Some environmental groups have called, in an October 9 Guelph Mercury column, for a ban on use of neonicotinoid insecticides. They support this with dubious information and claims. This column provides an alternative perspective.
Neonic insecticides do kill insects, including bees if not used carefully. In some situations, with certain dust-emitting corn planters, there can be deaths at seeding time in spring. Farmers, seed and equipment suppliers, and governments have moved quickly to reduce this risk. Preliminary statistics from Health Canada indicate springtime bee deaths were down significantly in 2014.
But to state that neonics are “the primary cause” of increased bee mortality is simply untrue. University of Guelph bee experts tell me the biggest contributor to increased bee deaths has been bee parasites and diseases, mostly associated with the arrival of varroa mites a few years back. Poor nutrition was another big factor last winter. Many bees, which don’t hibernate but clump within hives and buzz to keep warm, simply ran out of food reserves and starved.
Dr. Guzman at U Guelph says 85% of spring-time deaths are linked to varroa. Neonic usage in spring may also contribute (see above), but claims that neonics have any effect on over-winter survival are conjecture. Dr. Guzman’s views match those of the responsible government agencies in Health Canada, the US, Australia, and Europe. The two-year moratorium in Europe was imposed by politicians, not the science-based EFSA, Europe’s equivalent to Health Canada. Australia with abundant neonic usage but no varroa has low bee mortality.
Some claim that seed-applied neonics kill bees exposed to corn pollen later in the season. But canola seed is also treated with neonics (same per-acre application rate as corn) and bees flourish in Canadian canola fields. This is even though European research shows bee exposure is about 10 times greater with canola flowers as with corn pollen.
Neonics are sometimes found in some farm ponds at concentrations of a few parts per trillion, about the same as found for caffeine and Tylenol in the Great Lakes.
The “task force” referenced in the October 9 column is a group of academics committed to pesticide use elimination – and they did not release a report of “more than 800 scientific studies” at their NGO-sponsored June news conference in Ottawa – only a promise that release was forthcoming. No one could check accuracy. Most of the promised material is still unavailable.
The EU ban was imposed, effective September 1, 2014. Since then, unprotected fall-seeded canola plants (called oilseed rape in Europe) have been attacked voraciously by fleabeetles. The result is both huge crop losses (45,000 acres in the UK, alone) and increased insecticide spraying. Many farmers have sprayed three or more times. The UK has authorized emergency usage of two new pesticides (ironically, both neonics) to help.
The European experience is thus far only for fall-seeded canola. Damage reports for other crops await next spring’s plantings.
And organic farmers don’t have the answer. Some have suggested hand-picking or covering plants with mesh – good for a garden, maybe, but farm fields?
Neonics are used in more than agriculture, largely because of proven safety for non-insect species including humans, mammal, fish and birds. Control of pet fleas is one. Control of the European Ash Borer is another. Ban advocates never mention this.
Terry Daynard is a former associate dean, research and innovation, University of Guelph