Beetle vs. Bird: Expert Panel Weighs in on Biocontrol of Invasive Tamarisk Trees


What do you do when a problem is also a solution? Such is the case with exotic tamarisk (a.k.a., Tamarix spp., saltcedar), criticized for its ability to take over riverbanks, salinize soil, increase fire risk, and trap river sediments, among other ills. Tamarisk was introduced to the Western U.S. from Eurasia in the late 1800s, and over the next 50 years it was widely planted as a fast-growing, drought-resistant ornamental and riverbank stabilizer. However, the

Among the actions taken to reduce tamarisk populations was the development of a biological control agent, the tamarisk leaf beetle (Diorhabda spp.), which eats the leaves in both its adult and larval (pictured above) stages. It was released in 2003 and currently is rapidly spreading, leaving a sea of defoliated tamarisk in its wake.

Except there was a problem, and not the one you might expect. Most aspects of the beetle release were positive: the beetles kept true to their target, leaving native species to recover in the understory of the dying tamarisk trees. They also found their place in the food chain, being prey to both ants and birds. The problem was that tamarisk had become habitat to a number of bird species, including —> Read More Here


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