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Raymond I. Carruthers - One of the best experts on this subject based on the ideXlab platform.
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host preference between saltcedar Tamarix spp and native non target frankenia spp within the diorhabda elongata species complex coleoptera chrysomelidae
Biological Control, 2009Co-Authors: John C Herr, Jack C Deloach, Daniel W Bean, Raymond I. Carruthers, Javid KashefiAbstract:Since its release in 2001 for the biological control of saltcedar (Tamarix spp., Tamaricaceae), the leaf beetle Diorhabda elongata (Brulle) from China and Kazakhstan, has become successfully established in many locations in the western United States. However, it failed to establish in the southern and western portions of the saltcedar infestation, creating the need to test additional populations of the beetle from other areas within its region of origin. The host specificity of seven Eurasian populations of D. elongata was evaluated by testing larval development and adult ovipositional preference on a variety of non-target agricultural, ornamental and native plants, with emphasis placed on native Frankenia spp. (Frankeniaceae), which were shown to be laboratory hosts in previous tests. No larvae survived on any of the non-target test plants except for Frankenia spp., where survival to the adult stage ranged between 15% and 92%, and was often not significantly different from survival on Tamarix controls. Adult Diorhabda from Crete laid significantly more eggs on Tamarix ramosissima Ledebour than on Frankenia spp. in a multiple-choice oviposition test but showed very little discrimination between Tamarix and Frankenia species in a no-choice test. In paired-choice tests, all seven Diorhabda populations laid significantly more eggs on T. ramosissima than Frankenia salina (Molina) I.M. Johnston. However, the percentage of total eggs laid on F. salina ranged from 0.8% to 15.7%, suggesting that some utilization of this native plant might occur in the field, despite the presence of a preferred host plant. Significant differences were found between some Diorhabda populations in the percent of total eggs laid on F. salina, indicating a variable degree of risk to these non-target plants.
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assessment of risk to native frankenia shrubs from an asian leaf beetle diorhabda elongata deserticola coleoptera chrysomelidae introduced for biological control of saltcedars Tamarix spp in the western united states
Biological Control, 2003Co-Authors: Phil A Lewis, Jack C Deloach, Tom L. Dudley, John C Herr, Raymond I. CarruthersAbstract:Exotic saltcedars, Tamarix spp. (Tamaricaceae: Tamaricales) from Central Asia and the Mediterranean area, have invaded much of the western United States, where they degrade natural riparian areas, reduce water supplies, and interfere with agriculture and recreation. The major taxa are Tamarix ramosissima Ledeb., Tamarix chinensis Lour., and hybrids with these and Tamarix canariensis Willd. throughout much of the West, and Tamarix parviflora DC. in parts of California. The biology and host range of the leaf beetle, Diorhabda elongata Brulle subspecies deserticola Chen from Central Asia, indicate that it is a safe and potentially effective biological control agent. Here we report that species of the somewhat related native North American shrubs, Frankenia spp. (Frankeniaceae: Tamaricales), appear to be at little risk from the introduction of Diorhabda elongata deserticola. In laboratory, greenhouse, and outdoor cages at Temple, Texas and Albany, California, 0–27% of larvae were able to complete their development on four North American species of Frankenia compared to 53–56% on Tamarix host species, depending on the species tested and the growing conditions of the plants. However, adults were not attracted to, did not feed upon, and rarely laid eggs on Frankenia spp. Forced closer contact with Frankenia in smaller cages and even removing all Tamarix host plants did not increase adult selection of Frankenia plants nor oviposition on them. Adults from larvae reared on Frankenia did not show adaptation to nor increased utilization of the plant, compared to those reared on Tamarix. D. e. deserticola, therefore, appears sufficiently host-specific for field release in North America.
