The Experts below are selected from a list of 318 Experts worldwide ranked by ideXlab platform
Thomas Baumgartl - One of the best experts on this subject based on the ideXlab platform.
-
the potential of three halophytes tecticornia pergranulata sclerolaena longicuspis and Frankenia serpyllifolia for the rehabilitation of brine affected soils
Land Degradation & Development, 2018Co-Authors: Mandana Shaygan, D R Mulligan, Thomas BaumgartlAbstract:Brine, produced as a by-product of oil extraction, when contained in evaporation ponds can cause soil salinization in the vicinity of these ponds. Native halophytes may assist revegetation and rehabilitation of these salt-affected soils. This study was conducted to investigate the revegetation and rehabilitation potential of brine-affected land using native halophytes (Tecticornia pergranulata (J.M.Black) K.A.Sheph. & Paul G.Wilson, Sclerolaena longicuspis (F.Muell.) A.J.Scott and Frankenia serpyllifolia Lindl). Soil samples from adjacent bare and vegetated areas of brine-affected land were compared to assess the physico-chemical properties associated with the vegetation cover. The salt contents of the halophytes, plant bioaccumulation, bioconcentration, and translocation factors were measured to evaluate remediation capacity of the species. We hypothesized that the halophytes reduce the ions' concentrations and thus soil salinity and sodicity. The examined halophytes were associated with a reduction in salinity and sodicity by an average of 38.5% and 33% in the top 10 cm of the soil, respectively. T. pergranulata had the highest shoot Na content (98 g/kg dry wt), bioaccumulation (14.21), and translocation (23.09) factors for Na that indicated the higher remediation potential of this species. Despite the high remediation potential of the examined species, halophytes are not able to reduce the salt content of the landscape to create conditions for the growth of glycophytes. However, the salt-affected land can be revegetated by halophytes, and halophytes probably provide a stable vegetation cover for the landscape in ecological succession. An improvement in soil physical properties is required for revegetation success.
-
The potential of three halophytes (Tecticornia pergranulata, Sclerolaena longicuspis, and Frankenia serpyllifolia) for the rehabilitation of brine‐affected soils
Land Degradation & Development, 2018Co-Authors: Mandana Shaygan, David Mulligan, Thomas BaumgartlAbstract:Brine, produced as a by-product of oil extraction, when contained in evaporation ponds can cause soil salinization in the vicinity of these ponds. Native halophytes may assist revegetation and rehabilitation of these salt-affected soils. This study was conducted to investigate the revegetation and rehabilitation potential of brine-affected land using native halophytes (Tecticornia pergranulata (J.M.Black) K.A.Sheph. & Paul G.Wilson, Sclerolaena longicuspis (F.Muell.) A.J.Scott and Frankenia serpyllifolia Lindl). Soil samples from adjacent bare and vegetated areas of brine-affected land were compared to assess the physico-chemical properties associated with the vegetation cover. The salt contents of the halophytes, plant bioaccumulation, bioconcentration, and translocation factors were measured to evaluate remediation capacity of the species. We hypothesized that the halophytes reduce the ions' concentrations and thus soil salinity and sodicity. The examined halophytes were associated with a reduction in salinity and sodicity by an average of 38.5% and 33% in the top 10 cm of the soil, respectively. T. pergranulata had the highest shoot Na content (98 g/kg dry wt), bioaccumulation (14.21), and translocation (23.09) factors for Na that indicated the higher remediation potential of this species. Despite the high remediation potential of the examined species, halophytes are not able to reduce the salt content of the landscape to create conditions for the growth of glycophytes. However, the salt-affected land can be revegetated by halophytes, and halophytes probably provide a stable vegetation cover for the landscape in ecological succession. An improvement in soil physical properties is required for revegetation success.
Jack C Deloach - One of the best experts on this subject based on the ideXlab platform.
-
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, Raymond I Carruthers, Daniel W Bean, 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.
