UPDATED: PMRA Reviews Imidacloprid, Clothianidin, Thiamethoxam, and Lambda-cyhalothrin
May 20, 2021
Recently the Pest Management Regulatory Agency (PMRA) reviewed Imidacloprid, Clothianidin, Thiamethoxam, and Lambda-cyhalothrin.
On March 31, 2021 PMRA released their long awaited Special Review Decisions for Clothianidin and Thiamethoxam Risk to Aquatic Invertebrates, and affirmed that in many cases these tools can be used without posing unacceptable risks to aquatic invertebrates.
This decision is a change from the 2018 proposed re-evaluation decision to cancel all outdoor agriculture uses of these products due to concerns over the potential risk to aquatic invertebrates that was based on conservative modelling. Due to an extensive amount of data that was made available to the PMRA after the publications of the proposed re-evaluation decision, they were able to come to a more informed, risk-based decision that is based on the best available real-world data.
This re-evaluation decision will impact thiamethoxam use for Saskatchewan growers, as rates will be reduced to 30 g a.i./100 kg seed for soybeans. This will result in the cancellation of the use for bean leaf beetle, European chafer, soybean aphid, and wireworm. The number of foliar applications of thiamethoxam is reduced to one per year on dry beans and soybeans.
On April 27, 2021 PMRA also released a summary of Lambda-cyhalothrin based on revised human health and environment risk assessments. Based on the revised assessments, the registration of this product will remain in place for pulses. Lambda-cyhalothrin is foliar insecticide used to control pests such as cutworms, grasshoppers, pea aphids, lygus bugs, and pea leaf weevil.
SPG has been heavily involved throughout the PMRA review processes, collaborating with the other provincial pulse organizations and Pulse Canada to formulate an in-depth Canadian Pulse Industry Stakeholder submission in response to the proposed decisions for clothianidin, thiamethoxam, and lambda-cyhalothrin. SPG also funded water monitoring data to help address critical gaps in the original data set. This new water monitoring data was a critical piece to the change in the proposed decision by PMRA.
There are label amendments for using and handling lambda-cyhalothrin still to be clarified, as well as a requirement for mandatory Vegetative Filter Strip (VFS) use. Pulse Canada will continue to review the full details of the final special review decision documents and more information will be shared as it is made available.
On May 19, 2021 PMRA released an update on the re-evaluatoin of imidacloprid. In 2016 the PMRA decision on imidacloprid was to phase out all outdoor uses over 3-5 years due to environmental concerns. The re-evaluation impact on pulses means seed treatment options for pulses against wireworms and pea leaf weevil, but it will mean a reduced maximum rate for soybeans, reducing soybean aphid control.
SPG was again heavily involved with the other pulse commissionsa cross the country in response to the proposed phase-out of imidacloprid. There will be label amendments for imidacloprid use moving forward. More information on this re-evaluation can be read on the Government of Canada website here.