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Host specificity of the leaf beetle, Diorhabda elongata deserticola (Coleoptera: Chrysomelidae) from Asia, a biological control agent for saltcedars (Tamarix: Tamaricaceae) in the Western United States
Biological Control, 2003Co-Authors: C. Jack Deloach, Phil A Lewis, James L Tracy, Raymond I. Carruthers, John C Herr, Joye JohnsonAbstract:Abstract Four species of saltcedars, Tamarix ramosissima Ledeb., Tamarix chinensis Lour., Tamarix parviflora DC., and T. canariensis Willd. and their hybrids, are exotic, invasive small trees from Asia that cause great damage to riparian ecosystems of the western United States. They displace native plant communities, degrade wildlife habitat (including that of many endangered species), increase soil salinity and wildfires, lower water tables, reduce water available for agriculture and municipalities, and reduce recreational use of affected areas. Phytophagous insects are abundant on saltcedar in the Old World and we selected Diorhabda elongata Brulle deserticola Chen as the top candidate biological control agent because of the great damage it causes, and its high host specificity, broad geographic range, and presumed adaptability in the United States. Literature review and our overseas surveys indicated that this insect is associated only with species of Tamarix and occasionally with Myricaria but not with Reumaria or Frankenia (all Tamaricales) in the Old World. In quarantine facilities in the United States, and overseas, we tested beetles from China and Kazakhstan on six species and three hybrids (26 accessions) of Tamarix and on 58 species of other plants, in 15 tests of different types, using 1852 adults and 3547 larvae, over 10 years. Survival from larvae to adults averaged 55–67% on the Tamarix species, 12% on Myricaria sp., and only 1.6% on the three Frankenia spp. No larvae completed their development on any of the other 54 plant species tested, where most larvae died during the first instar. Adults oviposited readily on T. ramosissima accessions, less on Tamarix aphylla (L.) Karst. (athel), and only rarely on other plants. The host range of the D. e. deserticola we tested from Kazakhstan was not different from those we tested from China. Therefore, D. e. deserticola , is sufficiently host-specific and was approved for field release in North America. This is the first biological control agent introduced into the United States for control of saltcedar.
Tom L. Dudley - One of the best experts on this subject based on the ideXlab platform.
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field demonstration of a semiochemical treatment that enhances diorhabda carinulata biological control of Tamarix spp
Scientific Reports, 2019Co-Authors: Daniel W Bean, Tom L. Dudley, Alexander M Gaffke, Sharlene E Sing, Justin A Russak, Agenor Mafraneto, Robert K D Peterson, David K WeaverAbstract: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 specialized matrix formulated for controlled release of this aggregation pheromone was developed as a lure to manipulate adult densities in the field. One application of the lure at onset of adult emergence for each generation provided long term attraction and retention of D. carinulata adults on treated Tamarix spp. plants. Treated plants exhibited greater levels of defoliation, dieback and canopy reduction. Application of a single, well-timed aggregation pheromone treatment per generation increased the efficacy of this classical weed biological control agent.
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patterns of herbivory induced mortality of a dominant non native tree shrub Tamarix spp in a southwestern us watershed
Biological Invasions, 2015Co-Authors: Kevin R Hultine, Daniel W Bean, Tom L. Dudley, Edward P Glenn, Dan F Koepke, Adam M LambertAbstract:The capacity for plant species or populations to cope with herbivory depends in large part on the complex interactions between resource availability, life history and adaptive strategies to maximize defense and/or tolerance to herbivory. Given these complex interactions, the impacts of repeated herbivory on plant stress and subsequent mortality is often difficult to predict. To better understand relationships between herbivory and environmental condition, we studied the relationship between the non-native shrub/tree tamarisk (Tamarix spp.) and a specialist herbivore, the northern tamarisk leaf beetle (Diorhabda carinulata) released as a biological control agent of Tamarix in the Virgin River watershed in the southwestern United States. The beetle feeds exclusively on Tamarix foliage resulting in complete stand foliage desiccation (i.e. defoliation) that lasts several weeks. Approximately 900 Tamarix plants were surveyed over three consecutive growing seasons for 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 (δ13C). Canopy dieback increased from 27 % by volume in the spring of 2012 to 41 % and 54 % in 2013 and 2014, respectively. Tree mortality increased from 0 % in 2012 to 6 % and 10 % in 2013 and 2014, respectively. Surprisingly, percent canopy dieback was not related to the number of defoliation events that ranged from 2 to 7 across the 10 sites prior to the 2013 growing season. On the other hand, canopy dieback increased with soil salinity in both 2013 (R 2 = 0.39, F = 5.07, P = 0.055) and 2014 (R 2 = 0.56, F = 10.26, P = 0.015). Canopy dieback in 2013 increased with bulk leaf δ13C (R 2 = 0.38, F = 4.08, P = 0.078), although δ13C also decreased with the number of defoliation events (R 2 = 0.64, F = 14.17, P = 0.0055), suggesting that photosynthetic rate or drought stress (as indicated by leaf δ13C) may serve as a poor predictor for Tamarix canopy dieback in response to defoliation. Percent canopy dieback was correlated with shifts in NDVI measured from annual MODIS imagery (R 2 = 0.61, F = 12.32, P = 0.008), demonstrating that the tree surveys reflect site-scale changes in canopy cover. Results show that patterns of Tamarix canopy dieback and subsequent mortality following episodic defoliation by D. carinulata are likely to vary across broad gradients in soil salinity and other abiotic and biotic factors. 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.
