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2023-36-021-22686

Project Abstract

Project Location

Wheeler County 

Project Need 

Russian knapweed and Canada thistle are both persistent perennial weeds being difficult to control with chemicals. Ignoring these small sites may result in much larger infestations. Crooked River Weed Management Area (CRWMA) will collect Aulacidea acroptilonica (AUAC) and Jaapiella ivannikovi (JAIV) from the insectary at Rimrock Springs to be distributed on new sites. In 2018 Rimrock Springs was limited with few galls, we had adult AUAC shipped from Colorado. We will do this again if needed, but from surveys at Rimrock Spring in Fall 2021 and 2022, numbers of galls are back up. Both CRWMA, Wasco SWCD, and Jefferson County will survey new infestations of Russian knapweed (690 gross acres) and use past survey data of known infestations to introduce the AUAC and JAIV.

Proposed Project Work 

This project aims to expand the current range of AUAC, to 35 new sites in 2023 throughout Crook, Wasco, Deschutes, and Jefferson counties (345 net acres treatment). 32 past release sites in Wheeler county will be monitored for effectiveness. Canada thistle (24 net acres/96 gross acres) biocontrol (Puccinia punctiformis) will be released (1-2 new sites) in Crook, Jefferson, Deschutes or Wasco county . CRWMA has been working with The Deschutes Land Trust and will be monitoring SIMP Plots in Deschutes and Crook counties. Plots in Wheeler county will be monitored as well working with Wheeler SWCD. Infestations will be located and surveyed through informed observations and in partnership with other entities working in the target lands. Monitoring new sites during the project will be important to ensure biocontrol establishment.

Project Parnters 

CRWMA will partner with Jefferson County, Crook County SWCD, USDA APHIS, private landowners, ODA, Crook County Weed Control, Deschutes Land Trust, and Wasco SWCD, and Deschutes County for the project (total 369 net acres/786 gross acres). Any new biocontrol agents in Oregon available for release, will work with the ODA (hoary cress, teasel, or perennial pepperweed).

A landscape with cloudy sky and scrubland, but the image is rotated 90 degrees to the left.
Spots of Diffuse knapweed
Lush green field under blue sky with cattle grazing and hills in the background.
Canada thistle encroaching whole field
A grassy hillside with dried plants, a vehicle parked to the left, and trees scattered around under a cloudy sky.
Spots of Diffuse knapweed
The image is rotated, showing a dry grass field under a blue sky with clouds.
Diffuse knapweed and Scotch thistle within CREP Buffer
A rotated landscape with clear blue sky and a green field with sparse trees in the background.
Scotch thistle
A rotated view of a grassy field under a clear blue sky.
Spots of Scotch thistle/ Spray road leading to field
Rural landscape with a sign, dry plants, a dirt path, and a wooden structure in the background.
Large Scotch thistle infestation
A sideways image of a scenic landscape with a mountain, trees, clear sky, and a path or road with a fence.
Upper part of large Scotch thistle infestation
Rustic fence line with grassy field and hillside against a blue sky with clouds.
Field with spots of Scotch thistle
A rotated landscape with a grassy field, trees, and a cloudy sky.
Large stand of Scotch thistle
A landscape with cloudy sky and scrubland, but the image is rotated 90 degrees to the left.
Lush green field under blue sky with cattle grazing and hills in the background.
A grassy hillside with dried plants, a vehicle parked to the left, and trees scattered around under a cloudy sky.
The image is rotated, showing a dry grass field under a blue sky with clouds.
A rotated landscape with clear blue sky and a green field with sparse trees in the background.
A rotated view of a grassy field under a clear blue sky.
Rural landscape with a sign, dry plants, a dirt path, and a wooden structure in the background.
A sideways image of a scenic landscape with a mountain, trees, clear sky, and a path or road with a fence.
Rustic fence line with grassy field and hillside against a blue sky with clouds.
A rotated landscape with a grassy field, trees, and a cloudy sky.