Photo: Kochia. © 2020 Delena Norris-Tull
Biocontrol in Montana
The Montana Biocontrol Coordination Project website provides general biological weed control information, specifics about the biocontrol agents, and a calendar of events.
According to the MTBCP website, biological controls have been used in Montana since 1948, when Chrysolina beetles were first used to suppress St. John’s wort. In the 1970s, a greater effort was made to incorporate biological controls in weed management. In the late 1980s, the use of biological controls was expanded again. A wide variety of State and Federal Agencies, tribes, and university scientists are engaged in researching and implementing biological controls.
Montana maintains “two containment facilities for the study and importation of new agents.” In 2008, the Montana Weed Control Association initiated the Montana Biocontrol Coordination Working Group (MBCWG). In 2015, that group produced the Montana Action Plan for Biological Control of Invasive Plants. The group identified four focus areas: coordination, research and development, implementation, and outreach and technology transfer. Within the area of research and development, they identified the need to study the impact of biological control agents on invasive species, on non-target species, and on ecological systems.
Melissa Maggio interview on Montana Biocontrol Programs
406-660-0197, mmaggio@missouleduplace.org
Website: https://www.mtbiocontrol.org/
Dr. Delena Norris-Tull interviewed Melissa August 24, 2020. Approved 12/2/2020
Melissa Maggio was hired as the Montana Biocontrol Coordinator in 2013. This project is not housed within any State or Federal Agency. It was formed from the grassroots, as a partnership between many County, State, Tribal, and Federal agencies and private landowners in Montana, to coordinate biocontrol education and to provide biocontrol agents to landowners and agencies as needed.
Melissa also manages the website for the Montana Biocontrol Coordination Project.
Montana expanded its work with biocontrol agents in the 1980s. During the 1980s and 1990s, Montana was the leader in the nation, in regards to biocontrol. During those years, many diverse agencies and individual landowners worked on biocontrol
Most of the early funding evaporated by the end of the 1990s. Melissa believes much of the early funding came from Federal grants.
As interest has grown on managing weeds on rangeland, and more landowners have become engaged in the use of biocontrol. The majority of today’s work is conducted through grants obtained from County, State, and Federal agencies.
Around 2011, the various groups located in Montana decided that they needed a coordinated Statewide biocontrol agent distribution system, monitoring and a coordinated education program. Melissa was hired in 2013, to coordinate efforts among all the partners in Montana, to facilitate the distribution of biocontrol agents in Montana, to develop and implement a standardized monitoring program, and to provide education to landowners and agencies.
Currently, there is a need for additional funds to develop new biocontrol agents. Moving agents through the Federal approval process is rigorous and time consuming. Prior to the 1960s, the approval process for introducing new biocontrol agents into the USA was not rigorous enough, and some mistakes were made that resulted in native plants species being negatively impacted by a few agents. Today’s standards are much more thorough. As a result, it is very rare to observe impacts of agents on native plant species.
[However, refer to the section on Biocontrol Agents: “Direct Impacts,” and “Indirect Impacts,” for research on this topic.]
Unfortunately, there is little funding for research and monitoring of biological control projects. Most of the emphasis has been on distributing agents, with little follow-up on the success or failure of those efforts. What research is conducted on establishment and impact after release is at the local level.
Currently, some individuals are conducting research to determine the impact of Mogulones cruciger, a root weevil that attacks Houndstongue, on native plant species. The biocontrol agent has been approved for use in Canada, and the insects have been in use there since 1997. The insect has not been approved for distribution in the United States, due to concerns of the impact it may have on some native members of the Borage Family. APHIS has labeled the root weevil an “agricultural plant pest,” a very unusual step for APHIS to take. But insects do not recognize National or State boundaries. The insect has worked its way across the border into Montana, Idaho, and Washington.
Melissa has established partnerships with many different landowners and non-profit groups, and County, State, and Federal agency representatives, Tribal, university researchers and extension agents. These partnerships are absolutely essential to the success of biocontrol efforts. As a statewide coordinator, who is not employed by a State or Federal agency, Melissa has greater flexibility to get projects started fairly rapidly. This makes her an asset to other agency representatives that do not have that degree of flexibility.
Melissa mentioned that a key role that she has is to educate landowners regarding how biocontrol works. Too often, scientists that conduct research on biocontrol have not had the opportunity to interact with the landowners that must make the decisions on managing noxious weeds in the way that Melissa does. She provides a valuable bridge to fill the knowledge gap between researchers and landowners.
