Core Activities

Pest Problems

Asian Longhorned Beetle (top)

albThe Asian long-horned beetle (Anoplophora glabripennis) is a wood-borer that attacks healthy hardwood trees. The only method of control is the destruction of infested trees. In the 1990's, Anoplophora was intercepted from wooden spools and other packing materials imported into Canada. Extensive surveys in both Canada and the USA revealed the presence of live wood-boring insects in many wood items entering North America. In 1992 hundreds of Asian long-horned beetles were intercepted in wood from China in one shipping container. The cargo and dunnage were fumigated. Regulations limiting the movement of wood to Canada from China are now in effect.

Asian long-horned beetles are about 2.5 to 4 cm in length, are black and shiny with white spots, and have long antennae that are banded with black and white.

holeThe first report of this beetle being established outside of it's native range was from the cities of Brooklyn and Amityville, New York in 1996. Many trees were found to be heavily attacked, particularly maples. Quarantine and eradication procedures were quickly implemented to prevent further spread and to eliminate the population. More recently (July-August, 1998), three separate infestations were discovered in Chicago, Illinois. These infestations are also under quarantine and eradication actions. (CFIA, 2001-08-15)

The beetle causes damage to host trees by its wood-boring activity. Since beetle larvae live deep inside trees for most of the year, they can easily and unknowingly be moved in firewood, live trees, or untreated lumber.

For up-to-date information on the Asian long-horned beetle, visit the Canadian Food Inspection Agency:

Canker Worms (top)

cankerlWhat's the problem?

Fall cankerworms, also called loopers or inchworms, devour the leaves of hardwood trees including maple, oak, cherry and apple as part of their natural cycle. They are yellow, green or brown caterpillars.

Tell me about cankerworms

Cankerworm populations go through 10-year cycles which often peak for two to three years. In much of the affected area, this is the second and possibly the last year of the cycle. Many will be eaten by birds and other predators. The remaining cankerworms will feed until mid-June and then will crawl into the ground to pupate. In October, they will begin to re-emerge as moths.

Will they damage my trees?
The defoliation of trees by insects occurs naturally and will not kill healthy trees. These trees will grow new leaves by the end of june after the caterpillars have gone underground. Trees already in marginal health may eventually decline should repeated defoliation occur.

cankeraWhat can be done?
There are several options:

1. One is to do nothing except wait for the caterpillars to go underground and for the trees to grow new leaves.

2. If you are concerned that particular trees are already in frail health and might not survive, you can call a licensed contractor who can use one of several pesticides such as Sevin, a chemically-based contact insecticide.Remember that caution is needed when using insecticides and spraying is not practical in many circumstances.

3. A safe organic control agent called Bt can be used in some cases where the location of cankerworms on individual trees can be predicted ahead of time. The insects must eat the Bt early in their feeding cycle.

4. In the fall, individual trees can also be protected by placing a plastic band with a sticky substance such as Tanglefoot around the truck.This prevents the wingless female moths from climbing the trunk to lay eggs.

5. Ensure that your trees get enough water through the summer and fall.

6. Do not use a high nitrogen fertilizer on a lawn near a defoliated tree. It causes the tree to use up its starch reserves. Wait until fall and use a complete granular fertilizer.

Emerald Ash Borer (top)

In May 2002, an unknown species of beetle was reported by researchers to be attacking and killing red and green ash trees (Fraxinus pennsylvanica) in Michigan. The species was subsequently identified as the emerald ash borer (EAB), Agrilus planipennis (also known as Agrilus marcopoli) on July 08, 2002. Extensive mortality of ash trees attributed to EAB has been reported in the Detroit area of Michigan and it appears to be a damaging pest to trees growing in both urban and forested sites.

On July 17, 2002, the Michigan Department of Agriculture announced that quarantine action would be taken to contain the US population of the EAB. The quarantine prohibits the movement of ash trees, nursery stock, logs, un-treated lumber, wood and bark chips as well as firewood from five counties in southeastern Michigan, including the City of Detroit.

eab_insctIn July 2002, the EAB was discovered in Windsor, Ontario (County of Essex). As of August, 2002, the EAB has been found in the City of Windsor along with the neighbouring municipalities (Towns) of Amherstburg, Essex, LaSalle, and Tecumseh. Positive identification of A. planipennis was provided to CFIA by US specialists on August 07, 2002. A Pest Risk Assessment (PRA) completed by the CFIA in August 2002, states that EAB should be considered as a serious pest that may have a potential negative impact on the Canadian economy and environment. A preliminary delimitation survey in the Windsor area to determine the extent of the infestation was completed in mid-August, 2002. Based on the results of this survey, there is reason to believe that EAB is present only in the Greater Windsor area of Ontario. The CFIA and stakeholder groups are developing potential regulatory options.

EAB is an introduced (exotic) beetle, native to China and eastern Asia and had not been found in North America prior to the current infestations in Canada and the United States.

In North America, EAB has been found to attack and kill red and green ash trees (Fraxinus pennsylvanica) as well as white ash (F. americana). In Asia, walnut and elm trees are also affected by EAB.

Asia: The EAB is native to China and eastern Asia.
North America: The EAB has been confirmed in Windsor, Ontario (County of Essex), and in six (6) counties in Michigan.

For up-to-date information on the emerald ash borer, visit the Canadian Food Inspection Agency:

Eastern Tent Caterpillars (top)

Cherry and apple trees and noticeable in the spring when the buds flush.

Prune and destroy egg mass that can be noticed on branches the size of a pencil in the fall and winter.

tentThe easiest control for trees up to 3 to 4 meters (13 to 16 feet) tall is to use a stick, broom handle, etc. and when the caterpillars are in their nests (usually at noon or during rains) poke the stick into the center of the nest and roll the stick. The silk fibers of the nest will adhere to the stick and as you roll the stick, the silk will wrap the caterpillars up tight in their nest. Then slide the nest and caterpillars off the stick with your foot and squash the whole mass.

For smaller trees or shrubs you can wash the caterpillars off the leaves with a garden hose and squash them with your foot where they land on the lawn.

DO NOT BURN the nests. Setting fire to the nest will damage or kill the branches.

If you want to use pesticide try Bt (available as Dipel, Thuricide, or other trade names), a bacterial spray which when applied to the leaves being eaten by the caterpillars, poisons the caterpillars, killing them usually in about 12 hours or less. Bt only kills caterpillars of the moth and butterfly family and does not harm insects of other families which are beneficial including many insects that may eat the tent caterpillars. Bt is the safest material that can be used, but be sure to read the instructions on the label!

I have a 'nest' of caterpillars in my tree, what are they?
Answer: It's almost certainly tent caterpillars. These insects make silk nests in which they hide from predators when they are not feeding.

Will my trees that have had the flowers and leaves eaten recover?
Answer: Yes trees that have had tent caterpillar damage will put out a second set of leaves and should look normal by mid July.