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Tag: Pests

Latest Update on Beech Leaf Disease in New England

Written by Lou DiToro on . Posted in Blog.

Beech trees are a keystone species in many ecosystems. Their fruit – the beechnut – is a food source for many animals, including squirrels, deer, birds, and bears. Their canopies shelter animals and provide nesting sites for birds. Their wood is solid and hard with a beautiful grain. Beeches are also famous for their fall foliage and smooth bark. Plus, they have some cultural significance. Ancient people used their bark as paper.

But beeches are under attack now from Beech Leaf Disease (BLD), a deadly disorder that threatens native American beeches and ornamental European beeches. Researchers first detected BLD in Ohio in 2012. It then spread to other states and Canada. It’s now in 12 U.S. states and several Canadian provinces. Researchers found BLD in CT in 2019 and RI and MA in 2020. BLD is especially deadly to young beech trees and the ecosystems they support.

What is Beech Leaf Disease?

Nematodes cause BLD. These microscopic worms (Litylenchus crenatae mccannii) spend the winter in beech buds and beech leaves and emerge in the spring, showing damage to the tree. Infected leaves have dark brown bands between leaf veins or are crinkled, smaller, and leathery than typical beech leaves. Symptoms are more noticeable on North American beeches than on European beeches.

Some beech buds won’t open on heavily infected trees. Severely damaged leaves will fall off soon after emerging in May. New leaves may appear in June in new buds and won’t show signs of the disease, but they will be paler and weaker than typical healthy leaves. Wind plays a big role in spreading the disease. So does the movement of infected plant material like firewood or nursery stock. BLD can spread fast in a forest

Impact of Beech Leaf Disease

Researchers are seeing beeches die within 6-12 years of infection. In Southern New England, beeches often die within a few years of infection. The disease’s effects on trees are critical. Like many tree diseases, BLD reduces photosynthesis and growth and increases susceptibility to other pests and diseases that can kill trees. BLD also causes loss of biodiversity and alteration of the forest ecosystem. Plus, it impacts the timber industry and tourism.

Researchers are working on management solutions for BLD. But there isn’t a cost-effective solution for forested environments yet. There are no effective fungicides for BLD, and treating large mature trees is difficult. Management options are limited but include the following:

  • Early detection and removal of infected trees
  • Development of resistant beech tree varieties
  • Biological control agents
  • Public awareness and education campaigns

In 2017, Ohio researchers had some success managing the disease by treating the soil around small beech trees (about 2-4 inches deep) with a phosphite product called PolyPhosphite 30. Phosphite products are known to stimulate a plant’s defenses.

The researchers treated the trees twice a month with the product about a month apart. The trees were much better after five years than the untreated control trees. They also found fewer nematodes on treated trees than on control trees. We hope to see similar results in New England.

How to Treat Beech Trees

Phosphite products for BLD are available to homeowners. Look for a product that is designed for BLD treatment. Agri-Fos and ProPhyt are good options for BLD. These products are in liquid form. Below are the seven steps to treating a BLD outbreak using a phosphite-based product and a soil drench approach:

1.     Measure the tree’s diameter at breast height—about 4.5 feet high

2.     Follow the product’s label instructions for dosage

3.     Mix the product with water according to the label

4.     Clear the area around the tree’s base of debris and leaf litter.

5.     Slowly pour the diluted phosphite solution into the soil.

6.     Let the solution soak into the root zone.

7.     Water the soil after application to help the solution penetrate deeper

Treat BLD in early spring before new growth begins. You may need to treat the area again later in the growing season. Depending on the disease’s severity and dosage instruction, you may need to treat the soil again.

You can also use a soil injection method to treat BLD. However, you need special equipment to inject phosphite into the soil around the root zone. Follow the manufacturer’s instructions for injection depth and spacing.

If you still have questions about BLD or its treatment, contact an arborist or RITree.  

DEM Warns of Invasive Insects Set to Appear This Spring

Written by Lou DiToro on . Posted in Blog, Pests to Watch.