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evolution of critical day length for diapause induction enables range expansion of diorhabda carinulata a biological control agent against tamarisk Tamarix spp
Evolutionary Applications, 2012Co-Authors: Daniel W Bean, Peter Dalin, Tom L. DudleyAbstract:In classical weed biological control, small collections of arthropods are made from one or a few sites in the native range of the target plant and are introduced to suppress the plant where it has become invasive, often across a wide geographic range. Ecological mismatches in the new range are likely, and success using the biocontrol agent may depend on postrelease evolution of beneficial life history traits. In this study, we measure the evolution of critical day length for diapause induction (day length at which 50% of the population enters dormancy), in a beetle (Diorhabda carinulata) introduced into North America from China to control an exotic shrub, Tamarix spp. Beetle populations were sampled from four sites in North America 7 years after introduction, and critical day length was shown to have declined, forming a cline over a latitudinal gradient At one field site, decreased critical day length was correlated with 16 additional days of reproductive activity, resulting in a closer match between beetle life history and the phenology of Tamarix. These findings indicate an enhanced efficacy and an increasingly wider range for D. carinulata in Tamarix control.
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assessment of risk to native frankenia shrubs from an asian leaf beetle diorhabda elongata deserticola coleoptera chrysomelidae introduced for biological control of saltcedars Tamarix spp in the western united states
Biological Control, 2003Co-Authors: Phil A Lewis, Jack C Deloach, Tom L. Dudley, John C Herr, Raymond I. CarruthersAbstract:Exotic saltcedars, Tamarix spp. (Tamaricaceae: Tamaricales) from Central Asia and the Mediterranean area, have invaded much of the western United States, where they degrade natural riparian areas, reduce water supplies, and interfere with agriculture and recreation. The major taxa are Tamarix ramosissima Ledeb., Tamarix chinensis Lour., and hybrids with these and Tamarix canariensis Willd. throughout much of the West, and Tamarix parviflora DC. in parts of California. The biology and host range of the leaf beetle, Diorhabda elongata Brulle subspecies deserticola Chen from Central Asia, indicate that it is a safe and potentially effective biological control agent. Here we report that species of the somewhat related native North American shrubs, Frankenia spp. (Frankeniaceae: Tamaricales), appear to be at little risk from the introduction of Diorhabda elongata deserticola. In laboratory, greenhouse, and outdoor cages at Temple, Texas and Albany, California, 0–27% of larvae were able to complete their development on four North American species of Frankenia compared to 53–56% on Tamarix host species, depending on the species tested and the growing conditions of the plants. However, adults were not attracted to, did not feed upon, and rarely laid eggs on Frankenia spp. Forced closer contact with Frankenia in smaller cages and even removing all Tamarix host plants did not increase adult selection of Frankenia plants nor oviposition on them. Adults from larvae reared on Frankenia did not show adaptation to nor increased utilization of the plant, compared to those reared on Tamarix. D. e. deserticola, therefore, appears sufficiently host-specific for field release in North America.
Daniel W Bean - One of the best experts on this subject based on the ideXlab platform.
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field demonstration of a semiochemical treatment that enhances diorhabda carinulata biological control of Tamarix spp
Scientific Reports, 2019Co-Authors: Daniel W Bean, Tom L. Dudley, Alexander M Gaffke, Sharlene E Sing, Justin A Russak, Agenor Mafraneto, Robert K D Peterson, David K WeaverAbstract: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 specialized matrix formulated for controlled release of this aggregation pheromone was developed as a lure to manipulate adult densities in the field. One application of the lure at onset of adult emergence for each generation provided long term attraction and retention of D. carinulata adults on treated Tamarix spp. plants. Treated plants exhibited greater levels of defoliation, dieback and canopy reduction. Application of a single, well-timed aggregation pheromone treatment per generation increased the efficacy of this classical weed biological control agent.
