Spring’s Earliest Pests: Aphids

Jean R. Natter, OSU Extension Service Master Gardener

After all we’ve been through this past year, what with the COVID pandemic and quarantine, gardeners are getting itchy about planting. I was, too, until the middle of March when night time temperatures dropped into the 20s in mid-March. I imagine it was even colder for many of you.

Even though my dreams of planting soon were dashed – tomatoes, peppers and eggplants need consistent night temps of 50 to 55F – my thoughts soon drifted to insect pests, then to their natural enemies.

The leaders of the potential pest parade will be various species of aphids, also several kinds of caterpillars, the latter specializing on crucifers (cabbage and kale crops), among them cabbage whites (Pieris rapae) and several species of cabbage worms. Unfortunately, various species of both kinds may be present throughout the growing season.

Oh, and let’s remember that slugs and snails are ever-present through the season.

So, let’s review a few things, including safe management.

We should begin with the preferred pest remedy: An alert gardener, ready to spring into action, who knows which natural enemies (NEs) are allies, and who acts promptly. Prompt action, aided by the numerous beneficial insects already present, means pesticides are often unnecessary.

Aphids are small, soft-bodied, pear-shaped pests that tend to cluster on new growth which they sometimes distort as they remove plant sap from plant parts. (If you have roses, you’ll likely see them there first.) Aphids may be almost any color, perhaps even spotted, banded, or striped. Most infest buds, flowers and new leaves, often distorting them which sometimes mimics disease.

Caterpillars, also called chewing worms, are the plant-munching larvae of various moths and butterflies. (More about caterpillars next month.)

Recall that pest control is a lot like mowing the grass; it requires repetition. You get to do it over, and over, and over, again. (sigh)
Always start with the safest methods
, namely search-and-destroy missions throughout the garden or ornamental planting. Reserve pesticides for those instances when the pests get out of hand. Always identify the pests and apply the appropriate product only to the hot spots of pest insurrections. Then, too, use pesticides strictly according to label directions.

As you likely know, aphids of one kind or another are present year-round locally. They’re perhaps the most common plant pest you’ll encounter. Aphids pierce plants with their hollow mouthparts to withdraw sugary fluids. Often, they’re undetected until leaves curl or the plant is coated with sticky honeydew (aphid excretions). Repeated sharp water sprays are often sufficient against aphids. Or increase your fire-power with a commercial insecticidal soap such as Safer’s, mixed according to label directions. For soap sprays to be effective, they must contact the pests. No home remedies, please; they may damage plant tissue.

Fortunately, you have lots of free help readily available among insects. Your skilled assistants (the NEs) are typically most active during the morning and late afternoon but hide during the heat of the day.

Four photos show life cycle of Lady Beetle (Hippodamia convergens). Egg stage, larva stage, pupa stage, adult stage.
– Life cycle of Lady Beetle (Hippodamia convergens) (Source: A Pocket Guide to Common Natural Enemies [revised 2021] https://catalog.extension.oregonstate.edu/ec1613)

Ladybugs (aka lady beetles) are the most colorful aphid killers. Most of these ¼-inch, glossy, hemispherical adults are red, often dotted with black. The ladybug’s elongated ¼-inch youngsters are quite different, resembling the tiniest of alligators. Their soft bodies are slate-gray or black with tufts of dull orange hairs. Both adult and child chomp on aphids. In time, even the aphids’ toes will be gone.

In spite of advertising hype promoting sales of ladybugs, realize that they typically leave for other bug-filled garden. But, if you are determined to purchase natural enemies, know that lacewings are more valuable

because their diet is more diverse. After lacewings decimate the aphids, they’ll switch to other small, soft-bodied pests including young caterpillars, various insect eggs, or even mites.

– Green Lacewing adult (Chrysoperla species) compared to fingertip. (Source: A Pocket Guide to Common Natural Enemies [revised 2021] https://catalog.extension.oregonstate.edu/ec1613)

Hereabouts, lacewings are naturally present year-round. You’re most likely to see the fragile, 5/8-inch, filmy-green adults fluttering from shrubs at dusk. The larvae are the aphid eaters, though. Look for 3/16-inch tan or gray, soft-bodied creatures similar to ladybug larvae but with Jaws that resemble old-fashioned ice-tongs. Eggs are easy to recognize, they’re small, greenish-white, and mounted on hairlike stalks.

Worm-like larvae of certain flies also kill aphids. The largest larvae (Syrphid flies, aka flower flies) are about 1/4 inch long but are difficult to spot because of their greenish or grayish color whereas the tiny, almost dot-sized, orange fellows (Midges) are easy to spot because of their color. All such larvae search for lunch by blindly groping. Just as do lacewing larvae, fly larvae pierce aphids, drain them, then abandon the empty carcasses.

