Browntail Moth Response
February 20, 2024:
The City of Bangor Public Works Forestry Division conducted an educational event to help residents and businesses in Bangor recognize and remove browntail moth (BTM) nests. One of the least environmentally impactful ways to mitigate a BTM infestation in the spring is to remove the winter nests while the caterpillars are dormant. Each nest removed in the winter months eliminates up to 400 BTM caterpillars in the spring. These caterpillars present a health risk for residents due to the toxic hairs they shed while growing. Attendees had an opportunity to watch a demonstration and then use the pole pruners. Learn about the pole pruner loan program here.
February 1, 2024:
The City of Bangor Public Works Forestry Division demonstrates how to properly trim browntail moth nests from trees and dispose of them.
November 6, 2023 Update:
Now that leaves are falling off the trees and people are cleaning up their yards, people need to use caution to avoid contact with the irritating hairs of the BTM. If your yard was infested with BTM caterpillars this year, there is a good chance that many of the leaves will have cocoon remnants in them. These remnants may still contain the shed bodies of the caterpillar, which are covered in the toxic hairs. Raking and blowing leaves can cause the hairs to become dislodged from the cocoon and cause them to become airborne. Once airborne, they can land on exposed skin and cause irritation.
The good news is that the Bangor area has received a significant amount of rain this year, so a lot of the hairs are likely to have washed out of the trees and into the ground. Unless you start vigorously scratching at the ground with your rake, those hairs are likely to stay lodged in the soil.
Our advice to residents is to be aware of the potential for BTM hairs to become airborne and take some precautions. Hats, gloves, pants, and full sleeve shirts can minimize exposed skin. Fortunately, this is the standard dress code for outdoor work in cooler fall weather. Raking on damp mornings will also decrease the chances of hairs becoming airborne. When you are raking, it is ok to leave some of the leaves in place – it is preferable to leave some behind versus raking the ground hard and stirring up hairs. This has an added bonus of allowing the decaying leaves to add nutrients to your soil. If you are using a blower to move your leaves, avoid stepping into the whirlwind of leaves, no matter how fun it sounds. Lastly, I know it’s a time-honored tradition to see kids hiding or jumping into leaf piles. If you were seeing an infestation on your property this year, physically entering the leaf pile is a sure recipe for exposure to BTM hairs and the resultant skin irritations.
The last piece of information I want to share is our plan for winter web clipping of smaller, more accessible trees. The new generation of caterpillars, that hatched in August, have entered into communal webs that are generally located at the tops of trees (see photo below). As leaves fall off the trees, these webs will become very visible, especially when the sun angle is right – the webbing around the winter nest will shine a silvery white color. We will be holding workshops this winter to demonstrate winter web clipping on ornamental and fruit trees. Public Works will also be opening a lending library to allow residents to borrow extendable pole clippers to remove nests on their own properties. Keep your eyes open for more information!
Please continue to report your winter web, caterpillar, and moth sightings through our website at Request for Service - City of Bangor, ME (bangormaine.gov). These reports allow us to track infested areas. We use reported locations and report frequency to identify areas of focus for our work. Your assistance is greatly appreciated.
Photo Credit: Bangor Public Works 11/29/21
August 15, 2023 Update:
It appears that adult browntail moths have finished breeding and laying their eggs. Residents should be safe to turn on their outdoor lights without fear of attracting the adult moths.
This year’s adult moth population appeared to be greater than 2022, but still much less than 2021. At this point the egg sacs, pictured below, are likely to be hatching. The caterpillars are very tiny at this point and are not large enough to be shedding toxic hairs. The primary evidence you will see of their existence will be skeletonized leaves. They are not large enough to eat entire leaves so they eat the soft plant material between the veins of a leaf. If you notice these skeletonized leaves, you are likely to see winter nests this fall.
It is possible to treat trees with pesticide this fall, either injections or topical spraying. The best way to determine the most effective treatment, with the least ecological side-effects, for your specific application is to speak with a licensed pesticide applicator. You can find a list of pesticide applicators licensed by the State of Maine Pesticide Board here, List of Licensed Pesticide Applicators Willing to Treat Browntail Moth and/or Hemlock Woolly Adelgid: Browntail Moth (Euproctis chrysorrhoea): Forest Health & Monitoring: Bureau of Forestry: Maine DACF .
