Natter’s’ Notes
By Jean R. Natter, OSU Master Gardener

Asian Giant Hornet on finger
Fig 1- An Asian giant hornet (Vespa mandarinia) resting on hand. (Photo: Takehiko Kusama; found in Niigata, Japan;

As is true with the introduction of numerous other invasive species, there is no real way to tell how the Asian giant hornets (AGH; Vespa mandarinia) arrived in the Pacific Northwest. Among the possibilities are via international container ships, imported products, travelers visiting the US, or people returning from another country. The hornets are native to temperate and tropical eastern Asia, including parts of Japan, China, India, and Sri Lanka. (


  • An adult is 1 1/4″ to 2″ long with a striped abdomen, orange head, and black eyes
  • AGH predators and are a potential serious threat to honeybees
  • AGH are ground-nesters, active from May to August
  • AGH has an annual colony, with cooperative care of the larvae by the workers.

Current distribution  

To learn where AGH have been sighted, see the map at  (Be patient; the map loads slowly.) The map will be updated as additional reports are made.

Life cycle

Fig 2
Dorsal view of an Asian giant hornet, Vespa mandarinia. (forestryimages – 5570920 Allan Smith-Pardo, Invasive Hornets, USDA APHIS PPQ,

AGH nests underground, often in abandoned rodent burrows. It’s an annual colony in which all, except the mated queens, die at the end of the season, August, in their native land. Metamorphosis is complete, with 4 life stages: Egg; larva; pupa, a non-feeding resting stage; and adult. The life cycle is about 40 days. The larvae are fed masticated prey by the workers. Adults are predators of many large-bodied insects such as grasshoppers and beetles. European honey bees (Apis mellifera) are very susceptible to attack.

In the spring, the overwintering queens locate a nest site and lay about 40 eggs. She rears the first generation which then takes over food gathering and larval care. The colony is aggressively defended throughout the season. In the fall, males wait at the entrance for the females, mate, then die.


  • This is definitely not an opportunity to be a hero. AGH’s half-inch long stingers can easily penetrate a traditional beekeeper’s suit. After your sighting is verified, let the pros do the heavy lifting.
  • Commercial traps for wasps and/or hornets won’t work because the holes are too small.

Critical cautions

  • AGH seldom sting humans but, when they do, the effect can be very serious.
  • Use extreme caution near Asian giant hornets. The venom is more toxic than local bees or wasps.
  • Beekeeping gear won’t protect you.
  • Persons allergic to bee or wasp stings should never approach an Asian giant hornet and/or its nest.
  • If you find an individual or colony, report it to your state Department of Agriculture immediately. (See the list of Resources.)

Opportunities for MGs

Well, as is common when a new invasive insect is reported, numerous “sightings” have been reported but only 2 verified. A newspaper in Louisiana even ran a story saying essentially “It’s not here.”

A prime opportunity for every Master Gardener is to share a research-based Teachable Moment with family, friends, and the public. One way is to provide a Pictorial ID of Look-a-Likes (at the end of this story) which compare sizes of insects which might be confused with AGH.


Asian giant hornet – A list of reliable resources related to this recent invader which includes a link to report a sighting in Oregon.

“Don’t panic over Asian giant hornet” (KGW8 News: text and brief video; May 4, 2020)  –

By Margaret Bayne, OSU Extension Service Staff Retired, OSU Master Gardener

Team Shows How Butterfly Wings Can Shift in Hue:Recent study leads to a deeper understanding of how butterfly wing color is created and evolves.” Diana Kenney, Marine Biological Laboratory, University of Chicago

A Field Guide to the Miniature Menagerie Inside Your Own Home: “There’s no social distance between you and your face mites.” Jessica Leigh Hester,

Hummingbirds Show Up When Tropical Trees Fall Down: “Treefalls happen all the time, but this one just happened to occur in the exact spot where a decades-long ecological study was in progress, giving University of Illinois researchers a rare look into tropical forest dynamics.” Lauren Quinn, Illinois ACES

Yellowjacket on food, “Western Yellowjacket” by K Schneider is licensed under CC BY-NC 2.0

Wasps: “Wasps make up an enormously diverse array of insects, with some 30,000 identified species. We are most familiar with those that are wrapped in bright warning colors—ones that buzz angrily about in groups and threaten us with painful stings.  But most wasps are actually solitary, non-stinging varieties. And all do far more good for humans by controlling pest insect populations than harm.”

