The Biology of Biocontrol: Enhancing the Biological Control of Tamarisk to Better Serve Riparian Restoration and Recovery
 
Dan Bean1*, Alex Gaffke2, Tom Dudley3, Levi Jamison4, Amanda Stahlke5 and Zeynep Ӧzsoy6
 
1Colorado Department of Agriculture, Palisade Insectary, Palisade, CO, USA; dan.bean@state.co.us
2USDA ARS, Gainesville, FL, USA; alexander.gaffke@gmail.com
3Marine Science Institute, University of California, Santa Barbara, CA, USA; tdudley@msi.ucsb.edu
5University of Idaho, Moscow, ID USA; amandastahlke@gmail.com
6Colorado Mesa University, Grand Junction, CO, USA; aozsoy@coloradomesa.edu
 
 
Beetles in the genus Diorhabda were first released in North American in 2001 for the control of shrubs in the genus Tamarix.  Since then they have spread to many river systems in the western US and have more recently entered Mexico. They have been successful in reducing Tamarix densities in some areas and yet have been difficult to establish in other areas.  They have also moved into areas where Tamarix is utilized by the endangered southwestern willow flycatcher, Empidonax traillii extimus, raising concerns that episodic defoliations could negatively impact this and other wildlife species.  Resource managers are searching for methods to better predict and increase the likelihood of defoliation events as well as to prevent defoliation in areas in which Tamarix serves as nesting substrate for the endangered flycatcher. Our knowledge of the behavior and phenology of Diorhabda has steadily increased since beetles were first released. In addition, through the use of new techniques in genomics we are developing an ever richer array of molecular tools for tracking population genetics as well as the potential identification of genes involved in biological processes critical to biocontrol efficacy such as host plant interactions, behavior, and phenology.  We will present recent work on manipulation of beetle populations using the male-produced aggregation pheromone (beetle herding), prediction of phenological events using a newly developed model as well as progress and potential in Diorhabda genomics.  These will be presented in the context of using science to better manage riparian ecosystems.
 
 
 
 
 
Bean_Dan_REW_2020.pdf