Clark et al. evaluated theoretical predictions for evolution of reproductive life-history and dispersal traits in the range expansion of the tamarisk biological control agent, Diorhabda carinulata, or northern tamarisk beetle. With experiments run on field-collected populations, they found that females at the expansion front had increased fecundity and body mass, and reduced age at first reproduction; and that dispersal increased at the expansion front in males, especially when unmated and reared at low density.
Does hybridization among tamarisk beetles change the risk of non-target attack in the field? Clark et al. study the consequences of hybridization in tamarisk beetles (Diorhabda). They paired laboratory phenotyping with genomics to assess changes in risk of non-target attack and body size and fecundity. Body size and early fecundity were similar in pure and hybrid females, indicating that hybridization is not detrimental to insect fitness or the biocontrol program and may provide variation that allows populations to become locally adapted.
What site conditions are associated with greater recovery and overall higher cover of willows? Goetz et al. performed a meta-analysis of tamarisk removal and willow (Salix) recovery across the southwest, compiling data from 260 sites where tamarisk was subject to active removal and/or biocontrol and 132 reference sures. Cut-stump method with biological control was the most effective method to improve native species dominance. Willow cover was generally highest in locations with low drought stress, as reflected by soil properties, distance to water, and climate.
The leaf beetle Diorhabda elongata Brullé subspecies deserticola Chen, collected in northwestern China, has been released in the western United States to control tamarisk (Tamarix spp.). While beetle establishment and saltcedar defoliation have been noted at northern study sites, this species has not established at latitudes south of the 38th parallel.
The northern tamarisk beetle Diorhabda carinulata (Desbrochers) was approved for release in the United States for classical biological control of a complex of invasive saltcedar species and their hybrids (Tamarix spp.). An aggregation pheromone used by D. carinulata to locate conspecifics is fundamental to colonization and reproductive success.
A presentation by Dan Bean at the 2020 RiversEdge West Conference about new knowledge on aggregation phermones, phenology, and genomics.
In this chapter, Carothers et al have three objectives: first, they document the value of nonnative Tamarix as summer habitat for birds compared to native riparian habitats of mesquite bosques and cottonwood/willow, and mixed deciduous gallery woodlands; second, they specifically focus on the unintended consequences to native avifauna of dam construction, Tamarix invasion, native vertebrate colonization of the Tamarix-dominated riparian habitat, and subsequent biocontrol along approximately 300 miles of the Colorado River in Grand and Glen Canyons; and, third, the
Remote sensing methods are commonly used to monitor the invasive riparian shrub tamarisk (Tamarix spp.) and its response to the northern tamarisk beetle (Diorhabda carinulata), a specialized herbivore introduced as a biocontrol agent to control tamarisk in the Southwest USA in 2001.
A 2006 review of the saltcedar (Tamarix) biocontrol program.
DeLoach, C.J., Milbrath, L.R., Carruthers, R., Knutson, A.E., Nibling, F., Eberts, D., Thompson, D.C., Kazmer, D.J., Dudley, T.L., Bean, D.W. and Knight, J.B., 2006. Overview of saltcedar biological control. In Monitoring science and technology symposium: unifying knowledge for sustainability in the Western Hemisphere. Proceedings RMRS-P-42CD. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fort Collins, Colorado (pp. 92-99).
"This case challenges the Animal and Plant Health Inspection Service’s (“APHIS”) 2010 decision to terminate, without taking necessary remedial action, the agency’s program authorizing wide-scale release of an invasive species known as the tamarisk leaf-eating beetle (“beetle”) that is having, and will continue to have, devastating effects on the highly endangered Southwestern willow flycatcher (“flycatcher”) and its habitat, including designated critical habitat."
Ctr. for Biological Diversity v. Vilsack, 276 F. Supp. 3d 1015 (D. Nev. 2017)