Tamarisk Leaf Beetle

The tamarisk leaf beetle (TLB) was first introduced in 2001, in an attempt to curb dense stands of saltcedars (tamarisk) that line southwestern rivers. The beetles spread quickly and now range from Montana to Mexico and California to Texas. While the TLB is a saltcedar obligate, meaning it only eats saltcedar leaves as both larvae and adult beetles, the intention behind the TLB introduction was not to entirely wipe out saltcedar, but to eliminate some of the population to allow regrowth of the native riparian plants like willows and cottonwoods. Land managers and researchers estimate that the TLB will probably contribute to the defoliation and eventual mortality of 70-85% of saltcedars in infested areas over the next several years. As saltcedar gradually dies back space will open up, allowing native plants to re-grow if conditions are suitable. One unforeseen consequence of TLB defoliation is the risk posed to the endangered southwestern willow flycatcher, where beetle populations and flycatcher critical habitat overlap. Saltcedar defoliation during the flycatcher breeding season can expose nests and eggs to the elements and predators. Reestablishment of native trees can provide good habitat in the future, but takes a considerable amount of time. Monitoring of beetle dispersal is needed to assess impacts to the flycatcher and to identify where restoration should be focused to minimize risks