🍃 Invasive LDD Spongy Moths🐛

2022

They have a new name: spongy moths! They are officially the  Lymantria dispar dispar (LDD) moths. It's the caterpillars that give the most trouble.

In the winter, I noticed the spongy stuff on the trees. I couldn't possibly remove them all. 

May 8th – see post: I brought some up to the house. The ones above the snow line did not hatch.

May 13th, there was a report on the nearby lake of the first instar. 

May 16th – the first sign of them here. I only found a few. Whew!

May 30th – people on the lake sprayed BTK.

For information on how to complete a 2022 defoliation forecast on your own property, and to view the 2021 defoliation map.

2022 predictions

2021

LDD moth update! Ontario Natural Resources and Forestry has posted their map of areas defoliated by the LDD moth in 2021 across Ontario. Their findings are based off aerial forest health surveys and ground surveys.

I was correct to be worried. They are everywhere. Lymantria dispar dispar (LDD) moth caterpillars, otherwise known as European gypsy moth caterpillars. ("Gypsy" is politically incorrect, as it is considered a pejorative term, a racial slur. Gypsies, known as Romani or Roma, were called such, as Europeans thought they came from Egypt.)

• Monday, May 16th began the assault. I kept on washing off the railings. Every few hours, with soap in the water. They were all over the back deck📹. (4 mm)
• Thursday, May 20th – Apps and technology for fauna and the skies, on the railings and in the rain gauge. I cannot spray them, as we've gray tree frogs everywhere. 
• Friday, May 21 – they are on the elm tree in the meadow
• May 21 – Chores, Butch, ducklings, and crow<= more on the railings.
• May 22 – regular washing down of the railings. 
• May 23 & 24 – all over my rose bushes, elm trees 6 mm.
• Third and 4th instars: Gramma Camp – continued...Week 30 13 and 18 mm.
• May 29 – Blackflies, fallen tree, LDD 15 mm.
• May 31 – They are up to 19mm.
• June 6 – They are increasing in numbers, on the aspen, spruce, elm and birch. Sunday chores!
• June 9th – roses, rhodos, spruce tree, pines: Gramma Camp – Week 31
• June 10 – Backyard trees, pine trees: Gramma Camp – Week 31 32 mm.
• June 11 – up to 35 mm.  
• June 18 – now 42 mm long. Chipmunk was eating them! One day at a time
• Reported on the lake: They are displaying a familiar inverted V-shape, which means they have been killed by the virus.  I am a wreck! 
• Thursday vs. Monday (photos below) the trees are growing new leaves. The caterpillar poop, and the fallen leaf parts, will fertilize the land. 
•  July 1st – they are pupating. Hopeful article re: fungus and viruses.
• July 9th – there are moths everywhere📹.
• July 15 – Stewart Park

2021

I noticed all the LDD moths mating and laying eggs.

They came from the USA. Most US sites stop at the border!

The danged things are moving north with climate change.

Lanark County European Gypsy Moth fact sheet (PDF)

From Facebook: <= click for the whole article. June 30th

The up side of having multiple years of high caterpillar population is that the virus that reduces their population (multicapsid nuclear polyhedrosis virus or LdMNPV) is now becoming quite established in the local ecosystem and, despite the thousands of egg masses and the tens of thousands of tiny hatchlings I saw this spring, the damage to the trees is far less than I was expecting this summer.

From Ontario Parks... regarding the LDD infestation. 

While insecticidal sprays do exist, they are very expensive, and there are no available insecticides for broad-scale use that target only LDD Moths. Bacillus thuringiensis (or Btk), the product commonly used to control LDD Moth outbreaks, can kill all Lepidoptera (butterflies and moths) that are caterpillars when the spray is applied, usually in June.

Ottawa Valley – Wed., May 26, 2021

The ministry says although the moth is still considered an invasive species, it has evolved to a state of naturalization and may have periodic predictable outbreaks as seen last year. Outbreaks typically occur every seven to 10 years, with outbreaks averaging three to five years. In Ontario, major outbreaks have occurred in 1985, 1991 and 2002. The previous outbreak, which peaked in 2008, was much less severe than earlier ones.

Bugs and blooms

I have discovered that they don't like the sun. They'll move out of the sun to the shade, on the railing.

They have been trapped in the rain gauge! Only 4 mm long, in May, they will grow!

Other people are wrapping burlap around trees. With our 16 acres, I just cannot. Some are spraying Btk, but if you dilute to the recommended dosages, it is ineffective.

🐛🐛🐛🐛🐛🐛🐛🐛🐛🐛🐛🐛🐛🐛🐛🐛🐛🐛🐛🐛🐛🐛🐛🐛

One entomologist says to leave them alone. The spray kills all the moths and butterflies.

2020

This is the first year I spotted any eggs. I was worried. 

• Aug. 14, 2020 – First eggs I've spotted at Foley Mountain Wednesday afternoon at Gramma Camp
• Sept., 2020 – Painting the decks, back to school, trailcams

Wiki: The European gypsy moth was first brought to North America in 1869 ^[3]:9 and rapidly became an invasive species. Étienne Léopold Trouvelot imported the destructive European species with the intent of interbreeding them with silk moths in order to establish a new silkworm industry in the West.^[3]:10 The moths were accidentally released from his residence in Medford, Massachusetts.^[3]:10 

  LDD moths  <=Ottawa Citizen

Ontario’s Ministry of Natural Resources and Forestry estimates caterpillar defoliation increased a staggering 1,200 per cent last year, from 47,203 hectares in 2019 to 586,385 hectares in 2020. Aerial surveys and ground searches for gypsy moth egg masses show this year’s infestation could be even worse.

Each egg mass can contain 100 to 500 eggs. These are the egg masses I spotted last year. I scraped them off and put them in soapy water. With 16 acres, there is no way I can keep that up.  [Painting the decks, back to school, trailcams]

We visited Foley Mountain Park last year. The moth eggs were all over the trees. 

 

Well, they have hatched. I noticed them Monday, May 17th.  They fling themselves out into the world on gossamer threads, and their 4 mm bodies are spread on the wind.

gypsy moth caterpillars from Jennifer Jilks on Vimeo.

There is a spray, but experts say they will damage all the butterflies and moths, not just these. Plus, now they've hatched, 

This is the adult Moth (Wiki)

I only found one caterpillar last year. 

Ontario Ministry information 

People are really concerned, as am I. I didn't realize they were invasive. The tent caterpillars have life cycles, they ebb and flow over the years. Eventually they die down, only to come back. The question is if the Gypsy Moths will do the same thing. A biologist thinks so. The problem is, the deciduous trees can recover, coming back the next year. The impact on the evergreen needles is different.