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Tamarisk Leaf Beetle

Project Summary
Date December 2, 2008
Project Lead Tanya Meyer/John Reynolds/Allie Scrivener
Partners USDA

Project Overview

After over 10 years of careful study, the USDA-Agricultural Research Service released a biological control agent in the Capay Valley to help control the tamarisk, or salt cedar (tamarix parviflora).  The tamarisk leaf beetle (Diorhabda elongata) was released on Jan Lowrey’s property upstream of Rumsey four years ago.  Despite a wet year in 2006 and a very dry and cold winter of 2007, the population of beetles is starting to expand its range.  Leaf beetles have been found as far upstream as the High Bridge on Bear Creek and as far downstream as the Casino.  The beetles are making the most impact on tamarisk plants from Camp Haswell to the Guinda bridge.  The beetles lay their eggs on the tamarisk, and the larvae and adult beetles work to kill the plants by feeding on them, which defoliates the plants completely.  The process to completely kill the plant could take up to 5-7 seasons.