Natter’s Notes 

When Pesticides Change

Jean R. Natter, OSU Master Gardener

You know the rule about pesticides: “Read and follow label directions.”

Well, that catchy little phrase has become more critical than ever. Several popular home-use products have changed their formulations with minimal fanfare. There’s no indication of “new” on the label.

To compound the confusion, labels on the revised formulation closely resemble the old ones. Unless the user is more observant than average, it’s very likely something may go awry. The application method may have changed; the precautions may have been modified; and/or the end result may be different than expected.

The explanations below were published in “When Familiar Pesticides Change.” (“Pests in the Urban Landscape;” August 29, 2018. https://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=28074)

When Sevin is no longer carbaryl

Sevin is a familiar insecticide brand name for home gardeners used to control insects in lawns, on ornamental plants, and on vegetables. Sevin and the active ingredient carbaryl are practically synonymous. Recently, the active ingredient in some Sevin products was changed from carbaryl (a carbamate) to zeta-cypermethrin (a pyrethroid).” . . .  This pyrethroid is less toxic to mammals but both carbaryl and zeta-cypermethrin are highly toxic to bees and aquatic species. The new label on Sevin Insect Killer states that it controls more pests than the old product containing carbaryl, which may seem great, but the product may also kill some of the good bugs like lady beetles (ladybugs).

Another very important difference is the time the products can safely be applied on fruits and vegetables before harvest (called preharvest interval or PHI). Following the PHI reduces your pesticide exposure when you eat the food. For fruits such as apples and peaches, the PHI for the zeta-cypermethrin Sevin is 14 days, but for the Sevin with carbaryl it’s 3 days. For other fruits and vegetables, the PHI for the new Sevin label may be shorter than the carbaryl label. Again, check the label.

When Roundup is no longer glyphosate

Another familiar pesticide name is Roundup, a product known historically for containing the herbicide active ingredient glyphosate. Monsanto, the manufacturer of Roundup, now produces an extensive line of Roundup products containing multiple active ingredients, rather than just glyphosate alone. Many of these products contain triclopyr or diquat in addition to glyphosate. Some don’t contain any glyphosate at all

“Roundup Landscape Weed Killer” is a new product which contains pendimethalin instead of  glyphosate. It’s both a non-selective herbicide and a pre-emergent.

When Corry’s Slug and Snail Killer is no longer metaldehyde

In 2012, the active ingredient of the well-known Corry’s Slug and Snail Killer was changed from metaldehyde to sodium ferric EDTA, but the general look of the product box didn’t change. This relatively new active ingredient is less toxic and less attractive to dogs and still effective against snails and slugs. However, the amount users apply and how quickly it works both differ from the previous active ingredient. If you are familiar with the old product you may have noticed a change, but unless you read the label, you may not know why.

A Bonus Snippet on a different topic

MGs who volunteered this summer probably received multiple inquiries about the seemingly overabundant wasps this summer.  Well, the general public is seriously confused concerning the differences among bees, yellowjackets, and paper wasps. When they see a somewhat elongated yellow and black insect, they assume “wasp;” that is, yellowjacket. (Don’t bother asking how I know.)

But yellowjackets have a near twin: European paper wasps, Polistes dominulus, invasive insects officially identified in Oregon years ago. Most paper wasps are mild-mannered whereas P. dominulus is nasty. To easily differentiate them from yellowjackets, check the antennae. Text and images are at “Invasive paper wasp responsible for increasing yellow jacket complaints.” (http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=11412 )

PDF Version:
When Pesticides Change

Natter’s Notes

Coping with the Heat; Leafrollers on Succulents;
Japanese Beetle Update

Jean R. Natter, OSU Master Gardener

Japanese Beetle Update from ODA

The Oregon Department of Agriculture has completed its main treatment operations for Japanese beetle for 2018. From April 2 to June 1, ODA and General Tree Service, a contracted pesticide applicator, treated approximately 5,800 residences, 5 schools and 4 parks, 2 shopping centers and 1 golf course for Japanese beetle in Washington County. This number was increased from the 2,100 homes treated in 2017. In addition, an area of Portland International Airport and about 30 homes in Oakland, OR, were also treated due to beetle detections in 2017.

 

Community support for the project is very positive. We received consent to treat from over 5,100 residents! This success of this project depends on this kind of support from the community. We also served around 400 administrative warrants to residences from which we had not received a response. Residents have been sending in reports of beetle sightings. Thankfully, almost all of the reports of “serious infestations” of Japanese beetle have been determined to be box elder bug or other pests. [Editor’s emphasis.]

 

The project has entered trapping and detection phase for 2018. Seasonal survey staff are in the process of deploying 5,900 traps to detect Japanese beetle throughout the greater Portland metro area and the northern Willamette Valley. . .

 

It’s still too early to make any conclusions about success of the project from this season’s data, but early numbers are very encouraging. Our first detection of JB in Washington County this year was on June 17. . .  As of July 21, 2018, we have captured 386 beetles total in the 9 traps. At the same time in 2017, we had captured 2961 . . .  these numbers are early and there are many more traps to check, but a reduction is good news, especially in the most active beetle areas. Final trap catch numbers will tell the whole story, and will be available late Summer/early Fall . . .

 

Our containment operations are also in full swing. Curbside yard debris bin contents are being redirected to Hillsboro landfill, as they were in 2017. Debris moved offsite by landscapers working in the quarantine area are being reminded and encouraged to take debris to our drop-off site at Northwest Landscape services. Residents in the area and landscapers that we have contact information for have been sent two reminders this season. Flyers in English and Spanish are also available on our project website, https://www.japanesebeetlepdx.info/prevention.html.

 

The Oregon Department of Agriculture would like to express its sincere appreciation to the residents in the Japanese Beetle treatment area for their cooperation, as well as all of the partner agencies that have offered support, advice, time and energy to the project. This eradication is one of the largest ever undertaken by the department and would not be possible without the help of the community and partner agencies. This is a multi-year project, and is proposed to continue until 2021. . .  In the meantime, . . .  check for updates on www.JapaneseBeetlePDX.info.

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Coping w/ the continuing heat:

– Water early morning (by 6 am) or late day.

– Don’t assume a droopy plant is dry; check the soil with a trowel or finger. Excess soil water can kill.

– Realize that plants (and soil or potting mix) are drying more rapidly than usual. (Blossom end rot is rampant during heat waves because of erratic water supply.)

– Move containers to the shade and/or rig temporary shade 18 inches above sensitive plants.

– Mulch: Add two inches of bark dust or, for shrubs and trees, 4 inches of bark chips.

– Don’t fertilize.

– Mow the lawn high, at 3 inches or so.

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Oblique banded leafroller on succulents

Leafrollers and leaftiers are common minor pests of various trees but, this year, the oblique banded leafroller has targeted several succulents, making an unsightly mess of tip growth, precisely where the flower buds should be. The victims: two rather stately sedum cultivars, ‘Matrona’ and ‘Autumn Joy.’ The remedy is simple: Pull the webbing apart and squish the little beasts. See “leafroller and leaftier” in the PNW Insect Management Handbook:  https://pnwhandbooks.org/insect/hort/landscape/common/landscape-leafroller-leaftier.

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PDF version

Coping with the Heat; Leafrollers on Succulents; Japanese Beetle Update PDF

Natter’s Notes

Blister Mites: Grapes; Pears; Walnuts

Jean R. Natter, OSU Master Gardener

Blister mites are running wild this season. It seems that the perfect conditions combined for population explosions of these tiny, elongated mites which noticeably disfigure the leaves of grapes, pears, walnuts, and more. Among pears, even newly planted trees are victims. The symptoms are similar on all three genera but the specific causal agents – also referred to as eriophyid mites or simply eriophyids – vary.

Blister or eriophyid mites reside on the undersides of the leaves, injecting fluids into the leaf tissue as they feed. Those fluids cause the blistering on the top surface with the associated white “fuzz” (enlarged plant hairs) in the concave areas on the reverse. (So, no, it’s not fungal growth.)

Blister mites are far different than the more common spider mites. Adults are microscopic, light in color, cylindrical, tapered at the posterior end, with two pairs of short legs just behind the head. Nymphs are the same but are smaller.

Grape Erineum Mites (Colomerus vitis) are microscopic, wormlike, with 2 short pairs of legs at the head end, and white-yellow in color. They overwinter between the outer bud scales and bud tissue and feed on leaves during spring and summer. Feeding from the undersides of the leaves produces a blistered appearance on the top of the leaves. At the same time, the corresponding depressions on the underside are filled with enlarged light-colored leaf hairs which shelter the mites from natural enemies and pesticides. In spite of how extensive and nasty-looking the infestation is, blister mites seldom affect grape health or production.

As the season progresses, the enlarged leaf hairs progress from white to yellow and, finally, brown. Then, from mid-August until leaf drop, the mites return to their overwintering sites beneath the bud scales.

Home management for grape erineum mites: Sprays aren’t needed. “Dormant-season oils and insecticides used for other pests and sulfur applications for powdery mildew usually control this pest.”

Pear Leaf Blister Mites (Eriophyes pyri) feeding causes reddish to yellowish green blisters on the top surface of the leaves, often in 2 lengthwise rows, one at each side of the main vein. With time, the blisters turn brown or black. Leaves may drop prematurely. Loss of excess foliage weakens trees, reduces shoot growth, and interferes with fruit maturation and fruit bud formation. Feeding on fruit causes irregular, russeted spots which feel rough and somewhat scaly. PNW Insect says “Eriophyid mites move from tree to tree, perhaps by wind or carried on birds or insects.”

Home Management for Pear Leaf Blister Mites: Lime sulfur applications in the fall can significantly reduce populations of these mites the following year. (The trick, though is to obtain it in small home-use packaging.) Applications before bud swell can also be effective. Or apply superior oil as buds begin to swell.

Walnut Blister Mites (Aceria erineus)

Just as do the previous two mites, walnut blister mites overwinter beneath bud scales. When springtime temperatures rise, the mites feed among the leaf hairs on the undersides of the leaves. Several generations occur during the summer, which attack new foliage as soon as it unfurls.

Home Management of Walnut Blister Mites: Naturally-occurring predator mites almost always keep mites under control if broad-spectrum insecticide applications are avoided. Heavy rain and cold weather also suppress mite numbers.

Broadleaf weeds like mallow, bindweed, white clover, and knotweed enhance mite numbers. Avoid excessive nitrogen applications, as this encourages mites.

Horticultural oil is the only spray suggested for home-use.

Resources

Eriophyid Mites: https://utahpests.usu.edu/uppdl/files-ou/factsheet/eriophyid-mites2010.pdf

Grape Erineum Mites: https://pnwhandbooks.org/insect/small-fruit/grape/grape-grape-erineum-mite

Pear Leaf Blister Mites: https://pnwhandbooks.org/insect/tree-fruit/pear/pear-eriophyid-mite

Walnut Blister Mites: https://pnwhandbooks.org/insect/nut/walnut/walnut-walnut-blister-mite

(Click the link below for PDF containing the above text and all the images.)

Blister Mites – PDF

Natter’s Notes

Pear Trees: Rust, times 2

Jean R. Natter, OSU Master Gardener

Pear trees are having a rough time of it this spring. It seems that this year supplied  the perfect conditions for rust on pears. So, let’s compare and contrast  the two important rust diseases of pears in Oregon. Recall that cedar-apple rust is not an issue in our region.

Seven different Gymnosporangium species cause rusts on members of the rose family in Oregon. For this discussion, let’s differentiate between Pacific Coast Pear Rust (G. libocedri) and Trellis Pear Rust (G. sabinae).

Most rust fungi have two different hosts: the primary host  — in this case, pear– on which growth and yield may be severely affected and a secondary host which typically displays subtle effects. With both diseases, pear trees exhibit brilliant orange spores on affected tissues, spores which readily rub off.

Pacific Coast Pear Rust is a well-established disease in the northwest and, this spring, is on a spree infecting leaves, twigs, blossoms, and newly set fruit. All ages of trees are affected, from venerable specimens to newly planted saplings. Incense cedar is the alternate host.

Trellis rust, aka European Pear Rust, was found in western Oregon in 2016. It’s considered well -established in western Washington, coastal British Columbia and Contra Costa County, CA. Known infections in Oregon are in Benton, Marion, and Clackamas Counties. Junipers are the alternate hosts.

Differentiating between these two rust diseases of pear relies on careful examination of symptoms on submitted sample(s) and images. Both rusts sport bright orange, powdery spores on pears. A diagnostic symptom for the trellis variety is an “acorn-like” eruption on the backs of leaves later in the season.

Be certain to ask about potential alternate hosts nearby.  Both alternate hosts of these pear rusts ooze orange gel during wet spring weather. Off-season, affected junipers have subtle, elongated galls while incense cedars may develop  a more obvious symptom, witches’ broom(s). (http://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/pests-and-problems/diseases/witches-broom.aspx)

Management choices are limited for home gardeners who fear for their fruit crop.

– Sanitation –The common advice to collect and discard affected parts is unlikely to limit rust unless alternate hosts are removed.

– Resistant varieties – Growing resistant varieties is commonly suggested for disease management for backyard trees. In pear rust, both Asian and European kinds are affected. ‘Bartlett’ is usually less affected while ‘Winter Nellis’ is severely affected. Resistant varieties aren’t listed for trellis rust.

The PNW Disease Handbook states “Eliminating either host [primary or secondary] is the only practical cultural control.” For Pacific Coast Rust the PNW says “Remove alternate hosts around the orchard.” (It also states that, spores from the gel on incense cedar can be blown 6 for 10 miles.) The advice is more specific for trellis rust: “Remove all junipers within 1000 feet.”

– No home-use chemicals are listed for either rust. So, the gardener’s next predicament is to locate a company which sprays fruit trees. Clients will need to research local companies that spray landscape trees. (I found that company websites usually offer a link to “contact us” while some list a phone number. You’ve heard it before: Let your fingers do the walking.)

Resources

Pear Trellis Rust

–  Pear, primary host – https://pnwhandbooks.org/plantdisease/host-disease/pear-pyrus-spp-trellis-rust-european-pear-rust

– Juniper, secondary (alternate) host- https://pnwhandbooks.org/plantdisease/host-disease/juniper-juniperus-spp-pear-trellis-rust

Pacific Coast Pear Rust

–  Pear, primary host – https://pnwhandbooks.org/plantdisease/host-disease/pear-pyrus-spp-pacific-coast-pear-rust

– Incense cedar, secondary (alternate) host- https://pnwhandbooks.org/plantdisease/host-disease/juniper-juniperus-spp-pear-trellis-rust

(Click the link below for PDF containing the above text and all the images.

Pear Trees: Rust, times 2 – PDF

Natter’s Notes 

Update: Japanese Beetle

Jean R. Natter, OSU Master Gardener

The Oregon Department of Agriculture (ODA) has an extensive website with information about their continuing efforts to eradicate the invasive Japanese beetles (JBs) from Washington County, Oregon, which is expected to require 5 consecutive years of treatment. (Treatments began in 2017..) For a history and overview of the project, including all public updates beginning with March 2017, see ODA’s website at http://www.japanesebeetlepdx.info/.

ODA advises that adult Japanese beetles (JBs) found within the designated treatment area should be disposed of in soapy water. If JB adults are observed outside the treatment area, capture it/them and, then, promptly notify ODA by email at japanesebeetle@oda.state.or.us or phone 1-800-525-0137.

The following is the full text of the most recent Oregon Department of Agriculture update (April 16, 2018) for the ongoing eradication effort of the Japanese beetle in Washington County:

– – – –

The Oregon Department of Agriculture has begun treatment operations of residences in Washington County as part of the second year of Japanese beetle eradication. Oregon Department of Agriculture has contracted General Tree Service to perform the applications of the larvicide. General Tree Service (GTS) worked with ODA during the first year of the project, and has worked with ODA on past eradication projects for Japanese beetle in Oregon in years prior.

The treatment area in Washington County for 2018 is approximately 2000 acres containing an estimated 6500 residences. As of Friday, April 13, ODA and GTS had treated 2,049 properties for Japanese beetle. Four application crews consisting of one ODA team lead and two General Tree Service applicators and staff meet each morning at 7:30am to prepare the day’s plans. Treatment begins at around 8:15 am when the ODA team member visits each home to inform the resident of the treatment, inspects the property for hazards or areas to avoid application, and flags the property to let the crew know it’s ok to treat. Residents are notified about treatment schedules the week before.

There have been some delays due to weather, but mostly treatment has been able to be completed as scheduled. This is due in large part to the hard work being done by the seemingly tireless application crews and crew leads who are working long days, rain or shine, to make sure treatment is correctly and done on time. Operations are expected to continue until mid-May, with some applications planned in Douglas County and at the Portland International Airport.

 

 

 

 

 

 

Support from resident in the area has been very positive. Before treatment, we’d received over 5,000 responses from residents allowing ODA and their staff to treat the properties, including 30 Home Owners Associations allowing treatment in common areas. Tualatin Hills Parks and Recreation Department and the Beaverton School District are also supporting the project and allowing treatment to parks and school fields. Applicator crews have said that residents in the area are expressing their support for the project, with many “Thank yous” and “Get those beetles!”

Containment will begin ramping up soon, with the yard debris quarantine still in effect and expanding in 2018. Residences will receive electronic notices from Oregon Department of Agriculture this week, along with other communications planned throughout the summer.

– Chris Hedstrom, Japanese Beetle Project Coordinator

(Click the link below for PDF containing the above text and all the images.)

Japanese Beetle Update PDF

Natter’s Notes:
Carpenter Ants

Jean R. Natter, OSU Master Gardener

Carpenter ants, sometimes referred to as “termites of the northwest,” can be important structural pests which typically nest in moisture-damaged wood. In our region, swarms of flying reproductives (males and females) often leave the nest during January. After mating, the surviving queens will shed their wings and search for a new nest site.

Once a thriving colony is established, it has 10,000 to 50,000 or more individuals. The main nest is in dead wood, perhaps a tree, stump, or landscape timbers.

But that’s only part of the story.

The pupae and some workers are in a secondary nest, one that’s in a relatively warm, dry structure such as a house, garage, or shed. When a colony is about 6 to 10 years old, it produces its first winged swarmers (reproductive males and females). The females, at 16- to 18-mm (about 5/8-inch), are larger than the males, the latter a scant 1/2-inch long.

It doesn’t matter which Camponotus species is in an infestation. In western Oregon, C. modoc (black with red legs) is more common than C. vicinus (black with red thorax and legs). A mature colony has 3 sizes of workers: minors (the smallest); media; and majors. They may invade households, just as nuisance ants will, but are unaffected by over-the-counter ant bait.

All ants have elbowed antennae, and a petiole (a slender connection between thorax and abdomen) with a noticeable node (a bump).  Carpenter ant workers are recognized by their particularly large node and an evenly convex thoracic profile. The additional musculature for the swarmers’ wings creates a beefier profile changing the thoracic outline to somewhat flattened and table-like. After females drop their wings, close examination of the lateral thorax with a hand lens will reveal small indentations – the places where the wings were attached.

Key points

• Secondary nests in structures begin in moisture-damaged wood.
• Buildings near a wooded area are more liable to attack than others.
• Carpenter ants don’t eat wood; instead, they excavate wood for housing.
• Carpenter ants feed on honeydew and captured insects.
• If winged ants emerge indoors from underneath the baseboard, the nest is probably in the wall; if via a ceiling light fixture, in the space above, in either the attic or ceiling void.

More often than not, clients don’t know if they are infested or where the main nest is.  These activities can provide answers:

• Look for piles of fresh sawdust in the attic and crawl space.
• To determine where the ants are entering the structure, look for 2-way trails outdoors. The best time is from 10 PM to 2 AM during April through October. Inspect along the foundation and other architectural lines, in the crawl space, and where utilities (pipes and wiring) enter the structure.
• If a trail is found, follow it to the main nest which, to limit structural re-infestations, must be treated by a pest control company.

Thwart the likelihood of a carpenter ant infestation with several ongoing practices:

• Create an airy clear zone around structures by trimming, or removing, any plant material within 12 to 18 inches.
• Maintain mulch at least 8 inches below the siding.
• Ensure roofing is intact.
• Inspect the perimeter of the structure periodically, to check for a 2-way trail which warns of an infestation.

Management practices for an infestation

• Hire a pest control company to treat the structure and, whenever possible, the main nest.
• Correct the moisture problem and replace damaged wood
• Over-the-counter ant baits available in the northwest are ineffective against carpenter ants.

Resources

– PNW Insect Management Handbook, the section titled Structural and Health Pests.

– “Identification and Habits of Key Ant Pests of Washington” (EB0671) has identification details for common ants.

“Carpenter Ants: Their Biology and Control” (EB0818; WSU)

– “The Technician’s Handbook” (Richard Kramer; PCT Handbooks) is a handy source of brief summaries about key pests. Each entry includes the pest’s description, a clear line drawing, life cycles, foods, habitats, and cultural management.  Still more details about ants are in “Structure-infesting Ants” (Stoy Hedges; PCT Handbooks). These professional handbooks offer insights as to the services pest control companies may offer. For one thing, pest control companies have effective ant baits not otherwise available to the public.

(Click the link below for PDF containing the above text and all the images.)

Carpenter Ants PDF

 

Natter’s Notes

Ants

Jean R. Natter, OSU Master Gardener

Ants! They’re likely major players in perhaps one of the oldest good-news-bad-news stories ever.

The good news is that ants are valued for their beneficial activities. They add large quantities of spent plant and animal remains into the soil surrounding their colonies as they cultivate and aerate the soil. They also create channels for water and roots. They’re predators, too, and are members of nature’s clean-up crew, carting away debris that includes stray crumbs indoors and dead insects outdoors.

The bad news is that, outdoors, ants sometimes get carried away. If they aerate the soil in and around a rootball excessively, water passes through the ground too rapidly to soak in, the plant wilts, and may die. Then, too, people take a dismal view of their uninvited excursions indoors when they trail across the floor, headed for the pet’s dish or wayward crumbs.

Overall, it’s safe to say that most people detest the little buggers. People don’t want to control them. They want to eradicate them. Forever!.

Well, the cold, hard truth is this: That’s not possible; ants are here to stay.

Everyone, clients and Master Gardeners alike, must discard their dreams to eradicate ants. The more accurate strategy, although far less comforting, is to hope to manage ants.

Odorous house ants, Tapinoma sessile, are probably the most common house-invading ants across the country. They’re small, dark brown or black ants, 1/16- to 1/8-inch long, with the usual 3 body parts of an insect – head, thorax, and abdomen. The characters which define them as ants are a petiole (a narrow connection between the thorax and abdomen) and a pair of elbowed antennae. The character which differentiates them from other ants is the single node on the petiole; it’s small and hidden by the abdomen. When crushed, these ants emit a rather penetrating odor, likened to rotted coconut.

Colonies are relatively small, to about 10,000 individuals, each with multiple queens. Nests are usually outdoors just below the soil surface, underneath pavers, wood piles, or other debris. But nests may also be indoors, in a wall void or near warmth-emitting sources.

Odorous house ant populations enlarge by one of two methods: mating of reproductives or via budding. Budding may be triggered when a hundred or so workers transport several of the colony’s queens to a new site. With time, a series of closely related, cooperative colonies—a supercolony – forms.

Sweets are a favorite food but they will eat most any people or pet food.

Managing ants requires a multi-pronged approach.

1. Sanitation (clean up regularly), and store perishable foodstuffs in tight, rigid containers.
2. Caulk and seal entries such as cracks in the foundation or gaps where utilities enter structures.
3. Limit honeydew-producing insects: ants, mealybugs, whiteflies, and scale, both soft and cottony scales.
4. Limit access indoors by trimming foliage away from structures.
5. Use commercially-formulated ant baits and repeat as needed.

Ant baits are superior to sprays but require more time to be effective, occasionally several weeks. The reason? They are shared with other ants within the colony, including the queens. If a bait is ineffective after a week or more, try a different kind. It can be useful to pre-bait by first setting out a small dab of jam or other food.

Active ingredients in commercial ant baits

• Avermectin – Derived from soil bacteria; affects the nervous system. https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/avermectin
• Boric acid – An inorganic compound used in ant management for years. Mode of action unknown.
• Fipronil – Causes hyperexcitation of the central nervous system causing convulsions and death. Very active against ants.
• Hydramethylnon – Interferes with energy production.
• Imidacloprid – Useful in baits for ants that prefer sweets.
• Insect growth regulators (IGRs) – The queen’s reproductive organs degenerate and immatures die before they become adults.
• Indoxacarb – Activated by enzymes inside the insect.
• Spinosad – Produced by soil actinomycetes; the insect dies of exhaustion because of continuous activation of motor neurons.
• Sulfuramid – Potentiated by enzymes inside the insect body; toxic metabolites inhibit energy production.

 

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Resources

• Identification and habits of Key Ant Pests in the Pacific Northwest (http://cru.cahe.wsu.edu/CEPublications/PNW624/PNW624.pdf)
• How to identify the odorous house ant, Tapinoma sessile: http://ipm.ucanr.edu/TOOLS/ANTKEY/odorous.html
• Professional pest control publications in each Metro MG office contain many insights useful for home-use:
  • PCT Technician’s Handbook
  • PCT Field Guide for the Management of Structure-Infesting Ants
  • NPMA Handbook of Pest Control
• Life in the Soil (James Nardi; University of Chicago; 2007)
• AntWeb – An online database about numerous ant species;  https://www.antweb.org/description.do?rank=species&genus=tapinoma&name=sessile

(Click the link below for PDF containing the above text and all the images.)

Ants PDF

 

Natter’s Notes

Japanese Beetle Eradication: Update

Jean R. Natter, OSU Master Gardener

Japanese beetle eradication: One year down, 4 to go.

Japanese beetles (JB) will remain front and center as important invasive pests in Washington County. The eradication effort began in 2017 and will extend through 2021. The Oregon Department of Agriculture’s (ODA) 2018 plans are progressing well for the continuing effort against these serious invasive pests of agriculture and home landscapes.

Few questions were submitted to the Washington County MG office during 2017 about JBs, so, ODA did an excellent job explaining the project to affected citizens and recruiting their cooperation. (I responded to just 2 client inquiries, both from far outside the quarantine area. One about the dying birch trees on Cooper Mountain where the client was concerned he “saw some of those bugs” and even “dug some out of the trunk.”)

 

 

 

News from ODA

“Using data from our 2017 trap detections and the resulting predicted JB trap catches for 2018, we have expanded our treatment area for next year in Washington County. As was the case in 2017, consent is needed from residents for ODA and our contractors to be able to enter the properties and treat with Acelepryn G. In January, residents within the treatment area will receive notice in the mail with details about the infestation, our plans for eradication, and consent forms to return to us. Consent can also be granted using our online form. Treatment is scheduled for April and May 2018. In addition to the treatments in Washington County, we also plan to treat [a] small area at Portland International Airport and a residential neighborhood in Oakland, OR, [Ed. Note: Douglas County] based on 2017 detections. These infestations are believed to be unrelated to the Washington County populations.”

ODA’s Proposed Response Plan for 2018

ODA’s 2018 Proposed Response Plan for Japanese beetle has been finalized and is now available. As previously announced, all known infested properties will be treated.

ODA’s directives about yard debris

ODA’s “newest alert about the quarantine” describes appropriate handling of potentially contaminated yard debris and contains a brief FAQ. (http://www.oregon.gov/oda/shared/documents/publications/ippm/jbyarddebrisquarantineflyerwinter18.pdf)

Informational Open Houses by ODA

ODA has scheduled two open house events for Cedar Mill and nearby neighborhood residents to have their questions answered about the JB eradication project:

– Tuesday, February 13 at Leedy Grange, 835 Saltzman Rd, 9:30am-12:30pm

– Monday, March 5 at Cedar Mill Community Library, 12505 NW Cornell Rd, 5:15pm-7:15pm

FAQ about the granular Acelepryn G

During 2017, a granular product was applied to turf areas of affected properties using a drop spreader. A detailed FAQ concerning Acelepryn G is at the Oregon Health Authority (http://www.oregon.gov/oha/PH/HEALTHYENVIRONMENTS/HEALTHYNEIGHBORHOODS/PESTICIDES/Pages/Chlorantraniliprole-and-Your-Health-FAQs.aspx)

 

 

 

What to do if a JB is seen

“If you see the adult Japanese beetle within the treatment area then the Oregon Department of Agriculture advises that you dispose of them in a container of soapy water.

“If beetles are observed outside the treatment area please put the specimen in a container or bag and email or call ODA.”

Resources

– ODA news release 2017-12-14: “ODA makes plans for Japanese beetle battle part 2“ (https://odanews.wpengine.com/oda-makes-plans-for-japanese-beetle-battle-part-2/)

– ODA’s Japanese Beetle website, an overview of the infestation and its management, now with extensive updates. (http://www.japanesebeetlepdx.info/)

– “Japanese Beetle Treatment Map with Trap Placement” outlines the proposed 2018 quarantine area in blue while dots indicate individual traps. (http://geo.maps.arcgis.com/apps/webappviewer/index.html?id=94f352bc881b410a911c252e69ca48f8)

– “Current Suppression and Eradication Projects” contains succinct summaries of the green waste quarantine, the 2017 JB detections, and a list of links to JB resources at ODA. (http://www.oregon.gov/ODA/programs/IPPM/SuppressionEradication/Pages/SuppressionEradication.aspx)

– Oregon Health Authority has an extensive FAQ fact about Acelepryn G, the granular insecticide used against JBs in Washington County.  http://www.oregon.gov/oha/PH/HEALTHYENVIRONMENTS/HEALTHYNEIGHBORHOODS/PESTICIDES/Pages/Chlorantraniliprole-and-Your-Health-FAQs.aspx

(Click the link below for PDF containing the above text and all the images.)

Japanese Beetle Eradication: Update, PDF

Natter’s Notes

Slugs & Snails

Jean R. Natter, OSU Master Gardener

Snails and slugs. Ugh. Slime and holey leaves. Yuck. Oregon’s rainforests offer prime habitat where slimy pests thrive.

Pests & natives

“Of the 29 species of slug [in Oregon], 15 are exotic.” (Resource #2.) Of those, the gray field slug is the scourge of home gardeners and commercial growers.

Slug lifetimes vary, from one to two years, according to the kind at hand. (Fig 1) But it’s a different story with snails. Brown Garden Snails (BGS) live to 4 years, Giant African Snails – they’re not here yet – 7 to 12 years.

Invasive Brown Garden Snails, Cornu aspersa were deliberately imported from Europe to California during the mid-1850s to be an upscale edible served in garlic-butter to moneyed goldminers. (Fig 2) Unfortunately for gardeners, snails escaped. Worse yet, when the market went bust, unsold stock was released. (More info at Pacific Northwest Nursery IPM: http://oregonstate.edu/dept/nurspest/brown_garden_snail.htm.)

The native Pacific Banded Snail, Monadenia fidelis, resembles BGS, but has different habits. It primarily inhabits wooded areas, and is seldom a garden pest. When you compare the brownish shells of BGS and Monadenia side-by-side, it’s easy to see that the pattern on BGS is somewhat tweedy whereas Monadenia is strongly banded. (Fig 3)

The Gray Field Slug, Deroceras reticulatum, also called the milky slug, has cloudy mucus. Although it’s a rather small slug, just 15 to 50 mm long – about ½- to 2-inches – it’s a

serious pest in both commercial agriculture (especially grass seed producers) and home gardens.

The European Red Slug, Arion rufus, is an accidental import from Europe. A showy one. When disturbed, it contracts into a bell-shaped blob.

Leopard Slugs, Limax maximus, are impressive because of their 4- to 8-inch length when extended. If you’ve ever found a mess of slime on a wall, window, or screen, likely this slug and an intimate buddy were the source. During their unique mating practices, the pair of slugs entwine around each other while suspended from a sturdy strand of mucus. (Explicit images at  http://oregonstate.edu/dept/nurspest/Limaxmaximuscourtship.htm.

Management of slugs and snails

– Natural slug predators exist, but are unlikely to limit populations as much as desired, especially if you plant from seed – seedlings are choice nibbles — or if your favorite plantings are leafy greens or hostas.

– Several different night-working, predaceous ground beetles labor on your behalf. Scaphinotus species, for one. (See https://www.flickr.com/photos/oragriculture/23611267674/in/photostream/)

– Regularly scheduled search-and-destroy missions, either early day or late evening. Besides that, revenge feels good!

– Forget about sharp things. You know; stuff like DE, coffee grounds and/or crushed filbert shells. Slime has a purpose, one of which is protection. Plus, such barriers must remain dry. (See “Snail barriers” – http://calag.ucanr.edu/archive/?article=ca.v037n09p15.)

– If you use baits, the best time to apply them is before the snails and/or slugs mate and lay eggs. Some species do so in August, others during fall. Then, some repeat in March.

The future of management

As you may know, gardeners in Europe supplement the natural populations of soil-dwelling, slug-killing nematodes (Phasmarhabditis hermaphrodita) with commercially reared preparations of the same tiny beasts. (See http://www.slugoff.co.uk/killing-slugs/nematodes.)  But, due to strict regulations, those nematodes can’t be exported elsewhere.

But wait. Help may be on the way. Rory McDonnell was hired by OSU about 2 years ago as the Invertebrate Crop Pest Specialist to help farmers manage pesky slugs and snails. (Yea! Gardeners will benefit, too.) He has since located a domestic strain of Phasmarhabditis hermaphrodita on the OSU campus. Just as with all potential biological control agents, requirements include extended testing and evaluation prior to formulation and release of a commercially available product.  (Keep your fingers crossed.)

McDonnell is also working with essential oils and novel attractants. Among the latter, an extract from cucumber slices looks particularly promising.

Illegal in Oregon

Oh, yes. Forget about pitting decollate snails, Rumina decollata, against pest snails and slugs. These predators are legal only in the 7 southern most counties of California. Simply put: Decollates are illegal in Oregon.

Resources

1. “Snails and Slugs”- Practical advice for day-to-day management: http://ipm.ucanr.edu/PMG/PESTNOTES/pn7427.html
2. “Slugs and Snails in Oregon” (J. Vlach, Oregon Dept. of Agriculture): Helps identify Oregon’s commonly encountered slugs and snails; prints well if set up with 2 pages per sheet. http://www.oregon.gov/ODA/shared/Documents/Publications/IPPM/ODAGuideMolluscs2016ForWeb.pdf
3. “Slug Portal” – All-in-one resource about slugs in Oregon. Lots for slime devotees to learn there, including identification, the life of a slug; monitoring; management; research; and more. Go to https://agsci.oregonstate.edu/slug-portal/identification.
4. “Terrestrial Mollusc Tool” – In-depth identification tool for enthusiasts.: http://idtools.org/id/mollusc/index.php

(Click the link below for PDF containing the above text and all the images.)

