Sul Ross State University
A Member of the Texas State University System

TAMARISK BIOCONTROL:
Saltcedar Beetle Project

Saltcedar (Tamarisk spp.) is a deciduous shrub or small tree native to the eastern Mediterrranean region and tropical Asia. Saltcedar was introduced to the United States in 1823 to stablize riverbanks, serve as a windbreaker, and an ornamental. In more recent years saltcedar has been depleting water supply and choking out native plants around rivers across the United States.

In 2006, attempts to establish the Tamarisk leasf beetle (Diorhabda spp.) at three locations along the Rio Grande River was conducted in an effort to control the spread of saltcedar and restore the riparian corridor, which has become populated by a monoculture of saltcedar.

In August through October of 2008 many of the sites were flooded and beetle populations were negatively affected. The flooding was a result of both unseasonally heavy rainfall and embergency releases of water into the Rio Conchos. The sites downriver from the Presidio9 through Bif Bend National Park were the most affected. Howeever, nearly every site swa a reduciton in beetle populations due to standing water. Standing water does not allow for the beetle to complete their life cycle because they pupate on the ground.

Currently, two release sites along the Rio Grande are showing early signs of success as beetles are becoming established and over 5,000 square meters of saltcedar have been defoliated.

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