Tiny, non-stinging wasps kill aphids, too. After they insert an egg into an aphid, their larva dines inside the aphid as it gradually transforms into a bloated, papery shell. Some weeks later, an adult wasp exits through a circular hole created in the aphid’s empty exoskeleton.

Impatient folks who would rather fight than wait for NEs to break into action need to understand that water,plain, or doctored with insecticidal soap, kills aphids but is safe for most helpful insects. Commercial pesticides are useful for uncontrolled hotspots but most kill more NEs than pests. When a pesticide is needed, consult with a garden center, then always follow label directions precisely. Because sprays rely on contacting the aphids, act before the pests are protected within crinkled and distorted leaves.

Power-assisted blasts can help you gain control quickly.Forceful water sprays are appropriate for sturdy plants whereas gentler handling is better for plants with rather soft tissue, among them such as violas and leafy lettuces. Aphids are so soft and squishy that harsh water sprays will injure them such that they’re unlikely to return to the plant. But, because healthy, intact aphids can give live birth to an aphid every 20-30 minutes, you’ll need to repeat the spray anyway. With more potent products, the goal is to only spray enough to coat the pests.

Realize that plant damage is possible with all pesticides, including soaps.That’s especially true if the spray is applied on a sunny day or was inadvertently – or not — mixed at too strong a rate. It’s always wise to test the spray on a few plants, then check for damage several days later. Browned or burned plant tissue is obviously serious whereas soap smudges are merely unsightly.


  • Sustainable Gardening: The Oregon Master Gardener Handbook
  • Book: Pests of the Garden and Small Farm (ANR #3332; University of California)- Available at booksellers.
  • Book: Natural Enemies Handbook {ANR #3386; University of California)- Available at booksellers.

Coming next month: Cabbage Worms and Other Chewers

Fern frond just beginning to unfurl.
Photo: Pixabay

A garden is a grand teacher. It teaches patience and careful watchfulness; it teaches industry and thrift; above all it teaches entire trust.

— Gertrude Jekyll

The patience we have learned as gardeners has certainly been a reservoir to draw on in the past year. Even with hope on the horizon, for when we can once again gather in-person with our Master Gardener community, we continue to cultivate patience and glean lessons from the garden. As we patiently wait to resume in-person volunteer service, we hope you will take part in the various Master Gardener online educational opportunities from the kick-off of the OSU Master Gardener ‘Culture of Gardening Series’ to three upcoming ‘BioBlitz’ dates.

An important message from State-wide Master Gardener Program Coordinator, Gail Langellotto

With the recent resignation of OSU President F. King Alexander, Gail Langellotto, our State-wide Master Gardener Coordinator addresses Master Gardener volunteers and staff, and offers reflection on the guiding principles of the Master Gardener program. Read Gail’s message HERE

Elevated Skills Training Remains Open

Two sets of hands holding together a terracotto bowl of red cherry tomatoes.  On set of hands is bare, the other set of hands is wearing garden gloves.
Photo: Pixabay

Thank you to all who participated in the state-wide ‘Elevated Skills’ Master Gardener training classes the past two months.  We have received lots of positive feedback from MGs who appreciated the opportunity to focus on skills that can be used in their roles as a garden educator; whether it was learning more about ‘Community Science’, how to ‘Superpower Your Education Garden’, ‘Garden Woody Plant ID with the OSU Landscape Plant Database’ or the other ‘Elevated Skills’ class offerings. 

Did you miss the training?  Don’t despair ‘Elevated Skills’ training is still open for your learning adventure!  Although in-person sessions of the training have passed, can still take part and dive deep into a subject to interest.

For Perennial Master Gardeners this training counts as ‘Continuing Education’ hours.

2020 Master Gardeners Trainees, the Elevate training can be counted towards your service hours to meet the requirements to complete the Master Gardener training.

See the entire Elevate course line-up, and register HERE.

Note: The metro area MG program is using a different online tool for our MG Helpline clinic and is not using the ECCO tool being highlighted in the “Learning How to Use the Extension Client Contact Online (ECCO) Tool in Plant Clinic” course.

Level Up

Time lapsed video of dahlia blooming in promotional graphic for Growing Oregon Gardeners Level Up Series. Also includes Oregon State University Extension Service logo.