We encourage residents to still be vigilant about exposure to toxic BTM hairs. While the new generation of caterpillars are not yet shedding hairs, the cocoons of last year’s caterpillars are still fresh. These cocoons from July, pictured below, still contain the shed skin of the caterpillar, along with all those hairs. If you are pruning trees, these may break open. As the leaves fall from trees this autumn (it’s closer than you think), the old cocoons may break open during leaf raking activities. Once the cocoons are open, wind can stir up the hairs, causing them to come into contact with your skin, and cause an allergic reaction.
The latest information regarding the browntail moth infestation across the state can be found at the Knock Out Browntail webpage, maintained by the Maine Department of Agriculture, Conservation, and Forestry, www.maine.gov/dacf/knockoutbtm
Bangor Public Works will be holding a number of educational events this winter to teach people how to clip and dispose of BTM winter webs on their own properties. If you are interested in managing BTM on your own property, stay tuned to this page and our social media pages for dates!
Courtesy of MDACF. Browntail Moth Euproctis chrysorrhoea : Forest Health & Monitoring: Bureau of Forestry: Maine DACF
Old cocoons at Public Works, Bangor. These still contain toxic hairs.
July 11, 2023 Update:
Adult browntail moths have begun to emerge from their cocoons in Bangor. You will see the white moths collecting pretty much everywhere there is an outside light left during overnight hours, as shown at Public Works, below. We did see significant evidence of caterpillar death in June, due to a fungus that is deadly to them. Many also appeared to have died in the process of spinning their cocoons. We are hoping these mortalities will result in a decreased BTM population, but only time will tell.
Photos taken at Public Work July 10, 2023
Having lights on between 9:00 pm and midnight during July and August is likely to attract BTM to your property. This includes the use of insect traps, bug lights, and other methods of attracting and catching the moths. These are less likely to kill the moths and more likely to result in an increase in caterpillars on your property in the fall and next year. We encourage residents to turn off outdoor lights to avoid drawing the moths to their houses or property.
The City of Bangor has streetlights all over the city and we realize most of these are adjacent resident properties. In the interest of public safety, we will not be turning off these lights. We are working on a comprehensive lighting plan that will explore the option of having automatic dimmers during BTM season.
You can view the latest update from the Maine Forest Service here, Browntail moth update #12: July 11, 2023 (govdelivery.com).
June 22, 2023 Update:
BTM caterpillars have caused a great deal of damage across the City of Bangor this spring. The warm, dry weather we experienced soon after they hatched created perfect conditions for their growth and spread. Caterpillars are mostly into cocoons now so you will see few actively feeding or on picnic tables, benches, etc. You can identify the cocoons by the cluster of leaves all pulled together with fine webbing, like the one pictured below.
Please remain cautious! As the caterpillar grew, it shed skin and hairs, sending them into the air. These hairs still get kicked up by the wind and by activities like mowing or raking. The hairs remain toxic for years. Nature will reduce the danger by washing the hairs into the soil when it rains – and we have had a lot of rain lately.
The next phase in their lifecycle is the moth emerging from the cocoon, sometime in July. These moths do not have toxic hairs, but the cocoon where they left their caterpillar bodies still has all those hairs in it. These cocoons break open in strong winds, and more hairs are introduced into the air. This means the potential for rashes continues through the summer, even through the caterpillars are gone. Please continue to take precautionary measures to prevent exposure to the hairs.
Now for some good news! The recent rains have increased the number of fungus killed moths we have seen. The entomophaga aulicae fungus occurs naturally and grows more easily in cool wet conditions – just as we have experienced over the last couple weeks. If you are monitoring your property and wonder what the fungus kill looks like, you will often see the caterpillar hanging by just a couple feet, the body shaped like an upside-down U, and the body and hairs are often covered with fine white particles. You really don’t need to identify it yourself, just be happy that something good has come from all the cool rainy weather we have experienced this month!
Our trial pesticide applications in the parks were very informative and effective. We saw significant BTM mortality in trees with pesticide applications. There does not appear to be a better response in the fast acting versus the slower acting pesticides that we trialed. Not all trees took up the pesticide at the same rate. It also appears the pesticide wasn’t spread to all parts of the tree equally, as some parts of the trees were untouched but some appeared to suffer significantly more defoliation. This is an ongoing trial and more information will be gathered in the fall when eggs hatch and new caterpillars start feeding. These young caterpillars are very susceptible to pesticide due to their small size so we hope the slower, but longer lasting, pesticide will significantly impact next year’s brood.
Below is a City park Oak tree that was injected with pesticide this spring. Note the red circle at the top of the tree. This is where it suffered from minor defoliation before the caterpillars ingested enough pesticide to stop them.
Below is another tree, not located in a City park, that was not treated with pesticide. The tree was defoliated nearly to the bottom branches, as indicated by the red circle.
We also trialed an application of Bacillus thuringiensis (Bt), a biological pesticide, on a couple ornamental fruit trees on City property. This is a natural bacterium that is deadly to caterpillars. It is used once the caterpillars are out and feeding. We used it on the shorter trees because we had the ability to spray the whole tree, which is very difficult to do on larger trees. This application was very successful at stopping the caterpillar feeding activity and preventing the trees from being completely defoliated.
If your trees look like they were killed by the BTM caterpillar horde, do not give up hope. You should already be seeing the tree budding out with new growth. Trees are remarkably resilient and will bounce back, if given the chance. Removing the tree should be a last resort. Get rid of the pest and the tree will reward you with years of service.
Our BTM mitigation efforts will continue. We are under no misconception that we will eradicate the BTM in Bangor. It’s an impossibility that we will never achieve. Historically, Mother Nature has helped the State of Maine beat back the BTM by giving us several years of wetter and cooler temperatures that allowed the entomophaga aulicae fungus to proliferate. That kind of widespread impact is the only way to beat the BTM.
We will put out updates as this year’s crop of BTM continues through its life cycle. Make sure to protect yourself as well as you can. As always, report your sightings through our website at Request for Service - City of Bangor, ME (bangormaine.gov). These reports allow us to track infested areas. We used reported locations and report frequency to choose the test areas for this year’s work. Your assistance is greatly appreciated.
May 16, 2023 Update:
Inspections of browntail moth winter nests in the City of Bangor show us that they have all opened. The tiny caterpillars are growing rapidly, shedding skin and hairs – see photo, below, taken on the West side of town today. These hairs will quickly become airborne, spreading easily on the wind. We encourage residents to be aware of their surroundings as they work and play outside. If you observe caterpillars with the telltale orange dots (clearly seen below) in the trees where you are working or recreating, take precautions to protect yourself. The best way to avoid exposure to the hairs is to leave the area where the BTM caterpillars are present. We understand that this isn’t always possible, though. If you must do work in an area with a strong BTM presence, try to cover as much exposed skin as possible. Plan your work for early mornings with a heavy dew or after a rain. Rain and dew will moisten the hairs and make it much harder for them to become airborne. Avoid mowing, digging, and raking when ground conditions are really dry or if the wind is blowing BTM hairs out of trees. When you are done working, remove your clothing and wash it separately from other clothes. Immediately wash all exposed skin with cool, soapy water to remove the hairs before they can get into your pores. If you cannot wash immediately after exposure, we have found that IVY-X wipes (a disposable wipe designed to remove poison ivy sap from skin) help remove the hairs in the field. We haven’t tried it yet, but we have also heard that using the sticky side of duct tape to lift the hairs off your skin (dab or blot the tape on your skin to grab the hairs) can help to limit exposure. Just watch out that it isn’t removing your hair too – that’s no fun, either! If you do end up with the rash, local pharmacies carry compounded mixtures that work well to relieve the itching.
For those who want to attempt to eliminate BTM from their properties, you have options. It is too late to snip winter nests but you can speak with a State of Maine certified pesticide applicator. Pesticides can be applied topically or can be injected into tree trunks to target the caterpillars. Now is the time to do this, though. They are actively eating and growing so pesticides will be very effective. The Maine Forest Service website has a wealth of information on combating browntail moth here, and they also maintain a list of pesticide applicators who will treat BTM here.
