The Minnesota Department of Agriculture (MDA) is preparing to treat two areas in Lake County to slow the spread of a gypsy moth (now known as spongy moth). Officials will conduct the aerial treatment July 18-20, beginning as early as 6:30 a.m. each morning and continuing throughout the day. The dates and times are dependent on weather conditions in the area.
The two areas in Lake County, Two Harbors NE and Upland Trail, total approximately 45,100 acres. The Two Harbors NE area includes Gooseberry Falls State Park, and the Upland Trail area is completely within the Superior National Forest. Residents can look up their address on an interactive map to determine if they are within either of these blocks.
The MDA will use a method of mating disruption involving the aerial application of an organically certified, waxy, food-grade substance containing pheromones specific to gypsy moths that confuses the male moths. This makes it difficult for the male moths to find females for mating, which means reduced mating success. The result is fewer caterpillars hatching and attacking trees next year. The application is timed just as adult moths emerge in early summer.
The mating disruption product will be applied by low-flying yellow planes contracted by the U.S. Forest Service in a joint project with the MDA. These planes fly approximately 150 feet above the treetops and will be traveling outside the treatment areas as the planes navigate through the gypsy moth infestation sites. The product is not harmful to humans, animals, birds, or other insects, and will help protect forest health, property values, and the state’s tourism industry.
To help area citizens stay informed, the MDA has set up a Report a Pest information line at 1-888-545-MOTH (6684). The hotline will offer the latest details about treatment dates and times. Residents can sign up for updates about treatment progress by texting “MDA LAKE” to 468311 to receive text notifications or texting “MDA LAKE [your email address here]” to 468311 to receive email notifications.
Gypsy moths are among America's most destructive tree pests, having caused millions of dollars in damage to Eastern forests. The moths are now threatening Minnesota. If present in large numbers, gypsy moth caterpillars can defoliate large sections of forest. Oak, poplar, birch, and willow are among their preferred hosts. The moths spread slowly on their own, but people can unintentionally help them spread by transporting firewood or other items on which the moths have laid their eggs.
Contact the Minnesota Department of Agriculture at 1-888-545-6684 or ReportAPest@state.mn.us with questions regarding gypsy moth and the planned treatment.
Gypsy Moth Name Background
As of July 2021, the Entomological Society of America (ESA) discontinued the use of “gypsy moth” as a common name for Lymantria dispar. A new common name, spongy moth, was selected by the ESA on March 2, 2022. The Minnesota Department of Agriculture will begin phasing out the discontinued common name and adopting the new common name over the next year in accordance with state and federal regulations.
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Media Contact
Allen Sommerfeld, MDA Communications
651-201-6185
Allen.Sommerfeld@state.mn.us
MDA Presenter: Raj Mann and Dan Stoddard
The following updates from the MDA were provided:
- Pesticide Management Plan (PMP) Revisions - The MDA is in the process of revising the PMP. Significant revisions include developing a process for removal of pesticides from list of "common detection" or "surface water pesticide of concern" status, updating the statutory language referenced, and various other technical changes related to pesticides and agricultural technology. A draft of the revised PMP will be published in the state register for public comment along with a summary of changes (anticipated in late 2021).
- Chlorpyrifos Update - Several lawsuits have been filed for chlorpyrifos’s potential adverse effects on human health. Of particular interest is lawsuit filed in 2007 to revoke all chlorpyrifos tolerances and cancel all registrations based on adverse human health effects. The EPA denied this petition in 2019; however, in a ruling issued on April 29, 2021, the Ninth Circuit Court of Appeals vacated the 2019 denial of the petition and instructed the EPA to either modify chlorpyrifos’s tolerances and publish findings to show they are safe or to revoke all chlorpyrifos tolerances within 60 days. The decision on this from the EPA or 9th circuit court is awaited.
The MDA has an ongoing special registration review focused on chlorpyrifos in Minnesota (scoping document is available on the Pesticide Special Registration Reviews page.
- Legislative Report Recommendations - In 2020, there was an audit of the MDA’s pesticide programs. The audit report supported the continued monitoring of pesticides in water and recommended three additional analytes be added to the program (triphenyltin hydroxide, glufosinate-ammonium and ethylenethiourea [ETU]). Unfortunately, analysis of these chemicals by the MDA Lab is not feasible at this time based on available instrumentation and methodology. The MDA will continue to seek funding for lab equipment and explore analytical options.
- MDA Laboratory Funding - The MDA had a legislative proposal to increase pesticide registration fees that would generate approx. $2,251,000 per year from pesticide gross sales. These funds would have been used to (1) replace analytical equipment required to maintain critical laboratory services, (2) replace Clean Water funding, (3) create two new urban pesticide positions, and (4) provide the necessary resources for the MDA Lab to expand pesticide monitoring and include specific analytes recommended by the audit. Ultimately, the Lab received $600,000 in general funds through the agricultural budget bill in 2021. These funds will be used to update/replace existing equipment, but they are not sufficient to purchase additional new equipment.
MDA Presenter: Raj Mann and Dan Stoddard
The following updates from the MDA were provided:
- Pesticide Management Plan (PMP) Revisions - The MDA is in the process of revising the PMP. Significant revisions include developing a process for removal of pesticides from list of "common detection" or "surface water pesticide of concern" status, updating the statutory language referenced, and various other technical changes related to pesticides and agricultural technology. A draft of the revised PMP will be published in the state register for public comment along with a summary of changes (anticipated in late 2021).