The Rhode Island Department of Environmental Management is warning RI residents to remain vigilant for two invasive species as their lifecycles progress and they emerge this spring. The spotted lanternfly (SLF) and the winter moth are two plant pests threatening Rhode Island’s agriculture and forest. These threats remain the focus of DEM’s Division of Agriculture and Forest Environment‘s Cooperative Agricultural Pest Survey (CAPS) and Forest Health Program.

One pest is the spotted lanternfly, which can cause significant damage to crops and native trees. The SLF threatens many fruit crops, such as apples, apricots, cherries, grapes, hops, nectarines, peaches, and plums, as well as native maple, oak, pine, poplar, sycamore, walnut, and willow trees. DEM officials note the lanternfly is an “excellent hitchhiker” spread through human movement.”

Lanternfly adults lay masses of 30 or more eggs on surfaces ranging from tree trunks to patio furniture. These egg masses are typically 1.5 inches long, grayish-brown, and resemble clay. DEM started spraying for SLFs in Rhode Island in 2022. DEM and its partners will continue targeted treatments of trees and bushes infested with SLF as they try to limit the spread of this invasive pest.

Winter moths are an invasive defoliator from Europe. First detected in New England in the early 2000s, the caterpillars of winter moths feed on the leaves of deciduous trees in early spring after larval hatch. Winter moth caterpillars are lime green with creamy-yellow stripes running lengthwise along each side of the body. Preferred hosts include maple, oak, birch, apple, and blueberry. Young larvae feed within their hosts’ leaf and flower buds and are often difficult to spot at this stage. Caterpillar frass (insect droppings) are often easier to observe than the actual caterpillars.

While the increased winter moth activity during the past autumn has generated increased public interest, the winter moth’s defoliation effort isn’t nearly as damaging or widespread as spongy moths, formerly known as gypsy moths. That’s because winter moths do not completely strip leaves. They only cause tree mortality if defoliation is repeated year after year. DEM initiated a successful biological program in 2005 to control winter moths with the specialist parasitic fly Cyzenis albicans.

For more information on the spotted lanternfly and the winter moth, see RI Tree’s Pest to Watch page on its website.

Spotted Lanternfly, an Invasive Pest Targeting Plants and Trees, Detected for the First Time this Year in Rhode Island

Written by Robin Enos on . Posted in Blog.

Published on Monday, August 22, 2022

PROVIDENCE, RI – The Department of Environmental Management (DEM) announces that the spotted lanternfly (SLF), an exotic pest that targets various plants and trees, has a detected population for the first time in Rhode Island. Native to Asia, SLF is most frequently associated with Tree of Heaven plants (Ailanthus altissima) and feeds on a wide range of agricultural crops such as grape, apple, and hops and several native species of plants and trees including maple, walnut, and willow.

Patches of SLF that were found along Route 7 in Smithfield indicate this is Rhode Island’s first find of a population of SLF. This was confirmed by US Department of Agriculture (USDA) last week. DEM is currently continuing to survey the area to get an idea of the extent of its spread. Additionally, DEM, USDA, and the University of Rhode Island (URI) are working on management options to minimize its spread. DEM’s Division of Agriculture and Forest Environment (DAFE) confirmed the sighting on Aug. 19 and is asking the public to report any suspected sightings at www.dem.ri.gov/reportspottedlanternfly. DEM will be conducting an extensive survey of the area based on USDA recommendations to determine if there is any further presence of the invasive insect and will be providing outreach materials to businesses in the area.

“In Rhode Island, we have about 69,000 acres of agricultural lands with many of those lands at risk of being infested with SLF including vineyards, orchards, berry crops, and nursery stock,” said Senior Environmental Planner Cynthia Kwolek . “It’s critical that we take the necessary steps to detect and stop the spread of this invasive pest, particularly since it has now been found in our state.”

DEM and URI conducted a statewide SLF survey in 2021 of local vineyards and areas with large populations of Tree of Heaven plants. Also in 2021, DEM and URI held a series of public workshops to help municipalities, the grower industry, and residents prepare for and respond to this pest, should it be detected in the state.

Along with spotted patterning, the adult SLF has scarlet underwings, yellow markings on the abdomen, and tan semi-transparent forewings. Adult lanternflies are about an inch long and are active from August until the first hard freeze, which typically occurs around late October into November.