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vegetation response to invasive Tamarix control in southwestern u s rivers a collaborative study including 416 sites
Ecological Applications, 2017Co-Authors: Daniel W Bean, Eduardo González, Anna A. Sher, Robert M. Anderson, Robin F. Bay, Gabriel J. Bissonnete, Berenger Bourgeois, David J. CooperAbstract:Most studies assessing vegetation response following control of invasive Tamarix trees along southwestern U.S. rivers have been small in scale (e.g., river reach), or at a regional scale but with poor spatial-temporal replication, and most have not included testing the effects of a now widely used biological control. We monitored plant composition following Tamarix control along hydrologic, soil, and climatic gradients in 244 treated and 172 reference sites across six U.S. states. This represents the largest comprehensive assessment to date on the vegetation response to the four most common Tamarix control treatments. Biocontrol by a defoliating beetle (treatment 1) reduced the abundance of Tamarix less than active removal by mechanically using hand and chain-saws (2), heavy machinery (3) or burning (4). Tamarix abundance also decreased with lower temperatures, higher precipitation, and follow-up treatments for Tamarix resprouting. Native cover generally increased over time in active Tamarix removal sites, however, the increases observed were small and was not consistently increased by active revegetation. Overall, native cover was correlated to permanent stream flow, lower grazing pressure, lower soil salinity and temperatures, and higher precipitation. Species diversity also increased where Tamarix was removed. However, Tamarix treatments, especially those generating the highest disturbance (burning and heavy machinery), also often promoted secondary invasions of exotic forbs. The abundance of hydrophytic species was much lower in treated than in reference sites, suggesting that management of southwestern U.S. rivers has focused too much on weed control, overlooking restoration of fluvial processes that provide habitat for hydrophytic and floodplain vegetation. These results can help inform future management of Tamarix-infested rivers to restore hydrogeomorphic processes, increase native biodiversity and reduce abundance of noxious species.
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Secondary invasions of noxious weeds associated with control of invasive Tamarix are frequent, idiosyncratic and persistent
Biological Conservation, 2017Co-Authors: Eduardo González, Daniel W Bean, Anna A. Sher, Robert M. Anderson, Robin F. Bay, Gabriel J. Bissonnete, David J. Cooper, Kara Dohrenwend, Kim D. Eichhorst, Hisham El WaerAbstract:Abstract Control of invasive species within ecosystems may induce secondary invasions of non-target invaders replacing the first alien. We used four plant species listed as noxious by local authorities in riparian systems to discern whether 1) the severity of these secondary invasions was related to the control method applied to the first alien; and 2) which species that were secondary invaders persisted over time. In a collaborative study by 16 research institutions, we monitored plant species composition following control of non-native Tamarix trees along southwestern U.S. rivers using defoliation by an introduced biocontrol beetle, and three physical removal methods: mechanical using saws, heavy machinery, and burning in 244 treated and 79 untreated sites across six U.S. states. Physical removal favored secondary invasions immediately after Tamarix removal (0–3 yrs.), while in the biocontrol treatment, secondary invasions manifested later (> 5 yrs.). Within this general trend, the response of weeds to control was idiosyncratic; dependent on treatment type and invader. Two annual tumbleweeds that only reproduce by seed ( Bassia scoparia and Salsola tragus ) peaked immediately after physical Tamarix removal and persisted over time, even after herbicide application. Acroptilon repens , a perennial forb that vigorously reproduces by rhizomes, and Bromus tectorum , a very frequent annual grass before removal that only reproduces by seed, were most successful at biocontrol sites, and progressively spread as the canopy layer opened. These results demonstrate that strategies to control Tamarix affect secondary invasions differently among species and that time since disturbance is an important, generally overlooked, factor affecting response.