-
open field host selection and behavior by tamarisk beetles diorhabda spp coleoptera chrysomelidae in biological control of exotic saltcedars tamarix spp and risks to non target athel t aphylla and native Frankenia spp
Biological Control, 2009Co-Authors: Patrick J Moran, Tom L. Dudley, Jack C Deloach, Joaquin SanabriaAbstract:Biological control of invasive saltcedars (Tamarix spp.) in the western U.S. by exotic tamarisk leaf beetles, Diorhabda spp., first released in 2001 after 15 years of development, has been successful. In Texas, beetles from Crete, Greece were first released in 2004 and are providing control. However, adults alight, feed and oviposit on athel (Tamarix aphylla), an evergreen tree used for shade and as a windbreak in the southwestern U.S. and Mexico, and occasionally feed on native Frankenia spp. plants. The ability of tamarisk beetles to establish on these potential field hosts was investigated in the field. In no-choice tests in bagged branches, beetle species from Crete and Sfax, Tunisia produced 30–45% as many egg masses and 40–60% as many larvae on athel as on saltcedar. In uncaged choice tests in south Texas, adult, egg mass and larval densities were 10-fold higher on saltcedar than on adjacent athel trees after 2 weeks, and damage by the beetles was 2- to 10-fold greater on saltcedar. At a site near Big Spring, in west-central Texas, adults, egg masses and 1st and 2nd instar larvae were 2- to 8-fold more abundant on saltcedar than on athel planted within a mature saltcedar stand being defoliated by Crete beetles, and beetles were 200-fold or less abundant or not found at all on Frankenia. At a site near Lovelock, Nevada, damage by beetles of a species collected from Fukang, China was 12–78% higher on saltcedar than on athel planted among mature saltcedar trees undergoing defoliation. The results demonstrate that 50–90% reduced oviposition on athel and beetle dispersal patterns within resident saltcedar limit the ability of Diorhabda spp. to establish populations and have impact on athel in the field.
-
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, Tom L. Dudley, Jack C Deloach, 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.
Mandana Shaygan - One of the best experts on this subject based on the ideXlab platform.
-
the potential of three halophytes tecticornia pergranulata sclerolaena longicuspis and Frankenia serpyllifolia for the rehabilitation of brine affected soils
Land Degradation & Development, 2018Co-Authors: Mandana Shaygan, D R Mulligan, Thomas BaumgartlAbstract:Brine, produced as a by-product of oil extraction, when contained in evaporation ponds can cause soil salinization in the vicinity of these ponds. Native halophytes may assist revegetation and rehabilitation of these salt-affected soils. This study was conducted to investigate the revegetation and rehabilitation potential of brine-affected land using native halophytes (Tecticornia pergranulata (J.M.Black) K.A.Sheph. & Paul G.Wilson, Sclerolaena longicuspis (F.Muell.) A.J.Scott and Frankenia serpyllifolia Lindl). Soil samples from adjacent bare and vegetated areas of brine-affected land were compared to assess the physico-chemical properties associated with the vegetation cover. The salt contents of the halophytes, plant bioaccumulation, bioconcentration, and translocation factors were measured to evaluate remediation capacity of the species. We hypothesized that the halophytes reduce the ions' concentrations and thus soil salinity and sodicity. The examined halophytes were associated with a reduction in salinity and sodicity by an average of 38.5% and 33% in the top 10 cm of the soil, respectively. T. pergranulata had the highest shoot Na content (98 g/kg dry wt), bioaccumulation (14.21), and translocation (23.09) factors for Na that indicated the higher remediation potential of this species. Despite the high remediation potential of the examined species, halophytes are not able to reduce the salt content of the landscape to create conditions for the growth of glycophytes. However, the salt-affected land can be revegetated by halophytes, and halophytes probably provide a stable vegetation cover for the landscape in ecological succession. An improvement in soil physical properties is required for revegetation success.
