• No single natural enemy or combination of natural control agents can completely eliminate a Gypsy Moth population.

• The Gypsy Moth is a major defoliator of over 500 different tree species which in the short term affects the aesthetic and recreational value of an infested area and in the long term, a Gypsy Moth infestation can cause twig, branch and, in some cases, whole tree mortality, invasion from secondary pests such as rot, and thin tree canopies. Repeated years of defoliation increase the risk that entire trees will not be able to survive and will die.

• The advantage of performing Aerial spraying would be the immediate and dramatic reduction in Gypsy Moth populations and preservation of tree health.

• Spraying leaves saves homeowners from the laborious efforts of trying to control large numbers of caterpillars by other means.

• BTK will keep a Gypsy Moth population in a manageable range next year. Spraying that controls these pests allows trees to remain strong and healthy.

• Aerial spraying is done with BTK, which is a naturally occurring bacteria that is applied when young Gypsy Moths are feeding on leaves, it is not a chemical. Its use is highly effective to decrease defoliation, is targeted to caterpillars only, is sprayed when few other species of caterpillars are around and feeding on leaves (thus targeting the Gypsy Moth caterpillars), and breaks down in 3-5 days. It has been in widespread use for 30+ years in Canada's forests and also in our biggest cities and is even used in farms that are officially designated as “organic”.

• In terms of environmental safety, BTK is considered to be a very safe option. It is a naturally occurring bacteria found in the soil, not a chemical, and it works by producing proteins that are toxic to larvae/caterpillars. It degrades rapidly in the environment (within 3 to 5 days) due to sunlight and other microorganisms, so the exposure window is limited. No residue remains and it does not multiply or accumulate in the environment. It does not travel into the soil beyond 25 cm, therefore there are no concerns with it leaching into groundwater.

• Note that BTK normally is found in the soil but not on tree leaves. As such, caterpillars don’t encounter BTK that occurs naturally in the environment and so do not become affected that way. This is why BTK must be applied to leaves in order to be an effective control mechanism for Gypsy Moth caterpillars.

• Pest control products containing BTK have been registered for use in Canada for 40 years and it is the most widely used pest control product in the world -- it can even be used on certified organic farms.

• BTK specifically targets immature insects (larvae/caterpillar) in the Lepidoptera family. An extensive literature exists on the reactions of non-target organisms to BTK, including reports of several long-term field studies. The data have been reviewed periodically over the years and the range of non-target species that have been found to be susceptible to direct toxic action of BTK has remained small. Spring feeding Lepidoptera species (leafrollers, fruitworms, cankerworms, and budmoths) may be affected and species richness may be locally and temporarily reduced following a spray event. Significant Lepidoptera species such as monarchs and swallowtails are not affected as they are not in the susceptible life stage when the spray is applied.

• BTK does not affect other insects, honeybees, fish, birds, or mammals. There is also no impact on animals or pets if they are exposed to or ingest BTK.

• According to the World Health Organization, BTK has been sprayed over populated areas in several countries including the USA, Canada, and New Zealand. Some of these applications have been followed by public health surveillance programs and in general no (or very few) harmful effects have been reported among residents of the sprayed communities. A large epidemiological study conducted by the University of British Columbia concluded that “the largescale spray program of BTK in the lower mainland for control of the Asian and European Gypsy Moth did not cause any measurable increase in serious community unwellness that could be attributed to the spray”. There are no documented cases involving toxicity or endocrine disruption potential to humans and other mammals after many years of use in Canada and around the world.

• Because BTK naturally persists in soil and is also sprayed on many crops (including those that are organically grown), it is likely that you have already been exposed to BTK during the course of your daily life. If you eat fruits and vegetables, you have probably already ingested BTK, without any ill effects.

• Any residue landing on structures will not damage paints or finishes on automobiles, houses, boats, or trailers and can be removed easily with water.

• Caterpillars that become ill or die after ingesting BTK are not considered dangerous to birds or other animals that feed on them.