Herbicide Carryover in Hay, Manure, Compost, and Grass Clippings: Minda Daughtry and last updated by Pam Kerley  NC Cooperative Extension)

A tale of two weeders – lessons in managing aggressive, perennial weeds Dr. Linda Chalker-Scott,

NASA Releases Satellite Images of California Superbloom From Space Madison Dapcevich,

Fertilizing Flower Gardens and Avoid Too Much Phosphorus – Tina Smith & Doug Cox, U of MASS at Amherst

A selection of apple varieties, Montana State University

Apple identification: “This website will help you identify apple varieties. If you have an unknown apple variety that you want to identify you can compare the key features you see on it with dozens of attributes and variety characteristics listed on this website.” Seattle Tree Fruit Society, Western Cascade Fruit Society Chapters, Home Orchard Society, BC Fruit Testers Assoc., & Orange Pippin

Websites and publications mentioned in ‘Enhancing Urban and Suburban Landscapes to Protect Pollinators’ webinar:

Oregon State Bee Keepers Association Swarm Call

Nurturing Mason Bees in Your Backyard in Western Oregon

Shrubs for Fall and Winter Bloom

Pollination Podcast

Oregon Bee Atlas Outreach Materials

Andony Melathopoulos

Link to the video:

Websites and publications mentioned in ‘Enhancing Urban and Suburban Landscapes to Protect Pollinators’ webinar:

Oregon State Bee Keepers Association Swarm Call

Nurturing Mason Bees in Your Backyard in Western Oregon

Shrubs for Fall and Winter Bloom

Pollination Podcast

Oregon Bee Atlas Outreach Materials

Natter’s Notes

By Jean R. Natter, OSU Master Gardener

The Winter Cutworm, Noctua pronuba, was officially identified by Oregon Department of Agriculture (ODA) as an invasive pest in Oregon during 2012. Even so, the metro Master Gardener offices had been receiving complaints about their activity since 2001.

Plants were nibbled and/or destroyed from fall through the winter. At first, most folks assumed the damage was due to slugs and snails. However, the mutilation was different than the shredded tissue left behind by slugs and snails. Seedlings were toppled; emerging bulbs lost their heads and sometimes flower buds; and hostas lost leaf tips or had gaping holes. At my place, the pests would climb my 3- to 4-foot tall delphiniums to eat the flower bud at the tip of the stalk, sometimes settling down for a snooze.  To accurately identify the culprits, MGs in the offices had to activate their Master Gardener CSI mode.

The Winter Cutworm, Noctua pronuba

As you likely recall, caterpillars (Order Lepidoptera) have complete metamorphosis, with 4 life stages.  After the adults mate, the female lays several hundred eggs in a large tidy patch, most often covering, or nearly so, the surface of a leaf. The larvae (youngsters) hatch in 2 to 4 weeks. These caterpillars have different habits than most you are familiar with because they feed at night, whenever the temperature exceeds 40F, from fall through winter.

Perhaps the most effective treatment strategy is to go outdoors about 10 pm or so, with a cup of soapy water and tongs or a pair of gloves. As you trek through your plantings keep any eye out for caterpillars chomping at your expense. They may be anywhere from ¾ to 1.5 inches long, the size depending on their age. They’re often aligned with the edge of a leaf, or out-of-sight among the leaves. Hand pick and drop into the cup.

During the day, the larvae hide just under the soil surface, typically quite close to the stem of the victimized plant. Disrupting a bit of soil often reveals their hiding place.

The caterpillars of the Winter Cutworm (Noctua pronuba, aka the Large Yellow Underwing) appear bright green after they have molted; the color will gradually change to the various browns within hours. Source:

Fun for gardeners

This spring, as you prepare your garden, it’s very likely you’ll find a number of Lepidoptera pupae in the soil. Rearing the pupa is the best way to determine the parent moth’s identity.

