Decision looming for neonics

Health Canada agency will rule this summer on fate of chemicals based on the threat to aquatic insects

The fate of two neonicotinoid seed treatments, applied to almost all of the canola and corn seeds in Canada and a portion of the soybean seeds, will be decided this summer.

For the last 18 months Health Canada has been studying neonicotinoid insecticides and assessing the risk to aquatic insects. The two products are clothianidin, a Bayer product, and thiamethoxam, which is manufactured by Syngenta.

Health Canada will release its findings, on whether the insecticides are safe for aquatic insects or not, in a couple of months.

“The results of these reviews are expected to be released, for consultation, in late summer of 2018,” said Scott Kirby, director general of environmental assessment with the Pest Management Regulatory Agency, a division of Health Canada.

Kirby made the comment May 31 in a technical briefing with journalists.

The PMRA decision on the two neonicotinoids, commonly known as neonics, could potentially alter how Canadian farmers protect their crops from insect pests. Most producers like using the seed treatments because the products reduce the need for foliar insecticides.

The PMRA is reviewing thiamethoxam and clothianidin because in November of 2016 Health Canada proposed a ban of all agricultural use of imidacloprid, a Bayer neonic.

The PMRA determined that levels of imidacloprid in water bodies near agricultural land are unacceptably high, which is putting aquatic insects at risk and is a threat to animals that depend on those insects for food. The types of aquatic insects at risk include mayflies and midges.

Water samples determined that most of the unacceptably high levels were happening in creeks and ponds in southern Ontario, in areas with intense fruit and vegetable production or a large number of greenhouses. Imidacloprid is widely used in in the horticultural industry. It’s applied to crops like apples, berries, sweet corn, field tomatoes and beans.

Horticulture producers in Ontario criticized the ban, saying Health Canada didn’t have sufficient evidence to justify the decision.

“Even though they claim they have some numbers (water monitoring data), they made their determination on the basis of a model,” said Craig Hunter, of the Ontario Fruit and Vegetable Growers Association, in December 2016. “They put numbers into a model and then said it was unsustainable.”

Since that time Health Canada has gathered more data on neonic levels in creeks and ponds.

“The PRMA received a large amount of additional neonicotinoid water monitoring data from agricultural use areas across Canada, in October 2017,” Health Canada says on its website.

“Discussion papers on possible ways to mitigate neonicotinoid exposure in the environment… were also provided to the PMRA at that time.”

The PMRA decision on thiamethoxam, clothianidin and the risk to aquatic insects is still a couple of months away. The main topic of the May 31 technical briefing with media was imidacloprid and whether it threatens bees and other pollinators.

For the last five years many scientists have linked the use of neonicotinoids to bee deaths and bee colony losses. The European Union banned the use of the neonics on agricultural crops.

Kirby said it does pose a risk to bees, when sprayed on a number of crops.

“Certain uses of products containing imidacloprid result in uptake by plants where it then moves into nectar and or pollen,” he said.

“Because bees use nectar and pollen as their primary sources of food, bees may be exposed to harmful levels of this insecticide when they visit certain flowers.”

Consequently, Health Canada is proposing the following changes for imidacloprid use:

  • Phasing out foliar application on orchard fruit, some tree nuts, and most small fruit and berries
  • Phase-out of soil uses on berries, some ornamentals and herbs, and outdoor-grown fruiting vegetables, cucurbits, and legumes
  • Changes to the timing of foliar application on some tree nuts, strawberries, grapes, fruiting vegetables, legumes, potatoes, peanuts, tobacco, hops, and some herbs.

The timing part means imidacloprid, in some cases, can only be used after the crop has bloomed.

Imidacloprid is also used as a seed treatment on some broad acreage crops. It’s used on wheat, for instance, to protect against wireworm.

Kirby said using imidacloprid as a seed treatment doesn’t pose a risk to bees and pollinators.

“The residues that are being found from seed treatment are not sufficient to cause restriction of the use.”

Kirby made it clear, several times during the technical briefing, that the PMRA risk assessment of imidacloprid on pollinators is separate from its proposed decision on imidacloprid, when it comes to aquatic insects.

Meaning, Health Canada is still proposing to phase out all agricultural uses of imidacloprid because of the threat to aquatic insects.

“(The) pollinator assessment is not changing that,” Kirby said.

The PMRA will make its final decision on imidacloprid and measures to protect aquatic life in December.

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