Although SLF can fly distances on its own, it is an excellent hitchhiker and mainly spreads through human movement. Its inconspicuous egg masses can be laid on pallets, vehicles, and other goods, so it is important to inspect shipping materials and adhere to travel restrictions when moving through areas that are under quarantine for SLF. The following tips can help stop the spread of SLF:

o Inspect firewood, vehicles, outdoor furniture, and camping gear for egg masses, nymphs, and adults.

o If you visit states with SLF, check all your gear and equipment before leaving and scrape off any egg masses.

o Take a photo, squash the insect, and make a report to DEM’s agricultural pest alerts website.

SLF was first detected in Pennsylvania in 2014 and has quickly spread through surrounding states. An invasive plant-hopper that is currently infesting parts of the mid-Atlantic region of the United States, SLF has established populations in Pennsylvania, New Jersey, Maryland, Delaware, Virginia, Indiana, Ohio, and recently Michigan with finds of populations also in New York, Connecticut, and Massachusetts. In Pennsylvania, where the pest has been spreading for over six years, there has been significant yield loss in vineyards and the insect has become a public nuisance.

To learn more about SLF, visit DEM’s Agricultural Pest Alerts website or the URI website. To report a potential finding, please visit: www.dem.ri.gov/reportspottedlanternfly.

For more information on DEM programs and initiatives, visit www.dem.ri.gov. Follow DEM on Facebook, Twitter (@RhodeIslandDEM), or Instagram (@rhodeisland.dem) for timely updates.

https://ridem.wufoo.com/forms/spotted-lanternfly-sighting-report-form/

Caterpillar Damage

Written by RITree on . Posted in Archives, Tree Care. No Comments on Caterpillar Damage

While most spring defoliators (Winter moth, Cankerworms, Gypsy moth and Eastern Tent Caterpillar are mostly done for the season, the larvae of the Forest Tent Caterpillar (FTC) are still feeding on foliage. The larvae are black with hour-glass-like spots running down the middle of their abdomen. Treat with registered pesticide, if the infestation is heavy.

Caterpillar damage is pretty bad this year. For some plants, this was the second year in a row that they defoliated.

What’s next for the affected trees and shrubs?
Will they re-foliate?
What’s the prognosis for their long-term health?
Is there anything their owners can do to help?

READ Defoliation of Deciduous Trees written by RITree’s Technical Advisor to learn the answers to these and other questions.

Trending Pests and Weather Conditions Impacting Plants

Written by RITree on . Posted in Pests to Watch. No Comments on Trending Pests and Weather Conditions Impacting Plants

The following is an excerpt of the lecture presented by RI Tree Council’s Technical Advisor, John T Campanini, Jr at the RI Federation of Garden Clubs Annual Education Day Program- Roger Williams Park Casino, November 4, 2019. The lecture’s title was “Trending Pests and Weather Conditions Impacting Plants.” In this article, I abridge my earlier lecture to examine specific pests which loom as future threats to woody ornamentals.

PLANT PESTS- There are five plant pests that should be on the radar of all plant stewards in 2020. Four are insects while the last is a disease causing fungus. They are itemized below:

  • Asian Long-horned Beetle (ALB- Anoplophora glabripennis)
  • Spotted Lanternfly (SLF- Lycorma delicatula)
  • Emerald Ash Borer (EAB- Agrilus plannipennis)
  • Bagworm (Thyridopteryx ephemeraeformis)
  • Boxwood Blight Disease

The ALB is by the #1 pest threat of hardwood trees including maple, birch, willow and elm in the Northeast according to the US-Forest Service. ALB kills trees by tunneling through the wood. Once the tree is infested it must be destroyed. The bittersweet news is while this pest has yet to be found in Rhode Island it is everywhere around us. It was discovered attacking trees in Worcester, MA in 2008 and in Boston in 2016. By imposing a quarantine on moving wood products and by inspecting vulnerable species, the Commonwealth has done a super job of containing the spread of this destructive pest into other New England States. Early detection is paramount to its management. In winter, the most obvious sign of this pest infesting host plants is the presence of numerous dime-sized, round holes on the trunk and on branches. For more information about ALB, visit http://www.na.fs.fed.us/spfo/alb.

