Establishment And Biological Success Of Diorhabda Elongata Elongata On Invasive Tamarix In Texas

A leaf beetle, Diorhabda elongata elongata (Brulle), from Crete, Greece, was released unrestricted at two field locations (Lake Thomas and Beals Creek) within the upper Colorado River watershed of Texas between the summers of 2003 and 2004 as part of a Tamarix biological control program. D. elongeta elongata released at the Lake Thomas site in August 2003 successfully overwintered and was recovered in the spring 2004; however, beetles were not recovered at Lake Thomas past June 2004 despite additional releases in July 2004. Following releases in April and July 2004 at Beals Creek, D. elongata elongata did establish and was subsequently recovered during 2005 and 2006. In August 2006, the D. elongata elongata population was dispersed throughout an area of approximately 12 hectares, beetles or larvae were present on 100% of the 47 trees surveyed and 57% of which (27 trees) were at least 90% defoliated by D. elongata elongata.