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patterns of herbivory induced mortality of a dominant non native tree shrub Tamarix spp in a southwestern us watershed
Biological Invasions, 2015Co-Authors: Kevin R Hultine, Daniel W Bean, Tom L. Dudley, Edward P Glenn, Dan F Koepke, Adam M LambertAbstract:The capacity for plant species or populations to cope with herbivory depends in large part on the complex interactions between resource availability, life history and adaptive strategies to maximize defense and/or tolerance to herbivory. Given these complex interactions, the impacts of repeated herbivory on plant stress and subsequent mortality is often difficult to predict. To better understand relationships between herbivory and environmental condition, we studied the relationship between the non-native shrub/tree tamarisk (Tamarix spp.) and a specialist herbivore, the northern tamarisk leaf beetle (Diorhabda carinulata) released as a biological control agent of Tamarix in the Virgin River watershed in the southwestern United States. The beetle feeds exclusively on Tamarix foliage resulting in complete stand foliage desiccation (i.e. defoliation) that lasts several weeks. Approximately 900 Tamarix plants were surveyed over three consecutive growing seasons for 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 (δ13C). Canopy dieback increased from 27 % by volume in the spring of 2012 to 41 % and 54 % in 2013 and 2014, respectively. Tree mortality increased from 0 % in 2012 to 6 % and 10 % in 2013 and 2014, respectively. Surprisingly, percent canopy dieback was not related to the number of defoliation events that ranged from 2 to 7 across the 10 sites prior to the 2013 growing season. On the other hand, canopy dieback increased with soil salinity in both 2013 (R 2 = 0.39, F = 5.07, P = 0.055) and 2014 (R 2 = 0.56, F = 10.26, P = 0.015). Canopy dieback in 2013 increased with bulk leaf δ13C (R 2 = 0.38, F = 4.08, P = 0.078), although δ13C also decreased with the number of defoliation events (R 2 = 0.64, F = 14.17, P = 0.0055), suggesting that photosynthetic rate or drought stress (as indicated by leaf δ13C) may serve as a poor predictor for Tamarix canopy dieback in response to defoliation. Percent canopy dieback was correlated with shifts in NDVI measured from annual MODIS imagery (R 2 = 0.61, F = 12.32, P = 0.008), demonstrating that the tree surveys reflect site-scale changes in canopy cover. Results show that patterns of Tamarix canopy dieback and subsequent mortality following episodic defoliation by D. carinulata are likely to vary across broad gradients in soil salinity and other abiotic and biotic factors. 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.
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evolution of critical day length for diapause induction enables range expansion of diorhabda carinulata a biological control agent against tamarisk Tamarix spp
Evolutionary Applications, 2012Co-Authors: Daniel W Bean, Peter Dalin, Tom L. DudleyAbstract:In classical weed biological control, small collections of arthropods are made from one or a few sites in the native range of the target plant and are introduced to suppress the plant where it has become invasive, often across a wide geographic range. Ecological mismatches in the new range are likely, and success using the biocontrol agent may depend on postrelease evolution of beneficial life history traits. In this study, we measure the evolution of critical day length for diapause induction (day length at which 50% of the population enters dormancy), in a beetle (Diorhabda carinulata) introduced into North America from China to control an exotic shrub, Tamarix spp. Beetle populations were sampled from four sites in North America 7 years after introduction, and critical day length was shown to have declined, forming a cline over a latitudinal gradient At one field site, decreased critical day length was correlated with 16 additional days of reproductive activity, resulting in a closer match between beetle life history and the phenology of Tamarix. These findings indicate an enhanced efficacy and an increasingly wider range for D. carinulata in Tamarix control.
John C Herr - One of the best experts on this subject based on the ideXlab platform.
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host preference between saltcedar Tamarix spp and native non target frankenia spp within the diorhabda elongata species complex coleoptera chrysomelidae
Biological Control, 2009Co-Authors: John C Herr, Jack C Deloach, Daniel W Bean, Raymond I. Carruthers, Javid KashefiAbstract:Since its release in 2001 for the biological control of saltcedar (Tamarix spp., Tamaricaceae), the leaf beetle Diorhabda elongata (Brulle) from China and Kazakhstan, has become successfully established in many locations in the western United States. However, it failed to establish in the southern and western portions of the saltcedar infestation, creating the need to test additional populations of the beetle from other areas within its region of origin. The host specificity of seven Eurasian populations of D. elongata was evaluated by testing larval development and adult ovipositional preference on a variety of non-target agricultural, ornamental and native plants, with emphasis placed on native Frankenia spp. (Frankeniaceae), which were shown to be laboratory hosts in previous tests. No larvae survived on any of the non-target test plants except for Frankenia spp., where survival to the adult stage ranged between 15% and 92%, and was often not significantly different from survival on Tamarix controls. Adult Diorhabda from Crete laid significantly more eggs on Tamarix ramosissima Ledebour than on Frankenia spp. in a multiple-choice oviposition test but showed very little discrimination between Tamarix and Frankenia species in a no-choice test. In paired-choice tests, all seven Diorhabda populations laid significantly more eggs on T. ramosissima than Frankenia salina (Molina) I.M. Johnston. However, the percentage of total eggs laid on F. salina ranged from 0.8% to 15.7%, suggesting that some utilization of this native plant might occur in the field, despite the presence of a preferred host plant. Significant differences were found between some Diorhabda populations in the percent of total eggs laid on F. salina, indicating a variable degree of risk to these non-target plants.