An important part of educating landowners is to help them overcome various misconceptions that landowners tend to have. For example, she has to explain that “Biocontrol is not a silver bullet.” It has to be combined with other methods of control, sometimes with a complex of biocontrol agents, rather than just one, and biocontrol takes much longer to see results than with herbicides. However, the cost-benefit ratio for use of biocontrol agents tends to be much better than with herbicides. With herbicides, the effect may appear to be immediate, but within a few years, the noxious plant often returns, and herbicides have to be applied again and again. With biocontrol agents, the effect usually takes several years, but is more long-lasting than with herbicides.
Another misconception is that the goal of management of noxious plants is to eradicate the plants all together.
Except in cases of very small infestations, it is not possible to completely eradicate a plant on a specific site. This is true with biocontrol and it is true with herbicides. As one example, at the National Bison Range northwest of Missoula, Montana: In the 1950’s, the Range had a large infestation of St. John’s wort, with about 10,000 acres infested. Klamath weed beetles were introduced as biocontrol agents. Today, on a good year the infestation can be as low as 1 acre, at a fraction of the cost of using herbicides. The amount of acreage that remains infested varies over time, in some years being as high as 1000 acres. It can be a challenge for some partners to understand that this is a success story. If more work had been done previously to better document, especially with photographs and monitoring, the decline of the infestation as a result of the introduction of the biocontrol agent, a more convincing story could be told. Some local landowners would like to see the rest of the plants sprayed with herbicides. In situations like this, often times the herbicides will not eradicate the plants, and that procedure is very likely to backfire. If they try to spray out the St. John’s wort, they will also eliminate the biocontrol insects that live on the plants. And if there is a large enough seedbank in the soil, the St. John’s wort will come back in a few years, with no biocontrol agents around to reduce the infestation. This would require repeated use of herbicides, at a much higher cost.
[Refer to the section “Herbicides” for more on the "Myth of Eradication," and the prevalence of noxious weeds that are becoming resistant to various herbicides.]
As part of the education process, Melissa helps landowners to understand that, in their natural habitat, biocontrol agents do not eradicate their host plants. There is always a delicate balance between the number of insects and the number of plants in any natural community.
As another example of the problem with using herbicides, Melissa reported that there had been a significant infestation of Dalmatian toadflax near Missoula beginning in the 1990s. Local partners had used a successful combination of grazing and biocontrol agents, which had a high degree of success in reducing the amount of Dalmatian toadflax with a low point around 2015. The group there decided to use herbicides to spot spray the remaining toadflax. This process eliminated the biocontrol insects. Today, toadflax is once again a problem infestation, due the presence of a significant Dalmatian toadflax seedbank and the elimination of the biocontrol insects.
When asked whether there are any instances when herbicides might be more successful than biocontrol agents, Melissa said that infestations on small acreages may be better tackled with herbicides. A small acreage farm might not have enough invasive plants to support biocontrol agents over time. But on large acreages, she has found that biocontrol agents in combination with other weed management tools like herbicides are more likely to have success.
An example she gave for a method to combine herbicides with biocontrol agents is the following: Leafy spurge has been a very challenging invasive plant to manage because of its extensive root system. Over time, they have been able to introduce multiple biocontrol insects to attack different parts of the plant. In large infestations, it can be effective to use herbicides along the periphery of the infestation, similar to the way large fires are often managed. Using herbicides on the outside edge of the infestation, to help prevent further spread of the invasive, and then using biocontrol agents on the interior of the infestation, can be an effective method.
A third misconception that is prevalent among landowners is that biocontrol agents are always successful on the target plant, and that a single biocontrol agent is always enough to do the job. Researchers have discovered that differences in site characteristics can be very important in determining the success or failure of the introduction of a biocontrol agent. Soil type, degree of slope, variations in winter precipitation and summer drought, high altitudes, and shorter growing seasons, all present their own challenges to the success of biocontrol agents.
For example, it is challenging to get the biocontrol agents that attack spotted knapweed to survive above about 5500 feet elevation. This could be due to winter temperature extremes or a shorter growing season.
She noted that they have had greater success in controlling spotted knapweed infestations with biocontrol in Western Montana than in Eastern Montana. They have used a variety of biocontrol agents. They find that seed head weevils are very effective, but they do not do enough damage by themselves. Reducing seed production alone is not adequate. So now they use a complex of biocontrol agents that work together to attack the seeds, the leaves, and the roots.
The root boring weevils that attack spotted knapweed do not fly, so they must be transported around the State. The individuals that assist with insect distribution must collect biocontrol agents each spring and summer, move them, and distribute them around the State, over and over again. This requires a lot of manual labor.
A new agent recently approved for use with whitetop is a mite. The mite attacks the seeds and flowers of the plant. But this is not adequate by itself because whitetop has long spreading roots.
