Tag Archives: tree pests

August is Tree Check Month

Did you know August is Tree Check Month?  August is the peak time of year for the Asian longhorned beetle (also known as the ALB) to be found in your trees!  The U.S. Department of Agriculture’s Animal and Plant Health Inspection Service (APHIS) is asking for your help to find and eliminate the ALB, which is a harmful and invasive pest.

Heavily Infested Maple Tree

Heavily ALB Infested Maple Tree in Massachusetts

ALB Infestation

About the Asian Longhorned Beetle

Long Horned Beetle Westchseter Tree Life

The Asian longhorned beetle is easily identifiable; they have long black and white antennae, six (possibly) light blue legs and a body which is black with white spots and an inch and a half long.  Once you identify your first ALB, you might notice that they also can be found in your pool filters, on walls, outdoor furniture, cars and sidewalks.Westchester Tree Life

While these beetles are slow to spreading on their own during the early stages of an infestation, containing the infestation is critical.  The most common way to spread an ALB infestation is through moving fireword (which we urge the Westchester community not to do).

Reporting the Asian Longhorned Beetle


What to do if you see signs of the ALB (via USDA):

  • Make note of what you found, where you saw it and take a photo, if possible.
  • Try to place the beetle in a container and freeze it for easy identification by the USDA.
  • Report findings by calling 1-866-702-9938

About the Hemlock Wooly Adelgid

How much do you know about the Hemlock Wooly Adelgid?

In New England, hemlock trees play an important ecological role.  They are important for limiting erosion along stream beds and provide food and shelter for deer and other wildlife.  The hemlock is valued as an ornamental tree as well as a source of lumber.  Unfortunately, hemlock trees are vulnerable to infestation by a pest called the Wooly Adelgid.

Wooly Adelgid

Wooly Adelgid

The Wooly Adelgid is a destructive insect that was accidentally introduced to the United States from Japan.  Wooly Adelgid infestations have been noted from Georgia to Massachusetts and can have drastic effects on hemlock populations.  Trees infested with the Wooly Adelgid become desiccated and typically die within ten years.  Specimens that survive the pest are often so weakened that they eventually die of secondary causes.  Westchester County’s tree care professionals, Westchester Tree Life want to keep your trees safe!

"Adelges tsugae 3225077" by Connecticut Agricultural Experiment Station Archive, Connecticut Agricultural Experiment Station / © Bugwood.org. Licensed under CC BY 3.0 us via Commons -

“Adelges tsugae 3225077” by Connecticut Agricultural Experiment Station Archive, Connecticut Agricultural Experiment Station / © Bugwood.org. Licensed under CC BY 3.0 us via Commons –

Wooly Adelgid infestations can be identified by the presence of the insect’s egg sacs.  These sacs look like fluffy tufts of cotton clinging to the underside of the hemlock’s branches.  Infested branches change from a healthy dark green color to a paler greyish-green shade.  This pest reproduces asexually and in North America can have two generations a year.  The Wooly Adelgid feeds on the hemlock’s sap and probably injects a toxin into the tree while feeding.  This results in a loss of needles and a lack of new growth.

There are a few options for addressing an infestation of the Wooly Adelgid.  Insectcides that are sprayed on the tree, injected into the tree, or applied to the soil around the tree can be effective in treating individual trees.  This sort of treatment will remain effective for two or three years.  However, such treatments can only be used when there is no risk of the insecticide contaminating nearby bodies of water.

Another option is use a non-toxic insecticidal soap or horticultural oil.  These products are applied to the hemlock’s affected foliage and work by smothering the pests.  Trees treated in this manner will need to be retreated annually.

When multiple hemlock trees are affected by the Wooly Adelgid, a biological approach to eradicating the pest may be best.  The Wooly Adelgid can be controlled by introducing a natural predator to the area.  There are two beetles that feed on the Wooly Adelgid and are highly effecting at keeping the pest’s numbers at a manageable level.  These are P. tsugae, a black lady beetle, and the larva of the L. nigrinus.  Releasing these beetles into areas where Wooly Adelgids threaten the health of hemlock trees has proven to be an effective and safe method of control.

P. tsugae and L. nigrinus

P. tsugae and L. nigrinus

If you have hemlock trees on your property and suspect they are infested by the Wooly Adedgid, contact Westchester Tree Life today for a consultation.  We can examine your trees and advise you on the best way to eradicate this pest in your unique situation.


The Gypsy Moth

This is the first time in a long time we’ve seen the Gypsy Moth in Westchester County.  This blast from the past is considered one of North America’s most devastating forest pests by the U. S. Forest Service.  Over the years the Gypsy Moth, or Lymantria dispar, has been on hiatus, but recently more and more have turned up in Westchester County.

Westchester Tree Life’s Jeff G. tells us about his experiences with this tree-munching pest:  When I was a kid, old enough for adventure too young to drive, I’d go bike riding with friends to go down to the local stores or the McDonald’s in town ( Wappinger Falls, NY ). I can still vividly remember the summers when all the trees were bare of leaves and gypsy caterpillars were everywhere: on the houses , roads and sidewalks.  You could not ride your bicycle  without fenders or you’d get covered in caterpillar guts from riding over so many as you peddled down the street!  And like I said the hillsides were bare and looked like winter in July; no leaves , no green.  They [the Gypsy Moths] ate every leaf on the trees!

Gypsy Moth Westchester Tree Life

The Introduction of the Gypsy Moth

A species native to Europe and Asia, the Lymantria dispar, or Gypsy Moth, was accidentally introduced to Boston, Massachusetts during the 1870’s by E. Leopold Trouvelot.  Trouvelot hoped to jump start the silk industry by further studying the Gypsy Moth.

E. Leopold Trouvelot Home Bedford Mass

E. Leopold Trouvelot’s Bedford, Mass. home, where the first Gypsy Moths escaped.

It took ten years for the species to noticably flourish; in 1890 the U. S. government unsuccessfully tried to eradicate the species from North America.  This species thrives on the foliage of many plants in North America, though its most frequented hosts are oaks and aspen trees.

Gypsy Moth Swarm Ann Pettigrew

Example of a Gypsy Moth swarm; Photo via: Ann Pettigrew

An Invasive Pest

Gypsy moth caterpillars collected during an outbreak. (Jodie Ellis, Purdue University)

Gypsy moth caterpillars collected during an outbreak. (Jodie Ellis, Purdue University)

North America is known to have explosive Gypsy Moth outbreaks.  Trees may become completely defoliated if a particular Gypsy Moth outbreak becomes too intense.

Predators to the Gypsy Moth

It has been suggested that the primary predator of the Gypsy Moth are small mammals.  Though birds in Westchester, New York and other parts of North America may feed on the insect, it does not substantially affect the population.

An Infestation Solution

Currently, the USDA Forest Service, the USDA Agricultural Research Service, the USDA Cooperative State Research Service, the USDA Animal and Plant Health and Inspection Service, and numerous state and private Universities have invested time and funding to research this invasive species.  To control the population and maintain a balanced eco-structure, areas of North America are aerially sprayed with pesticides to suppress the species.

Identifying the Gypsy Moth

Need some help identifying Gypsy Moth caterpillars from your native caterpillars?  Watch this video: