Natter’s Notes

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

Jean R. Natter, OSU Master Gardener

Japanese Beetle Update from ODA

Japanese Beetle

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. . .

No Japanese Beetle logo
Image courtesy of the Oregon Department of Agriculture

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,

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

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.

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:

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

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