More Biocontrol Interviews:
Interviews from other States:
Biocontrol in Montana
The Montana Biocontrol Coordination Project website provides general biological weed control information, specifics about the biocontrol agents, and a calendar of events.
According to the MTBCP website, biological controls have been used in Montana since 1948, when Chrysolina beetles were first used to suppress St. John’s wort. In the 1970s, a greater effort was made to incorporate biological controls in weed management. In the late 1980s, the use of biological controls was expanded again. A wide variety of State and Federal Agencies, tribes, and university scientists are engaged in researching and implementing biological controls.
Montana maintains “two containment facilities for the study and importation of new agents.” In 2008, the Montana Weed Control Association initiated the Montana Biocontrol Coordination Working Group (MBCWG). In 2015, that group produced the Montana Action Plan for Biological Control of Invasive Plants. The group identified four focus areas: coordination, research and development, implementation, and outreach and technology transfer. Within the area of research and development, they identified the need to study the impact of biological control agents on invasive species, on non-target species, and on ecological systems.
Melissa Maggio interview on Montana Biocontrol Programs
406-660-0197, mmaggio@missouleduplace.org
Website: https://www.mtbiocontrol.org/
Dr. Delena Norris-Tull interviewed Melissa August 24, 2020. Approved 12/2/2020
Melissa Maggio was hired as the Montana Biocontrol Coordinator in 2013. This project is not housed within any State or Federal Agency. It was formed from the grassroots, as a partnership between many County, State, Tribal, and Federal agencies and private landowners in Montana, to coordinate biocontrol education and to provide biocontrol agents to landowners and agencies as needed.
Melissa also manages the website for the Montana Biocontrol Coordination Project.
Montana expanded its work with biocontrol agents in the 1980s. During the 1980s and 1990s, Montana was the leader in the nation, in regards to biocontrol. During those years, many diverse agencies and individual landowners worked on biocontrol
Most of the early funding evaporated by the end of the 1990s. Melissa believes much of the early funding came from Federal grants.
As interest has grown on managing weeds on rangeland, and more landowners have become engaged in the use of biocontrol. The majority of today’s work is conducted through grants obtained from County, State, and Federal agencies.
Around 2011, the various groups located in Montana decided that they needed a coordinated Statewide biocontrol agent distribution system, monitoring and a coordinated education program. Melissa was hired in 2013, to coordinate efforts among all the partners in Montana, to facilitate the distribution of biocontrol agents in Montana, to develop and implement a standardized monitoring program, and to provide education to landowners and agencies.
Currently, there is a need for additional funds to develop new biocontrol agents. Moving agents through the Federal approval process is rigorous and time consuming. Prior to the 1960s, the approval process for introducing new biocontrol agents into the USA was not rigorous enough, and some mistakes were made that resulted in native plants species being negatively impacted by a few agents. Today’s standards are much more thorough. As a result, it is very rare to observe impacts of agents on native plant species.
[However, refer to the section on Biocontrol Agents: “Direct Impacts,” and “Indirect Impacts,” for research on this topic.]
Unfortunately, there is little funding for research and monitoring of biological control projects. Most of the emphasis has been on distributing agents, with little follow-up on the success or failure of those efforts. What research is conducted on establishment and impact after release is at the local level.
Currently, some individuals are conducting research to determine the impact of Mogulones cruciger, a root weevil that attacks Houndstongue, on native plant species. The biocontrol agent has been approved for use in Canada, and the insects have been in use there since 1997. The insect has not been approved for distribution in the United States, due to concerns of the impact it may have on some native members of the Borage Family. APHIS has labeled the root weevil an “agricultural plant pest,” a very unusual step for APHIS to take. But insects do not recognize National or State boundaries. The insect has worked its way across the border into Montana, Idaho, and Washington.
Melissa has established partnerships with many different landowners and non-profit groups, and County, State, and Federal agency representatives, Tribal, university researchers and extension agents. These partnerships are absolutely essential to the success of biocontrol efforts. As a statewide coordinator, who is not employed by a State or Federal agency, Melissa has greater flexibility to get projects started fairly rapidly. This makes her an asset to other agency representatives that do not have that degree of flexibility.
Melissa mentioned that a key role that she has is to educate landowners regarding how biocontrol works. Too often, scientists that conduct research on biocontrol have not had the opportunity to interact with the landowners that must make the decisions on managing noxious weeds in the way that Melissa does. She provides a valuable bridge to fill the knowledge gap between researchers and landowners.
