Uzbekistan
Saltcedars (Tamarix spp.)
Eggs are tan, spherical, and laid as small clusters on saltcedar foliage. Larvae are up to 1 cm long, spotted grayish-black, and have distinct yellow or cream longitudinal stripes. Adults are 5½–6 mm long with tan to yellow bodies. Two dark stripes on each elytron are less obvious on this ecotype compared to others.
Overwintering adults emerge from the leaf litter in spring and feed on saltcedar foliage. After aggregation and mating in response to a male-produced aggregation pheromone, females lay 100–200 eggs in small groups of up to 25 on saltcedar foliage. Larvae hatch after about five days and feed on young saltcedar growth through three instars. Mature larvae move into the litter beneath saltcedar plants to pupate. This ecotype tends to have 3–5 generations per year. Adults overwinter in the leaf litter beneath tamarisk, or in other sheltered microhabitats near the host plant, and emerge in spring to feed, mate, and lay eggs.
There is a moratorium in place for interstate movement and release of Diorhabda spp., and redistribution to federal lands remains prohibited. To abide by the limitations of the original permit (not to release beetles within 200 miles or 322 km of known nesting of the southwestern willow flycatcher in saltcedar), the states of Arizona and New Mexico do not allow beetle introduction or redistribution. Releases in other states are legal, though redistributions across state lines are not permitted.
Larvae and adults feed on saltcedar foliage and occasionally kill more foliage than they consume by scraping the bark off young twigs, resulting in stem desiccation. Newly defoliated plants are straw-colored and quickly refoliate while plants that have been defoliated multiple times may die back, leaving dead gray branches. Plants may re-grow from the plant base, but repeated defoliation reduces metabolic reserves which leads to incremental dieback, eventually killing some plants.
Bean, D.W. and T.L. Dudley. 2023. Saltcedar Biocontrol Agents: History and Ecology in North America. In: R.L. Winston, Ed. Biological Control of Weeds in North America. North American Invasive Species Management Association, Milwaukee, WI. NAISMA-BCW-2023-33-SALTCEDARS-A. https://bugwoodcloud.org/resource/files/28116.pdf