Invasive Insects & Forest Diseases
This information was provided by the LCPOA Environment Committee, December 2020.
Non-native insects and fungi can have serious consequences on our forests and ecosystems. A loss of trees affects the way we enjoy nature, can adversely affect wildlife and can have devastating economic implications.
Imported packaging materials and the movement of firewood have generally brought in forest pests, in the form of insects. Diseases have made their way into Ontario forests by imported plant material. Wind and water can spread these species further as can human activities such as being transported on hiking boots or recreational equipment that has not been properly cleaned. Any number of different organisms can affect the entire tree causing defoliated, root decay or cankers, all of which impede the flow of nutrients through the tree, resulting in tree mortality.
European Gypsy Moth
Imported packaging materials and the movement of firewood have generally brought in forest pests, in the form of insects. Diseases have made their way into Ontario forests by imported plant material. Wind and water can spread these species further as can human activities such as being transported on hiking boots or recreational equipment that has not been properly cleaned. Any number of different organisms can affect the entire tree causing defoliated, root decay or cankers, all of which impede the flow of nutrients through the tree, resulting in tree mortality.
European Gypsy Moth
European Gypsy Moths
Gypsy moth outbreaks occur sporadically in Ontario when the weather is favourable and egg production is high. They usually last about 3 years until associated viral and fungal pathogens increase enough to terminate the outbreak.
In the caterpillar stage this insect can completely defoliate any number of deciduous, and in some cases coniferous trees over large areas. Strong, healthy trees can often survive but the trees become weakened with each year of defoliation and may be susceptible to other diseases. Trees that are already stressed due to drought or other factors are often killed.
This information from the City of London about Gypsy Moths may be helpful to you:
https://london.ca/living-london/water-environment/trees/invasive-species/gypsy-moth
In the caterpillar stage this insect can completely defoliate any number of deciduous, and in some cases coniferous trees over large areas. Strong, healthy trees can often survive but the trees become weakened with each year of defoliation and may be susceptible to other diseases. Trees that are already stressed due to drought or other factors are often killed.
This information from the City of London about Gypsy Moths may be helpful to you:
https://london.ca/living-london/water-environment/trees/invasive-species/gypsy-moth
Frequently Asked Questions (FAQ's)
This insect has four stages: Beginning in the spring, small larvae grow into caterpillars, they become pupae after about 2 months of eating leaves, and then a week or so later, in late summer, metamorphose into moths. The brown male moths will fly around looking for stationary white females to fertilize. The females then lay egg masses that will stay in place through the winter into spring when each egg mass can produce hundreds larvae.
The following website has excellent photos and descriptions of each stage:
https://gypsymothalert.com/lifecycle.html
The following website has excellent photos and descriptions of each stage:
https://gypsymothalert.com/lifecycle.html
Gypsy moth caterpillar
Gypsy moth
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Gypsy moth larva
Size of gypsy moth
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Caterpillars are 5-6 cm long, dark coloured and have pairs of blue dots and red dots along their backs. Pupae are 3 cm long and brown with small white/yellow sparse hairs. Female adult moths have a 5 cm wingspan and are white with dark markings. Males are smaller (2.5cm wingspan) and are brown with dark markings. Egg masses can be about 4 cm long, tan-coloured, and can be found on any hard surface – including tree trunks, furniture, under leaves, rotting wood or buildings.
In the Lake Clear area, we see Gypsy Moths mostly on our Oak trees but they will also feed on the leaves of Birch, Aspen, Linden, Mountain Ash, Willow and possibly even attack Maple, Spruce and Pine.
Once the larvae hatch in the spring the caterpillars make their way up the trees and out onto the limbs where they chew large holes in the leaves. The caterpillars initially feed during the day but as they grow and mature they tend to feed at night, eating entire leaves and then making their way down the trunk to rest in shady areas during the heat of the day.
During severe outbreaks, trees or shrubs can be completely defoliated. Some may be able to grow an entire set of new leaves that season, but the energy expended severely weakens the tree and its ability to fight off other diseases and pests or to regrow healthy leaves the following year.
During severe outbreaks, trees or shrubs can be completely defoliated. Some may be able to grow an entire set of new leaves that season, but the energy expended severely weakens the tree and its ability to fight off other diseases and pests or to regrow healthy leaves the following year.
When the caterpillars first hatch as small black larvae, they are quite light and can easily be carried by the wind. Since female moths attach themselves to all sorts of solid objects they can be transported from one area to another.
As with all invasive species it is important to be able to recognize and properly dispose of Gypsy Moths in all of its stages. Clean any hiking boots, recreational equipment, vehicles, etc. before moving from one place to another.
A few methods have been found effective to remove the pests:
a) In the fall and winter examine tree trunks, the underside of limbs, lawn furniture, fire wood, rotting wood on forest floors, house foundations, garden hoses, etc. for egg masses. Scrape them off with a knife or paint scraper into a sealable container of soapy water and dispose of them in the garbage.
b) Attach burlap or a sticky barrier around the trunk of potential host trees to catch caterpillars as they ascend the trees during April, May and June. Each day you will have to pick the caterpillars off by hand and destroy them in a container of soapy water.
c) The burlap may be sprayed with insecticide in the early spring. Ask at your local garden centre which insecticides or pesticides are effective and safe to use.
d) A high pressured hose can be used to spray off caterpillars that are out of reach. They must then also be properly disposed of.
e) The Nucleopolyhedrosis virus can kill caterpillars naturally. If you see a caterpillar hanging upside down in an inverted V, leave them as other caterpillars may crawl by and contract the virus.
f) Encourage birds to hang around your property as many of our local species (blue jays, chickadees, sparrows, vireos, blackbirds…) will feed on the egg masses or even the caterpillars.
A few methods have been found effective to remove the pests:
a) In the fall and winter examine tree trunks, the underside of limbs, lawn furniture, fire wood, rotting wood on forest floors, house foundations, garden hoses, etc. for egg masses. Scrape them off with a knife or paint scraper into a sealable container of soapy water and dispose of them in the garbage.
b) Attach burlap or a sticky barrier around the trunk of potential host trees to catch caterpillars as they ascend the trees during April, May and June. Each day you will have to pick the caterpillars off by hand and destroy them in a container of soapy water.
c) The burlap may be sprayed with insecticide in the early spring. Ask at your local garden centre which insecticides or pesticides are effective and safe to use.
d) A high pressured hose can be used to spray off caterpillars that are out of reach. They must then also be properly disposed of.
e) The Nucleopolyhedrosis virus can kill caterpillars naturally. If you see a caterpillar hanging upside down in an inverted V, leave them as other caterpillars may crawl by and contract the virus.
f) Encourage birds to hang around your property as many of our local species (blue jays, chickadees, sparrows, vireos, blackbirds…) will feed on the egg masses or even the caterpillars.
Oak Leafshredder or Leaftier (Acleris semipurpurana)
Oak Leafshredder
The caterpillars of this small yellow brown moth have been found eating the leaves of Red Oak trees around our area. The eggs overwinter on bark or leaf scars and emerge as green larvae in early summer. They move to buds and tunnel through leaves (hence the name shredders). The larvae also fold sections of leaves together with silk webbing. They then drop to the ground to pupate. The moths will emerge from shrubs in late June or early July. This insect also has the ability to kill Oak trees after a few years of infestation. Spraying leaves with an appropriate insecticide in the early spring may slow down the larvae/ caterpillars. Alternatively, spraying the undergrowth in early July may hinder the moths from laying so many eggs.
Hemlock Woolly Adelgid (HWA)
Hemlock Woolly Adelgid (HWA)
Hemlock woolly adelgid is an aphid-like tiny, brown insect that attacks and kills hemlock trees by sucking sap from the base of the needles. After the initial infestation the tree will turn a greyish green colour, lose its needles and can die within 4 to 10 years.
HWA is native to East Asia where it only causes minor damage due to natural predators and host resistance. This also seems to be the case for Canada’s Western Hemlock in British Columbia. But in Eastern Canada, our Eastern Hemlock has been devastated by this invasive species in some forests in SW Nova Scotia. A few infested nursery trees that had been transported from Pennsylvania to Etobicoke, Ontario were found and destroyed in 2012. Since then, a very small population of Hemlocks infected by HWA were found and have been destroyed or are being currently monitored in the Niagara Falls area of Ontario.
Since the infestations are still small, it is imperative that any spread is detected early.
The presence of Hemlock woolly adelgid can be identified by egg sacs clinging to the underside of the branches that look like tufts of cotton.
HWA is native to East Asia where it only causes minor damage due to natural predators and host resistance. This also seems to be the case for Canada’s Western Hemlock in British Columbia. But in Eastern Canada, our Eastern Hemlock has been devastated by this invasive species in some forests in SW Nova Scotia. A few infested nursery trees that had been transported from Pennsylvania to Etobicoke, Ontario were found and destroyed in 2012. Since then, a very small population of Hemlocks infected by HWA were found and have been destroyed or are being currently monitored in the Niagara Falls area of Ontario.
Since the infestations are still small, it is imperative that any spread is detected early.
The presence of Hemlock woolly adelgid can be identified by egg sacs clinging to the underside of the branches that look like tufts of cotton.
Frequently Asked Questions (FAQ's)
Pine Engraver Bark Beetle (Ips pini)
Pine Engraver Bark Beetle (Ips pini)
These reddish brown to black, 4 cm long bark beetles are secondary pests that seem to attack stressed or weakened pine trees. Many of our red pines appear to be stressed from recent years of low rainfall or over crowding along the shoreline. These beetles then bore small circular holes into the bark to use as feeding and breeding tunnels. Peeling a small area of bark away will uncover the insects or just their tracks if they have already moved on. Trees with active insects should be removed and burned. It is best to contact a local arborist at this point.
Frequently Asked Questions (FAQ's)
Jumping Worms
The Ontario Horticultural Association has notified the Eganville and District Horticultural Society about an invasive and very destructive species of earthworms that were found in Southern Ontario in 2021 (Windsor, Hamilton and Toronto). They are Jumping Worms - see poster included here. If you have friends or relatives visiting this summer, please follow the advice here - or better yet, ask them not to share plants with you right now. If you know people coming here to their cottage, please advise them too. It's extremely important to prevent the spread.
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