Alton resident teaches about dangers of the gypsy moth

September 25, 2020   ·   0 Comments

By Constance Scrafield

Too often the introduction of a harmful invasive species is down to simple ignorance or carelessness. 

Like Gypsy Moths: in 1869, Etienne Trouvalot, living near Boston, brought in European Gypsy Moths to start a silk business. He attached them to his trees, rather than in a laboratory. While the silk idea failed, with no natural predator, the moths successfully moved on to to become entrenched across much of North America. 

Gypsy moth females do not fly but excrete a scent that attracts the more mobile, flying male to come to impregnate her. She can then crawl to many places to lay her “egg masses,” small woven packages, attached to many surfaces and harbouring from 600 to 1,000 eggs per nest.

Alton Resident, Pat Hertzberg, has been teaching people how to rid their own environment of these egg masses because, once the many eggs hatch, they produce a caterpillar that veraciously defoliates trees – completely. 

“When I first learned about this, living elsewhere, they were not yet in our area, predominated by oak trees. These insects have defoliated thousands of acres of forest. So, I contacted every authority and nobody had a plan in place for when these would hit our neighbourhood,” Pat told the Citizen. 

Mrs. Hertzberg talked about these dangerous invaders. “I wanted to be proactive. I researched and discovered we could get rid of the egg masses. That’s easy but, left to hatch, the caterpillars can defoliate a tree very quickly: within days. 

“These are not tent caterpillars,” she clarified. “The female doesn’t move that quickly, but she can attach them to travel on a vehicle, in the wheel well.

“The egg masses lay for six months, between late August and early May, then hatch into tiny caterpillars that eat the leaves of trees.”

Explaining the horror, “They will destroy the tree, not necessarily by defoliating once, but, uncontrolled, they will eat the leaves the next year; that will kill the tree. Each caterpillar lives 40 days, then wraps itself into a cocoon for 14 days. From the cocoon a moth emerges. Each female can lay a number of egg masses.”

Mrs. Hertzberg was demonstrating how to remove these egg masses on a private property last weekend as a workshop to a small number of people, assuring us, “All these people wore masks and kept social distancing.

“The moth population is getting very high,” she warned us. “I saw number of egg masses. It’s important to get rid of them. Think of the thousands of caterpillars you’re eliminating.”

She outlined the method: “You spray the egg mass with a spray bottle, of a soapy water solution; a small amount of liquid dish detergent to a litre of water. Soak it enough to wet the eggs mass so that when you remove it, it comes off in one piece, easier and faster. 

When hunting for the masses, they can stick to your vehicle under the wheel well, all winter. They’re visible but can look like dirt. Once people see what they look like – they’re a buff colour. If you have them and do a thorough search, you’ll find them. Or if your neighbour has them, you have them look too. This is something that communities should get together and watch for.

“And in all the trailways. One person attending the workshop is a member of the trailways. Start the search in one corner and look systematically – underside of branches, patios; they’re the same colour as chopped firewood. All the outdoor surfaces of your home; under mortar between bricks; bird houses, anywhere other than on the ground or in the grass.”

She commented, “I saw a planter with dozens of masses under the lip of the planter – that’s part of the problem.

“In size, from a dime to a toonie, usually oblong, irregularly shaped. When you look at it, you might not know there are eggs in it because it’s covered with this buff surface. 

“So the egg mass search will greatly reduce the incidence of the population.”

She was careful to say, “It’s very light, so you have to make it wet enough not to lose any eggs,” continuing, “Next, with a sharp instrument or paring knife scraping them off. It’s important not to scrape them on to the ground; the eggs are very very tough – you can’t squash them with a boot. They have to go into a container: a paper bag, adding to that bag and then you can put the bag into a fire. Burning will definitely get rid of them; or drop them into a container of soap and water and a small amount of bleach to destroy them. Being so tough requires bleach.”

Come May, “It’s guaranteed there’ll be more egg masses in the spring. Ideally, people will carry out two searches: now and in the spring, as well before hatching out in early May.”

For the sake of those missed masses, Pat Hertzberg brings another, well documented solution: “Spring hits late May early June. The eggs hatch and you don’t see them, they’re so tiny. As they grow, they’re eating the trees. So, look up into the canopy of your trees to see if they’re being eaten.

A further indication of the caterpillars is, “Frass – excrement – if the numbers are high, you can actually hear the excrement falling, like a light rain, falling, hitting a leaf or the deck.”

The hunt: “Skirt the tree at about eye level by the beginning of June; there may still be masses to remove. Place a piece of burlap around the tree. Tie a rope of string in the middle of the burlap and fold over the burlap over the string. It provides a resting place.

“They eat until they need to rest. They’ll climb down the tree to the grass, but the skirt provides a resting place underneath. Lift up the skirt and they can now be seen, as they have been growing and eating.

“Wear lightweight or gardening gloves,” she advised, “because the hairs have a chemical in them which is irritating, Remove cocoons which may be empty. It’s labour intensive everyday,” she admitted, “but you can see the enemy and understand the damage. People are willing to do this once they understand they have a problem.”

To dispose, Mrs. Hertzberg again suggests using soapy water. 

Garden centres also sell pheromone traps, a theoretical method of control for the male moth. 

Mrs. Hertzberg cautioned, “Residents can think they’re taking care of the problem but this is not correct. There will still be male moths. The traps are really only any good for governments to hang to get an idea of the population of gypsy moths but they don’t cure the problem.”

Also very importantly, as she observes, “The gypsy moth is different from just a nuisance. Complete defoliation is a danger to the trees. That cycle can be as long as ten years. It can be two to three years but we don’t know how much damage will be done.”

Mrs. Hertzberg urged, “This is an easy fix to begin with. Control what we can now and then wrap the trees in the spring to catch the caterpillars coming down to rest.”

She said, ““And, of course, an infestation and damaged trees can affect property value.”

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