Photo: Musk thistle. © 2020 Delena Norris-Tull
Interviews conducted by Dr. Delena Norris-Tull, Professor Emerita of Science Education of Science Education, University of Montana Western, & Becky McMillen, Insight Creative Independent Productions.
Biocontrol in Wyoming
Slade Franklin, Wyoming Weed and Pest Coordinator, told me: “We have had some issues with biocontrol agents in the past. For example, different southern agencies and states tried to use Diorhabda elongata to reduce tamarisk [salt cedar] infestations. APHIS (USDA) claimed that it would not travel north, but it did. This resulted in threats to the nesting habitat of the willow flycatcher, an endangered species.”
Robert Jenn, now retired Supervisor for the Sheridan, Wyoming, County Weed and Pest program, in an interview with Becky McMillen in 2014, said, “We are coming to rely a lot on biocontrol. The insects that we use now are the flea beetles, and they seem to do well, if we have the cooperation of the landowner. We know that the insects work well in some applications. They like the south-facing slopes better, I guess because they’re warmer. But the insects need to be moved, because they will eat themselves out of house and home. If you don’t go and collect them every year, and move them to a different area, you’re going to lose them. And those insects are worth a lot of money. We purchased 1 million insects this last year, and we have been doing this for 20 years. We spent $80,000 on insects this year. We come to rely on them quite a bit, because they do work better than chemicals. I wouldn’t have said that 30 years ago.
“When you release insects into an area, they’ll eat it down in a couple of years, and it won’t come back for 5 to 10 years. Whereas, if you use chemicals, you can only depend on it for a couple of years. I think that’s one of the biggest things that we found in the 30 years that I’ve been here.”
In an interview with Becky McMillen, Allen Mooney, retired Weed and Pest Supervisor for Campbell County, in Northeastern Wyoming, he said: “Yes, biocontrol was very important. I got involved in it in the early 1980s. I put out a lot of insects on leafy spurge to start with. I put insects out on Canada thistle. And in some cases, it was very effective. It was something none of us really knew about. It depends a little bit on environments. Different environments for different insects. It’s seem to work better on particular weeds at particular times. It would be the answer to our problems if we can get the right insects. It’s not something that’s going to happen overnight. It’s something that takes decades. Unfortunately, many of us don’t have decades to see how effective it is really going to be.”
Interview Becky McMillen conducted with Lars Baker, retired Weed and Pest Supervisor for Fremont County, Wyoming: “When I started in this job in 1975, we were not yet talking about biocontrol methods. We were very excited when we learned about this. We realized that weeds such as leafy spurge are not considered weeds in their natural habitats in Europe, because they have natural predators. Montana developed an insectary in Corvallis, to raise insects for biocontrol. By 1978, we had biocontrol insects to manage musk thistle. By 1990, we had our first beetles to control leafy spurge. The landowners were not excited about this at first. Finally, by 1995, biocontrol had shown its potential, and landowners finally were interested in it. One year, we were able to collect a lot of insects and re-distribute them where needed. The insects were very successful in reducing the weeds. The next year, we tried another collection day, but there were so few musk thistles left, that we could not collect enough insects for re-distribution. The musk thistle population had collapsed in one year, after 15 years of battling it! The credit goes to two species of beetles that attack the plant.
"I still have musk thistle in prairie dog towns, due to the deep soil disturbance, and in pastures that have been over-grazed due to being treated like feedlots. But in most other locations, it is well managed by biological control agents.
"I believe biocontrol works very well. We have some funds in our District for research on biocontrol of a number of weed species. We have learned that you do not have to eradicate a weed species. You just have to reduce the population enough to enable other plants to overcome the weeds. We still have musk thistle, but it’s no longer a problem. If you define a weed as a plant that interferes with management objectives, then musk thistle is not a weed anymore.
"Unfortunately, it’s easier for landowners to understand chemicals than biocontrol. So it’s hard to get landowners to rely on biocontrol.
