Geographic deployment of _Diorhabda elongata_ for Salt Cedar Biocontrol and Water Supply Restoration
Management of salt cedar with biocontrol insects is a relatively new and untested technology.
One goal of this project is to determine how to effectively use and monitor the northern-adapted beetle at a larger site and how to integrate it into an Integrated Pest Management (IPM) Program.
Another goal is to test new, southern-adapted beetles at appropriate sites to see if they will be effective at controlling salt cedar, and learn how to integrate these into IPM programs.
Need and Benefit
Salt cedar clogs waterways and consumes up to three times more water than native vegetation. It has invaded most riparian areas (approximately 1.6 million acres) of the arid Western United States, causing an annual water loss estimated to be as great as 2,500,000 acre-feet. The annual dollar value of lost irrigation water is estimated to be as high as $121,000,000, and the annual dollar value of lost power generation along the Colorado River alone is as great as $43,600,00. Total losses are set at $291,000,000 annually (Zavaleta 2000)
Costs for use of traditional methods of salt cedar control were estimated in the above article and by Reclamation weed managers and researchers to average about $2,000/acre (for root plowing or cut stump herbicide application). Equipment, supplies, and labor for these methods are costly.
Biocontrol insects, once developed, provide a less expensive option. Biocontrol methods would assist Reclamation to deliver water savings at lower monetary and environmental costs.
Since insect supply is frequently the bottleneck in biocontrol programs, this project will establish a site of supply and additional understanding for the use of insects to help control salt cedar at Reclamation facilities. This will be done for at least two types of the leaf-eating beetle, which are needed to cover the geographic extent and requirements for all 17 of the Western United States.
Zavaleta E., 2000. The Economic Value of Controlling an Invasive Shrub. Ambio vol 29 number 8 pages 462-467.
Contact the Principal Investigator for information about these documents.