Invasive Insect Species in Oregon

Invasive Insect Species in Oregon

Invasive Insect Species to look out for and report


Compiled from many web sources.

There are a number of invasive pest species that Linn County Master Gardeners have been alerted to.  The purpose of this monitoring and alert system is to slow the damage these pests can do.  They are labeled “invasive” because of their destructive and invasive behavior.  There are a few steps we use to determine when to alert our internal Invasive Species Expert, Rich Little.  Rich works very closely with the Oregon Department of Forestry and the Oregon Department of Agriculture to continually keep eye out for the appearance of these invasive species.

What can each of you in the community do to help?  Help us by alerting us to any ‘red flag’ pest activity that:

  • Is not controlled by normal treatments especially if you have gotten good control in the past.
  • Is the pest/pathogen different from the norm – from what you have typically seen.
  • Is the damage different from the norm.
  • Did the problem happened fast and is it a known big problem.

Who and how you let us know you think you have found something of concern:

Spot an invasive species? Or what you think is an invasive species? Use the Oregon Invasive Species Hotline to report it.  Report online at Oregon Invasive Species Hotline or call 1-866-INVADER.

Use these two Federal websites for the Spotted Lanternfly:

  1. Spotted Lanternfly | National Invasive Species Information Center
  2. USDA APHIS | Spotted Lanternfly

 Working together, we can slow and potentially minimize the impact of these pests on our plants and trees. Following are four “red flag” invasive species to look out for.  Links to additional detail are provided in blue.


Asian Long-Horned Beetle | Center for Invasive Species Research (


Anoplophora glabripennis Motschulsky; Last updated by: Faith Campbell, June 2020

The Asian longhorned beetle attacks dozens of species from 15 plant families, especially maples, elms, and willows. Forests dominated by vulnerable species make up more than 10% of all U.S. forests.

The Asian longhorned beetle has been introduced to North America and Europe at least 35 times beginning in the early 1990s. The pathway of introduction has been wooden crates and pallets. Asian longhorned beetles continue to be detected in wooden packaging, despite regulations intended to prevent their presence.

The Asian longhorned beetle, or ALB, is an invasive insect that feeds on a wide variety of trees in the United States, eventually killing them. The beetle is native to China and the Korean Peninsula and is in the wood-boring beetle family Cerambycidae. Adult beetles are large, distinctive-looking insects measuring 1 to 1.5 inches in length with long antennae. Their bodies are black with small white spots, and their antennae are banded in black and white. Checking your trees regularly for this insect and looking for the damage it causes and reporting any sightings can help prevent the spread of the beetle.

Asian Longhorned Beetle lifecycle - How it affects trees

Over the course of a year, beetle larvae develop into adults. The pupal stage lasts 13 to 24 days. After adult beetles emerge from the pupae, they chew their way out of the tree, leaving round exit holes approximately three-eighths of an inch in diameter. Once they have exited a tree, they feed on its leaves and bark for 10 to 14 days before mating and laying eggs.

Because ALB can overwinter in multiple life stages, adults emerge at different times. This results in their feeding, mating, and laying eggs throughout the summer and fall. While adult beetle activity is most obvious during the summer and early fall, adults have been seen from April to December. Adult beetles can fly for 400 yards or more to search for a host tree or mate. However, they usually remain on the tree from which they emerged, resulting in infestation by future generations.

Signs of ALB start to show about 3 to 4 years after infestation, with tree death occurring in 10 to 15 years depending on the tree’s overall health and site conditions. Infested trees do not recover, nor do they regenerate. Foresters have observed ALB-related tree deaths in every affected state.

Host Trees

Collectively, the tree species the insect favors are called ALB host trees. In the United States, known ALB host trees include all species of the following 12 genera:

London planetree/sycamore (Platanus)

Maple (Acer)

Horsechestnut/buckeye (Aesculus)

Katsura (Cercidiphyllum)

Mimosa (Albizia)

Mountain ash (Sorbus)

Poplar (Populus)

Willow (Salix)


EMERALD ASH BORER (EAB), Agrilus planipennis Fairmaire

Emerald ash borer detected in Oregon: Be alert and report sightings | OSU Extension Service (

Emerald ash borer resources | OSU Extension Service (

Alternatives to Ash in Western Oregon: With a Critical Tree Under Threat, These Options Can Help Fill Habitat Niche</em> (

On June 30, 2022, emerald ash borer (EAB), an exotic beetle that infests ash trees, was discovered in Forest Grove, Oregon, marking the first confirmation of the invasive pest on the West Coast.

Be alert: It is important to slow new outbreaks before they start. Early detection, coupled with rapid response, can slow the spread of this new and emerging invasive species. The EAB is here and established so we need to slow it down as we will not get rid of it.

  1. Learn to recognize ash trees.
  2. Know how to identify the emerald ash borer - Insect identification:
    • Adult: 5 to 13.5 mm (0.3 to 0.5 inch) long, slender, and metallic olive to emerald green with red abdomen; active June through July.
    • Larva: 6 to 3.2 cm (1 to 1.3 inches) long, creamy white, with bell-shaped segments; found under the bark throughout the year; causes damage to tree by eating tissue below the bark. See photos and learn the hosts, signs and symptoms.     


  1. Report sightings of emerald ash borer: Report online at the Oregon Invasive Species Council hotline.
  2. Share information about emerald ash borer with others, including neighbors, fellow gardeners, hikers, mushroom hunters and campers.
  3. Do not move or transport ash wood: Even after a tree has died or has been cut down, there is still the possibility for the emerald ash borer to be present in the wood. Keeping the wood on the same site as the infected tree can help to slow the spread of the insect.


JUMPING WORM; Amynthas agrestis


Slowing the spread of jumping worms

Slowing the spread of jumping worms calls for vigilance | OSU Extension Service (

A current concern is the invasive jumping worm (Amynthas species) being reported in the Pacific Northwest, and in the Willamette Valley. It has likely been here for many years.  We will not stop it, but we can slow it.  Sent to OSU’s online Ask Extension service, an inquisitive gardener found a worm that seemed “very energetic.” A video of jumping worms in a container helps to show why they received their "energetic" common name.

Why are jumping worms a concern for gardeners?

Jumping worms have a negative impact on soil structure. Their feeding creates a more porous soil (water moves through quickly) reducing moisture content. They consume most of the organic matter in the soil which degrades the soil value for growing plants. Jumping worms also easily spread to new garden areas by hitchhiking in contaminated soil and compost.

How to tell the difference between jumping worms and earthworms?

Jumping worms:

  1. Noticeably thrash and jump when disturbed.
  2. Have a smooth milky-colored band called the clitellum where eggs (cocoons) are released from.
  3. Have an incredibly large mouth that enables the worm to excavate, scoop and sort organic debris (akin to a mechanical excavator) for consumption. See a video displaying the large mouth.


SPOTTED LANTERNFLY; Lycorma delicatula

Spotted Lanternfly | National Invasive Species Information Center

USDA APHIS | Spotted Lanternfly


Report sightings of Spotted Lanternfly to the National Invasive Species Information Center (link above)

 Spotted lanternfly populations are currently found in 14 states including: Connecticut, Delaware, Indiana, Maryland, Massachusetts, Michigan, New Jersey, New York, North Carolina, Ohio, Pennsylvania, Rhode Island, Virginia, and West Virginia. This article was to give a perspective of what Oregon may face.

We in Oregon need to be looking for this pest.

Spotted lanternfly (SLF) is one of the latest invasive insects to make its way from Asia to the US.  They have been in the country nine years now and were first detected in Pennsylvania in 2014.  Since then, they have gradually spread to portions of nine other Northeastern states, including Virginia and North Carolina, and there are isolated, established infestations in Michigan, Indiana, and Ohio—one county each.

These are large colorful insects; some would even call them beautiful.  Adults are up to an inch long, which is especially large for a leafhopper, and have purple-gray forewings sprinkled with dark spots.  The hindwings, which are visible in flight, have patches of bright red.  The nymphs are colorful too; early instars are black with small white spots, but the large 4th instar nymphs are red, also covered with small white spots.  Damage is caused by both nymphs and adults feeding on shoots and stems with their strong, piercing-sucking mouthparts; larger nymphs can even feed through thin bark. SLF does not feed on fruit; they are strictly sap feeders, but the large amounts of sap they consume results in heavy accumulations of honeydew and sooty mold.

Although SLF has not yet been seen in Oregon, it is still a pest to be aware of.  SLF occurs on a wide range of perennial crops, including grapes, hops, fruit trees and hardwoods, and it is predicted to spread throughout the Northeast and, eventually, to California.
This is a pest we will hear a lot more about in coming years, and it certainly could show up here in the state at any time.  SLF lay their eggs in flat masses covered with a glue-like substance, and they will stick these egg masses on almost any surface, including vehicles, boxes, plastic yard toys and equipment, and similar items.  Egg masses deposited on such items can quickly and unknowingly be transported to other areas of the country.
As with many non-native insects that make their way here without their natural enemies, SLF can build to unusually high populations and heavy feeding by such numbers can damage sensitive crops such as grapes.  But the most favored host of spotted lanternfly is another invasive from China known as Tree of Heaven, Ailanthus altissima, also known as Chinese sumac.  Although older trees can exceed 50 feet, most trees encountered here will be much smaller.  You can identify them by their leaves, which are compound leaves ranging from one to four feet long with rows of 10 to 40 lancehead-shaped leaflets that are arranged opposite each other.  They look a lot like sumac or black walnut leaves but are usually considerably longer.
If you encounter Tree of Heaven trees this year, check them out to see if you can find spotted lanternflies, and if you do, please let your County Agent know about it. Take a picture or catch the critter if you can.  It is important that reports be supported by samples or photos so identification can be confirmed.

Blake Layton, Extension Entomology Specialist, Mississippi State University Extension Service.
The information given here is for educational purposes only – For additional information,
see the USDA Spotted Lanternfly Pest Alert



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