Pesticide tree injections in the City of Bangor parks listed on our April 19th update have been completed. The injection locations are hard to spot and the pesticide is very targeted. We are hoping this work will make a noticeable difference in the test locations. The Public Works Forestry Division is conducting surveys to determine efficacy of the injections. We will report our results later in the year.
As always, report your sightings through our website at Request for Service - City of Bangor, ME (bangormaine.gov). These reports allow us to track infested areas. We used reported locations and report frequency to choose the test areas for this year’s work. Your assistance is greatly appreciated.
April 19th, 2023 Update:
The City of Bangor Parks & Recreation Department and the Public Works Forestry Division are collaborating this spring to combat BTM through trial injections of pesticide into affected trees in select City of Bangor parks. City parks were chosen for two reasons:
1. Public parks, by design, are created to draw people to them. By conducting our trial in City parks, we expect to have the greatest positive impact on residents and visitors of the City of Bangor.
2. Public parks in the trial were reported through the City of Bangor QAlert system as having a browntail moth presence in prior years.
Direct tree injections are much more targeted than topical pesticide applications. The injection leaves no residue on the trunk of the tree so there is no opportunity for exposure to people or pets. The natural movement of fluids from the base of the tree to the leaves moves the pesticide naturally, without pressurized injections. The pesticide arrives at the leaves when caterpillars are emerging from their winter nest and are starting to eat. The incidental risk to other species is extremely low because browntail moth caterpillars are not a preferred source of food due to their toxic hairs. The injected insecticide has very little effect on non-target species, groundwater, air quality, and effects on humans are generally only applicable if leaves are ingested. Insecticide injections and public notice will be administered in compliance with the State of Maine Board of Pesticides Control regulations.
The trial injections will be followed up with weekly surveys through the spring to assess their affect. Follow up surveys will commence in the fall to determine the number of winter webs that are spun in treated trees. Our hope is there will be a positive follow-on effect from targeted pesticide application, reducing, or eliminating, infestations next year.
Parks with reported infestations were surveyed and all trees with observed winter webs in each park will be treated. The trial injections will include the following locations:
Broadway Park - 6 trees
Davenport Park - 2 trees
Fairmount Park - 9 trees
Old Cemetery Park - 2 trees
Talbot Park - 1 tree
March 9, 2023 Update:
The City of Bangor Parks and Recreation Department and the Public Works Forestry Division is collaborating this winter to target BTM winter nests in public parks. We rented a 40’ lift with jib to target nests from February 13 to March 10, 2023. However, the trees in our parks are proving to be too high to reach the winter nests, even when using an extension pole. We have now rented a 60’ lift and will attempt to clip nests with that. It is much heavier and we may run into problems with soft ground but the attempt to address the BTM problem in the City of Bangor continues!
February 21, 2023 Update:
The Maine Department of Agriculture, Conservation & Forestry has announced that February, 2023, is Browntail Moth Awareness Month. News: Newsroom: Maine Department of Agriculture, Conservation and Forestry
February is the perfect time to think about BTM because the winter webs are visible to the naked eye and caterpillars are safely ensconced in their winter webs, reducing the risk of exposure. The City of Bangor Public Works Department, Forestry Division is working with the Parks & Recreation Department to focus on winter web clipping in City parks this year. We have targeted City parks in an effort to make the biggest positive impact on residents during the upcoming summer season.
Residents and businesses can assist in the BTM mitigation effort by identifying and clipping BTM winter webs on their own properties. Clipping the nests can have a very positive effect on the number of caterpillars in the spring. Remember, each of these caterpillars is capable of shedding hundreds of toxic hairs into the environment. Each nest that gets clipped now contains up to 400 caterpillars that will never get a chance to grow and spread their menacing hairs next spring and summer!
You can read more about the statewide effort to reduce BTM populations by visiting the Maine Forest Service website. Browntail Moth Euproctis chrysorrhoea : Forest Health & Monitoring: Bureau of Forestry: Maine DACF You will not only find information about the browntail moth, but you can also see videos of how to clip winter nests and properly dispose of them.