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assessment of risk to native frankenia shrubs from an asian leaf beetle diorhabda elongata deserticola coleoptera chrysomelidae introduced for biological control of saltcedars Tamarix spp in the western united states
Biological Control, 2003Co-Authors: Phil A Lewis, Jack C Deloach, Tom L. Dudley, John C Herr, Raymond I. CarruthersAbstract:Exotic saltcedars, Tamarix spp. (Tamaricaceae: Tamaricales) from Central Asia and the Mediterranean area, have invaded much of the western United States, where they degrade natural riparian areas, reduce water supplies, and interfere with agriculture and recreation. The major taxa are Tamarix ramosissima Ledeb., Tamarix chinensis Lour., and hybrids with these and Tamarix canariensis Willd. throughout much of the West, and Tamarix parviflora DC. in parts of California. The biology and host range of the leaf beetle, Diorhabda elongata Brulle subspecies deserticola Chen from Central Asia, indicate that it is a safe and potentially effective biological control agent. Here we report that species of the somewhat related native North American shrubs, Frankenia spp. (Frankeniaceae: Tamaricales), appear to be at little risk from the introduction of Diorhabda elongata deserticola. In laboratory, greenhouse, and outdoor cages at Temple, Texas and Albany, California, 0–27% of larvae were able to complete their development on four North American species of Frankenia compared to 53–56% on Tamarix host species, depending on the species tested and the growing conditions of the plants. However, adults were not attracted to, did not feed upon, and rarely laid eggs on Frankenia spp. Forced closer contact with Frankenia in smaller cages and even removing all Tamarix host plants did not increase adult selection of Frankenia plants nor oviposition on them. Adults from larvae reared on Frankenia did not show adaptation to nor increased utilization of the plant, compared to those reared on Tamarix. D. e. deserticola, therefore, appears sufficiently host-specific for field release in North America.
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Host specificity of the leaf beetle, Diorhabda elongata deserticola (Coleoptera: Chrysomelidae) from Asia, a biological control agent for saltcedars (Tamarix: Tamaricaceae) in the Western United States
Biological Control, 2003Co-Authors: C. Jack Deloach, Phil A Lewis, James L Tracy, Raymond I. Carruthers, John C Herr, Joye JohnsonAbstract:Abstract Four species of saltcedars, Tamarix ramosissima Ledeb., Tamarix chinensis Lour., Tamarix parviflora DC., and T. canariensis Willd. and their hybrids, are exotic, invasive small trees from Asia that cause great damage to riparian ecosystems of the western United States. They displace native plant communities, degrade wildlife habitat (including that of many endangered species), increase soil salinity and wildfires, lower water tables, reduce water available for agriculture and municipalities, and reduce recreational use of affected areas. Phytophagous insects are abundant on saltcedar in the Old World and we selected Diorhabda elongata Brulle deserticola Chen as the top candidate biological control agent because of the great damage it causes, and its high host specificity, broad geographic range, and presumed adaptability in the United States. Literature review and our overseas surveys indicated that this insect is associated only with species of Tamarix and occasionally with Myricaria but not with Reumaria or Frankenia (all Tamaricales) in the Old World. In quarantine facilities in the United States, and overseas, we tested beetles from China and Kazakhstan on six species and three hybrids (26 accessions) of Tamarix and on 58 species of other plants, in 15 tests of different types, using 1852 adults and 3547 larvae, over 10 years. Survival from larvae to adults averaged 55–67% on the Tamarix species, 12% on Myricaria sp., and only 1.6% on the three Frankenia spp. No larvae completed their development on any of the other 54 plant species tested, where most larvae died during the first instar. Adults oviposited readily on T. ramosissima accessions, less on Tamarix aphylla (L.) Karst. (athel), and only rarely on other plants. The host range of the D. e. deserticola we tested from Kazakhstan was not different from those we tested from China. Therefore, D. e. deserticola , is sufficiently host-specific and was approved for field release in North America. This is the first biological control agent introduced into the United States for control of saltcedar.