To rear pupae, place in clear container with a porous lid, such as paper toweling secured with a rubber band. Set the container somewhere you’ll see it, but not in the sun, then wait for the adults to emerge.

The Gray Garden Slug

Slugs, especially gray garden slugs (Deroceras reticulatum) thrive throughout the northwest, feeding in gardens, greenhouses, roadsides and fields. They’re omnivores which feed on live plant material and much more, including mushrooms, dead slugs, earthworms. They have the ability to detect predatory carabid beetles through the use of olfactory cues. And, because slugs are hermaphrodites, reproduction is by cross-fertilization which may occur year-round when conditions are favorable. Mating occurs mainly at night with each animal capable of laying approximately 60-75 eggs (4 mm each) in a clutch, totaling about 700 eggs per year per slug. Each slug may live a year or two. ( reticulatum)

The Gray Garden Slug (Deroceras reticulum) is perhaps the most damaging slug in local gardens. Damage often avoids (stringy) leaf veins. Source: reticulatum

Fun for gardeners

If you happen upon a clutch of slug eggs – they’re transparent and either round or tear-drop shape – scoop them up with a bit of surrounding soil, put them in a clear container with a porous lid, and wait.


“Winter Cutworm: A New Pest Threat in Oregon” –

 “Slugs and Snails in Oregon” (ODA) –

“Snails and Slugs” –

 “Cornu aspersum” [The Brown Garden Snail, formerly Helix aspersa] –

 “Terrestrial Mollusc Tool” (USDA, University of Florida, & Lucidcentral: Incudes Fact Sheets with images; and a Glossary –

By Margaret Bayne, OSU Extension Staff-retired, OSU Master Gardener

Bernedine Strik, OSU

NEW: Pruning video course series from OSU.  Five courses offered: Pruning Blueberry, Grapes, Kiwifruit, Raspberries and Blackberries.

“You can take any of these courses individually or take them all to become a pruning master. In these self-paced online courses, you will navigate through several 10–20 minute video lectures. You will have access to the course and the materials for one year after you enroll. You will also receive a bundle discount if you enroll in multiple courses at the same time.” (OSU)

Radiation-munching fungi are thriving on the walls of Chernobyl’s reactors. (

Mosquitoes are drawn to flowers as much as people — and now scientists know why. (James Urton, University of WA; UWNews)

Fun and informative video: Licking bees and pulping trees: The reign of a wasp queen. (Kenny Coogan, TED-ED via

Evaluating the hidden risks of herbicides– Gut microbes of wasps evolve after exposure to common treatment, leading to pesticide resistance, study says (Mary Todd Berman, Harvard Gazette)

OSU Photo Archive

Accuracy varies for commercially available soil test kits analyzing Nitrate-Nitrogen, Phosphorus, Potassium, and pH. (Ben Faber, et al; American Society of Horticulture Science)

Stunning! – The magical beauty of looking up at trees in the middle of a forest captured by photographer. (Beauty of the

Scientists learn how plants manipulate their soil environment to assure a cheap, steady supply of nutrients. (Rice University via

‘Profound’ evolution: Wasps learn to recognize faces. One wasp species has evolved the ability to recognize individual faces among their peers—something that most other insects cannot do—signaling an evolution in how they have learned to work together.” (Cornell U via

Fruit Tree Pruning Basics. (Jim Downer,

Revised OSU publication: Noncrop Host Plants of Spotted Wing Drosophila in North America. (Amy Dreves, et al, OSU)

Plants copy nematode pheromones to repel infestations. (Sterling Admin,

Fail to plan or plan to fail? Planning for a year of garden success. (John Porter,

Urban gardens contain too much organic matter, OSU study finds. (Kym Pokorny, OSU via

We’ve figured out how mosquitos sense our warmth.Unfortunately, they still seem to be able to find us without it.“ (John Timmer,

By Margaret Bayne, OSU Extension Staff-retired, OSU Master Gardener

Asian Giant Hornet, WSDA

Pest Alert: Asian Giant Hornet-This month, [December] WSDA entomologists identified a large hornet found near the Canadian border as an Asian giant hornet (Vespa mandarinia), an invasive species not previously found in Washington State.”

