Boxelder County 2021
Rush skeletonweed continues to invade Utah’s northern borders and while cooperators continue the battle, rush skeletonweed constantly stretches its range in Northern Utah. The Utah Weed Supervisor’s Association in coordination with Box Elder County conducted biocontrol releases on rush skeletonweed in July of 2021.
Root boring moths were collected from a field site near Boise, Idaho and released in two sites in Box Elder County. Rush skeletonweed sites were scouted ahead of the biocontrol release in June to look for ideal locations and conduct pre-release monitoring. The team set up an insectary cage in Hansel Valley to help increase biocontrol populations. The insectary cage will help increase moth populations in order to create a new biocontrol insectary in Utah.
Biocontrol Collection Field Day
The collection field day for the rush skeletonweed root boring moth (Bradyrrhoa gilveolella) was hosted by the US Forest Service, Forest Health Protection, Boise Field Office. A group of collectors traveled to Boise on Wednesday, June 30. The drive included a caravan of cooperators from Cache, Summit and Box Elder Counties through a 105 degree heat wave in Boise.
Cooperators from Utah met with the Boise Field Office on Thursday, July 1st to collect B. gilveolella. The collection took place near Garden Valley, Idaho. We chased moths along the hillsides through the high heat hoping to take at least one release back to Utah. We were able to collect 688 moths over 5 hours.
They also learned how to root sample for the presence of moths. They were able to view several examples of biocontrol damage at the collection site. They traveled to an earlier collection field site to view the successful collapse of a biocontrol site.
Cooperators selected two locations for root moths. The first site was located on the north end of Promontory Point and the second site was in Hansel Valley. They took SIMP monitoring data on both sites. An insectary cage site was set up in Hansel Valley to concentrate biocontrol. They placed 388 moths in Hansel Valley with half inside the cage and half outside. They placed 300 moths at the Promontory Site.
Both sites will be monitored again in June 2022 to determine establishment. The root moth is difficult to establish. It is recommended that the cooperators return to the collection field day in 2022 and attempt additional releases of the moth in Utah over the next several years.
Get more data in the Rush Skeletonweed Special Project Report