Photo 1: The Asian Lon-horned Beetle adult is about ¾ to 1 ¼” long with mottled spots on the back. Note the dime-sized exit hole made by adult beetles as they emerge from the tree.

The Emerald Ash Borer is an exotic beetle from Asia discovered in 2002 feeding on ash trees in Michigan. Since then this small, bright green beetle has been responsible for the loss of millions of ash trees in North America. In July 2017, adult beetles were discovered in bait traps set out by RIDEM plant health inspectors in Westerly, Providence, Lincoln and Woonsocket, RI. These findings show the EAB is here, and that ash species are at risk. Plant damage and death is caused by the worm-like larval stage of EAB. The larva feed on the inner bark and phloem, creating “S” –shaped galleries. The feeding activity destroys the plant’s ability to transport water and nutrients to other parts of the tree, killing it. Unlike the ALB, there are options for protecting ash trees from EAB damage. But these options require comprehensive planning and should be directed with the assistance of a certified arborist. Learn about these options and more on EAB at www.emeraldashborer.info.

Photo 2: EAB adult beetles are smaller than a penny. They emerge in July to feed on ash leaves before laying their eggs between layers of bark and in bark crevices.

The Spotted Lanternfly is the latest exotic pest discovered in the United States with the potential to become a major plant problem. This sap-feeding plant-hopper was discovered attacking fruit trees, woody ornamentals and timber crops in Pennsylvania in 2014. New York and Connecticut authorities have also reported finding adults feeding on nursery stock in the past two years. SLF nymphs and adults are very colorful making them easy to detect. Young nymphs are “tick-like” with black and white spots. As they age, the nymphs develop red patches and grow to ½” long. The adults have two sets of wings. The forewing is gray with black spots. The hindwings are bright red at the base. Both nymphs and adults cause damage by feeding in huge populations (swarming) on the tissues under the bark of the trunk and branches. Plants literally starve to death from nutrient depletion from this type of voracious feeding. To learn more on the SLF, visit: www.uri.edu/biocontrol/spotted-lanternfly.

Photo 3: The important life stages of the Spotted Lantern-fly: eggs, wingless nymphs and the adult with wings for flight.

The bagworm is a native insect that, until recently, was mostly found in Pennsylvania and south. In the past decade, however, it has migrated to Northern areas through infested nursery stock. For years the bagworm was considered just a nuisance in RI with scattered outbreaks here and there. But, as the winters have gotten milder, this pest has learned to adapt and thrive and is today much more common. The bagworm prefers attacking evergreens. They include Arborvitae, Juniper, Leyland Cypress, Spruce and Pine. Certain deciduous species such as Black locust, Honeylocust and American Sycamore are also known host plants. The pest damage is done by the worm-like larvae. They feed on needles and leaves from late May through July. This causes the plant foliage to discolor yellow, turn brown before eventually dying. Plant injury can be very severe and entire plants can be killed in a single season. Bagworm infestations generally go undetected until damage is complete, and the large bags constructed by this pest is conspicuous. The bags provide over-wintering shelter to the egg-laying female adults inside. A simple control measure is to remove and destroy these bags as they appear. The other is to apply Captain Jack’s Dead-bug Spray (i.e., Spinosad) to the plant from early to mid-June while the larvae are small. For more bagworm details, visit www.info.psu.edu/extension/factsheets/bagworm.

Photo 4: The tell-tale sign of bagworm infestation is the dangling of inch long, oval-shaped bags from the twigs of plants.