Anna A. Sher - One of the best experts on this subject based on the ideXlab platform.
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Success of active revegetation after Tamarix removal in riparian ecosystems of the southwestern United States: A quantitative assessment of past restoration projects
2020Co-Authors: Robin F. Bay, Anna A. SherAbstract:Abstract Invasion by the non-native tree Tamarix has led to implementation of restoration projects aimed at maintaining the ecological integrity of many riparian communities in the southwestern United States. These restoration efforts may include Tamarix removal, manipulation of hydrologic regimes, and active revegetation of native species. The goal of this study was to determine which site characteristics are correlated with restoration success, defined in terms of reductions of undesirable species such as Tamarix and establishment of desirable, native species. To accomplish this, vegetative and environmental data were collected at 28 sites in the southwestern United States where active revegetation was completed after Tamarix removal. These data were incorporated into regression tree models with predictor variables that included number of years since removal (1-18 years) and multiple management, climate, soils, and hydrological variables to determine success of Tamarix control, revegetation success, and general plant community responses. Our results suggest that there are easily measurable site characteristics that are associated with greater native cover and richness, planting success, and Tamarix control. Close proximity to perennial water, sufficient precipitation, recent flooding, and good drainage as well as coarser soil texture, and lower soil pH all favored native species. Overall, those site characteristics associated with native species success were the same as those related to lower Tamarix cover. These quantitative models are intended to assist researchers and land managers to design more effective riparian restoration efforts in this critical arid lands ecosystem
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vegetation response to invasive Tamarix control in southwestern u s rivers a collaborative study including 416 sites
Ecological Applications, 2017Co-Authors: Daniel W Bean, Eduardo González, Anna A. Sher, Robert M. Anderson, Robin F. Bay, Gabriel J. Bissonnete, Berenger Bourgeois, David J. CooperAbstract:Most studies assessing vegetation response following control of invasive Tamarix trees along southwestern U.S. rivers have been small in scale (e.g., river reach), or at a regional scale but with poor spatial-temporal replication, and most have not included testing the effects of a now widely used biological control. We monitored plant composition following Tamarix control along hydrologic, soil, and climatic gradients in 244 treated and 172 reference sites across six U.S. states. This represents the largest comprehensive assessment to date on the vegetation response to the four most common Tamarix control treatments. Biocontrol by a defoliating beetle (treatment 1) reduced the abundance of Tamarix less than active removal by mechanically using hand and chain-saws (2), heavy machinery (3) or burning (4). Tamarix abundance also decreased with lower temperatures, higher precipitation, and follow-up treatments for Tamarix resprouting. Native cover generally increased over time in active Tamarix removal sites, however, the increases observed were small and was not consistently increased by active revegetation. Overall, native cover was correlated to permanent stream flow, lower grazing pressure, lower soil salinity and temperatures, and higher precipitation. Species diversity also increased where Tamarix was removed. However, Tamarix treatments, especially those generating the highest disturbance (burning and heavy machinery), also often promoted secondary invasions of exotic forbs. The abundance of hydrophytic species was much lower in treated than in reference sites, suggesting that management of southwestern U.S. rivers has focused too much on weed control, overlooking restoration of fluvial processes that provide habitat for hydrophytic and floodplain vegetation. These results can help inform future management of Tamarix-infested rivers to restore hydrogeomorphic processes, increase native biodiversity and reduce abundance of noxious species.
