ARS | Publication request: Natural enemies associated with the invasive weed, Lepidium latifolium L., in its introduced range

Submitted to: Weed Science Society of America Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: May 15, 2011
Publication Date: February 7, 2012
Citation: Williams Iii, L.H., Tonkel, K.C. 2012. Natural enemies associated with the invasive weed, Lepidium latifolium L., in its introduced range. Weed Science Society of America Meeting Abstracts. 1:31.

Technical Abstract: Perennial pepperweed, Lepidium latifolium L., is a perennial mustard (Brassicaceae) native to Eurasia. It was unintentionally introduced to North America in the early 1900s, and has since spread over millions of acres. This weed is an aggressive invader of wetlands, meadows, roadsides, and agricultural fields where the soil is slightly alkaline or saline. It grows 1 to 3 meters tall with a heavy, sometimes woody, crown and a spreading, well-developed root system. It reproduces from seed, as well as from the roots. Control of this weed is problematic; physical control (mechanical removal, prescribed burning, and inundation) and chemical control are generally not effective and have other adverse consequences. In North America the occurrence of several native Lepidium species, as well as brassicaceous crops, makes biological control a challenge. However, foreign exploration in regions where perennial pepperweed co-occurs with other Lepidium species may nevertheless yield promising candidate agents. The natural enemy complex of perennial pepperweed in its introduced range is poorly understood. This information would be useful in future control efforts because it would help evaluate whether existing natural enemies could be enhanced, as well as determine the potential for interference, or perhaps synergistic effects, between candidate agents for introduction and natural enemies that are already present. This poster describes our work toward characterization of the natural enemies attacking L. latifolium in its introduced range. This will provide baseline information that will aid foreign exploration and guide biocontrol agent selection.