- Chlorpyrifos Update - Several lawsuits have been filed for chlorpyrifos’s potential adverse effects on human health. Of particular interest is lawsuit filed in 2007 to revoke all chlorpyrifos tolerances and cancel all registrations based on adverse human health effects. The EPA denied this petition in 2019; however, in a ruling issued on April 29, 2021, the Ninth Circuit Court of Appeals vacated the 2019 denial of the petition and instructed the EPA to either modify chlorpyrifos’s tolerances and publish findings to show they are safe or to revoke all chlorpyrifos tolerances within 60 days. The decision on this from the EPA or 9th circuit court is awaited.
The MDA has an ongoing special registration review focused on chlorpyrifos in Minnesota (scoping document is available on the Pesticide Special Registration Reviews page.
- Legislative Report Recommendations - In 2020, there was an audit of the MDA’s pesticide programs. The audit report supported the continued monitoring of pesticides in water and recommended three additional analytes be added to the program (triphenyltin hydroxide, glufosinate-ammonium and ethylenethiourea [ETU]). Unfortunately, analysis of these chemicals by the MDA Lab is not feasible at this time based on available instrumentation and methodology. The MDA will continue to seek funding for lab equipment and explore analytical options.
- MDA Laboratory Funding - The MDA had a legislative proposal to increase pesticide registration fees that would generate approx. $2,251,000 per year from pesticide gross sales. These funds would have been used to (1) replace analytical equipment required to maintain critical laboratory services, (2) replace Clean Water funding, (3) create two new urban pesticide positions, and (4) provide the necessary resources for the MDA Lab to expand pesticide monitoring and include specific analytes recommended by the audit. Ultimately, the Lab received $600,000 in general funds through the agricultural budget bill in 2021. These funds will be used to update/replace existing equipment, but they are not sufficient to purchase additional new equipment.
Discussion topics included:
- The MDA’s investigation into potential propazine sources.
- Detections in surface water are likely the result of impurities in atrazine products. Propazine has not been sold in MN in over 30 years and detections correlated well with atrazine detections.
- This relationship between atrazine and propazine is unique and similar trends with other chemicals (particularly triazines) have not been observed.
- Sources of metribuzin detections outside of PMR 4 and method reporting limits (MRLs) for its main degradates.
- Detections have been limited and occur in different areas throughout the state. Because detections are erratic, the source has not been fully investigated by the MDA.
- Metribuzin has been making a reappearance as part of pre-emergence tank mixes to address resistant weeds in soybean.
- The MDA is not able to lower the MRLs for metribuzin and its degradates at this time.
- Availability of raw data for 4-hydroxychlorothalonil (report table only shows a single maximum concentration).
- Requested data was sent after the meeting. Raw data is also available through the Water Quality Portal.
- The MDA’s actions regarding increasing metolachlor trends in groundwater.
- The MDA is continuing to promote Water Quality Best Management Practices for Metolachlor (PDF).
- While some PMRs do show increasing trends, concentrations remain well below human health reference values in groundwater. The MDA will continue to carefully monitor metolachlor and its degradates.
- Increased metolachlor use is anticipated due to resistance issues with glyphosate and other herbicides.
- The continued use of Roundup-Ready crops despite the development of glyphosate-resistance.
- Growers are continuing to use Roundup-Ready crops and glyphosate is still an important part of weed management programs from corn and soybean.
- The new addition of piperonyl butoxide to the monitoring list and the lack of detections.
- Piperonyl butoxide is a synergist often used with pyrethroid insecticides. It has been detected by other monitoring programs, but it was not detected in 2020 by the MDA.
Discussion topics included:
- The MDA’s investigation into potential propazine sources.
- Detections in surface water are likely the result of impurities in atrazine products. Propazine has not been sold in MN in over 30 years and detections correlated well with atrazine detections.
- This relationship between atrazine and propazine is unique and similar trends with other chemicals (particularly triazines) have not been observed.
- Sources of metribuzin detections outside of PMR 4 and method reporting limits (MRLs) for its main degradates.
- Detections have been limited and occur in different areas throughout the state. Because detections are erratic, the source has not been fully investigated by the MDA.
- Metribuzin has been making a reappearance as part of pre-emergence tank mixes to address resistant weeds in soybean.
- The MDA is not able to lower the MRLs for metribuzin and its degradates at this time.
- Availability of raw data for 4-hydroxychlorothalonil (report table only shows a single maximum concentration).
- Requested data was sent after the meeting. Raw data is also available through the Water Quality Portal.
- The MDA’s actions regarding increasing metolachlor trends in groundwater.
- The MDA is continuing to promote Water Quality Best Management Practices for Metolachlor (PDF).
- While some PMRs do show increasing trends, concentrations remain well below human health reference values in groundwater. The MDA will continue to carefully monitor metolachlor and its degradates.
- Increased metolachlor use is anticipated due to resistance issues with glyphosate and other herbicides.
- The continued use of Roundup-Ready crops despite the development of glyphosate-resistance.
- Growers are continuing to use Roundup-Ready crops and glyphosate is still an important part of weed management programs from corn and soybean.
- The new addition of piperonyl butoxide to the monitoring list and the lack of detections.
- Piperonyl butoxide is a synergist often used with pyrethroid insecticides. It has been detected by other monitoring programs, but it was not detected in 2020 by the MDA.