The last pest problem we will discuss is one that is causing great harm to the nursery industry as well as public and private landscapes and gardens where boxwood (Buxus sp.) is grown. The culprit is the fungus, Calonectria pseudonavicilata. It causes the fungal disease called Boxwood Blight. Boxwood Blight was confirmed for the first time in North America in 2011 on samples collected in North Carolina and Connecticut. Today, this disease is found in more than 25 states, including Rhode Island. Hosts of the fungus include plants in the Buxaceae family. American, English and Korean boxwoods are all susceptible. Disease symptoms begin as dark leaf spots that coalesce to form brown blotches. Rapid defoliation usually follows, starting on the lower branches and moving upward in the canopy. As the disease progresses, black cankers girdle the stems, killing them. There is no easy way to control this disease. Fungicides are effective at protecting plants from boxwood blight infection, but do not cure plants with the disease. For now, the best advice to help prevent introducing the boxwood blight fungus is to avoid introducing new boxwood plants to landscapes that already have established boxwoods. Find out more about boxwood blight at www.ext.vt.edu/agriculture/commercial-horticulture/boxwood-blight.html.

Photo 5: Boxwood blight has become a serious threat to nursery production and to boxwoods in the landscape.

Finally, the RI Tree Council has staff available to present lectures or workshops on many topics from plant selection to plant health care. The Tree Council also publishes a monthly newsletter, ROOT TIPS, during the annual plant growing season (April to October) providing invaluable information on the weather, pest alerts and tree and shrubbery management. To avail yourself of these or other offerings such as the Tree Council’s signature Tree Stewards Education Course, contact us by phone 401-764-5885 by e-mail ritree@ritree.org, or visit the website www.ritree.org.

Trending Pests and Weather Conditions Impacting Plants

Written by RITree on . Posted in Pests to Watch.

Trending Pests and Weather Conditions Impacting Plants

The following is an excerpt of the lecture presented by RI Tree Council’s Technical Advisor, John T Campanini, Jr at the RI Federation of Garden Clubs Annual Education Day Program- Roger Williams Park Casino, November 4, 2019. The lecture’s title was “Trending Pests and Weather Conditions Impacting Plants.” In this article, I abridge my earlier lecture to examine specific pests which loom as future threats to woody ornamentals.

PLANT PESTS- There are five plant pests that should be on the radar of all plant stewards in 2020. Four are insects while the last is a disease causing fungus. They are itemized below:

  • Asian Long-horned Beetle (ALB- Anoplophora glabripennis)
  • Spotted Lanternfly (SLF- Lycorma delicatula)
  • Emerald Ash Borer (EAB- Agrilus plannipennis)
  • Bagworm (Thyridopteryx ephemeraeformis)
  • Boxwood Blight Disease

The ALB is by the #1 pest threat of hardwood trees including maple, birch, willow and elm in the Northeast according to the US-Forest Service. ALB kills trees by tunneling through the wood. Once the tree is infested it must be destroyed. The bittersweet news is while this pest has yet to be found in Rhode Island it is everywhere around us. It was discovered attacking trees in Worcester, MA in 2008 and in Boston in 2016. By imposing a quarantine on moving wood products and by inspecting vulnerable species, the Commonwealth has done a super job of containing the spread of this destructive pest into other New England States. Early detection is paramount to its management. In winter, the most obvious sign of this pest infesting host plants is the presence of numerous dime-sized, round holes on the trunk and on branches. For more information about ALB, visit http://www.na.fs.fed.us/spfo/alb.

Photo 1: The Asian Lon-horned Beetle adult is about ¾ to 1 ¼” long with mottled spots on the back. Note the dime-sized exit hole made by adult beetles as they emerge from the tree.

The Emerald Ash Borer is an exotic beetle from Asia discovered in 2002 feeding on ash trees in Michigan. Since then this small, bright green beetle has been responsible for the loss of millions of ash trees in North America. In July 2017, adult beetles were discovered in bait traps set out by RIDEM plant health inspectors in Westerly, Providence, Lincoln and Woonsocket, RI. These findings show the EAB is here, and that ash species are at risk. Plant damage and death is caused by the worm-like larval stage of EAB. The larva feed on the inner bark and phloem, creating “S” –shaped galleries. The feeding activity destroys the plant’s ability to transport water and nutrients to other parts of the tree, killing it. Unlike the ALB, there are options for protecting ash trees from EAB damage. But these options require comprehensive planning and should be directed with the assistance of a certified arborist. Learn about these options and more on EAB at www.emeraldashborer.info.

