Gyspy Moth Outbreak Update
Since our last update, the team has continued researching how to determine the degree of severity of our current gypsy moth infestation and options to control it.
Despite efforts by many Huron Woods residents to rid their property of caterpillars and the use of pheromone traps to interrupt mating, indications are we will experience a far greater infestation next year unless remedial actions are taken. The number and size of egg masses sighted, in addition to there being little evidence of the virus or fungus that leads to a decline in population, suggests the outbreak is set to grow and spread. The municipality will be conducting an egg mass survey this fall or winter, which will provide a more accurate prediction of expected infestation levels for 2021.
The Ontario Ministry of Natural Resources has determined that egg mass densities above 1236 egg masses per hectare (about 500 egg masses per acre) indicate moderate to severe defoliation in the following year. Some residents are reporting over 50 egg masses per tree and more will be revealed once the leaves fall in the autumn, as most of the masses are higher up in the trees.
Each egg mass can produce between 500 and a 1000 caterpillars. Egg masses longer than 25mm are linked to a strong and growing gypsy moth population; egg masses under 20mm are linked to a population in decline. Some residents are reporting egg masses as large as 50mm.
We have received quotes for aerial spraying from Zimmer Air Services, along with information about the process for individual property owners wishing to contract them to spray next spring. If the contract is signed before March 31, 2021, the cost per property is $357 per acre with each additional acre being $96. There is no urgency to sign a contract at this time, but signing before the deadline is important because rates increase in April, and the manufacturers of the biological insecticide only produce as much as has been ordered for the season.
The gypsy moth team and the HWCA Board have communicated with our municipal councillor to say we would like the municipality to lead an aerial spraying program for the affected areas next spring because it would be more effective in controlling the outbreak, less expensive overall, and because the logistics of implementing aerial spraying by, or on behalf of, individual property owners would be exponentially more challenging. We will share the councillor’s response when we receive one. Their course of action will decide next steps for our team, Huron Woods, and surrounding communities. We are sharing information and coordinating efforts with subdivisions in Grand Bend and Port Franks.
Aerial spraying will significantly reduce the infestation next year, but will not kill every caterpillar. The next step of an integrated pest management program you can conduct on your property is the destruction of egg masses. The attached document shows you how to destroy egg masses by scraping and soaking them, or by spraying them with an oil, soap and water mixture. A large number of egg masses will be found in trees above 5 meters, but it is NOT recommended you attempt to remove them, as it is difficult to stabilize a ladder in this situation.
If you would like to keep a tally of the size and number of egg masses you find on your property, feel free to share this with Jacqui Krech: jacqui.krech@gmail.com
Your Huron Woods Gypsy Moth Outbreak Team,
Jacqui Krech, Anne Thornton, Paul Mennill, Angela Arenberg
Thank you so much for taking on this important project. The spraying is absolutely necessary!
Thank you for the information It was very helpful. We have to share information in order to get rid of this pest. I live in Cumberland Village (Ottawa East) we had a bad outbreak in our neighbourhood. I wrapped tinfoil around my trees. The larger caterpillars had difficulty climbing past this barrier as they would either fall off or be blown off with the wind. The smaller ones had less difficulty. So far it provided the opportunity to kill a lot at this stage as there would be a traffic jam under neath the tinfoil each time I checked it. Now I am working destroying any egg masses i find. So far I have destroyed two or three hundred egg masses on my property. I am fearful about next spring. I am well armed for next spring.
I read somewhere that the caterpillars climb down from the trees at night and return during the day. Can you confirm this for me.