An important part of educating landowners is to help them overcome various misconceptions that landowners tend to have. For example, she has to explain that “Biocontrol is not a silver bullet.” It has to be combined with other methods of control, sometimes with a complex of biocontrol agents, rather than just one, and biocontrol takes much longer to see results than with herbicides. However, the cost-benefit ratio for use of biocontrol agents tends to be much better than with herbicides. With herbicides, the effect may appear to be immediate, but within a few years, the noxious plant often returns, and herbicides have to be applied again and again. With biocontrol agents, the effect usually takes several years, but is more long-lasting than with herbicides.
Another misconception is that the goal of management of noxious plants is to eradicate the plants all together.
Except in cases of very small infestations, it is not possible to completely eradicate a plant on a specific site. This is true with biocontrol and it is true with herbicides. As one example, at the National Bison Range northwest of Missoula, Montana: In the 1950’s, the Range had a large infestation of St. John’s wort, with about 10,000 acres infested. Klamath weed beetles were introduced as biocontrol agents. Today, on a good year the infestation can be as low as 1 acre, at a fraction of the cost of using herbicides. The amount of acreage that remains infested varies over time, in some years being as high as 1000 acres. It can be a challenge for some partners to understand that this is a success story. If more work had been done previously to better document, especially with photographs and monitoring, the decline of the infestation as a result of the introduction of the biocontrol agent, a more convincing story could be told. Some local landowners would like to see the rest of the plants sprayed with herbicides. In situations like this, often times the herbicides will not eradicate the plants, and that procedure is very likely to backfire. If they try to spray out the St. John’s wort, they will also eliminate the biocontrol insects that live on the plants. And if there is a large enough seedbank in the soil, the St. John’s wort will come back in a few years, with no biocontrol agents around to reduce the infestation. This would require repeated use of herbicides, at a much higher cost.
[Refer to the section “Herbicides” for more on the "Myth of Eradication," and the prevalence of noxious weeds that are becoming resistant to various herbicides.]
As part of the education process, Melissa helps landowners to understand that, in their natural habitat, biocontrol agents do not eradicate their host plants. There is always a delicate balance between the number of insects and the number of plants in any natural community.
As another example of the problem with using herbicides, Melissa reported that there had been a significant infestation of Dalmatian toadflax near Missoula beginning in the 1990s. Local partners had used a successful combination of grazing and biocontrol agents, which had a high degree of success in reducing the amount of Dalmatian toadflax with a low point around 2015. The group there decided to use herbicides to spot spray the remaining toadflax. This process eliminated the biocontrol insects. Today, toadflax is once again a problem infestation, due the presence of a significant Dalmatian toadflax seedbank and the elimination of the biocontrol insects.
When asked whether there are any instances when herbicides might be more successful than biocontrol agents, Melissa said that infestations on small acreages may be better tackled with herbicides. A small acreage farm might not have enough invasive plants to support biocontrol agents over time. But on large acreages, she has found that biocontrol agents in combination with other weed management tools like herbicides are more likely to have success.
An example she gave for a method to combine herbicides with biocontrol agents is the following: Leafy spurge has been a very challenging invasive plant to manage because of its extensive root system. Over time, they have been able to introduce multiple biocontrol insects to attack different parts of the plant. In large infestations, it can be effective to use herbicides along the periphery of the infestation, similar to the way large fires are often managed. Using herbicides on the outside edge of the infestation, to help prevent further spread of the invasive, and then using biocontrol agents on the interior of the infestation, can be an effective method.
A third misconception that is prevalent among landowners is that biocontrol agents are always successful on the target plant, and that a single biocontrol agent is always enough to do the job. Researchers have discovered that differences in site characteristics can be very important in determining the success or failure of the introduction of a biocontrol agent. Soil type, degree of slope, variations in winter precipitation and summer drought, high altitudes, and shorter growing seasons, all present their own challenges to the success of biocontrol agents.
For example, it is challenging to get the biocontrol agents that attack spotted knapweed to survive above about 5500 feet elevation. This could be due to winter temperature extremes or a shorter growing season.
She noted that they have had greater success in controlling spotted knapweed infestations with biocontrol in Western Montana than in Eastern Montana. They have used a variety of biocontrol agents. They find that seed head weevils are very effective, but they do not do enough damage by themselves. Reducing seed production alone is not adequate. So now they use a complex of biocontrol agents that work together to attack the seeds, the leaves, and the roots.
The root boring weevils that attack spotted knapweed do not fly, so they must be transported around the State. The individuals that assist with insect distribution must collect biocontrol agents each spring and summer, move them, and distribute them around the State, over and over again. This requires a lot of manual labor.
A new agent recently approved for use with whitetop is a mite. The mite attacks the seeds and flowers of the plant. But this is not adequate by itself because whitetop has long spreading roots.
More Biocontrol Interviews:
Interviews from other States: