Current and projected distribution of three species of leaf beetle (Diorhabda spp.) in Texas released for biological control of saltcedar

Since 2001, four species of leaf beetles, Diorhabda spp., have been released in Texas for biological control of invasive saltcedar (Tamarix spp.).  D. carinulata failed to established.  Three species established and have increased to densities sufficient to impact large expanses of saltcedar.  Diorhabda sublineata is widely established in the Rio Grande and Pecos River watersheds in southwest Texas, while D. elongata is established in some areas of the Colorado River watershed in west Texas.  In 2012, D. carinata established in northwest Texas.  The current distribution of these three species is compared to their potential distribution as projected by a climate-matching model developed by J. Tracy et al. (2009).  Potential factors influencing differences between current and projected distributions are presented.