Author : Joel R. Price
Publisher :
ISBN 13 :
Total Pages : 242 pages
Book Rating : 4.:/5 (98 download)
Book Synopsis Post-release Assessment of Classical Biological Control of Canada Thistle (cirsium Arvense) in the Western United States by : Joel R. Price
Download or read book Post-release Assessment of Classical Biological Control of Canada Thistle (cirsium Arvense) in the Western United States written by Joel R. Price and published by . This book was released on 2014 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt: Classical biological control of weeds has been used almost 50 years to control Cirsium arvense (Canada thistle) in the United States. However, few field studies have assessed the efficacy of approved biological control agents, a stem-galling fly Urophora cardui and stem-mining weevil Hadroplontus litura. We reviewed literature on C. arvense control, and between 2008 and 2012, monitored release transects of U. cardui, H. litura, both species, or no insects released at C. arvense infestations across the western United States. At each study transect (n = 87), we measured U. cardui parasitism pressure, biological control agent establishment and abundance, vegetation cover, C. arvense density, and abiotic variables; each as potential factors in inter-annual C. arvense density fluctuation. We found that U. cardui galls are attacked by five parasitoid species at low rates and that C. arvense infestations are negatively affected by perennial grass competition and not by biological control agent herbivory.