|Sobhian, Rouhollah - RETIRED USDA-ARS-EBCL|
|Cristofaro, Massimo - ENEA C.R. CASACCIA|
Submitted to: Western Society of Weed Science Meeting Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: December 5, 2006
Publication Date: March 13, 2007
Citation: Smith, L., Sobhian, R., Cristofaro, M. 2007. Prospects for Biological Control of Russian thistle (tumbleweed). Western Society of Weed Science Meeting Proceedings. 60:44 Interpretive Summary: Russian thistle (tumbleweed) is an important alien weed that has invaded about 100 million acres in the western U.S. Tumbleweeds invade fallow fields, clog irrigation systems, are hazardous to automobile traffic, spread wildfires and harbor insect pests that transmit viruses to many vegetable crops. Previously introduced biological control agents became established but are not providing sufficient control. We have evaluated several prospective new agents of these two weeds and have requested permission to introduce one of them. These new biological control agents should help reduce the populations of this weed to innocuous levels over extensive regions. Successful biological control would provide self-perpetuating long-term management of this weed, reduce the need to apply pesticides, and increase the productivity and utility of millions of acres in the western U.S.
Technical Abstract: I submitted a petition to the APHIS Technical Advisory Group (TAG) requesting permission to release the blister mite (Aceria salsolae) to control Russian thistle (Salsola tragus) and its close relatives in December 2004. TAG recommended approval for release in Aug. 2005. APHIS-PPQ has not yet issued a release permit. Host specificity experiments conducted in the quarantine laboratory in Albany, CA indicate that the mite will not attack native North American Chenopodiaceae species (goosefoot family) nor commercial species such as beats, spinach or quinoa. A seed-feeding and stem-boring caterpillar, Gymnancyla canella, from France is undergoing a third year of host-specificity evaluation in Albany. Two interesting weevils (Anthypurinus biimpressus and Baris przewalskyi) have been discovered during foreign exploration in Tunisia and Kazakhstan.