-
The potential of three halophytes (Tecticornia pergranulata, Sclerolaena longicuspis, and Frankenia serpyllifolia) for the rehabilitation of brine‐affected soils
Land Degradation & Development, 2018Co-Authors: Mandana Shaygan, David Mulligan, Thomas BaumgartlAbstract:Brine, produced as a by-product of oil extraction, when contained in evaporation ponds can cause soil salinization in the vicinity of these ponds. Native halophytes may assist revegetation and rehabilitation of these salt-affected soils. This study was conducted to investigate the revegetation and rehabilitation potential of brine-affected land using native halophytes (Tecticornia pergranulata (J.M.Black) K.A.Sheph. & Paul G.Wilson, Sclerolaena longicuspis (F.Muell.) A.J.Scott and Frankenia serpyllifolia Lindl). Soil samples from adjacent bare and vegetated areas of brine-affected land were compared to assess the physico-chemical properties associated with the vegetation cover. The salt contents of the halophytes, plant bioaccumulation, bioconcentration, and translocation factors were measured to evaluate remediation capacity of the species. We hypothesized that the halophytes reduce the ions' concentrations and thus soil salinity and sodicity. The examined halophytes were associated with a reduction in salinity and sodicity by an average of 38.5% and 33% in the top 10 cm of the soil, respectively. T. pergranulata had the highest shoot Na content (98 g/kg dry wt), bioaccumulation (14.21), and translocation (23.09) factors for Na that indicated the higher remediation potential of this species. Despite the high remediation potential of the examined species, halophytes are not able to reduce the salt content of the landscape to create conditions for the growth of glycophytes. However, the salt-affected land can be revegetated by halophytes, and halophytes probably provide a stable vegetation cover for the landscape in ecological succession. An improvement in soil physical properties is required for revegetation success.
Raymond I Carruthers - One of the best experts on this subject based on the ideXlab platform.
-
Field Testing Diorhabda elongata (Coleoptera: Chrysomelidae) From Crete, Greece, to Assess Potential Impact on Nontarget Native California Plants in the Genus Frankenia
Environmental Entomology, 2014Co-Authors: John C Herr, Angelica M. Herrera-reddy, Raymond I CarruthersAbstract:When laboratory host specificity tests on weed biological control agents produce ambiguous results or are suspected of producing false-positive findings, field cage or open field tests can be used to help determine the true ecological host range of the agent. The leaf beetle Diorhabda elongata (Brulle) from Crete, imported to the United States for the control of saltcedar (Tamarix spp., Tamaricaceae), showed a low but variable ovipositional response to nontarget Frankenia spp. (Frankeniaceae) in previous laboratory tests conducted in small cages, where up to 11.4% of eggs were laid on these native plants. Results from field tests presented in this article show that no eggs were laid on Frankenia palmeri S. Watson and significantly more eggs were always laid on Tamarix ramosissima Ledebour than Frankenia salina (Molina) I. M. Johnston. Furthermore, the ovipositional response to F. salina was substantially lower than that recorded in laboratory tests. The percent of eggs laid on F. salina in field tests was 3.7 in a paired choice cage test, 4.3 in a multiple choice cage test, and 2.5 in a multiple choice open field test, suggesting that the true acceptance rate of the nontarget by D. elongata in the field will be lower than laboratory tests predicted. However, some damage was caused to F. salina by adult and larval feeding in the field, although this occurred only at the very end of the open field test, when D. elongata densities were extremely high, and all of the surrounding saltcedar had been totally defoliated. Scientific representatives from various stakeholder organizations (state, county, university, and environmental groups) viewed the open field test when in progress and reviewed the final results before advising State regulatory agencies on beetle redistribution. These test results, and the open review process, led regulators to conclude that redistribution of D. elongata in California was warranted owing to its significant ability to defoliate saltcedar, and its low rate of feeding on nontarget Frankenia spp. The introduction of D. elongata provides an interesting case study for risk assessment of a potentially efficacious weed biocontrol agent that may also be capable of using nontarget native plants.
-
field testing diorhabda elongata coleoptera chrysomelidae from crete greece to assess potential impact on nontarget native california plants in the genus Frankenia
Environmental Entomology, 2014Co-Authors: John C Herr, Angelica M Herrerareddy, Raymond I CarruthersAbstract:ABSTRACT When laboratory host specificity tests on weed biological control agents produce ambiguous results or are suspected of producing false-positive findings, field cage or open field tests can be used to help determine the true ecological host range of the agent. The leaf beetle Diorhabda elongata (Brulle) from Crete, imported to the United States for the control of saltcedar (Tamarix spp., Tamaricaceae), showed a low but variable ovipositional response to nontarget Frankenia spp. (Frankeniaceae) in previous laboratory tests conducted in small cages, where up to 11.4% of eggs were laid on these native plants. Results from field tests presented in this article show that no eggs were laid on Frankenia palmeri S. Watson and significantly more eggs were always laid on Tamarix ramosissima Ledebour than Frankenia salina (Molina) I. M. Johnston. Furthermore, the ovipositional response to F. salina was substantially lower than that recorded in laboratory tests. The percent of eggs laid on F. salina in field ...
