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​Pests & Diseases

Urban forestry preventative maintenance programs include pest preparedness measures to ensure that the City of Barrie’s trees are safe and healthy.

Help combat th​​e Spongy (LDD) Moth with a FREE burlap kit

The City is offering free burlap kits for residents to help combat this invasive species that feeds on tree leaves, destroying tree growth and taking away a trees ability to produce new leaves.

Placing a burlap sack around the tree trunk from June to mid-July provides a resting place for caterpillars, which can then be removed to prevent them from morphing into cocoons. Residents can pick up a free burlap kit at the following locations (while supplies last):

The City has handed out all of the Spongy (LDD) moth kits available for the May 27 giveaway event at City Hall. Our apologies for the inconvenience. More kits have been ordered and will be available (while supplies last) at the other giveaway dates/locations.

  • Friday, May 27: City Hall, 70 Collier Street, from 9 a.m. – 4 p.m.
  • Saturday, May 28: Dorian Parker Centre, 227 Sunnidale Road, from 8 a.m. – 3 p.m.
  • Wednesday, June 1: Peggy Hill Team Community Centre, 171 Mapleton Avenue, from 3 – 6 p.m.   
  • Friday, June 3: Southshore Community Centre, 205 Lakeshore Drive, from 3 – 6 p.m.   
  • Saturday, June 11: Dorian Parker Centre, 227 Sunnidale Road, from 8 a.m. – 3 p.m.  ​

Kits include burlap (approx 5' x 2'), twine, ​rubber gloves, instructions and a general info sheet about Spongy (LDD) moths. Maximum of 1 kit per household.

Please review more tips to protect your trees from spongy (LDD) moth infestation in 2022.

There are several diseases and insects that affect trees. Some trees are more susceptible to certain diseases while other trees might be the preferred host for specific insects. Many of these insect populations are kept under control through natural predators and pathogens.

If populations arise to an infestation the City takes on an Integrated Management Approach. Different management techniques are used to address pest populations starting with the least harmful to the environment.

Invasive Insects in Barrie

Invasive insect species to be on the lookout for in Barrie:

  • Asian Longhorned Beetle: Attacks mainly maple trees, but also poplar, birch, willow and elm.
  • Emerald Ash Borer (EAB): Attacks and kills all species of white, green and red ash trees (Fraxinus). Poses a major economic and environmental threat to urban and forested areas.
  • Spongy (LDD Moth): Feed on tree leaves, destroying tree growth and taking away trees' ability to produce new leaves. Prefer oak, birch, aspen, sugar maple, American beech, eastern white pine and Colorado blue spruce trees.

    Note on the naming convention of the moth:
    On March 2, 2022, the Entomological Society of America adopted "spongy moth" as the new common name for the LDD moth. The common name of LDD moth is currently under review internationally and within Canada, including by the Canadian Food Inspection Agency. The City of Barrie will refer to the moth as "spongy (LDD) moth" for the 2022 season.

Protect your Trees from Spongy (LDD) Moth Infestation

2021 was a significant year for spongy (LDD) moth infestation in Ontario and staff applied an integrated management approach on City property in specific areas, which will continue into 2022. Steps to protect trees on your property are outlined below and should be continued in 2022.

Residents who would like to help beyond their property can submit a Departmental Contact Form to Parks Maintenance & Operations for information.

August–April: Destroy Egg Masses
Scrape egg masses off surfaces into soapy water to destroy them:

  1. Wear gloves and safety glasses for protection.
  2. Place a container below the egg mass.
  3. Use a plastic scraper tool or butter knife to remove the egg mass.
  4. Empty the contents into a bucket of soapy water.
  5. Leave the eggs sitting in the bucket for two days to destroy the eggs.
thumbnail images of egg masses 

Helpful videos to reference:

Spongy (LDD) Moth Egg Mass Removal
Source: The City of Toronto

Finding and Removing Spongy (LDD) Moth Egg Masses
Source: The City of Toronto

How to Remove Spongy (LDD) Moth Egg Masses
Source: The City of London
Mid-May to June: Tape
When the caterpillars are in their first instar (tiny stage) they will dispense in the wind and fall to the ground. Instinctively, they find a tree, crawl up to the canopy and begin feeding. Sticky tape can be applied around the tree trunk to prevent caterpillars from reaching the top of the tree.