"I believe biocontrol should be the first layer of technology for Integrated Pest Management. But biocontrol does not help with annual crops – with annual crops, you must get rid of the weeds immediately to preserve the yield. Just a few weeks of weed competition in the field will reduce the yield by 20% or more.
"It’s challenging to get researchers to work on biocontrol. Many grants have a two-year time limit, or the researcher is working on a master’s degree and needs to get results within one-two years. Biocontrol takes longer than that. Also, biocontrol is not profitable, in the way that chemicals are. There’s no product to sell. A landowner can collect insects on their own land, to sell to other landowners, but within three years, they won’t have a profitable number of insects anymore, because the weed population will be depleted. Or the insects will be so wide spread that everyone has them and there is no longer a market. Biocontrol needs to be a public endeavor over many years. When you have the biocontrol insects established, you can work on restoring the natural ecology, planting native plants. The weeds never go completely away, but they are under control.”
Interview Becky McMillen conducted with Gale Lamb, Co-Supervisor for the Sweetwater County Weed and Pest District:
"My County has only dabbled in biocontrol. The Board members and landowners want to see results tomorrow.
"About 20 years ago, we put out insects on musk thistle and Canada thistle, on BLM ground on really steep slopes. We didn’t see any changes one year out, two years out, three years out. We thought it wasn’t working. 10 years, we went back, and we started to see some change. Those steep slopes and drainages now have very little thistle on them. It does work.
"We have some salt cedar weevils out, that we’re trying to get established. One problem in Sweetwater County is we’re at nearly 7000 feet elevation. We are having trouble getting those little bugs to overwinter at high elevation. But we have had some success with them. We’re starting to get the Board to see some of this, and we’re starting to get more insects out, especially on the tamarisk and salt cedar, on the Gorge. In the riparian areas, we can’t use chemicals, so the biocontrol is useful there. We have to convince the Board and the landowners to give it time."
For more Wyoming commentary on biocontrol, refer to the interview with Robert Parsons.
For more interviews related to biocontrol:
Interviews conducted by Dr. Delena Norris-Tull, Professor Emerita of Science Education of Science Education, University of Montana Western, & Becky McMillen, Insight Creative Independent Productions.
Biocontrol in Wyoming
Slade Franklin, Wyoming Weed and Pest Coordinator, told me: “We have had some issues with biocontrol agents in the past. For example, different southern agencies and states tried to use Diorhabda elongata to reduce tamarisk [salt cedar] infestations. APHIS (USDA) claimed that it would not travel north, but it did. This resulted in threats to the nesting habitat of the willow flycatcher, an endangered species.”
Robert Jenn, now retired Supervisor for the Sheridan, Wyoming, County Weed and Pest program, in an interview with Becky McMillen in 2014, said, “We are coming to rely a lot on biocontrol. The insects that we use now are the flea beetles, and they seem to do well, if we have the cooperation of the landowner. We know that the insects work well in some applications. They like the south-facing slopes better, I guess because they’re warmer. But the insects need to be moved, because they will eat themselves out of house and home. If you don’t go and collect them every year, and move them to a different area, you’re going to lose them. And those insects are worth a lot of money. We purchased 1 million insects this last year, and we have been doing this for 20 years. We spent $80,000 on insects this year. We come to rely on them quite a bit, because they do work better than chemicals. I wouldn’t have said that 30 years ago.
“When you release insects into an area, they’ll eat it down in a couple of years, and it won’t come back for 5 to 10 years. Whereas, if you use chemicals, you can only depend on it for a couple of years. I think that’s one of the biggest things that we found in the 30 years that I’ve been here.”
In an interview with Becky McMillen, Allen Mooney, retired Weed and Pest Supervisor for Campbell County, in Northeastern Wyoming, he said: “Yes, biocontrol was very important. I got involved in it in the early 1980s. I put out a lot of insects on leafy spurge to start with. I put insects out on Canada thistle. And in some cases, it was very effective. It was something none of us really knew about. It depends a little bit on environments. Different environments for different insects. It’s seem to work better on particular weeds at particular times. It would be the answer to our problems if we can get the right insects. It’s not something that’s going to happen overnight. It’s something that takes decades. Unfortunately, many of us don’t have decades to see how effective it is really going to be.”