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Secondary invasions of noxious weeds associated with control of invasive Tamarix are frequent, idiosyncratic and persistent
Biological Conservation, 2017Co-Authors: Eduardo González, Daniel W Bean, Anna A. Sher, Robert M. Anderson, Robin F. Bay, Gabriel J. Bissonnete, David J. Cooper, Kara Dohrenwend, Kim D. Eichhorst, Hisham El WaerAbstract:Abstract Control of invasive species within ecosystems may induce secondary invasions of non-target invaders replacing the first alien. We used four plant species listed as noxious by local authorities in riparian systems to discern whether 1) the severity of these secondary invasions was related to the control method applied to the first alien; and 2) which species that were secondary invaders persisted over time. In a collaborative study by 16 research institutions, we monitored plant species composition following control of non-native Tamarix trees along southwestern U.S. rivers using defoliation by an introduced biocontrol beetle, and three physical removal methods: mechanical using saws, heavy machinery, and burning in 244 treated and 79 untreated sites across six U.S. states. Physical removal favored secondary invasions immediately after Tamarix removal (0–3 yrs.), while in the biocontrol treatment, secondary invasions manifested later (> 5 yrs.). Within this general trend, the response of weeds to control was idiosyncratic; dependent on treatment type and invader. Two annual tumbleweeds that only reproduce by seed ( Bassia scoparia and Salsola tragus ) peaked immediately after physical Tamarix removal and persisted over time, even after herbicide application. Acroptilon repens , a perennial forb that vigorously reproduces by rhizomes, and Bromus tectorum , a very frequent annual grass before removal that only reproduces by seed, were most successful at biocontrol sites, and progressively spread as the canopy layer opened. These results demonstrate that strategies to control Tamarix affect secondary invasions differently among species and that time since disturbance is an important, generally overlooked, factor affecting response.
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planning riparian restoration in the context of Tamarix control in western north america
Restoration Ecology, 2008Co-Authors: Patrick B Shafroth, Anna A. Sher, Vanessa B Beauchamp, Mark K Briggs, Kenneth D Lair, Michael L ScottAbstract:Throughout the world, the condition of many riparian ecosystems has declined due to numerous factors, including encroachment of non-native species. In the western United States, millions of dollars are spent annually to control invasions of Tamarix spp., introduced small trees or shrubs from Eurasia that have colonized bottomland ecosystems along many rivers. Resource managers seek to control Tamarix in attempts to meet various objectives, such as increasing water yield and improving wildlife habitat. Often, riparian restoration is an implicit goal, but there has been little emphasis on a process or principles to effectively plan restoration activities, and many Tamarix removal projects are unsuccessful at restoring native vegetation. We propose and summarize the key steps in a planning process aimed at developing effective restoration projects in Tamarix-dominated areas. We discuss in greater detail the biotic and abiotic factors central to the evaluation of potential restoration sites and summarize information about plant communities likely to replace Tamarix under various conditions. Although many projects begin with implementation, which includes the actual removal of Tamarix, we stress the importance of pre-project planning that includes: (1) clearly identifying project goals; (2) developing realistic project objectives based on a detailed evaluation of site conditions; (3) prioritizing and selecting Tamarix control sites with the best chance of ecological recovery; and (4) developing a detailed tactical plan before Tamarix is removed. After removal, monitoring and maintenance as part of an adaptive management approach are crucial for evaluating project success and determining the most effective methods for restoring these challenging sites.
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Seedling competition between native Populus deltoides (Salicaceae) and exotic Tamarix ramosissima (Tamaricaceae) across water regimes and substrate types
American journal of botany, 2003Co-Authors: Anna A. Sher, Diane L. MarshallAbstract:Populus deltoides subsp. wislizinii (Salicaceae), a cottonwood native to the Middle Rio Grande of New Mexico, must potentially compete against exotic Tamarix ramosissima (Tamaricaceae) during establishment after flooding. We investigated competitive interactions between seedlings of Tamarix and Populus in two substrates representing field textures and declining (i.e., draw-down) or stagnant water tables. The experiment was performed using a full-additive series design and interpreted with response surface models for each species. As reflected in both aboveground mass and height, Populus suppressed aboveground growth of Tamarix across all treatments, whereas competitive effects of Tamarix against Populus could only be seen at low Populus densities. Clay substrates with draw-down stimulated the greatest growth and created the most intense competitive environment for both species. Tamarix was competitively suppressed in every substrate tested, with the weakest response in sand with no draw-down, where growth of Populus was poorest. These results suggest that stream flow management that promotes Populus establishment could also aid in controlling Tamarix invasion across a range of substrates.