or shrubs—or simply want expert guidance—our team is here to help diagnose the issue and recommend the right solutions for long-term plant health.