• To give you an idea about cost, this past spring in 2021 the all-inclusive charge (positioning, 2 sprays, taxes, etc.) for spraying (if contracts were received by April 1) was $357 for each property up to one acre in size. Properties over one acre were charged an additional $96 / acre beyond that for both sprays. So for example, a person with a 3-acre lot would have been charged $549 to have their property sprayed this year. Note that Zimmer Air Services will base their charge on the size of your lot from municipal records and will pro-rate based on partial acres. Next year’s rates may be slightly higher.

• The cost of aerial spraying is much less than the removal of a dead tree, or what you typically pay for car and/or house insurance.

• Each landowner who wants their property sprayed will submit a signed Contract For Services agreement and a signed Spray (Objection) Waiver form (for each adjacent property owner who is NOT spraying their property - for information about the waiver, see below, in the question regarding neighbours who do not want their property sprayed). Zimmer Air Services will then calculate the accurate area of the property being sprayed using the tax roll numbers and map. Payment information will be obtained after acres verification has occurred by the Zimmer mapper. A Payment Authorization form will be sent out separately. Payment is by way of a post-dated cheque or Visa/Mastercard. Payments are deposited/processed by Zimmer Air Services after the first spray is completed.

• There is a minimum number of spray lots that would be required to contract Zimmer Air Services for spraying. Once Zimmer Air Services commits to spraying in our area, even if it were only 5 properties, they will do it. Having said that, there will be a minimum crucial acreage in order for Zimmer Air Services to operate in our area.

• In the absence of community consensus, it may be that a smaller number of individual cottage owners commit to a spray program for 2022.

• Doing nothing is always an option to be considered and may be the most practical option depending on the support received from the Lake Community at large.

• Based on the historical record of Gypsy Moth in North America and Ontario, it is likely that the current outbreak in the Big Cedar Lake area will collapse naturally over the next several years, however with a population as severe as this currently is, it is very unlikely that management on private property alone would control 2022’s outbreak unless the fungus and/or the virus known as NPV collapses the population.

• If aerial spraying is not done, then in some cases residents will choose to mitigate impacts to their properties by applying pesticides on their own or through a commercial tree care company. The end result of a large number of property owners taking their own control measures is a significant increase in the overall use of pesticides in the Lake Community as a whole, and the consequent increased risk of exposure for users, bystanders and the environment. Homeowners with a lack of sufficient training or knowledge of pesticide application may also apply pesticides incorrectly or use products that are not approved nor environmentally friendly. The “Do Nothing” option may actually result in an increase in pesticide use. Other innovative control measures employed by homeowners may not be very effective and some may actually cause more harm than good to the trees.

• If residents attempt to spray BTK from the ground, the height of the trees may be a difficulty. Ground applications tend to be most effective when the spray is able to cover a high percentage of the canopy – effectiveness tends to decrease significantly if spray equipment does not reach the upper canopy. When the caterpillar first hatches, they move to the top of the tree and start eating at the top. If the BTK does not reach those heights, then it will not be effective to stop the caterpillars at an early stage.

• If defoliation is severe in 2022, then the trees will have experienced two consecutive years of defoliation, putting them at risk for survival and at minimum will negatively impact tree health leaving it susceptible to other environmental stressors and resulting in an overall decline which may start to be observed as branch dieback or reduced vigor, and tree mortality in some cases.

• Many trees have been defoliated this year by the Gypsy Moth caterpillars. Already dangerous with drought, this dramatically increases the Fuel Load within our Lake Community and increases the threat of forest fire. That threat will exist especially if the drought continues in the summer. Some of our weakened trees may recover, many will not. Another Gypsy Moth infestation in 2022 may be the death knell for those trees that do survive this year, and our Fire Index may increase again in 2022.

• If aerial spraying is not done, property owners may incur other financial costs. These include:

o Treating Gypsy Moth with a pesticide;

o Removing larvae/caterpillars or their droppings;

o Removing egg masses;

o Repainting buildings;

o Pruning or removing declining or dead trees, including trees that become a hazard;

o Replacing damaged or dead trees and shrubs;

o Increased liability for damage or injuries sustained from falling trees and branches. It can be $1000 to $2500 to remove a dangerous tree from your property. It can cost +++$ more to repair structural damage caused by a fallen tree.

