Gypsy Moths in the Sugar Bush

Sugar Bush in Early May 2021

Here at White Meadows Farms, we love sharing our Sugar Bush with all of the birds, insects and furry friends who call our forest their home. Each of us has our own role in maintaining the balanced ecosystem that exists in the forest throughout the year. This year however, a large population of unwelcome gypsy moths are threatening to upset this balance and cause potentially fatal damage to our maple trees.

Gypsy Moths are not native to North America. They were introduced here when an experiment went horribly wrong back in 1869 (kind of like the Hulk sort of wrong)… A door was left open and the moths escaped into the wild. Now, decades later they wreak havoc over our woodlands every spring.

Caution — Reading further risks the possibility of learning something!

Truth be told this is a bit of an over-exaggeration (for dramatic affect), but they can cause serious harm to our forests when populations get out of hand. Eggs laid in Autumn of the previous year hatch every May and the caterpillars start looking for food. Their favourite snack is Oak tree leaves, but when there is short supply basically any tree leaf will do. Usually this is no big deal, after all — a tree has a lot of leaves!

The problems start when there are so many caterpillars that there are just not enough leaves in the forest to satisfy them. When this happens, it is possible for them to literally eat every stitch of green in the forest.

Since Gypsy Moths are invasive, it is important to monitor and control their population. For reasons you will understand in a moment, we don’t count exactly how many caterpillars are in our forest. Mature moths lay an egg mass which contains anywhere from 100 to 1000 eggs. Each year to get an idea of how many caterpillars we might expect, we count these egg masses in random locations through our forest and then extrapolate our counts. This year’s count gave us an estimated 150,000 egg masses throughout our Sugar Bush which gives a very large window of a possible infestation of between 1.5 to 15 Million caterpillars!

Of course this doesn’t really paint the whole picture since we need a benchmark to compare it to. So the question becomes, how many of these little Hulk’s are too many? This depends on many factors such as when the eggs will hatch, Spring weather conditions and even droughts from previous years that put trees under stress. All in all it’s generally considered that a population in our forest higher than 750,000 could be detrimental to the survival of the trees. Yes that’s right, our estimate is up 20 times higher than our forest could survive.

So where does that leave us? Well, as a maple farm we kind of depend on our trees to make our living, so we need to protect them! We’ve enlisted the help of science and will be spraying our Sugar Bush to fend off these tree killing giants. The product we will use is called Bacillus thuringiensis kurstaki (Btk), if you’d like to learn how it works I recommend reading about it here. In short, it kills the caterpillar by creating a toxin once ingested. This is only toxic to the caterpillar and not to other animals, so it doesn’t hurt birds or any of our other furry forest friends. Since the trees are so tall, a helicopter is required to apply this treatment throughout our forest. Of all the equipment we have here at the farm, a helicopter is NOT something we keep around. We’ll be hiring a specialized helicopter service to distribute the Btk around our forest.

This isn’t the first time we’ve dealt with these invaders, but luckily it doesn’t happen often. The last time that the Gypsy Moths caused a significant problem that required treatment was in the mid 1990’s. Unfortunately for us, these moths have decided that 2021 is going to be a BIG year for them which means a big expense for us! Haven’t they heard that we’re already in a Pandemic?