Tamarix mortality in response to herbivory by Diorhabda carinulata
To better understand relationships between herbivory and environmental condition, we have been studying the relationship between Tamarix and a specialist herbivore, the northern tamarisk leaf beetle (Diorhabda carinulata) released as a biological control agent of Tamarix in the western US. The beetle feeds exclusively on Tamarix foliage resulting in complete stand foliage desiccation (i.e. defoliation) that lasts several weeks. Surveys of approximately 900 Tamarix plants have been ongoing since 2012 to study patterns of canopy dieback and mortality across 10 sites varying in the number of defoliation events, tree height, soil salinity, soil texture and bulk leaf carbon isotope ratios (13C). Documented impacts of this biocontrol agent reported here will aid management efforts aimed at preserving riparian habitat in the short-term with conservation efforts targeting the removal and control of Tamarix over the long term.
Funding support provided by the US Department of Agriculture, National Institute of Food and Agriculture (Award number 2015-67013-23138), and the Bureau of Reclamation, Desert Landscape Conservation Cooperative (Agreement number R12AP80909).