-
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, Raymond I Carruthers, Daniel W Bean, 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.
-
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, Tom L. Dudley, Jack C Deloach, 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.
-
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, John C Herr, Raymond I Carruthers, James L Tracy, 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.
John C Herr - One of the best experts on this subject based on the ideXlab platform.
-
Field Testing Diorhabda elongata (Coleoptera: Chrysomelidae) From Crete, Greece, to Assess Potential Impact on Nontarget Native California Plants in the Genus Frankenia
Environmental Entomology, 2014Co-Authors: John C Herr, Angelica M. Herrera-reddy, Raymond I CarruthersAbstract:When laboratory host specificity tests on weed biological control agents produce ambiguous results or are suspected of producing false-positive findings, field cage or open field tests can be used to help determine the true ecological host range of the agent. The leaf beetle Diorhabda elongata (Brulle) from Crete, imported to the United States for the control of saltcedar (Tamarix spp., Tamaricaceae), showed a low but variable ovipositional response to nontarget Frankenia spp. (Frankeniaceae) in previous laboratory tests conducted in small cages, where up to 11.4% of eggs were laid on these native plants. Results from field tests presented in this article show that no eggs were laid on Frankenia palmeri S. Watson and significantly more eggs were always laid on Tamarix ramosissima Ledebour than Frankenia salina (Molina) I. M. Johnston. Furthermore, the ovipositional response to F. salina was substantially lower than that recorded in laboratory tests. The percent of eggs laid on F. salina in field tests was 3.7 in a paired choice cage test, 4.3 in a multiple choice cage test, and 2.5 in a multiple choice open field test, suggesting that the true acceptance rate of the nontarget by D. elongata in the field will be lower than laboratory tests predicted. However, some damage was caused to F. salina by adult and larval feeding in the field, although this occurred only at the very end of the open field test, when D. elongata densities were extremely high, and all of the surrounding saltcedar had been totally defoliated. Scientific representatives from various stakeholder organizations (state, county, university, and environmental groups) viewed the open field test when in progress and reviewed the final results before advising State regulatory agencies on beetle redistribution. These test results, and the open review process, led regulators to conclude that redistribution of D. elongata in California was warranted owing to its significant ability to defoliate saltcedar, and its low rate of feeding on nontarget Frankenia spp. The introduction of D. elongata provides an interesting case study for risk assessment of a potentially efficacious weed biocontrol agent that may also be capable of using nontarget native plants.
-
field testing diorhabda elongata coleoptera chrysomelidae from crete greece to assess potential impact on nontarget native california plants in the genus Frankenia
Environmental Entomology, 2014Co-Authors: John C Herr, Angelica M Herrerareddy, Raymond I CarruthersAbstract:ABSTRACT When laboratory host specificity tests on weed biological control agents produce ambiguous results or are suspected of producing false-positive findings, field cage or open field tests can be used to help determine the true ecological host range of the agent. The leaf beetle Diorhabda elongata (Brulle) from Crete, imported to the United States for the control of saltcedar (Tamarix spp., Tamaricaceae), showed a low but variable ovipositional response to nontarget Frankenia spp. (Frankeniaceae) in previous laboratory tests conducted in small cages, where up to 11.4% of eggs were laid on these native plants. Results from field tests presented in this article show that no eggs were laid on Frankenia palmeri S. Watson and significantly more eggs were always laid on Tamarix ramosissima Ledebour than Frankenia salina (Molina) I. M. Johnston. Furthermore, the ovipositional response to F. salina was substantially lower than that recorded in laboratory tests. The percent of eggs laid on F. salina in field ...
-
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, Raymond I Carruthers, Daniel W Bean, 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.
-
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, Tom L. Dudley, Jack C Deloach, 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.
-
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, John C Herr, Raymond I Carruthers, James L Tracy, 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.