Researchers discover a potential window for managing insects without chemicals. (Simon Fraser University)

Houseplant Problems- A diagnostic guide. (Paul C. Pecknold, Purdue University)

When good plants go bad-some native plants can behave as invasive species. (American Society for Horticultural Science via

Video: The Life of Blister Beetles.(Insect Worlds, Episode 3 Preview, BBC Four via youtube)

Vanilla is anything but Vanilla. (Indefenseofplants)

Introduction to Abiotic Disorders in Plants​​-Great detailed info! (Megan Kennelly, Judith O’Mara, Cary Rivard-Kansas State; G. Lee Miller, U of Missouri; Damon Smith, U of Wisconsin-Madison; American Phytopathological Society)

Woodpecker damage, OSU, PNW Handbook

Woodpeckers: Friends or Foes? (Bec Wolfe-Thomas,

Oregon Small Farm News publication. (Oregon State University)

UK insects struggling to find a home make a bee-line for foreign plants. “Non-native plants are providing new homes for Britain’s insects – some of which are rare on native plants, a new study has found.” (University of York)

Video: Travel deep inside a leaf – Annotated Version. (California Academy of Sciences via YouTube)

Spotted Wing Drosopila, Vaughn Walton OSU

“This has been one of the worst years’- Oregon farmers are losing billions to fruit flies.” (Kelsey Christensen and staff via

Natter’s Notes

Jean R. Natter, OSU Master Gardener

The Japanese Beetle (Popillia japonica) Eradication Project

Because Japanese beetles (Popillia japonica) typically feed in groups, they can decimate their host plants in short order. Roses are a particular favorite. (Image downloaded 2017-02-06:

The Japanese Beetle (Popillia japonica) Eradication Project of the Oregon Department of Agriculture (ODA) issued its most recent update in late 2019.

Overall, 95% of you [within the quarantine boundary] consented to treatment this year. With your help we treated 8,500 residences, 6 schools, 8 parks, 3 shopping centers, and 1 golf course. This came out to roughly 3,000 acres.

This year we trapped 7,749 Japanese beetles in the Cedar mill area. The overall number of beetles trapped in 2019 was a 56% reduction from the previous year. There was a 65% reduction in the number of beetles trapped within the 2018 treatment boundary as a result of the 2018 granular treatment and 2019 foliar treatment. We saw a 75% decrease within the boundaries of the supplementary foliar treatment.

In order to eradicate this pest, we will continue our treatment next season. We are thrilled with our success, and will be more aggressive with our approach next year while we have the upper hand. We are currently planning a larger treatment boundary for the 2020 eradication and will update everyone soon with the new map. We thank you all for your continued support with helping Oregon eradicate Japanese beetle.  It wouldn’t be possible without all of you!

We would also like to introduce the 2020 Japanese beetle team: Ashley Toland (Eradication Entomologist), Jessica Rendon (Japanese Beetle Eradication Specialist), and Austin Johnson (Japanese Beetle Outreach Coordinator). 

For more information on the Japanese beetle eradication project please visit our website:

New exotic Agrilus species beetle on twinberry in Portland

During 2019, a new exotic beetle was reported by the Oregon Forest Pest Detector (OFPD) program.

In May, an OFPD program graduate submitted a report to the Oregon Invasive Species Hotline after finding D-shaped exit holes and a green insect on a twinberry in her yard in southeast Portland. She recognized the signs as characteristic of insects in the genus Agrilus, which includes the bronze birch borer (A. anxius) and the deadly forest pest, emerald ash borer (A. planipennis).

Evidence of new exotic beetles (Agrilus cyanescens) attacking twinberry, a native honeysuckle, were found by citizen scientists in their Portland, OR, gardens during 2019. Fortunately, the beetles are not expected to become serious economic pests. But if you see the characteristic damage, report it to Invasive Species. (Image Camden, New Jersey, 2019:

The green insect she found was later identified as Agrilus cyanescens, an exotic beetle that has been established in the eastern U.S. since the 1920s, but this is the first detection in the Pacific Northwest. (

Then, in early August 2019, another OFPD graduate submitted a report to the Oregon Invasive Species Hotline after she noticed similar damage to a twinberry in her yard in northeast Portland. This was also later confirmed to also be Agrilus cyanescens. (

Known host plants in U.S. and Europe include those in the genus Lonicera (honeysuckles) including the native plant, twinberry (Lonicera involucrata Richardson). The Oregon Department of Agriculture does not believe Agrilus cyanescens will be an economic, ecological, or horticultural pest.