• The aesthetic appeal of Big Cedar Lake is undeniably one of our most valuable assets. The charm of our lake is a combination of many features: our water, our forests, and our unsullied flora & fauna. Weak, dying, and dead trees do not hold the same appeal as the healthy green forest that originally attracted us all to this area and they will reduce the aesthetic appeal of our properties.

• The trees provide food, shelter and resting areas for the animals and birds -- from the acorns of the oaks, to the nectar and pollen and seeds that feed the bees, birds and butterflies, to the nesting areas and holes that are dens and homes for squirrels, porcupines and birds. With their root structures, trees also are a valuable safeguard against soil erosion. Many of the mature trees that provide these benefits will be affected by another year of severe defoliation and will not survive.

• In a weakened state, the trees become more susceptible to insect and other invasion by local predators such as beetles which will continue to weaken the host tree and can fuel broader destruction to even more trees.

• If aerial spraying is not done, then residents and cottage owners should be educated on what their personal treatment options are as well as the pros and cons associated with each option, focusing on cost and efficacy.

• The spray must be applied while the early/young caterpillar larvae are actively hatching and feeding on the foliage, usually early to mid-May. Within about two to three hours of consuming the product, the larvae stop feeding and die within a few days.The spray is most effective in the first 2 days after spraying.

• The seasonal spray window is set for the middle of May through the middle of June. On the day of the sprays, the helicopters will begin spraying just before sunrise (5 A.M.) and will take approximately 2.5 hours to complete. Applications can occur any day of the week, including weekends. Once the leaves are a certain size, the caterpillars have reached almost 90% emergence and the caterpillars begin feeding, the spray window can be narrowed. Once it is determined that those factors are met, the weather conditions then need to be monitored. The BTK application is weather dependent. Ideal application conditions consist of:

o Calm winds (1-16 km/h)

o High humidity (> 40%)

o Temperatures between 2 and 25 degrees Celsius

o No precipitation within the spray window and ideally not for 24 to 48 hours after application

• There are some challenges such as these environmental conditions and weather, but also there is only one company that offers Aerial Spraying in Southern Ontario, so they have competing demands of customers all across Southern Ontario.

• It would make sense to do some sort of assessment before finally contracting the vendor to do the Aerial spraying, so that we are fairly confident that next year's outbreak will in fact defoliate trees for a second year in a row.

• Egg mass counts are considered to be the most reliable and is a good indicator of outbreak status – large egg masses (greater than 30mm) indicate a healthy, increasing population and small egg masses (less than 20mm) indicate a decreasing population. Fixed-area plots: Observers count all egg masses within a standardized area. In Ontario, the 10m by 10m Modified Kaladar Plot (MKP) has been used since the 1980’s. Trees Unlimited can be contracted to conduct egg mass surveys.

• Note that Gypsy Moth defoliation is difficult to predict with a high degree of probability. One thing that complicates Gypsy Moth population assessments and forecasts is the tendency of early-stage caterpillars to disperse by ballooning over the landscape, often in large numbers. This can result in areas suffering high defoliation rates even though egg mass densities were low, or in some cases, non-existent.

• Trees can be surveyed by examining the trunk and scanning the entire tree, from base to crown, using binoculars. At least two opposite sides of each tree should be surveyed. All egg masses observed on the tree, both old and new, should be recorded. The total number of egg masses on each tree can then be summed. In a separate count, egg masses that are easily distinguishable as old or new can be tallied. As many intact egg masses within reach should be measured and recorded as old or new, in order to obtain current year egg mass size data. Predicted defoliation values can then be obtained using a USDA defoliation prediction model based on egg mass counts.

• Egg mass surveys should be conducted in the fall/winter, after leaf drop.

• The actual size of the egg mass is a vital statistic for assessing Gypsy Moth populations. Larger egg masses (more than 500 eggs per mass, greater than 30mm) indicate a healthy, increasing population whereas smaller egg masses are characteristic of a decreasing population (less than 20mm in size). The number of eggs per mass can be estimated by measuring the length of egg masses in the field.

• 1 to 10 egg masses on an individual tree could result in light to moderate defoliation. More than 50 egg masses per tree could result in severe defoliation.

• Zimmer Air Services is the only company that we are award of that provides aerial application services in Southern Ontario.

• Zimmer Air Services was originally founded as Zimmer Airspray in 1975 and was renamed in 1961 to better reflect their expanded range of services. With almost 40 years of providing professional aviation services, Zimmer Air Services Inc. has gained a respected reputation for quality, integrity, and safety in company operations.

• With close to 40 years of continuous aerial application service to the Pulp and Paper Industry and Ministry of Natural Resource managed forests, Zimmer Air Services is by far the most experienced rotary wing operator in the Province of Ontario if not Canada.

• Their goal is to provide the highest quality applications, carried out with safety, and environmental stewardship in compliance with current legislation. Their work is guaranteed and they will provide the customer all data to demonstrate they have met their obligations.

• The website for Zimmer Air Services is https://zimmerair.com/

• The bacterium are grown in sterilized tanks and mixed with water or a mineral oil similar to baby oil, along with stabilizers, stickers and preservatives safe for humans and the environment (e.g. potato starch, glucose, soy proteins). It is comprised of 3% BTK bacteria, 75% water and 22% of these food grade inerts. The term ‘food grade inerts’ refers to a special blend of additives that give the formulation protection against ultraviolet light and help make it stick to foliage.

• The mixture is sprayed over large areas by air. It must be sprayed on the leaves at the tops of trees when the caterpillars are actively feeding.

• For this program, helicopters with spray systems will fly approximately 15 metres above the tree-tops. The spray zones are created using scientifically designed methods.

• The spray rate of 4.0 litres of active ingredient (ai) per hectare which is equivalent to 1.6 ai litres/acre will be used.

• The spray pattern from the helicopter is 30 m wide. Comprehensive spray drift modelling has been done to ensure accurate and effective application.

• Residents will be notified prior to spraying times to allow personal choice in limiting exposure. Droplets usually clear in the air within an hour.

• There is no need to vacate your premises but for cautionary measures, it is suggested that you bring pet food indoors and disconnect any roof-collecting cisterns.

• The public is unlikely to experience any symptoms and no special precautions are necessary. BTK aerial spraying is also not expected to have adverse effects on vulnerable populations including children with asthma, people with weakened immune systems, pregnant women or the elderly. However, infrequently there may be some residents who are more sensitive and may experience skin, eye or respiratory irritation, so individuals who have concerns may wish to remain indoors during the spray application window and remain indoors for 30 minutes after spraying to allow for the droplets to deposit onto the tree leaves.

• The application time is approximately 30 – 60 minutes depending on the size of the spray area, with the biological insecticide staying suspended for only approximately 5-10 minutes. BTK will remain lethal to the caterpillars for approximately 4 days. Ultra-violet light and rain will gradually break down the bacteria.

• It may be prudent to bring in laundry, and toys and cover lawn furniture, outdoor tables, pools, BBQs, play equipment and sandboxes, else you may rinse them off with water after spraying is finished. It is suggested to bring your pets indoors as well, in order to reduce pets bringing BTK indoors; however, BTK is not considered a risk to pets or animals.

• If you are concerned that a personal medical condition may be aggravated by the spraying, then please consult your family physician.

• Zimmer Air Services pilots are able to provide real-time information for special needs such as health-compromised residents, covering bees during the spray window, etc. For any specific issues, Zimmer Air Services are helpful and prompt in responding.

• Post spray surveys indicate a significant reduction in caterpillars and tree defoliation.

• BTK will not eradicate the Gypsy Moth population but is intended to sufficiently reduce the population (60 – 80% or more) to minimize the defoliation and protect the tree canopies. When optimally applied, BTK kills 80%- 85% of Gypsy Moth caterpillars.