Photo 2: EAB adult beetles are smaller than a penny. They emerge in July to feed on ash leaves before laying their eggs between layers of bark and in bark crevices.

The Spotted Lanternfly is the latest exotic pest discovered in the United States with the potential to become a major plant problem. This sap-feeding plant-hopper was discovered attacking fruit trees, woody ornamentals and timber crops in Pennsylvania in 2014. New York and Connecticut authorities have also reported finding adults feeding on nursery stock in the past two years. SLF nymphs and adults are very colorful making them easy to detect. Young nymphs are “tick-like” with black and white spots. As they age, the nymphs develop red patches and grow to ½” long. The adults have two sets of wings. The forewing is gray with black spots. The hindwings are bright red at the base. Both nymphs and adults cause damage by feeding in huge populations (swarming) on the tissues under the bark of the trunk and branches. Plants literally starve to death from nutrient depletion from this type of voracious feeding. To learn more on the SLF, visit: www.uri.edu/biocontrol/spotted-lanternfly.

Photo 3: The important life stages of the Spotted Lantern-fly: eggs, wingless nymphs and the adult with wings for flight.

The bagworm is a native insect that, until recently, was mostly found in Pennsylvania and south. In the past decade, however, it has migrated to Northern areas through infested nursery stock. For years the bagworm was considered just a nuisance in RI with scattered outbreaks here and there. But, as the winters have gotten milder, this pest has learned to adapt and thrive and is today much more common. The bagworm prefers attacking evergreens. They include Arborvitae, Juniper, Leyland Cypress, Spruce and Pine. Certain deciduous species such as Black locust, Honeylocust and American Sycamore are also known host plants. The pest damage is done by the worm-like larvae. They feed on needles and leaves from late May through July. This causes the plant foliage to discolor yellow, turn brown before eventually dying. Plant injury can be very severe and entire plants can be killed in a single season. Bagworm infestations generally go undetected until damage is complete, and the large bags constructed by this pest is conspicuous. The bags provide over-wintering shelter to the egg-laying female adults inside. A simple control measure is to remove and destroy these bags as they appear. The other is to apply Captain Jack’s Dead-bug Spray (i.e., Spinosad) to the plant from early to mid-June while the larvae are small. For more bagworm details, visit www.info.psu.edu/extension/factsheets/bagworm.

Photo 4: The tell-tale sign of bagworm infestation is the dangling of inch long, oval-shaped bags from the twigs of plants.

The last pest problem we will discuss is one that is causing great harm to the nursery industry as well as public and private landscapes and gardens where boxwood (Buxus sp.) is grown. The culprit is the fungus, Calonectria pseudonavicilata. It causes the fungal disease called Boxwood Blight. Boxwood Blight was confirmed for the first time in North America in 2011 on samples collected in North Carolina and Connecticut. Today, this disease is found in more than 25 states, including Rhode Island. Hosts of the fungus include plants in the Buxaceae family. American, English and Korean boxwoods are all susceptible. Disease symptoms begin as dark leaf spots that coalesce to form brown blotches. Rapid defoliation usually follows, starting on the lower branches and moving upward in the canopy. As the disease progresses, black cankers girdle the stems, killing them. There is no easy way to control this disease. Fungicides are effective at protecting plants from boxwood blight infection, but do not cure plants with the disease. For now, the best advice to help prevent introducing the boxwood blight fungus is to avoid introducing new boxwood plants to landscapes that already have established boxwoods. Find out more about boxwood blight at www.ext.vt.edu/agriculture/commercial-horticulture/boxwood-blight.html.

Photo 5: Boxwood blight has become a serious threat to nursery production and to boxwoods in the landscape.

Finally, the RI Tree Council has staff available to present lectures or workshops on many topics from plant selection to plant health care. The Tree Council also publishes a monthly newsletter, ROOT TIPS, during the annual plant growing season (April to October) providing invaluable information on the weather, pest alerts and tree and shrubbery management. To avail yourself of these or other offerings such as the Tree Council’s signature Tree Stewards Education Course, contact us by phone 401-764-5885 by e-mail ritree@ritree.org, or visit the website www.ritree.org.