Residents are also encouraged to report sightings of winter webs and live caterpillars on public property through the File A Service Request feature of our website, Request for Service - City of Bangor, ME (bangormaine.gov). These reports get mapped and allow us to more appropriately target our mitigation efforts.
August 8, 2022 Update:
In the Bangor area, the female adult moths have laid their eggs and completed their life-cycle. We have not seen a moth in over a week. It is now safe to turn on your outside lights at night, again, without fear of attracting these moths to your property!
Anecdotally, the adult moth population seemed much less noticeable this year in Bangor. I took note of the number of adult moths around a security light that was on every night at Public Works and there were never more than 10 moths on any given morning. Our Service Request/Reporting system seems to support this as we only received 2 reports of moths in the month of July this year versus 57 reports last July. As I mentioned previously, I witnessed a number of caterpillar deaths earlier this year, due to fungal infection. This was just prior to the cocoon stage. I’m hoping the low moth observations may be due to a high death rate as they were entering cocoons. That is a very unscientific theory and is likely just hopeful thinking on my part.
Though I haven’t witnessed any egg sacs starting to hatch in Bangor, the Maine Forest Service has been seeing young caterpillars starting to feed around the State. They are very small (less than ¼” long) and hard to spot but they leave behind a telltale sign – skeletonized leaves.
These small caterpillars do not shed hairs like the larger ones and, therefore, do not pose a high risk to people. We are unlikely to be bothered by their hairs for the balance of the year. However, I am seeing a lot of old cocoons that still have tightly clumped leaved. When/If these open, they will likely release toxic hairs into the air. If you are trimming branches and disturb these cocoons, hairs from the caterpillar may emerge and cause problems for you. Similarly, if you are mowing your lawn or we experience strong winds, hairs that fell to the ground may get stirred up and cause problems.
Pesticide treatment this time of the year isn’t recommended due to the way these young caterpillars feed coupled with the difficult in identifying where they are active. If you choose to apply pesticide, please do so carefully or hire a State of Maine licensed pesticide applicator to minimize impact to non-target insects. Again, our best and safest bet to reduce the number of caterpillars and their toxic hairs next year will be winter web clipping after the caterpillars spin their winter nests.
You can always find the latest information about browntail moth in Maine by visiting the Maine Forest Service Knockout Browntail Moth page at Browntail Moth Euproctis chrysorrhoea : Forest Health & Monitoring: Bureau of Forestry: Maine DACF
Here’s a great picture, from the MFS, of the size of the BTM size this time of year.
Not caused by BTM but this is an example of a skeletonized leaf with bronze-copper color.
July 6, 2022 Update:
Adult browntail moths have begun to emerge from their cocoons over the last few days in Bangor. You will see the white moths have gathered on walls and objects each morning, nearly anywhere there is an outside light left on overnight. This will be especially true on the west side of the city where surveys have indicated a much more robust BTM population. As more of the moths leave the cocoon their numbers will grow and they will become much more noticeable.
(from Maine Forest Service website) (taken at Public Works 7/6/22)
Insect traps, bug lights, and other methods of attracting and catching the moths is sure to be ineffective and are more likely to encourage the female moths to lay eggs on your property. The use of bug zappers may also reduce the population of parasitic flies and wasps that are natural enemies of the BTM. The best thing you can do is to turn off your outdoor lights between 9:00 pm and midnight, when the moth is most active.
The City of Bangor has streetlights all over the city and most of these are adjacent resident properties. We will not be turning off these lights, in the interest of public safety. Additionally, there are not enough Electrical Division staff to turn off even a fraction of the lights before the BTM lays its eggs and dies. Future plans for street lighting include remote control options that may allow for dimming during certain hours. Unfortunately, we are not there at this time.
Stay tuned to this page for periodic updates about BTM in Bangor. For more information on the statewide BTM problem, please visit the Maine Forest Service Knock Out Browntail webpage.
June 23, 2022 Update:
Our observations in Bangor indicate that browntail moth is currently entering pupal (cocoon) stage. There are very few feeding larvae (caterpillars) being observed at this point. This means the caterpillars will not be actively shedding their barbed and toxic hairs into the environment much longer. The caterpillar hairs will be encased in the cocoon as it transforms into the adult moth. In July we should see moths emerging from the cocoon to mate. The good news is that the adult moth does not shed these toxic hairs. The bad news is that the process of breaking out of the cocoon allows the hairs from their old caterpillar body can be released into the atmosphere where they can affect people.
The adult moth is very recognizable with bright white wings and a brown fuzzy tail poking out from under the wings. The moth is attracted lights at night, especially between 9:00 pm and midnight. If residents turn off their porch lights they can avoid attracting the moth to their property. The male moth will cluster around lights and the females will hang back in tree foliage close to the lights. Residents can remove clustered moths (and caterpillars) using a vacuum with HEPA filter and a few inches of soapy water, allowing them to drown in the water for a few days before disposing of them. Removing the moths may feel satisfying but, unfortunately, it is not an effective population control method. The moths that cluster around lights are male and we will never be able to remove enough of them to prevent the females from mating and laying their eggs.
The moths will be laying eggs sacs of approximately 200-400 eggs in August. The eggs will hatch approximately 2 weeks later. These caterpillars will feed on leaves and you will see skeletonized leaves on affected trees. These trees will end up with winter webs in mid-late October as the caterpillars prepare for winter. During this early feeding period the caterpillars will shed hairs but the effect doesn’t seem to be as severe as in the spring.
Despite the fact that there will be fewer hairs being actively shed by caterpillars, there are still plenty of hairs already in the atmosphere, ready to cause a rash. These hairs will eventually be washed out of trees and into the soil but they remain active there. Raking your lawn, digging a hole, mowing, leaf blowing, etc. can all disturb these hairs and cause them to become airborne again. We recommend that people survey the area where they plan to work or recreate and look for signs of the browntail moth. Trees with old winter webs and cocoons made of leaves and silk are telltale signs that the caterpillar has been active there. If you must be in the area of that type of tree, please take precautions to prevent a rash. Working after a rain, or when there is heavy morning dew, when trees and the ground are wet means the hairs are less likely to become airborne. Long sleeves, long pants, socks that cover your ankles, closed toe shoes, gloves, and a hat with a brim that covers your neck are all methods of preventing the hairs from landing directly on your skin. Once you leave the affected area you should remove these clothes and put on fresh clothes. This will prevent hairs from moving through the clothes and being forced into your skin. Washing or showering with cool, soapy water can wash the hairs off your skin before they can get into your pores. Some people have experienced success with application of pre-contact poison ivy wipes and similar barrier creams on exposed areas of skin.
The City of Bangor is performing some very limited scope testing of pesticides to identify effective treatments. There will also be a winter web clipping program on public property again in the winter of 2022-2023. The City of Bangor has no program to provide browntail moth mitigation services on private property.
We encourage people to report browntail moth sightings whether they be caterpillars, cocoons, moths, or winter webs. Reports can be entered through our website at Request for Service - City of Bangor, ME (bangormaine.gov).
These reports are mapped with time/date stamps to allow us to gather real-time data that will help us determine the scope of the problem and develop cost effective counter-measures.
Please check in on this page regularly for updates. You can also monitor the Maine Forest Service website at Browntail Moth Euproctis chrysorrhoea : Forest Health & Monitoring: Bureau of Forestry: Maine DACF for more frequent updates regarding the problem statewide.
May 24, 2022 Update:
Browntail moths in the Bangor area have now exited their nests. Trees with winter nests are likely to be covered with tiny caterpillars that are growing fast. The recent windy weather has knocked a lot of the caterpillars out of trees so you may see a lot of them on the ground under the canopy of the tree, too.
It is well past the point where nest clipping is effective; the nests are now empty. Residents experiencing a large number of BTM caterpillars on their properties have a few options:
- Call a license insect pesticide applicator to apply pesticide to your affected trees
- Responsibly apply pesticide, yourself, to your affected trees
- Pray for a wet month of June to allow the natural enemy of the BTM caterpillar, entomophaga aulicae fungus, to proliferate and kill the BTM
Pesticide application is most effective when the BTM caterpillar is small, so now is an ideal time to treat trees. Please be safe, follow all instructions to protect yourself, and only use in a prescribed manner.
If you have BTM caterpillars on your property and you are stuck dealing with them, please be careful to minimize contact with the irritating hairs. Don’t try to clean them up with a leaf blower. Don’t mow on dry days. Don’t stand under or near infected trees on windy days.
If you do get some hairs on you, or feel the telltale itch, immediately wash the affected area with cold soapy water to wash away as many of the hairs as possible. Avoid hot water as that will open your pores for the hairs to enter. Local pharmacies also sell creams to alleviate the symptoms of the rash.
There is a wealth of knowledge regarding the BTM on the Maine Forestry Service website. When you do see outbreaks of moths you can report them to the city, for mapping purposes, through the GoBangor app or through the Service Request page on the City of Bangor Website.
The City of Bangor is not applying pesticides to public properties due to the wide variety of people who use them. While a homeowner can easily determine pesticide sensitivity of those who use their property, this is not something that can be easily determined for public properties across the City. While BTM exposure is unpleasant, we do not want to inadvertently cause an adverse reaction in individuals who are sensitive to pesticides, especially children. Additionally, the City of Bangor will not be applying pesticides to trees on private property.
January 6, 2022:
The City of Bangor has initiated the browntail moth winter operations plan. This includes a survey to determine the extent of the browntail moth infestation on public property, which will be used to guide our winter web clipping efforts. Once the survey is completed the Public Works and Parks & Recreation departments will send out teams to start clipping browntail moth winter webs in parks, roadsides, and other public properties.
Winter web clipping is a very impactful way to limit the spread of the browntail moth. The larvae are very small at this stage, they have not begun to molt, and their webs are tightly woven, which keeps all the caterpillars contained inside. Each web contains up to 400 caterpillars, each having the ability to massively defoliate trees, pupating into moth form, and laying up to 400 more eggs. Each web clipped could potentially prevent up to 160,000 more caterpillars from munching on our trees next year!
Residents can do this same thing to protect their own property. We encourage residents to look at trees on their own land to see if there are winter webs present. The Maine Forest Service (MFS) created a nice video to help you identify the winter webs, clip them, and dispose of them. https://www.youtube.com/watch?v=L6VmwsXE3lg&t=4s [embed?]
If you are unable to remove winter webs yourself and would like assistance, MFS has assembled a list of State of Maine licensed arborists here, https://www.maine.gov/dacf/mfs/forest_health/documents/arborists_prune_btm_webs.pdf
If you would like to speak to a State of Maine licensed pesticide applicator about your browntail moth problem, MFS has assembled a list of companies who are willing to treat for browntail moth here, https://www.maine.gov/dacf/mfs/forest_health/invasive_threats/browntail_moth_pesticide_applicator_info.htm
Maine Forest Service also has a page that helps you identify browntail moth winter webs versus abandoned webs of the fall webworm or eastern tent caterpillar. https://www.maine.gov/dacf/mfs/forest_health/insects/browntail_moth_id_winter_nests.htm
Their browntail moth webpage has a wealth of information and will be a great resource if you want additional information about the browntail moth and other methods of management. https://www.maine.gov/dacf/mfs/forest_health/invasive_threats/browntail_moth_info.htm
Lastly, we also ask that residents report their winter web sightings through the city’s service request page, https://bangormaine.gov/311/request/add . By reporting the location of winter webs under the “Browntail Moth Reporting” type of issue, you will help us track the extent of their spread and aid in future planning. Remember, the city is unable to provide assistance to residents in removing winter webs on private property but the information regarding their location is still helpful.
UPDATE: July 12, 2021
Residents of Bangor have been diligently reporting the caterpillar, at first, and now the adult moths. Our infestation map is starting to come together, you can view that below. Thank you to everyone who has participated in reporting. You can file your own report by clicking here.