Interview Becky McMillen conducted with Lars Baker, retired Weed and Pest Supervisor for Fremont County, Wyoming: “When I started in this job in 1975, we were not yet talking about biocontrol methods. We were very excited when we learned about this. We realized that weeds such as leafy spurge are not considered weeds in their natural habitats in Europe, because they have natural predators. Montana developed an insectary in Corvallis, to raise insects for biocontrol. By 1978, we had biocontrol insects to manage musk thistle. By 1990, we had our first beetles to control leafy spurge. The landowners were not excited about this at first. Finally, by 1995, biocontrol had shown its potential, and landowners finally were interested in it. One year, we were able to collect a lot of insects and re-distribute them where needed. The insects were very successful in reducing the weeds. The next year, we tried another collection day, but there were so few musk thistles left, that we could not collect enough insects for re-distribution. The musk thistle population had collapsed in one year, after 15 years of battling it! The credit goes to two species of beetles that attack the plant.
"I still have musk thistle in prairie dog towns, due to the deep soil disturbance, and in pastures that have been over-grazed due to being treated like feedlots. But in most other locations, it is well managed by biological control agents.
"I believe biocontrol works very well. We have some funds in our District for research on biocontrol of a number of weed species. We have learned that you do not have to eradicate a weed species. You just have to reduce the population enough to enable other plants to overcome the weeds. We still have musk thistle, but it’s no longer a problem. If you define a weed as a plant that interferes with management objectives, then musk thistle is not a weed anymore.
"Unfortunately, it’s easier for landowners to understand chemicals than biocontrol. So it’s hard to get landowners to rely on biocontrol.
"I believe biocontrol should be the first layer of technology for Integrated Pest Management. But biocontrol does not help with annual crops – with annual crops, you must get rid of the weeds immediately to preserve the yield. Just a few weeks of weed competition in the field will reduce the yield by 20% or more.
"It’s challenging to get researchers to work on biocontrol. Many grants have a two-year time limit, or the researcher is working on a master’s degree and needs to get results within one-two years. Biocontrol takes longer than that. Also, biocontrol is not profitable, in the way that chemicals are. There’s no product to sell. A landowner can collect insects on their own land, to sell to other landowners, but within three years, they won’t have a profitable number of insects anymore, because the weed population will be depleted. Or the insects will be so wide spread that everyone has them and there is no longer a market. Biocontrol needs to be a public endeavor over many years. When you have the biocontrol insects established, you can work on restoring the natural ecology, planting native plants. The weeds never go completely away, but they are under control.”
Interview Becky McMillen conducted with Gale Lamb, Co-Supervisor for the Sweetwater County Weed and Pest District:
"My County has only dabbled in biocontrol. The Board members and landowners want to see results tomorrow.
"About 20 years ago, we put out insects on musk thistle and Canada thistle, on BLM ground on really steep slopes. We didn’t see any changes one year out, two years out, three years out. We thought it wasn’t working. 10 years, we went back, and we started to see some change. Those steep slopes and drainages now have very little thistle on them. It does work.
"We have some salt cedar weevils out, that we’re trying to get established. One problem in Sweetwater County is we’re at nearly 7000 feet elevation. We are having trouble getting those little bugs to overwinter at high elevation. But we have had some success with them. We’re starting to get the Board to see some of this, and we’re starting to get more insects out, especially on the tamarisk and salt cedar, on the Gorge. In the riparian areas, we can’t use chemicals, so the biocontrol is useful there. We have to convince the Board and the landowners to give it time."
For more Wyoming commentary on biocontrol, refer to the interview with Robert Parsons.
For more interviews related to biocontrol: