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.
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).