• To be most effective, 2 applications are sprayed over the course of 2 weeks while the caterpillars are young.

• The overall goal is to lower pest populations to tolerable levels in terms of tree impacts and effects on human health and safety.

• Gypsy Moth caterpillars have an alkaline stomach, unlike the acidic one of humans as well as other animals, birds, fish etc. and after they ingest it, by chewing on leaves that have been treated by BTK, it destroys the lining of their gut, killing them within days.

• Advances in research have improved application methods and on-target deposition.

• There is significant time associated with organization, communication and implementation. A committee of approximately 5 volunteers would be optimal.

• It is suggested to assign a Spray Marshall who monitors the hatching of the Gypsy Moth eggs and development of the caterpillars. The Spray Marshall would work as a single-point-of-contact for Zimmer Air Services as to the ideal spray window.

• Communications is a key component, so it is crucial to have a point of contact for community communication. Consider holding an information session or two. (Could be done via Zoom).

• Other committee members can help with contacting the community, with research, distributing information, following up with residents not signed up to spray for information and encouragement, obtaining any waivers needed for crown / municipal / road allowances / common properties, etc.

• Commitment from individual property owners would be needed.

• Early contact with Zimmer Air Services will be key as being the sole provider of this service and with the increased spread of the Gypsy Moths in Ontario, the volume of requests could be a challenge next year. Zimmer Air Services requires signed contracts from all landowners by March 31 each year but sending them in earlier is preferred. (Zimmer has to put in their order for the BTK bacteria which is grown in the U.S., by March 31 of each year.)

• A data repository should be set up to catalog all information including copies of contracts and waivers.

• Each individual property owner is responsible for financials and anything specific to their property – including completing the contract application and for obtaining spray waivers from abutting property owners that are not spraying.

• Sub committee pulls complete package of contracts/waivers on behalf of all property owners thus requiring only a few people to be dealing directly with Zimmer Air Services. Assign a point person to liaise with Zimmer Air Services. However, for specific issues with a landowner about a specific property, they should deal directly with Zimmer Air Services.

• 2-3 weeks before spray send out an info sheet about what to do pre – during – post spray.

• Send Zimmer Air Services a final list of properties being sprayed as a double check a week or two before the spray.

• Monitor the Zimmer Air Services website for projected spray dates (they list by county)

• Place white sheets on the ground under a few sample areas to determine #’s of caterpillars pre-spray and then count sample for up to 4 days after spray to gain an idea of efficacy with some amount of objectivity

• As mentioned earlier, advances in research have improved application methods and on-target deposition.

• The contract for spraying requires owners to contact abutting property owners to determine whether they are participating in the spray program OR want to sign a Spray Waiver.

• If the Spray Waiver for adjacent property owners is not submitted by the person contracting for spray services, then Zimmer Air Services may decline to enter into a contract to spray the property or will leave a 20 meter buffer zone inside the property line...whichever is appropriate. So, the onus is on the property owner contracting for the spraying to provide the waivers on behalf of the neighbours. Depending on the width of the property to be sprayed, the requirement to include 20m buffers could result in little or no property left to spray.

• Zimmer Air Services will not enter into a contract unless they feel they can do the job properly.

• The Spray Waiver also clearly allows neighbours to either accept some overspray or object and thereby have a 20m non-spray buffer beyond their property line.

• Here is an example of what the waiver looked like for 2020: https://zimmerair.com/wp-content/uploads/2021/01/spray-waiver-sample-2020.pdf

• Logistically and impact wise, it is better if the spray areas are contiguous, but Zimmer Air Services will still spray if they are not. Non-contiguous areas take more time including administration. The spray program will be more effective for each landowner if a buffer does not have to be left within their property boundaries.

• Property boundaries are determined based on tax roll numbers provided by the landowner. These are mapped by Zimmer Air and confirmed with the landowner who clarifies any discrepancies.

• Note that caterpillars can move from an unsprayed area into the spray area, so it is optimal to have continuous spray zones.