Recent rains have done a great job washing toxic Browntail moth hairs into the soil where they are much less likely to cause allergic reactions in residents (unless you are actively digging in the soil). Forecasted rain this week will continue to reduce the negative impact of these hairs. We are seeing the adult moths (pictured below) emerging from cocoons in large numbers and gathering near bright lights at night. The Maine Forest Service is recommending that people do not try to manage Browntail moths in the adult moth stage. However, they do recommend that people turn off unnecessary outside lights between 9:00 pm and 12:00 am (midnight) to avoid attracting them to your property. If they are not being attracted to your property then the chances of them laying eggs is decreased. The good news is that the hairs of the adult moth are not toxic, so they are not contributing to additional outbreaks of rash and itching.
These moths were found in Bangor on July 8.
Unfortunately there is not a lot we (you or the City of Bangor) can do to control this year’s population. The next step, and a very important step, in controlling next year’s population will be the winter nest snipping. These nests are very visible, each nest snipped removes 200-400 caterpillars (and literally billions of toxic hairs) from the 2022 lifecycle, and snipping causes no harm to the tree, to beneficial insects, to wildlife, or to people. As these winter nests appear we will be sharing more information about identification and how you can help prevent the spread on your own property.
More information:
Browntail Moth - Home and Garden IPM from Cooperative Extension - University of Maine Cooperative Extension
Browntail Moth Euproctis chrysorrhoea : Forest Health & Monitoring: Bureau of Forestry: Maine DACF
June 4, 2021:
(Photo credit: Maine Department of Agriculture, Conservation & Forestry)
The City of Bangor is experiencing a marked increase in the number of complaints regarding Browntail Moth exposure. This spring, many residents suffered from direct exposure to caterpillar hair and indirect exposure from windblown hairs.
The City has developed a plan to address the increase in Browntail Moth activity that includes a public information campaign, tracking of locations where nests are seen, a clipping program to remove winter nests, and determining the appropriate methods to treat and target impacted foliage.
(Photo credit: Maine Department of Agriculture, Conservation & Forestry)
The browntail moth is an invasive species normally found on the coast of Maine and Cape Cod, but in 2021 the winter webs were discovered in all 16 Maine counties. This moth is an insect of both forest and human health concern.
Caterpillars are active from April to late June. Hairs remain toxic throughout the summer but get washed into the soil and are less of a problem over time.
Health Concerns
The browntail moth caterpillar has tiny poisonous hairs that cause dermatitis similar to poison ivy on sensitive individuals. People may develop dermatitis from direct contact with the caterpillar or indirectly from contact with airborne hairs.
The hairs become airborne from either being dislodged from the living or dead caterpillar or they come from cast skins with the caterpillar molts. Most people affected by the hairs develop a localized rash that will last for a few hours up to
several days but on some sensitive individuals the rash can be severe and last for several weeks. The rash results from both a chemical reaction to a toxin in the hairs and a physical irritation as the barbed hairs become embedded in the skin.
What are the symptoms of browntail moth toxin exposure?
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A skin rash on any part of your body that was exposed. The rash tends to be red, bumpy, and itchy.
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Respiratory issues such as breathing difficulty can occur if the browntail moth hairs are inhaled.
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If you are having trouble breathing, swallowing, or swelling of your mouth, tongue, or throat, call 9-1-1.
How do I treat the rash?
According to the Maine CDC, mild rashes can be treated at home with:
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A cool bath with baking soda or Aveeno Oatmeal Bath
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Hydrocortisone cream, such as Cortaid, applied sparingly to the itchiest areas
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Calamine or caladryl lotion
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If home remedies are not working, see your healthcare provider. There are medications that your healthcare provider might recommend.
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Be careful not to apply any creams or lotions to places where young children may rub them into their eyes or mouth.
Is the rash contagious?
You cannot "catch" the rash from another person like you can a cold. The hairs need to come in contact with your skin, mouth, throat, or respiratory tract for symptoms to appear.
As part of the City's informational campaign, signage like this will be placed in City parks and other public properties:
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Learn more about the Browntail Moth by visiting the Maine Department of Agriculture, Conservation & Forestry's website.
Maine CDC Browntail Moth fact sheet