The state-wide Level Up series continues with a wealth of timely gardening topics.  This month’s presentation,  ‘Dazzling Dahlias’ with Julie Huynh, owner of Julie’s Dahlias, will be broadcast on Tuesday, April 13, 3pm

Take your gardening knowledge to a new level and check out the details for ‘Dazzling Dahlias’ and future presentations.  Registration opens on a rolling basis for upcoming webinars throughout the year.

If you find that registration has filled for a class, please check out the presentation live streamed on the OSU Master Gardener Facebook page or look for a recording of the presentation to be posted on the Level Up Series website a few days following.

Preview and register for the Level Up Series classes, and view recordings of past presentations HERE.

Dirt Gone Bad: When your soil amendment has been contaminated

Screen shot of webinar presentation. Large machine moving steaming pile of compost. Dirt Gone Bad: When Your Soil Amendment Has Been Contaminated.

If you missed Weston presenting for the March ‘Level Up’ series, here is a link to view a recording of his informative presentation: ‘Dirt Gone Bad: When your soil amendment has been contaminated’

Referenced in Weston’s presentation are two valuable publications:

The Culture of Gardening Series

Promotional graphic for The Culture of Gardening Series. The work is in our hands. Abra Lee.  With photo of Abra Lee and decorative elements of hands, flowers, leaves, hearts.

The OSU Master Gardener Program’s ‘Culture of Gardening’ Series kicks off with a special presentation with Abra Lee, “The Work is in Our Hands”, on Tuesday, May 18, 12noon.

Through determination, enthusiasm, and willpower Black women overcame ugliness in America to cultivate beauty in the landscape. This is a discussion of how their self-expression and activism through gardening led to a lasting legacy of community pride throughout generations. 

Abra Lee is a national speaker, writer, and owner of Conquer the Soil,a platform that combines Black garden history and current events to raise awareness of horticulture. She has spent a whole lotta time in the dirt as a municipal arborist, extension agent, airport landscape manager, and more. Lee is a graduate of Auburn University and alumna of the Longwood Gardens Society of Fellows, a global network of public horticulture professionals. 

This presentation is free and open to all OSU Master Gardeners and the public.  Register in advance here: https://beav.es/JCF

Join-in the OSU Master Gardener Bio Blitz

Promotional graphic for OSU Master Gardener Bio Blitz May 22, July 24, September 25. with flowers, butterflies, leaves.

Grab your camera and join the OSU Master Gardener Program on our iNaturalist project page to capture the insects, birds, wild plants, and other wild organisms in your garden or a nearby community or public garden space. Your efforts will help to document garden biodiversity in Oregon! Learn all the details and register here: https://beav.es/Jyg

In reflection of a ‘Year Like No Other’

Screen shot of Zoom presentation with three smiling faces of presenters.
‘Ask a Master Gardener’ webinar with Eric Butler, Dennis Brown and Claudia Groth

Although we are well on our way in 2021, we pause one more time to look back at 2020, when Master Gardeners rose to the challenge, embraced patience, stepped up and reached out during a year like no other!  We are grateful to our Master Gardener community and want to share the 2020 Impact Reports for the OSU Master Gardener Program and our metro area Master Gardener Program.

2020 Impact Report of the OSU Extension Master Gardener Program

2020 Metro area Master Gardener Impact Report and Volunteer Recognition

Pest Alert!  Zebra Mussels and Moss Balls

Hand holding a green moss ball that has a small zebra mussel embedded in the ball.
Moss ball with Zebra Mussel. Photo: US Geographical Survey

Although not specifically related to gardening, we as Master Gardeners, have the opportunity to educate ourselves and share the information with others, regarding an important pest alert about Zebra Mussels.  Recently this highly invasive pest was discovered in products sold at aquarium and pet supply stores.  Specifically, the mussels were found in aquatic ‘moss balls’.

Currently, the Columbia River basin is the only area in the US that has not been infested with Zebra Mussels.  If established, the mussels will have a devastating impact on the health of our waters, including water recreation and critical water infrastructure.

Each of us can help by educating ourselves and others and making sure to take all precautions for preventing the establishment of this highly invasive pest to Oregon.

For details about this pest and preventive actions check out these links:

Upcoming Virtual Garden Education Opportunities

Oregon Master Gardener Mini College – Goes Virtual!

Promotional image for Mini College. Connect. Collaborate. Cultivate. July 16-17, 2021

Registration is now open for 2021 Oregon Master Gardener Mini College.  The conference will be held online, July 16 & 17.  With an outstanding slate of horticulture experts presenting, Mini College is a great continuing education opportunity. 

Robert Michael Pyle, author, educator and scientist will kick-off the event as the keynote speaker.  In addition, there will be a great array of interactive classes and workshops from leading horticulture experts and educators. Cost for the two-day event is $49 and is open to Master Gardeners and the public.  So grab a friend, and join-in an enriching garden education opportunity.

OMGA 2021 Mini College (mastergardenerminicollege.org)

More virtual opportunities with the International Master Gardener Conference!

Promotional poster for International Master Gardener Conference. Humming bird landing on flower. Beak inserted in flower blossom. Virtually September 12-17, 2021. Registration opens April 5.

Every two years Master Gardeners have the opportunity to participate in the International Master Gardeners Conference, that is hosted by a rotation of Extension Master Gardener Programs.  This year the event is being sponsored by Virginia Cooperative Extension and you have the opportunity to participate from the comfort of your own home!  The Conference is going virtual for 2021!

This educational confluence of horticultural experts and Master Gardeners from the US, Canada and South Korea is taking place September 12 – 17, 2021. Virginia Cooperative Extension is planning “a unique and creative virtual conference that will offer not only the chance to attend live webinars and workshops, but also opportunities to socialize with and learn from EMGs from around the nation, to learn about gardening in the Commonwealth of Virginia, and to participate in interactive activities such as virtual tours of Virginia and small group sessions.” 

Learn more about this exciting educational opportunity and register NOW!

Our April Garden Checklist

Spring is in the air with lots to attend to in the garden.  Our garden checklist highlights fertilizing your berries, planting early spring vegetables, and going on slug patrol!

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

Asian giant hornet being held between a thumb and forefinger.
Asian giant hornet. Photo: Washington Department of Agriculture

Beneficial wasp found in Asian giant hornet hunt. (Calvin Bratt, Lynden Tribune) https://bit.ly/3vpTUNj

WATCH!- A Zoom presentation with Dr. Linda Chalker-Scott on Arboricultural Myths. (State of Missouri) https://bit.ly/2OTp4fe

New Study Illuminates Dung Beetles’ Attraction to Death. (By Ed Ricciuti, Entomology Today) https://bit.ly/38JXQ1H

The Dirt on Rock Dust. (Dr. Linda Chalker-Scott, Garden Professors blog) https://bit.ly/38HAgTs

VIDEO: Introduction to Lichen: Growth Forms, Reproduction, and Value. (Microcosmic via youtube) https://bit.ly/3rQU5iy

Silencing the alarm- An enzyme in the saliva of certain insects prevents their food plants from warning neighboring plants of an attack. (Sara LaJeunesse Penn State News) https://bit.ly/3vsN0H5

Why seasonal climate forecasts aren’t always accurate. (Pam Knox, The Garden Professors) https://bit.ly/2ODGAEp

Paleontologists discover new insect group after solving 150-year-old mystery. (Simon Fraser University, Phys.org) https://bit.ly/3qW9g92

VIDEO:  Bypass vs. anvil pruners. (Oklahoma Gardening via Youtube) https://bit.ly/2OQKCZX

Cambridge moonflower: Wait over for ‘UK’s first’ bloom. (BBC) https://bbc.in/2OU5nUL

Monarch butterfly.
Monarch butterfly. Photo: Oregon State University

Monarch Winter 2020–21 Population Numbers Released. (Susan Day, University of Wisconsin-Madison Arboretum) https://bit.ly/38DxlLp

WATCH: I Cannot Tell a Lie But Cherry Trees Do Die. (Jay Pschdeit, OSU via Youtube) https://bit.ly/3eHVkNa

Scientists discover attacking fungi that show promise against emerald ash borer. (University of Minnesota, via Phys Org) https://bit.ly/3eHSuYs

Compost in Seed Starting Mix: Recipe for Success…. or Failure? (John Porter, The Garden Professors) https://bit.ly/30OE1C5

To Fruit or Not to Fruit – The Story of Mast Seeding (Awkward Botany) https://bit.ly/38IiKhw

January warm spells, March freezes: How plants manage the shift from winter to spring (Richard B. Primack, Boston University via The Conversation) https://bit.ly/3qRilQn

Red rose bloom.

The contrarian rosarian–debunking rose mythology. (Jim Downer, The Garden Professors) https://bit.ly/3bRhJ9c

Catnip repels insects. Scientists may have finally found out how.  The plant triggers a receptor that, in other animals, senses pain and itch. (Erin Garcia de Jesus, Science News) https://bit.ly/3eHMI9p

Cold Comfort  (How Bees survive cold temperatures) (Jon Zawislak, U of Arkansas Extension) https://bit.ly/3cxQwYe

Parasitic plants conspire to keep hosts alive-Mistletoe sends treemail.(Jules Berstein, UC Riverside) https://bit.ly/3tkstCM