But, if you do notice any signs or symptoms of Agrilus cyanescens (branch dieback; 2 mm. D-shaped exit holes; serpentine-shaped galleries beneath the bark; and metallic green beetles feeding on leaves in April-May), we encourage you to submit a report. (  

The OFPD program trains volunteers to monitor for and report potential infestations of invasive forest pests. Thank you to these two Oregon Forest Pest Detector graduates for being on the lookout and submitting reports to the Oregon Invasive Species Hotline!  Details about the OFPD training program of citizen scientists are at

Rose hips covered with a light frost

He who marvels at the beauty of the world in summer will find equal cause for wonder and admiration in winter.

~John Burroughs

Congrats 2019 Master Gardeners!

Carrie Allen smiles and holds her Master gardener Certificate of Completion and is wearing her OSU Master Gardener badge.
Carrie Allen dons her new OSU Master Gardener badge

We offer our sincere congratulations and a warm welcome to the newly inducted Master Gardener Class of 2019!   We hope you have been enriched by your training and service as a community garden-educator. We know your energy and passion have enhanced the Master Gardener program.  Thank you for your volunteer service and welcome to the Master Gardener family!   We look forward to having you as part of our team!

Note: MG badges will be mailed to individuals who were not able to pick up their badge at the Fall Recertification.  Look for badges to arrive in December.

2019 Master Gardener Program Report

Thank you, Master Gardeners for giving your time and energy toward OSU’s outreach mission in 2019.

New for this year, we have created a detailed report of your accomplishments.

Please take a look.

Display Your 2020 Sticker

For those who have fulfilled the requirements to maintain their status as an active and “current” Master Gardener you will receive a 2020 Recertification sticker to proudly display on your MG badge.  The sticker is a designation that you are current and up-to-date, having completed all required volunteer service hours, continuing education opportunities, and completed forms.

Stickers will be mailed (by year’s end) to those who have met the annual requirements, who did not receive a sticker at Fall Recertification.

For MGs still needing information about how to remain current, please refer to the Volunteer Portal’s How to Maintain Active OSU Master Gardener Status page.

If you have yet to send in the annual required forms, please send them in as soon as possible, so you too can receive your 2020 Recertification sticker and remain on our ‘active’ Master Gardener roll.

  1. 2018_2019 Volunteer log sheet
  2. 2019_2020 Conditions of Volunteer Service form
  3. Youth Safety and Compliance training. To take the training read the Basic Training (2 pages) and sign the Certification Form. Return the form to the MG program office by December 31,2019.

A New Adventure for Janet!

Janet Hohman peeks around wooden bear sculpture.
Janet Hohman gets her dream job!

We extend our immense thanks and best wishes to our metro MG team member, Janet Hohman.  Janet has accepted a new position (actually, her dream job)!   We are extremely happy that she has this new opportunity, yet she will be sorely missed!

Although Janet started her new job in October, she has generously been working additional hours assisting the Master Gardener program and the Clackamas Extension administrative team. 

We are truly grateful to Janet for her many contributions to the metro MG program; with her ever-cheerful presence, sharp eye for detail, focus streamlining processes – all to ensure a great experience for volunteers.  As she moves on, we thank her for her incredible generosity and wish her the very best in her new career adventure!

Spread the Word! 
2020 MG Training Registration Open!

You can help to spread the word about 2020 Master Gardener training!  Let others know about the rewarding opportunities available serving as a Master Gardener volunteer.  Registration is now open for the 2020 Master Gardener Training!  Share the word with your gardening friends, wanna-be gardeners, and fellow community members.  Direct those interested to our Metro-area Master Gardener website for easy online registration. Note: our Portland training site has filled, but there are still available class slots at the Hillsboro and Oregon City training sites.

Be Our Brand Advocate!