  1. Wrap two layers of duct tape around the tree then twist is so that the sticky side of the tape is on the outside. Wrap it several times. It should be at a height of 5 feet from the ground.
  2. Complete step 1 but do it a foot below the first tape wrapping.
  3. If the tape is no longer sticking or full off caterpillars remove tape and reapply.
  4. Remove tape in August to prevent damage on the tree trunk.                        

Helpful video to reference: Tree wrapping to mitigate spongy (LDD) moths Source: The City of Grand Rapids

June to Mid-July: Place Burlap Bands, Collect Pupae, Leave Dead Caterpillars on Tree

If you taped your tree in the spring, remove the tape to prevent damage to the tree.   

Place Burlap Bands Around Tree Trunk

When the caterpillars are in the large caterpillar stage they will move down the tree during the day to seek shelter then return up the tree to feed at night. Placing burlap bands around the tree trunk provides a resting place for caterpillars which can be removed and killed. You will need burlap (length depends on the size of the tree but about 2' wide for the overhang), twine and rubber gloves.                    

  1. Wrap a piece of burlap cloth around the tree trunk.
  2. Tie rope around the center of the burlap.
  3. Drape the burlap cloth over the rope. This will create an overhang where the caterpillars can crawl underneath to seek shelter during the day.
  4. Check the trap by lifting the overhanging burlap cloth every afternoon and collect any hiding caterpillars.
  5. Put them into a bucket of soapy water for a few days to destroy them.

Helpful video to reference: Spongy (LDD) Moth Burlap trap for caterpillars Source: The City of Toronto

Collect Pupae (Cocoons)

The spongy (LDD) moth caterpillar morphs into the pupal (cocoon) stage in July. This stage generally lasts 10 to 13 days. To help control next year's population, collect the pupae, put them a pail of soapy water, and leave them in the pail for a few days. Then dispose of the pupae in a sealed garbage bag. 

Leave Dead Caterpillars in Place on Tree

If you notice dead caterpillars on your tree, leave them. Dead caterpillars indicate decline. If you leave them, it will help spread the virus or fungus that kills the caterpillars.

How to protect your trees from LDD moths

Once in the moth stage, there are few control options. The moth stage is short-lived and it's best to focus on the other stages when applying control methods.

Boulevard Tree Health Concerns

If you are concerned about the health of your boulevard tree due to spongy (LDD) moth infestation, please provide your address to Service Barrie at 705-726-4242 or An inspection workorder will be created to review the health of your tree following this season’s LDD moth outbreak (fall 2022​). Note: If your tree is in overall good health, defoliation will only stress your tree, not kill it.

Pest Preparedness

Urban forestry staff are responsible for pest preparedness programs and monitoring on City property. Urban forestry preventative maintenance programs include pest preparedness measures to ensure that the City’s trees are safe and healthy.

Two serious threats to the health of our urban forests have been monitored by staff since 2004: the Emerald Ash Borer (Agrilus planipennis) and the Asian Longhorned Beetle (Anoplophora glabripennis). No natural predators or control agents are known to control the populations of these two insects.

Spongy (LDD) Moth Management Approach
City staff monitor the populations of spongy (LDD) moth along with our municipal and provincial partners. Related links: Gypsy Moth (County of Simcoe); Gypsy Moth (Province of Ontario).

We cannot eradicate this moth as it is well established throughout North America. Spongy (LDD) moth outbreaks usually occur every 7–10 years and may last for a period of 1–3 years. 2022 is expected to be the last year of the current outbreak. LDD moth populations naturally collapse from the NPV virus and fungal Entomophaga maimaiga.

2021 was a significant year for LDD moth infestation in Ontario. City staff acted in high infestation areas through an Integrated Pest Management Approach.

In 2022, surveys of egg masses in areas of high spongy moth populations estimate a collapse in the population of 90% in most areas of Barrie. However, there still will be areas of significant caterpillar hatch (these areas include the north portion of Sunnidale Park, Barwick Park, Hogans Woods, Vine Crescent Ravine, as well as areas in southeast Barrie). City staff are monitoring these areas. 

The aerial spray industry is fully booked for 2022. The City was unable to procure aerial spraying through the public tendering process due to provincial demand for spraying large tracts of forested areas and limited contractor availability, particularly for small, isolated spraying projects such as would be requested in Barrie (35 hectares spaced over 5 geographic areas).

As a result, staff will use the resources allocated by Council to implement other management options of spongy (LDD) moth control in parks and natural areas as directed. Other management options will include ground and mechanical control techniques as presented by Bioforest at the February 8, 2022 City Building Committee meeting​The following are the planned activities by the City for 2022:

  • ​​April to early May – egg mass scraping of City trees in signficant areas, as well as sharing educational material the City's website and social media channels
  • Early May – distribute educational information for landowners, hold public education sessions to provide instruction and advice on protecting private trees
  • Late May to mid June – sticky-banding City park trees, injecting TreeAzin to protect high value city trees where multiple years of defoliation has occurred, as well as further public education and information sessions
  • Mid June to end of July – burlapping park and street trees in high-population areas, continue with public education efforts
  • August – egg mass scraping and public education to prepare for 2023
Emerald Ash Borer (EAB) Program
In 2006, City staff instituted a moratorium on planting Ash species on public lands in Barrie and recommended that land developers and consultants omit ash from planting on private property. As of April 1 2014, the County of Simcoe (including Barrie) has been included in the zone under regulation for EAB. Signs and symptoms of EAB-infested ash trees:

  • premature yellowing of leaves
  • dead branches
  • thinning crown
  • branches sprouting from the base of the tree
  • bark cracks
  • a “zig-zag” path under dead portions of bark, and
  • D-shaped holes from where new adults exit the tree.
If a City tree exhibits these signs please report to Service Barrie at 705-726-4242 or If you're concerned that your private tree is infested, staff suggest calling a certified arborist to have it inspected. There are several local tree companies with certified, licensed and insured arborists who can assess your trees and provide recommendations on the best course of action.

Phase 1: 2012 until EAB is discovered in Barrie
a) Identify specimen ash trees for treatment

b) Begin systematic removal and replacement of young ash trees on boulevards

c) Proactive planting in areas of high ash component

d) Public education on EAB

Phase 2: Post Discovery of EAB in Barrie
e) Begin bi-annual treatment of specimen ash

f) Systematic removals to include mature ash where integration with other programs create efficiencies (e.g. block pruning program)

g) Removal of all ash trees on a street or within a park where EAB has been discovered.
On March 26, 2012, after review of Staff Report re Pest Preparedness, Council adopted the EAB Program, a 2-phase project expected to last 15 years. In August 2014, EAB was confirmed within several locations in Barrie. As a result, forestry staff commenced Phase 2 of the EAB Program.

Please refer to tree removals due to Emerald Ash Borer to view areas of the city where street boulevard Ash trees must be removed.
Asian Longhorned Beetle (ALHB) Monitoring
ALHB is native to China and is considered a major pest of hardwood trees in many parts of the country. Based on the Chinese experience with this insect and the infestations in the United States and Vaughan, this beetle would survive and reproduce in the hardwood forests of southern Canada.

A variety of hardwood trees serve as hosts to ALHB. In Asia, the primary hosts are maple (Acer), poplar (Populus) and willow (Salix). Other hosts include; horse chestnut (Aesculus), birch (Betula), elm (Ulmus), sweet-gum (Liquidambar), ash (Fraxinus), mountain ash (Sorbus), mulberry (Morus), plum (Prunus), pear (Pyrus), black locust (Robinia), silk tree (Albizia), hackberry (Celtis), and sycamore (Platanus). All of these genera represent over 1,000 vulnerable species; the first five genera have been found to support reproducing populations in New York and Vaughan.

The ALHB infestation is considered “under control” within the Vaughan/Toronto Regulated Area, and the CFIA are monitoring the area for any further signs of its presence. However, ALHB was found in Mississauga in September 2013, prompting the CFIA to begin the process of starting an eradication program for that population. City staff continue to monitor the CFIA information provided on this pest.

Reporting Pests & Diseases

It is critical to properly identify new introductions and be on the lookout for invasive species before they get established. The spread of pests and diseases cause harm to the ecosystem, economy, society, and potentially human health. If you think that you have spotted an invasive species on City property, please send photos and report location details to Service Barrie at If it's found on your own property please report on EDDMaps Ontario.

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