Snails and Slugs PDF

Natter’s Notes

Rose stem girdler, a new pest of caneberries & roses

Jean R. Natter, OSU Master Gardener

As insects go, rose stem borers, Agrilus cuprescens, (Fig 1) are small metallic beetles in the Family Buprestidae, about a 1/4-inch long when mature. This imported European species attacks two favorite garden plants: Roses and caneberries. Their larvae bore into the stems, eventually girdling them. The growth beyond that point wilts and dies. (Figs 2 & 3)

The older name, Agrilus aurichalceus, is still used in various resources. Other common names include bronze cane borer, cane fruit borer, and raspberry borer.

Facts about borers

Before we delve into further details, we need to understand that all insects that bore into plants behave similarly. For rose stem borers, it’s essentially this:

1. Stressed plants release volatiles (e.g.: ethanol) to attract the pests.
2. The borers find the host by following a scent emitted by the plant.
3. The beetles “taste” the plant and, if it’s suitable for attack – adequately stressed – release aggregation pheromones which attract more of their kin.
4. After sufficient beetles have arrived, they release a “de-aggregation” pheromone which essentially says “Back off, dude.”

5.The beetles lay eggs on the canes. The larvae hatch and immediately bore into cambium where they feed in a spiral pattern, girdling the stem.

6. The stem develops a gall (a slight enlargement); the growth beyond the girdle dies.
7. The 4^th instar larvae overwinter in the stem.
8. Adults emerge about mid-May, mate, and lay eggs singly on canes.
9. Repeat from #5 the next season.

Description

“Flatheaded borers are larvae of a remarkable group of beetles known as buprestids or metallic wood boring beetles, so named for their luminous, metallic exoskeletons. While the adults levy no particular offense other than to nibble a few leaves, their youngsters are real trouble makers and some of the most devastating pests of woody plants.” (http://bugoftheweek.com/blog/2013/1/2/gnarly-roses-rose-stem-girdler-agrilus-aurichalceus)

Here in the northwest, we’re already familiar with another small invasive buprestid, the Bronze Birch Borer (Agrilus anxius). They inflict serious damage and, often kill, stressed birch trees by girdling them, thereby disrupting the flow of the phloem and xylem. (Details at “Bronze Birch Borer” – https://www.na.fs.fed.us/spfo/pubs/fidls/bbb/bbb.htm)

Host plants

As you might suspect, hosts of rose stem borers include roses, but also certain other members of the rose family, among them caneberries commonly grown in home gardens, including both raspberry (red and black) and blackberry. Affected roses may be wild or cultivated kinds.

Damage

Affected canes develop a gall (enlargement) at the feeding site which dries, weakens and may break. Fruit production may decrease. Caneberry plants with normally lush growth may die. (Figs 4-6)

Management

Management of rose stem girdler in Oregon is currently limited to cultural methods.  Plant in well-drained soil and provide adequate water and fertilizer to avoid plant stress. When telltale enlargements are seen on the canes, remove them by pruning below the damage, then destroy the prunings.

MGs as First Responders

Here’s an important project for you: Help track the spread of Rose Stem Girdler in caneberries and roses.

If you suspect such a diagnosis while volunteering as an MG, or in your own berry patch or rose bed, get images and/or samples. Jot down a history with at least a few known facts, among them the cultivar name of the plants; when the damage was first detected; also, in which town the plants are growing. The most useful images to verify a diagnosis are the entire plant; a view of the affected cane(s); and a cut-away of the affected section.

Next, email the images and history to me (j.r.natter@aol.com). After I verify your tentative diagnosis, I will notify both you and the entomologist. And, yes, continue to keep your eyes peeled for this new invasive pest, the rose stem girdler in the future.

Resources

Be cautious while researching rose stem borers. Several insects have similar common names which can lead you astray. (It may be risky to trust information that uses only a common name for the pest.) What you can tell clients, with confidence, about the rose stem girdler is that management is currently limited to removing and discarding (or burning, where allowed) the galled cane(s).

– PNW Insect Handbook contains a brief entry. Chemicals aren’t currently listed for use in Oregon. (https://pnwhandbooks.org/insect/small-fruit/cane-fruit/cane-fruit-rose-stem-girdler)

– “Rose Stem Girdler, Agrilus cuprescens”: A useful one-stop resource concerning the beetle’s life cycle and damage to raspberries. The suggested pesticides are for use in Utah, not Oregon. (https://utahpests.usu.edu/uppdl/files-ou/factsheet/ENT-178-15.pdf)

– Garden Insects of North America; Whitney Cranshaw; 2004; pages 476-477; a copy is in each of the metro MG offices.

– “Gnarly Roses – Rose Stem Girdler” (http://bugoftheweek.com/blog/2013/1/2/gnarly-roses-rose-stem-girdler-agrilus-aurichalceus)

 

 

 

Click the link below for PDF containing the above text and all the images.

Rose Stem Girdler PDF