If social media is a favorite communication avenue for you, please consider sharing about the Master Gardener training registration on the social media sites on which you participate.  Share posts from our Facebook and Twitter accounts or direct those interested to our website.  We would love to cover all Nextdoor neighborhoods in the metro-area.  Need more information or want a promotional photo to post?  Please contact, Marcia McIntyre:

2020 Master Gardener Training

Join us in 2020 for Master Gardener training.  We will be holding 8 weeks of training classes starting the last week of January, running through March.  So mark your calendars.  Each AM or PM session attended counts as 3 hours MG continuing education credit for 2020.

The training sites and days are:

Tuesdays, January 28 – March 17, 9AM to 4PM
Hillsboro United Methodist Church,
168 NE 8th Avenue Hillsboro

Thursdays, January 30 – March 19, 9AM to 4PM
Museum of the Oregon Territory, 3rd floor
, 211 Tumwater Drive, Oregon City

Fridays, January 31 – March 20,9AM to 4PM
Multnomah County Headquarters, Board Room,
501 SE Hawthorne Blvd., Portland

Fall Recertification Recap

Saucer and cup of tea, sitting on a book, with fall leaves floating in the cup and on the book.

Over 370 engaged Master Gardeners attended Fall Recertification on Saturday, November 9. The City of Portland’s Offices of Equity and Human Rights, Glenn Arhens, OSU Extension Forester, and Gail Langellotto, Professor of Horticulture, OSU Extension Master Gardener Program coordinator all presented valuable information to support metro Master Gardeners in their role as garden educators.   Our sincere thanks to all the presenters!

Hearty thanks to the three area Chapters for funding refreshments for the day and providing a wonderful array of door prizes.

Presenter Glenn Arhens shares his presentation and resource list for Master Gardeners to continue to explore the subject:

Appreciation Shout-out!

Our Fall Recertification training on November 9, was an opportunity to extend a special certificate of appreciation, to eight Master Gardeners for their significant contributions to the Metro Master Gardener Program.  We are grateful for their generous and dedicated service!  Our hearty thanks to them all!

Heidi, Marilyn, Rich, Claudia, and Dennis
  • Dennis Brown for service in the Speaker’s Guild, Solve Pest Problems advisory, the June Key Delta and Voz community project
  • Louise Gomez-Burgess for coordinating the Master Gardener training in Hillsboro
  • Claudia Groth for her dedicated instruction for the Master Gardener training and the public
  • Sally Campbell for stepping up to instruct at the MG training and years of coordinating Mult. helpline
  • Rich Becker for assisting with the Master Gardener training in Portland, serving as a liaison, and assistance with the soil workshop
  • Marilyn Frankel for volunteering at each class date for BOTH the Portland and Hillsboro training and hauling PNWs to each training
  • Judy Froemke for her many years of dedicated coordination of the Speaker’s Guild in Wash. Co.
  • Jennesa Datema for coordinating Speaker’s Guild in Mult. Co. and educating the public through Speaker’s Guild presentations
  • Heidi Maybach for her dedication coordinating the Milwaukie Farmers Market

Join-in the Master Gardener Speakers Guild!

Take your role as a garden educator to the next level, by volunteering to be a presenter for the Master Gardener Speakers Guild!

The metro MG program receives dozens of requests every year for garden presentations to community groups.  We have a small, but mighty, group of MGs who answer the call and present throughout the three counties – but requests greatly exceed what these dedicated MGs can handle.  Therefore, we are looking for additional MGs to share their research-based gardening know-how.  We will supply support materials, and those interested can shadow experienced presenters.  Volunteers can select how many presentations a year they would like to make and the topics they feel most comfortable presenting. Please consider joining in this fun, valuable volunteer activity!

Presentations are needed on a variety of subjects: beginning gardening, vegetable gardening, fruit trees, pruning, composting, container gardening, IPM for the home gardener, small fruits, perennials, soil, beneficial insects, pollinator gardens, tomatoes, small space gardening, native plants, seed starting, propagation, or your garden passion that you are willing to share!

Would you like to be part of this vital community outreach?  If so, contact Marcia McIntyre,

2019 Master Gardeners Sporting Their OSU Master Gardener Badges